Dissertations / Theses on the topic 'Flux coronaire'
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Adjedj, Julien. "Circulation coronaire : Principes et méthodes de mesure invasive du flux coronaire segmentaire en pratique clinique." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC0006/document.
Coronary circulation is complex and highly regulated while invasive coronary flow measurements techniques allow the assessment of coronary physiology in clinical practice. Material et methods We describe in two reviews the principles and methods of different invasive coronary flowmeasurements techniques in clinical practice. We study the clinical impact of fractional flow reserve(FFR) in intermediate coronary stenosis, the hyperemic agents and dosage to measure FFR and FFRcorrelation with angiographic indices according to risk factors accumulation. Finally, we describe the principle and method of coronary flow and microvascular resistances measurements with a dedicated infusion microcatheter for coronary thermodilution to obtain assessment of macro and microvascular components of coronary circulation. Results We recommend the FFR cut off value of 0.80 to guide revascularization based on our study showing higher myocardial infarction and death rate in patients treated with medical therapy and FFR<0.80compared to those with FFR>0.80, respectively 9.4 versus 4.8%, P=0.06 and 7,5 versus 3,2%, P=0.06. We studied different hyperemic agents and dosages and showed that intracoronary adenosine at 100μg to 200 μg induce maximal hyperemia while contrast medium induce 65% of maximal hyperemia. Therefore, FFR measurements with contrast medium is feasible and has better accuracy than restindices compared to FFR. We establish the weak correlation between FFR and angiographic indicesand weakens correlation as risk factors accumulates, especially in diabetic patients. Finally, we described in three studies the method of absolute coronary flow and microvascular resistancesmeasurements based on thermodilution principle with a dedicated infusion catheter. We showed anaccurate measurement with this technique (R=0.98), which induces maximal hyperemia without theneed of hyperemic agent with reproducible measurements in humans (R=0,91).Conclusion The use of invasive coronary flow measurements to study the coronary circulation is essential inclinical practice and in research
Taurel, Marianne. "Evaluation de la réserve coronaire et/ou de la fonction endothéliale dans l'insuffisance cardiaque et l'athérosclérose expérimentales : effets des inhibiteurs du système rénine-angiotensine." Paris 11, 2001. http://www.theses.fr/2001PA11T021.
Lethimonnier, Franck. "Evaluation des cardiopathies ischémiques par IRM quantification du flux et de la réserve coronaire : visualisation des sténoses par angiographie 3D : étude du retentissement fonctionnel par analyse de la fonction ventriculaire gauche." Angers, 1999. http://www.theses.fr/1999ANGE0508.
Rasser, Charlotte. "Biocompatibility improvement conferred by the immobilization of a CD31 peptide on endovascular stents." Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCC317/document.
Over the last decades, coronary stents and intracranial flow diverting stents have revolutionized the endovascular treatment of two different arterial pathologies: coronary artery disease and intracranial aneurysms. The working mechanisms of these metallic endoprostheses are different but both are associated with complications stemming from biocompatibility issues. In particular, the rapid covering by endothelial cells presenting an anti-inflammatory and anti-thrombotic phenotype is key to the integration of the endoprosthesis at the blood/vessel interface. Thus, the development of solutions to improve the endothelialization and the integration of these two types of stents in the vessel wall would represent a major progress in their respective field.In this context, this thesis work deals with the immobilization of a bioactive molecule on coronary stents and flow diverting stents in order to solve their biocompatibility issues. The bioactive molecule that we used is a synthetic peptide, named P8RI, which promotes the regulatory functions of the transmembrane glycoprotein CD31 : the inhibition of platelets and leukocytes activation, as well as the enhancement of endothelial cell survival, migration and barrier function.The first part of this thesis work consisted in the development of a process for the immobilization of P8RI on metallic stents. We adopted three successive approaches: the direct immobilization of the peptide on plasma-functionalized alloy surfaces; the plasma-enhanced chemical vapor deposition of an intermediate polymeric layer; and the deposition of a polydopamine coating by self-polymerization, followed with the immobilization of a linker and the binding of P8RI by copper-free click chemistry.We then carried out an in vitro evaluation of the biocompatibility of the resulting coated alloy surfaces, in terms of anti-thrombotic, anti-inflammatory, and pro-endothelialization properties. The surfaces on which P8RI had been immobilized were shown to exhibit a tendency to decrease platelet adhesion, increase endothelial cell adhesion and barrier function, and promote an anti-inflammatory and anti-thrombotic phenotype in human vascular endothelial cells.Finally, coronary stents and flow diverting stents were evaluated in vivo. Coronary stents were implanted in the coronary arteries of farm pigs, and preliminary results showed a more complete endothelialization and a lesser density of adherent leukocytes on ‘P8RI-coated’ stents than on the controls. ‘P8RI-coated’ flow diverting stents were implanted in a rabbit elastase-induced carotid aneurysm model. Compared with the controls, they were associated with the formation of a thicker and better organized neointima, in particular on the stent struts in front of the aneurysm neck, which implies lesser risks of persistence of blood flow and aneurysm rupture
Gibb, Gordon P. S. "The formation and eruption of magnetic flux ropes in solar and stellar coronae." Thesis, University of St Andrews, 2015. http://hdl.handle.net/10023/7069.
Abdalla, Luiz Antonio 1953. "Efeitos da vitamina E sobre o fluxo coronario endotelio-dependente em cães hipercolesterolemicos." [s.n.], 2002. http://repositorio.unicamp.br/jspui/handle/REPOSIP/313462.
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas
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Resumo: Foram estudados os efeitos da vitamina E sobre o fluxo coronário endotélio-dependente em cães hipercolesterolêmicos. A pesquisa foi realizada em 21 cães machos adultos, pesando em média 7,4±1,0 kg, que foram divididos em três grupos: controle, hipercolesterolêmico e vitamina E. Os animais do grupo hipercolesterolêmico foram alimentados com uma dieta rica em colesterol (5% g/g) e óleo de coco (10% g/g) por 40 dias. O grupo vitamina E recebeu a mesma dieta, acrescida de 400 Ui de vitamina E, durante os últimos 15 dias do experimento. Os níveis de colesterol total sérico foram avaliados no começo e no final do estudo, por meio de "kits" enzimáticos e espectrofotômetro Beckman 700. O fluxo coronário foi medido por um fluxômetro eletromagnético (Caroline Instruments, Inc.), usando-se um probe, posicionado na artéria coronária descendente anterior esquerda, próximo ao óstio. Uma agulha, conectada a uma bomba de infusão, foi introduzida na artéria coronária para administração de acetilcolina (ACH) e nitroprussiato de sódio (NPS), à velocidade de 5 mg/kg/min. A aorta foi canulada para medida da pressão arterial por intermédio de transdutor acoplado a polígrafo da marca Siemmens (Mingograph 804). Os teores de colesterol e malonodialdeído (MOA) foram, também, medidos em segmentos de vaso coronário.Após 40 dias, os níveis de colesterol sérico haviam aumentado em 203%, no grupo hipercolesterolêmico e, em 198%, no grupo da vitamina E. Entretanto, esta diferença não foi significante (P>0,05). A pressão sangüínea na aorta e a freqüência cardíaca permaneceram sem alteração, durante a administração de ACH. Contudo, a pressão sistólica e a diastólica diminuíram e a freqüência cardíaca aumentou durante a infusão de NPS.O teor de colesterol tecidual e MOA aumentaram, significativamente, (P<0,05) nas amostras de artéria coronária do grupo hipercolesterolêmico, comparativamente aos animais do grupo-controle. A vitamina E reduziu o colesterol tecidual e o MDA nos animais hipercolesterolêmicos (P<0,05).A elevação do percentual do fluxo coronário, durante a administração da ACH, foi significativamente menor no grupo hipercolesterolêmico, quando comparada com an1ma1_ do grupo-controle (P
Abstract: The effects of vitamin E on endothelium-dependent coronary flow were studied in hypercholesterolernic dogs. Adult mongrel dogs weighing 7.4±1.0 kg were divided into control, hypercholesterolernic and vitamin E groups. The animals in the hypercholesterolernic group were fed a diet enriched with cholesterol (5%w/w) and coconut oil (l0%w/w) for 40 days. The vitamin E group received the same diet plus 400 IU of vitamin E during the last 15 days of the experiment. Total serum cholesterol levels were evaluated at the beginning and at the end of the experiment using a commercial enzyme kit and a Beckman analyzer. The coronary flow was determined byelectromagnetic flowmetry using a probe positioned in the left anterior descending coronary artery, near the ostium. A needle connected to a perfusion pump was introduced into the coronary artery for the administration of acetycholine and sodium nitroprusside at a rate of 5 ug!kg per min. The aorta was cannulated for the measurement of arterial blood pressure via a pressure transducer coupled to a Siemens multi-channel recorder. The tissue cholesterol content and malonic dialdehyde (MDA) were also measured in isolated coronary vessel specimens. At the end of 40 days, the serum cholesterol levels had increased by 203% and 198% in the hypercholesterolernic and vitamin E groups, respectively. However, the difference in the levels of these two groups was not significant (P>0.05). The aortic blood pressure and heart rate remained inchanged during acetylcholine administration. In contrast, systolic and diastolic pressure fell and the heart rate increased during the infusion of sodium nitroprusside. The tissue cholesterol content and MDA were significantly (P<0.05) increased in coronary artery specimens from the hypercholesterolernic compared to control animals. Vitamin E was able to reduce these increases in cholesterol treated animals (P<0.O5). The percent change in coronary flow during acetylcholine administration was significantly lower in the hypercholesterolernic group when compared with control animals (P<0.05) but was unaltered in the vitamin E group (P>0.05). During sodium nitroprusside administration, the coronary flow increased in the vitamin E group (P
Medicina Interna
Doutor em Ciências Médicas
Melis, Riera Gaspar. "Papel de la disfunción endotelial en la respuesta a la cocaína del flujo coronario y la contractilidad miocárdica." Doctoral thesis, Universitat de Barcelona, 2003. http://hdl.handle.net/10803/2174.
Nuestra hipótesis es que la cocaína causa una depresión de la función ventricular independiente de su efecto sobre el flujo coronario y que esta depresión se agrava en presencia de disfunción endotelial. Analizamos los efectos de la administración sistémica de cocaína sobre el flujo coronario y la función ventricular en un modelo experimental porcino, y si la inhibición de la síntesis de óxido nítrico mediante L-NAME intracoronaria modifica la acción de la cocaína sobre la función ventricular.
2. METODOLOGIA
Se utilizaron 57 animales, en un modelo experimental con anestesia general y con un protocolo quirúrgico que permite analizar las siguientes variables:
a)Parámetros hemodinámicos: Tensión arterial, frecuencia cardíaca, doble producto y presión telediastólica del ventrículo izquierdo.
b)Fracción de acortamiento de la fibra miocárdica
c)Flujo coronario y resistencias coronarias
d)Parámetros adicionales: dP/dt del ventrículo izquierdo, gasto cardíaco y resistencias vasculares sistémicas.
Los animales se aleatorizarón en seis grupos.
Grupo control: salino i.v. (n=5). Grupo 1: cocaína i.v. 10 mg kg -1 durante 20 min. (n=17); Grupo 2: la misma dosis de cocaina después de una infusión intracoronaria de L-NAME 20 mg/kg min -1 (n=16); grupo 3:la misma dosis de cocaína administrada después de la reducción mecánica del 20% del flujo coronario de la arteria descendente anterior mediante una oclusión mecánica externa (n=9); grupo 4: la misma dosis de cocaína después de la administración simultanea de L-arginina y L-NAME intracoronaria (n=5); grupo 5: la misma dosis de cocaína administrada después de la administración simultanea de L-NAME y nitroglicerina intracoronaria ( n=5).
3. RESULTADOS
La cocaína no altero el flujo coronario, mientras que indujo una reducción significativa del gasto cardíaco, de la dp/dt del ventrículo izquierdo y de la fracción de acortamiento. Cuando se administró la cocaína después de la infusión i.c. de L-NAME durante 30 min se produjo una mayor reducción de la fracción de acortamiento, este efecto se abolió con la administración simultanea al L-NAME de L-arginina y nitroglicerina. Los resultados de la administración de cocaína después de la reducción mecánica del 20% del flujo coronario no difieren de los producidos con cocaína sola.
4. CONCLUSIÓN
La cocaína produce una depresión directa de la contractilidad miocárdica. Al inhibir la síntesis de óxido nítrico con L-NAME se produce una vasoconstricción de la microcirculación coronaria que aumenta el efecto depresor de la cocaína sobre el miocardio.
"Role of endotelial dysfuntion on cocaine effects in coronary flow and myocardial contractility "
1. Hypothesis
Cocaine has been associated with myocardial ischaemia and left ventricular dysfunction. Whether nitric oxide (NO) inhibition may potentiate the effects of cocaine on coronary circulation and ventricular function is still unknown.
2.Material and methods
In order to test this hipótesis, 57 pentobarbital-anaesthetized pigs were instrumenteted for systolic blood pressure, coronary blood flow, left ventricular dp/dt, cardiac output, left ventricular end-diastolic and end-systolic leghts and shortening fraction.
The pigs were randomized into six groups: control group: i.v. saline(n=5); group 1: cocaine, 10 mg kg-1 over 20 min (n=17); group 2 : the same dosis of cocaine 30 min after i.c. L-NAME 20 mg/kg min-1 infusion( n=16); group 3: The same dosis of cocaine after the proximal left anterior descending (LAD) flow was reduced to around 20% of the basl value by means of a mechanical occluder (n=9); group 4: the same dosis of cocaine after i.c. simultaneously L-arginina and L-NAME infusion (n=5); group 5: the same dosis of cocaine after simultaneously i.c. L-NAME and nitroglicerine infusion.
3.Results
Cocaine i.v. did not change the coronary blood flow, while it induced a significant reduction in cardiac output, left ventricular dp/dt and shortening fraction. When cocaine was administered after L-NAME infused i.c. a significant more severe reduction of the shortening fraction was induced; this effect was abolished by simultaneosus perfusion of L-arginine and NAG i.c.. The results when cocaine was administered after 20% LAD flow reduction by mechanical occluder did not differ from those of cocaine alone.
4.Conclusions
NO inhibition intesifies the cocaine-induced left ventricular funtion.
Sant'Anna, Fernando Mendes. "Influência da avaliação rotineira do fluxo fracionado de reserva durante intervenções coronárias percutâneas na estratégia terapêutica." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/5/5131/tde-06092006-192836/.
BACKGROUND: In complex and multivessel coronary artery disease, it is often difficult to assess which lesions are associated with reversible ischemia and should be stented. Fractional flow reserve (FFR) is a well established methodology to indicate which lesions are culprit or not. Yet, frequently the selection of lesions to be stented is based on the angiogram alone. The main aim of this study in patients admitted for elective percutaneous coronary intervention (PCI) was to evaluate the percentage of change in the initial therapeutic plan if decision is based on FFR measurement rather than on angiographic assessment. METHODS: All patients scheduled for elective PCI between October 2004 and April 2005 were included in the study except those with chronic total occlusion. Two hundred and fifty patients and 471 arteries with a stenosis ≥ 50% by visual estimation and initially selected to be stented were assessed by FFR measurements. Before PCI, 3 cardiologists independently reviewed the diagnostic angiogram and classified lesions as those that should be treated by PCI by visual assessment and those that should not be treated. Next, the decision to stent was based upon FFR measurement. If FFR was < 0.75, actual stenting was performed; if FFR was ≥ 0.75, no interventional treatment was given. RESULTS: It was possible to perform optimal pressure measurements and FFR determinations in 452 (96%) lesions. Mean diameter stenosis was 62 ± 12% and average FFR 0.67 ± 0.17 for the entire group. In 68% of the stenoses initial therapeutic strategy as assessed from the angiogram was followed and in 32% there was a change in the planned approach based on FFR. In 100 stenoses (22%) PCI planned on the basis of angiography was deferred, and in 44 stenoses (10%) revascularization was performed although such stenosis was not considered as ischemia-related on the angiogram. In 48% of the patients there was at least one lesion in which the treatment decision was changed after physiologic measurements. CONCLUSIONS: In this prospective, non-selective, but complete study representing the real world of PCI, 32% of the coronary stenoses and 48% of patients would have received a different treatment if solely the visual assessment by angiography was followed, stressing the utility of physiologic assessment in refining decision making during PCI.
Redondo, Fernanda Roberta Roque. "Efeitos do uso de esteróides anabolizantes associados ao treinamento físico de natação sobre o fluxo sangüíneo para o miocárdio de ratos normotensos." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/39/39132/tde-20042007-100232/.
The abusive use of ergogenic resources as the anabolic steroid became an increasing problem in several segments of the population, beyond the athletical way, searching for better performance or physical appearance, without being worried about the risks of the collateral effects promoted by this practice. In the present work we studied the effects of the use of supraphysiological doses of anabolic steroids associated with aerobic swimming training on the coronary blood flow of normotensive rats, investigating the participation of adenosine as one of the possible mechanisms of blood flow regulation, besides the cardiac structural alterations that could influence the coronary blood perfusion. The effect of the physical training was efficient to promote beneficial adaptations of the cardiovascular system, as the presence of physiological cardiac hypertrophy and improves the coronary blood flow at rest, probably mediated by a higher circulating and cardiac adenosine production. The use of anabolic steroids associated with the swimming training attenuated the beneficial effect promoted by training, being observed the presence of cardiac hypertrophy, followed by reduction of cardiac output and coronary blood flow, mediated by lower circulating adenosine production, besides the impairment of the vasodilator response to the acetylcholine, demonstrating a probable endothelial dysfunction and reduction of the cardiac capillary density, characterizing in this way, a pathological state
Lima, Marta Fernandes. "Valor prognóstico da reserva de fluxo coronário e miocárdico obtida pela ecocardiografia contrastada em pacientes com cardiomiopatia dilatada de origem não isquêmica." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/5/5131/tde-30072012-081401/.
Despite advances in understanding of the pathophysiology and therapeutic approaches, dilated cardiomyopathy (DCM) remains as a condition with high mortality and one of the mechanisms involved in this process seems to be microvascular dysfunction. Recently, new echocardiographic techniques have been incorporated in the clinical practice and used for the assessment of microvascular dysfunction, including evaluation of left anterior descending coronary artery (LAD) by Doppler and quantitative analysis of myocardial flow by real-time myocardial perfusion echocardiography (RTMPE). In the present study, we evaluated the prognostic value of coronary flow velocity reserve (CFVR), obtained by transthoracic echocardiography, and parameters of myocardial flow reserve (MFR), obtained by RTMPE for predicting cardiac death and heart transplantation in patients with nonischemic DCM. In addition, we sought to detect the incremental value of flow reserve over clinical and echocardiographic parameters already known as predictors of events in this population. We studied 195 patients with DCM (130 men, mean age 54 ± 12 years) who had left ventricular ejection fraction (LVEF) less than 35% by echocardiography and no signs of obstructive coronary artery disease by invasive coronary angiography or noninvasive methods (nuclear medicine or angiography by computed tomography). We assessed conventional echocardiographic parameters of systolic and diastolic left ventricular function at rest. Coronary flow velocity was determined by pulsed Doppler in LAD and dynamics of microbubbles in the myocardium was measured by RTMPE using specific computer programs, both at rest and during dipyridamole stress (0.84 mg/kg). CFVR, MFR and the reserve of velocity of microbubbles in the myocardium ( reserve) were obtained as the ratio between parameters of flow during hyperemia and at rest, being considered abnormal when these were below 2.0. The mean follow-up was 29 months (ranging from 6 to 69 months). During this period, 45 patients (24%) had events, 43 cardiac deaths and 2 heart transplantations. In the univariate analysis, predictors of events were: Chagas disease, New York Heart Association functional class, use of angiotensin-converting enzyme inhibitors/angiotensin II receptor blocker (protective effect), left ventricular and atrial diameters, left ventricular volumes, LVEF, diastolic dysfunction, degree of mitral regurgitation, CVFR, MFR and reserve. By multivariate analysis, the only independent predictors of events were the left atrial diameter (OR = 1.16, 95% confidence interval = 1.078 to 1.264, p <0.001) and reserve 2.0 (OR = 3.219, confidence interval 95 % = 1.178 to 8.795, p <0.001). In the sequential model of events prediction, LVEF and left atrial diameter added prognostic value over clinical factors (chi-square from 15.2 to 58.5; p<0.001). reserve added power to the model (chi-square = 70.2, p<0.001). We concluded that CVFR, obtained by Doppler in LAD, MFR and reserve, obtained by dipyridamole stress RTMPE, are predictors of cardiac death and heart transplantation in patients with nonischemic DCM. However, only left atrial diameter and depressed reserve showed independent and incremental predictive value beyond that provided by current known prognostic clinical and echocardiographic factors
Santos, Larissa Ferreira dos. "Controle neurovascular do fluxo sanguíneo muscular e da atividade nervosa simpática durante o exercício em pacientes após síndrome isquêmica miocárdica instável com polimorfismos do receptor \'beta\'2-adrenérgico Gln27Glu." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/39/39132/tde-07042015-144133/.
Acute coronary syndrome (ACS) leads to important neurovascular abnormalities such as sympathetic hyperactivity and decreased forearm blood flow (FBF) at rest and during physiological maneuvers as exercise. The presence of some polymorphisms in human genetics, as the β2-adrenoceptor Gln27Glu, presents a significant association with cardiovascular functionality in healthy subjects. However, it is not known whether in patients with ACS, the presence of polymorphisms of the β2-adrenoceptor leads to distinct neurovascular responses during exercise, and if the exercise training can modify this response. OBJECTIVES: To study the influence of Gln27Glu \'beta\'2-adrenoceptor polymorphisms on neurovascular control of muscle sympathetic nerve activity (MSNA) and FBF at rest and during handgrip exercise, in patients with ACS; and to evaluate the effect of exercise training on neurovascular responses during exercise in these patients. METHODS: Initially, were selected 78 patients with ACS with ejection fraction >= 45% at the time of hospitalization. One month after the ischemic event, 61 patients returned for the initial assessments. Patients were genotyped and then divided into two groups according to the Gln27Glu \'beta\'2-adrenoceptor polymorphisms: 1-Gln27Gln (CC, n=35) and 2-Gln27Glu + Glu27Glu (CG +GG, n=26). Of these, 29 patients agreed to participate in an exercise training protocol for a period of 8 weeks, but only 25 patients completed the protocol (CC, n=17; CG+GG, n=8). The evaluation of neurovascular control was performed at rest and during a handgrip exercise at 30% of the maximum voluntary contraction. We evaluated the MSNA, by the direct technique of microneurography, the FBF, by venous occlusion plethysmography technique, blood pressure (BP), by indirect oscillometric device and heart rate, by electrocardiogram. All evaluations were performed one month after the ischemic event and, for those patients subjected to the exercise training protocol the same evaluations were repeated after 8 weeks of intervention. RESULTS: One month after the ischemic event, the MSNA (P=0.26) and mean arterial pressure (MAP, P=0.14) at rest were similar between groups with genotype CC and CG+GG. However, during exercise, the response of MSNA was higher in the CC group compared with the CG+GG group (\'delta\'=11±2 vs. 4±2 bursts/100HB, P=0.02). In addition, BP response during exercise was higher in the CC group compared to the CG + GG group (\'delta\' =24 ±2 vs. 18±2 mmHg, P=0.04). The forearm vascular conductance (FVC) response during exercise was similar in both groups. After exercise training, baseline MSNA decreased in the group with CC genotype (63± 3vs. 48±5 bursts/100HB, P <0.001) but not in the group with CG+GG genotypes (70±4 vs. 55±5 bursts/100HB, P =0.06). Similarly, exercise training decreases the level (P= 0.007) and the response of MSNA (\'delta\'= 12±2 vs. 5±2 bursts/100HB, P= 0.02) during exercise in the group with CC genotype but not in the CG+GG group (P= 0.10) and (\'delta\'=7±3 vs 7±3 bursts/100HB, P= 0.96), respectively. Exercise training did not change the levels of MAP and FVC, during exercise in both groups. However, in the post exercise training period, the CG+GG group had lower MAP response (P =0.01) and higher FVC (P =0.03) during exercise compared to the CC group. CONCLUSION: Patients with ACS, carrying the CC genotype of the \'beta\'2-adrenoceptor have increased MSNA response during physiological maneuver as exercise when compared with patients carrying the CG+GG genotype. Exercise training reverses this exacerbated response of MSNA in patients with CC genotype. These results suggest an increased cardiovascular risk in patients with ACS with CC genotype of the \'beta\'2-adrenoceptor. Furthermore, exercise training should be strongly recommended for patients with ACS, especially for those with the CC genotype
Osório, Altamiro Filho Ferraz. "Avaliação das reservas de fluxo coronariano e miocárdico pela ecocardiografia com Doppler e com contraste no território da artéria descendente anterior." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/5/5131/tde-03102014-102146/.
Real-time myocardial contrast echocardiography (RTMCE) is a recently developed technique that utilizes low-mechanical index imaging and allows for noninvasive evaluation of myocardial perfusion as well as for quantification of regional myocardial blood flow. Although previous studies have demonstrated that RTMCE permits determining myocardial blood flow reserve (MBFR), its diagnostic accuracy and correlation with the measurement of coronary flow reserve (CFR) by transthoracic Doppler echocardiography (TTDE) has not been fully demonstrated. The aims of this study were to compare the feasibility and diagnostic accuracy of MBFR obtained by RTMCE and CFR obtained by TTE for detecting angiographically significant obstruction in the left anterior descending coronary artery (LAD), and to determine the correlation between MBFR and CFR and the severity of stenosis determined by quantitative coronary angiography. We prospectively studied 71 patients, among them 56 patients (20 men, 59 ± 11 years) were considered for the determination of diagnostic accuracy. All patients underwent RTMCE at rest and during 140mcg/kg/min of adenosine infusion. Plateau acoustic intensity (A), myocardial replenishment velocity slope (B) and myocardial blood flow (A x B) were quantified using Q-Lab 3.0 (Philips Medical Systems). Coronary flow velocities were evaluated in the distal LAD using TTE and CFR was defined as the ratio between maximal diastolic velocity during hiperemia and baseline. LAD stenosis (obstruction >50% of luminal diameter) was determined by quantitative coronary angiography (QCA) performed within one month of RTMCE. The feasibility of CFR measurement by TTE was 83%, while the feasibility of MBFR measurement by RTMCE was 99%. CFR was significantly lower in patients with than in patients without angiographically significant LAD stenosis (2.86 ± 0.71 versus 1.57 ± 0.38; p = 0.0001), as was the MBFR (2.43 ± 0.80 versus 1.24 ± 0.48; p = 0.0001) and b reserve (2.08 ± 0.82 versus 1.23 ± 0.46; p = 0.001). Cutoff values for differentiating patients with and without LAD stenosis were 1.84 for CFR, 1.74 for MBFR, and 1.68 for b reserve. The sensitivity, specificity and accuracy for detecting LAD stenosis were 96%, 93%, and 95% for CFR obtained by TTE, 88%, 90%, and 89% for MBFR, and 88%, 84%, and 86% for b reserve. Multivariate logistic regression analysis revealed that CFR as measured by TTE was the best predictor of LAD (Odds ratio = 1.78, 95% confidence interval 1.28 to 2.47). There was a good correlation between b reserve (r = 0.89; p <0.05), MBFR (r = 0.79; p <0.05), and CFR (r = 0.88; p < 0.05) and the severity of coronary obstruction determined by QCA. In conclusion, CFR obtained by TTE and MBFR obtained by RTMCE were highly feasible and accurate for differentiating patients with and without angiographically significant LAD obstruction. CFR had a slightly higher diagnostic accuracy than other xxv evaluated parameters, despite lower feasibility. Both the CFR and MBFR were inversely correlated with the degree of luminal coronary obstruction determined by QCA
Santos, João Manoel Theotonio dos. "Avaliação da reserva de fluxo miocárdico pela ecocardiografia com perfusão miocárdica em tempo real em pacientes com disfunção ventricular esquerda, antes e após reabilitação cardiovascular por exercício físico supervisionado." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/5/5131/tde-23052009-150130/.
Introduction: Heart failure is a clinical, complex and progressive syndrome, which may result from any structural or functional heart disorder that changes its capacity of filling and/or ejection, and the majority of patients perform evolution with left ventricular dysfunction (DVE). The exercise training is accepted as an important adjuvant in the treatment of this clinical condition by promoting significant improvement in patients functional capacity; however the mechanisms by which this occurs are still not fully elucidated. In this context, Echocardiography with Real Time Myocardial Perfusion (EPMTR) can be a very useful method as much the evaluation of hemodynamic parameters as myocardial perfusion, facilitating a better understanding of the physiopathologic changes promoted by the cardiovascular rehabilitation by supervised exercise training (RCVEFS) and consequently, its therapeutic impact on the prognosis of this critical group of patients. Objective: Evaluate if the RCVEFS can improve the myocardial flow reserve, measured by echocardiography with real time myocardial perfusion, in patients with non-ischemic etiology DVE. Methods: We prospectively evaluated 40 patients over 18 years old with left ventricular dysfunction defined by ejection fraction of left ventricle (LVEF) calculated by Simpson Method <45% and without limitations of physical exercise practice, that were invited to a RCVES program in a period of 4 months. Patients were randomly assigned to a training group or control group. There were performed in their study beginning and after 04 months of group attendance, ergo spirometry and EPMTR. The perfusion analysis was performed by an independent examiner (blind), that verified the myocardial peak intensity regularized by the acoustic cavity intensity (An), micro bubbles refilling speed after their complete destruction with a high ultrasonic energy beam (ß) and myocardial blood flow (An x ß), using Q-Lab Philips Ultrasound Program. Results: From 40 patients initially selected, 23 concluded the study, being 13 in training group (average age 53 ± 13 years, 09 male, 15% smokers, 38% Dyslipedemia, 85% high blood pressure (HBP), 15 % mellitus diabetes (DM) and 31% Chagas disease) and 10 in the control group (mean age 59 ± 12 years, 04 male, 10% smokers, 50% dyslipidemia, hypertension 90%, 30% and 10% DM Chagas disease). There was no LVEF improvement in the group training (26 + 14 to 26 + 13) and the control group (26 + 6 to 27 + 6). In the training group there was An increase of 1.21 to 1.43 (p = 0.02) of ß from 1.51 to 2.20 (p = 0.0001) and An x ß of 1.81 to 3.05 (p = 0001), there was also VO2 peak improvement of 21.75 ml / kg / min to 24.76 ml / kg / min (p = 0, 0005). In the control group there was An increase of 1.14 to 1.15 (p = 0.91), ß decrease from 1.72 to 1.46 (p = 0.03) and reduction in An x ß of 1.89 to 1.55 (p = 0.01), there was also VO2 peak deterioration 21.14 ml/kg/min to 20.7 ml/kg/min (p =0.58). Conclusion: The Cardiovascular Rehabilitation Program by Supervised Physical Training improved the myocardial flow reserve, in patients with Left Ventricular Dysfunction of non-ischemic etiology.
Junior, Alcione Lescano de Souza. "Efeito do pré-tratamento com óleo de peixe sobre o infarto agudo do miocárdio em ratos." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/42/42137/tde-10072014-145247/.
Rats were treated with saline, fish (FO) or soybean (SO) oils by gavage for 20 days before myocardial infarction (MI). Infarct size, activities of plasma CK and caspase 3 in the left ventricle (LV) were decreased by FO as compared with saline or SO. The contents of IL-1β, TNF-α, CINC 2α/β, IL-6, VEGF-α in the LV and of IL-1β, TNF-α, MIP-3, IL-6, VEGF-α in the liver were increased by SO. Contents of ATP and lactate in the LV were increased and of glycogen decreased by FO. FO prevented the decrease in the coronary blood flow in the LV of infarcted rats. The mRNA contents of iNOS, eNOS, HIF-1α, GLUT 1, VEGF-α, p53 and Bax2 in the VE were increased by FO. Ejection fraction, fractional shortening and velocity of circumferential fiber-shortening were also increased by FO. So, treatment with FO leads to a preconditioning state that protected the heart from MI injury.
Bonini, Rômulo César Arnal. "Revascularização cirúrgica do miocárdio com utilização de enxerto de artéria radial esqueletizada ou com tecidos adjacentes: análise comparativa randomizada." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/5/5156/tde-12032008-100149/.
BACKGROUND: The use of artery grafts in the surgical revascularization of the myocardium is currently a well-established procedure by cardiovascular surgeons, and its skeletonization has posed some advantages, in principle, with the left internal thoracic artery. OBJECTIVE: With the purpose of analyzing this radial artery harvest method, the study evaluated the functional and hemodynamic early performance, as well as the morphological anatomic and histological features of the aortic coronary grafts of the radial artery, skeletonized or with surrounding tissues, in the surgical revascularization of the myocardium. METHODS: The study compared 40 patients, randomly distributed in two groups. In Group I, we employed a skeletonized radial artery (20 patients), and in Group II, the radial artery with surrounding tissues (20 patients), for the marginal branches of the left coronary artery. In total, 39 patients underwent cinecoronariography and fluxometry with a 12-MHz Doppler guide catheter (0.014 in., Flowire, Jometrics Inc.), in the immediate postoperative period. RESULTS: Both groups presented similar demographic features. The main intra-surgical variables of the radial artery were also similar, with an extension of 17.1 cm in Group I, and 16.3 cm in Group II, and the free flow was of 80.3 ml/min in Group I, and of 95.5 ml/min in Group II. No morphological anatomic and histological differences were observed in the compared groups. The diameters of the radial artery grafts, which were calculated by quantitative angiography in the postoperative period, were similar (2.66 mm in Group I, and 2.53 mm in Group II), as well as the flow variables (blood flow of 54.9 ml/min in Group I, and of 44.28 ml/min in Group II, and a flow reserve of 2.12 in Group I, and of 2 in Group II). On the other hand, the cinecoronariography revealed the presence of an occlusion in one graft, and of stenosis in five grafts of Group II, while Group I presented stenosis in only one radial artery graft (p = 0.091). CONCLUSIONS: The aortic coronary grafts of the radial artery displayed good functional and hemodynamic early performance. There was no difference between the groups regarding functional and hemodynamic early performance, and the morphological anatomical and histological features.
Ceccon, Conrado Lelis. "Eficácia da aplicação de ondas de choque para indução ao crescimento vascular em pacientes com angina refratária: avaliação pela ecocardiografia de perfusão miocádica em tempo real." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/5/5131/tde-13062018-094940/.
Chronic coronary artery disease shows high prevalence and morbidity levels in general population. In the clinical scenario, it is usually characterized by pain symptoms typically triggered or aggravated by physical effort - the angina. Refractory angina is defined as a documented and uncontrolled myocardial ischemia, untreatable by revascularization, despite maximum tolerated drug therapy. The use of extracorporeal cardiac shock wave therapy to treat myocardial ischemia has been suggested as a promising alternative to relieve angina symptoms and improve the ischemic load by promoting vasodilation and neoangiogenic phenomena. In the present study, we evaluated the effect of guided shock wave therapy on myocardial flow reserve, determined by real-time myocardial perfusion echocardiography (RTMPE), in patients with refractory angina. We also evaluated the implications of shock wave therapy in clinical variables by assessing the Canadian Cardiovascular Society (CCS) grading of angina pectoris, New York Heart Association (NYHA) functional classification and quality of life by the Seattle Angina Questionnaire (SAQ), as well as echocardiographic variables. Fifteen patients with refractory angina, from the refractory angina outpatient clinic of the Instituto do Coração (InCor, HC-FMUSP), were studied. Each patient underwent 9 shock wave therapy sessions over the course of 9 weeks and was followed for 6 months once the treatment was concluded. Using specific software, myocardial microbubble dynamics was quantified by RTMPE at rest as well as in stress by dipyridamole (0.84 mg/Kg). Normalized myocardial blood (Anor) reserve, myocardium microbubbles replenishment rate (?) reserve and myocardial flow reserve (Anor x ?) were obtained by the ratio of flow parameters during hyperemia and rest, before and 6 months after treatment. In the 15 patients included in the study, we evaluated 32 segments with myocardial ischemia submitted to therapy, 31 segments with myocardial ischemia not submitted to therapy and 60 non-ischemic segments. Researchers were blinded to all clinical data at the time of the perfusion analysis. Patients had mean age of 61.5 (± 12.8) years old, were predominantly men (67%), and 93% presented multiarterial disease. Six months after the completion of shock wave therapy, an improvement in CCS grading of angina pectoris was observed from 3.20 ± 0.56 to 1.93 ± 0.70 (p = 0.0001) and in NYHA functional classification (from 2.80 ± 0.56 to 2.33 ± 0.81; p = 0.048), results consistent with those found by SAQ, which evidenced a significant score improvement in all categories (global analysis with average score increased from 42.33 ± 13.0 to 71.16 ± 14.3; p = 0.0001). There was a variation in the left ventricular ejection fraction (from 50.3 ± 13.1% to 53.20 ± 10.6%; p = 0.049) in the absence of changes in end-diastolic diameter (from 53.80 ± 6.61 mm to 53.53 ± 7.05 mm; p = 0.81), the end-diastolic volume (from 134.67 ± 34.33 mL to 146.13 ± 59.45 mL; p = 0.29) or the diastolic function. Myocardial perfusion analysis by RTMPE evidenced a relevant increase in myocardial flow reserve (Anor x ?) from 1.33 ± 0.22 to 1.74 ± 0.29; p = 0.0001, as well as in the Anor reserve from 1.02 ± 0.21 to 1.24 ± 0.33 (p = 0.004) in ischemic segments submitted to shock wave therapy, but not in ? reserve (from 1.33 ± 0.24 to 1.47 ± 0.35; p = 0.055). There was no significant myocardial perfusion alteration in untreated ischemic segments or non-ischemic segments. Global analysis showed an improvement in myocardial flow reserve (from 1.78 ± 0.54 to 1.89 ± 0.49; p = 0.017) and ? reserve (1.63 ± 0.43 to 1.70 ± 0.40; p = 0.039). No major cardiac events were registered during the follow-up period. We concluded that RTMPE was able to identify an increase in myocardial flow reserve in the segments submitted to shock wave therapy, possibly due to vascular neoproliferation. Results suggest that shock wave therapy on patients with refractory angina is safe, with the potential to improve myocardial ischemia on treated ischemic segments, and positively affect symptoms and quality of life
Zabihian, B. "Spectral analysis of coronary bypass doppler blood flow signals." Master's thesis, 2011. http://hdl.handle.net/10400.1/3773.
The pulsed Doppler ultrasound (DU) is one of the important tools in the study of vessel diseases and the investigation of flow conditions. Due to its non-invasive nature, it has been increasingly used in medicine in the last few decades. Accurate estimation of DU spectral center frequency and bandwidth parameters are extremely important for blood flow diagnostic purposes. Under real-time data acquisition conditions the DU signal is generally corrupted with different types of noise. In these situations the identification of signal components solely belonging to the blood flow signal is a difficult task. This thesis was aimed to study spectral techniques to enhance spectral parameter estimation, in particular the center frequency. Spectral estimates were obtained using the Short Time Fourier Transform (STFT) and Continuous Wavelet Transform (CWT). STFT was applied to short duration data segments, respecting signals’ stationary properties. Two CWT functions have been studied: varying bandwidth filter and fixed bandwidth filter. Since different filter bandwidth values yield different results, bandwidths for fixed bandwidth filter were investigate and the most proper one has been used on the performance comparative studies. To enhance the blood flow signal content of noise-embedded clinical Doppler signals, a STFT-based technique was proposed to reduce the signals’ noise components. Quantitative evaluation of the spectral methods was primarily performed on simulated signals with deterministic center frequency and bandwidth. Different signal to noise ratio signals were simulated. It has been observed that STFT spectral center frequency and bandwidth estimators were less biased than the CWT ones, although the last ones were less sensitive to the center frequency variations. Applying the proposed noise cancellation technique to simulated signals reduces the spectral estimators’ errors. As an example, a typical noisy signal with 10dbSNR, a reduction of 88% and 97% was obtained on the RMS bias of the estimation of the center frequency and bandwidth estimators respectively.
"Efeitos da vitamina E sobre o fluxo coronario endotelio-dependente em cães hipercolesterolemicos." Tese, Biblioteca Digital da Unicamp, 2002. http://libdigi.unicamp.br/document/?code=vtls000242732.
Fernandes, Joana Isabel Faria. "Quantificação do fluxo sanguíneo miocárdico por PET." Master's thesis, 2018. http://hdl.handle.net/10316/90047.
A doença arterial coronária é, atualmente, a doença a nível global que causa mais mortes e incapacidade, acarretando, por isso, elevados custos económicos tanto no seu tratamento como também no seu diagnóstico.A avaliação dos doentes com esta patologia tem sofrido várias modificações ao longo das duas últimas décadas, e a tomografia de emissão de positrões cardíaca tem emergido como um poderoso e versátil exame de imagem que permite diagnosticar e estratificar o risco destes doentes.Esta revisão teve como objetivo avaliar a utilidade deste exame, nomeadamente através da quantificação do fluxo sanguíneo total miocárdico e do fluxo sanguíneo de reserva miocárdico, no diagnóstico e estratificação de risco da doença arterial coronária. Comparativamente com outros métodos de imagem, a aferição por tomografia de emissão de positrões cardíaca destes parâmetros contribui para uma melhor caracterização da doença arterial coronária, com especial relevância na doença microvascular e multivascular equilibrada.A doença arterial coronária é, atualmente, a doença a nível global que causa mais mortes e incapacidade, acarretando, por isso, elevados custos económicos tanto no seu tratamento como também no seu diagnóstico.A avaliação dos doentes com esta patologia tem sofrido várias modificações ao longo das duas últimas décadas, e a tomografia de emissão de positrões cardíaca tem emergido como um poderoso e versátil exame de imagem que permite diagnosticar e estratificar o risco destes doentes.Esta revisão teve como objetivo avaliar a utilidade deste exame, nomeadamente através da quantificação do fluxo sanguíneo total miocárdico e do fluxo sanguíneo de reserva miocárdico, no diagnóstico e estratificação de risco da doença arterial coronária. Comparativamente com outros métodos de imagem, a aferição por tomografia de emissão de positrões cardíaca destes parâmetros contribui para uma melhor caracterização da doença arterial coronária, com especial relevância na doença microvascular e multivascular equilibrada.
Currently, coronary artery disease is an important cause of mortality and morbidity worldwide thus leading to high economic costs in both treatment and diagnosis.Over the past two decades, the assessment of patients with this pathology has undergone several modifications, with cardiac positron emission tomography emerging as a powerful and versatile imaging exam that allows the diagnosis and risk stratification of these patients.This review aimed to assess the utility of this exam, namely through myocardial blood flow and myocardial flow reserve quantification in the diagnosis and risk stratification of coronary artery disease.Comparing with other imaging methods, the measurement of these parameters by cardiac positron emission tomography contribute to a better characterization of coronary artery disease, with a special relevance in microvascular and balanced multivessel disease.Currently, coronary artery disease is an important cause of mortality and morbidity worldwide thus leading to high economic costs in both treatment and diagnosis.Over the past two decades, the assessment of patients with this pathology has undergone several modifications, with cardiac positron emission tomography emerging as a powerful and versatile imaging exam that allows the diagnosis and risk stratification of these patients.This review aimed to assess the utility of this exam, namely through myocardial blood flow and myocardial flow reserve quantification in the diagnosis and risk stratification of coronary artery disease.Comparing with other imaging methods, the measurement of these parameters by cardiac positron emission tomography contribute to a better characterization of coronary artery disease, with a special relevance in microvascular and balanced multivessel disease.
Azevedo, Ana Catarina Soares Feio de. "Pressure-wire based functional assessment of coronary stenoses in surgical heart valve disease patients: impact in the coronary revascularization technique." Master's thesis, 2019. http://hdl.handle.net/10316/89728.
Objetivos: Descrever de que forma a informação obtida pela realização de avaliação funcional por guia de pressão afetou a estratégia de revascularização cirúrgica das artérias estudadas e realizar o seguimento clínico, a um ano, em termos de eventos cardio e cerebrovasculares: morte cardiovascular, enfarte agudo do miocárdio e revascularização não planeada.Métodos: Foi conduzida uma análise retrospetiva de um coorte prospetivo de 32 doentes com doença valvular cardíaca, de um grupo de 298 doentes submetidos a uma avaliação funcional de estenoses coronárias intermédias por guia de pressão no nosso centro entre outubro de 2013 e fevereiro de 2018. As características dos doentes foram retiradas de duas bases de dados. O tempo médio de seguimento clínico foi de 421 dias. Na análise dos dados usaram- se como valores de referência de FFR e IFR um cut-off de ≤0,80 e de ≤0,89, respetivamente.Resultados: Neste estudo foram incluídos 32 doentes com doença valvular cardíaca com indicação cirúrgica, tendo sido avaliadas através do FFR e/ou iFR 42 lesões coronárias. Foram integrados 23 doentes do sexo masculino e a idade média foi de 73 anos. Relativamente aos fatores de risco para doença cardiovascular, 81,3% dos doentes tinham hipertensão, 81,3% eram dislipidémicos, 31,3% tinham diabetes mellitus e 18,8% eram fumadores. A descendente anterior foi a artéria coronária mais vezes envolvida, afetando 23 (54,8%) doentes. Apenas 9 lesões foram classificadas como sendo hemodinamicamente significativas e 6 dessas foram revascularizadas. As 33 lesões restantes não tinham indicação para serem tratadas, no entanto 1 lesão foi revascularizada cirurgicamente.Conclusão: No nosso centro os cirurgiões cardíacos acreditam e atuam consoante os resultados da avaliação funcional. Após um ano de seguimento clínico não se registaram eventos cardiovasculares major nos doentes cuja avaliação funcional tinha sido negativa, confirmando a segurança da utilização do FFR e iFR nesta população com doença valvular grave.
Aims: Describe how the pressure-wire based functional assessment of intermediate coronary stenoses affected the strategy of myocardial revascularization and to perform a one-year analysis in terms of cardiovascular events: cardiovascular death, myocardial infarction and unplanned revascularization.Methods: We conducted a retrospective analysis on a prospective cohort of 32 patients with valvular heart disease out of 298 patients who underwent a pressure-wire based functional assessment of coronary stenosis between October 2013 and February 2018. The baseline data were extracted from two main databases. The median follow-up was 421 days. The cut- off values of 0.80 and 0.89 were used for FFR and iFR, respectively.Results: We included 32 patients with valvular heart disease, which of 42 coronary lesions were functionally assessed by FFR and/or IFR. There were 23 male and 9 female patients and the median age was 73 (66.0-78.0) years. Regarding risk factors for cardiovascular diseases, 81.3% of the patients had hypertension, 81.3% were dyslipidemic, 18.8% were smokers and 31.3% were diabetic. The most frequent lesion was on the left anterior descending coronary artery, affecting 23 (54.8%) patients. Only 9 lesions were classified as hemodynamically significant and 6 of them were treated, either by PCI or CABG. The 33 remaining lesions didn’t have an indication for revascularization, however, one lesion was treated with CABG. There were no major cardiovascular events within 12 months of follow-up.Conclusion: In our centre, the cardiothoracic surgeons believe and act accordingly to the functional assessment evaluation of the coronary lesions. During the follow-up time, no cardiovascular events were registered among the patients which coronary physiological measurements were negative, confirming the safe use of FFR or iFR in this population with valvular heart disease.
Ribeiro, Márcia Isabel Cardoso. "Avaliação da gravidade de lesões coronárias intermédias por guia de pressão em doentes transplantados cardíacos: tão precisa como nas lesões em coração nativo?" Master's thesis, 2019. http://hdl.handle.net/10316/89782.
Introdução e objetivosA doença coronária é a causa mais importante de morbimortalidade após o transplante cardíaco. A avaliação funcional invasiva tem revelado maior precisão na classificação das lesões coronárias, comparativamente com a avaliação baseada apenas na angiografia coronária e encontra-se bem validada na população de não transplantados cardíacos. Contudo, na população de transplantados cardíacos, a evidência científica relativa à avaliação funcional invasiva de lesões coronárias intermédias limita-se à publicação de casos clínicos isolados.Este estudo tem dois objetivos principais: 1) análise retrospetiva de todos os casos em que foi utilizada avaliação funcional em doentes transplantados cardíacos no nosso centro e 2) criação de um protocolo prospetivo para avaliação por iFR da gravidade de lesões intermédias em doentes transplantados cardíacos.MétodosFoi analisada retrospetivamente uma base de dados, previamente anonimizada, que inclui doentes transplantados cardíacos em seguimento angiográfico no Laboratório de Hemodinâmica e Cardiologia de Intervenção do Centro Hospitalar e Universitário de Coimbra – Hospitais da Universidade de Coimbra. Este estudo analisou os doentes com pelo menos uma lesão coronária submetida a avaliação funcional por FFR ou iFR desde janeiro de 2014 até abril de 2018. Foi criado um protocolo de avaliação funcional de lesões coronárias intermédias em doentes transplantados cardíacos, com vista ao desenvolvimento de um estudo prospetivo e multicêntrico.ResultadosA prevalência de doença coronária na nossa população de doentes transplantados cardíacos foi de 32%. Dos 39 doentes com doença coronária identificada por angiografia, 9 foram submetidos a avaliação funcional por FFR/iFR. Este procedimento decorreu com sucesso e sem complicações em todos os casos. Obtiveram-se resultados positivos para isquémia em 5 das lesões avaliadas, tendo sido estas submetidas a angioplastia coronária. Cinco doentes tinham lesões funcionalmente não significativas, tendo sido orientados para tratamento conservador. Durante o seguimento clínico destes doentes, não ocorreu nenhuma morte de causa cardiovascular nem nenhuma síndrome coronária aguda.Construímos um protocolo prospetivo para avaliação por iFR da gravidade de lesões intermédias em doentes transplantados cardíacos, com o objetivo de validar a utilização desta técnica e o respetivo limiar de deteção nesta população específica de doentes.ConclusõesNesta população específica de doentes transplantados cardíacos, a avaliação funcional invasiva decorreu com sucesso e sem complicações em todos os casos. As lesões funcionalmente significativas foram tratadas por angioplastia e as negativas foram orientados para terapêutica médica otimizada. Durante o seguimento clínico destes doentes, não se verificou nenhuma síndrome coronária aguda nem nenhuma morte de causa cardiovascular, evidenciando a segurança da avaliação funcional invasiva neste contexto. Estes resultados necessitam de validação por um estudo prospetivo de dimensão adequada.
Introduction and objectivesCoronary artery disease is the most significant cause of morbidity and mortality after cardiac transplantation. Invasive functional evaluation has revealed a greater precision in the classification of coronary lesions compared to the evaluation based on coronary angiography alone, and is well validated in the non-transplanted cardiac population. However, in the cardiac transplant population, the scientific evidence regarding the invasive functional evaluation of intermediate coronary lesions is limited to the publication of isolated clinical cases.This study has two main objectives: 1) retrospective analysis of all cases where functional evaluation was used in cardiac transplant patients at our center and 2) creation of a prospective protocol for iFR assessment of the severity of intermediate lesions in cardiac transplant patients.MethodsWe retrospectively analyzed a database, previously anonymized, that included transplanted cardiac patients in an angiographic follow-up at the Laboratory of Hemodynamics and Interventional Cardiology of the University Hospital Center of Coimbra – University Hospitals of Coimbra. This study looked at patients with at least one coronary lesion undergoing functional evaluation by FFR or iFR from January 2014 to April 2018. A protocol for the functional evaluation of intermediate coronary lesions in cardiac transplant patients was designed for the development of a prospective and multicenter study.ResultsThe prevalence of coronary artery disease in our population of cardiac transplant patients was 32%. Of the 39 patients with coronary disease identified by angiography, nine underwent FFR/iFR functional evaluation. This procedure was successful and uncomplicated in all cases. Positive ischemia results were obtained in 5 of the lesions evaluated, and these were submitted to coronary angioplasty. Five patients had functionally insignificant lesions and were assigned conservative treatment. During the clinical follow-up of these patients, no cardiovascular death or acute coronary syndrome occurred.We constructed a prospective protocol for iFR assessment of the severity of intermediate lesions in cardiac transplant recipients in order to validate the use of this technique and its detection threshold in this specific population of patients.ConclusionsIn this specific population of cardiac transplant patients, invasive functional evaluation was successful and uncomplicated in all cases. Functionally significant lesions were treated by angioplasty; insignificant lesions were treated with and optimized medical therapy. Invasive functional evaluation was found to be safe in this context, as demonstrated by the fact that no patient was found to have acute coronary syndrome or cardiovascular death during follow up. These results will need validation by a prospective study of adequate size.