An ovine model of postinfarction dilated cardiomyopathy in animals with highly variable coronary anatomy

Studies on cardiac regeneration require large mammalian models of dilated cardiomyopathy (DCM) after acute myocardial infarction (AMI), and pig and sheep models are increasingly used in this field of preclinical research. Given the large interindividual variability in ovine left anterior descending artery (LAD) anatomy, protocols based on the coronary arteries to be ligated often lead to significant variation in infarct sizes and hence to heterogeneous results, ranging from no ventricular remodeling to acute, lethal left ventricular (LV) failure. We designed an ovine model of postinfarction DCM based on estimated infarct size rather than on a predetermined menu of coronary artery ligatures. In seven adult sheep we induced an anterolateral AMI of approximately 25% of the LV mass by ligating the branches of the LAD that, by visual inspection, would lead to such an infarct size. In 10 to 12 weeks, LV end-diastolic volume more than doubled and LV end-systolic volume almost tripled. LV ejection fraction decreased dramatically, as did LV percent fractional shortening and LV percent wall thickening. Infarct size (planimetry) was approximately 25% of the LV endocardial surface. We conclude that in sheep, an anterolateral AMI of approximately 25% of the LV mass--regardless of the coronary branches ligated to attain that infarct size--results in a model of postinfarction DCM that may prove useful in preclinical research on myocardial regeneration.Fil: Locatelli, Paola. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro; ArgentinaFil: Olea, Fernanda Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro; ArgentinaFil: Mendiz, Oscar. Fundación Favaloro; ArgentinaFil: Salmo, Fabián. Fundación Favaloro; ArgentinaFil: Fazzi, Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Favaloro; ArgentinaFil: Hnatiuk, Anna. Universidad Favaloro; ArgentinaFil: Laguens, Rubén. Fundación Favaloro; ArgentinaFil: Crottogini, Alberto Jose. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro; Argentin

Rol del ecoestrés en el pronóstico de la miocardiopatía hipertrófica

Objetivos: Evaluar la utilidad de la obstrucción del tracto de salida del ventrículo izquierdo latente (OTSVI) y variables del eco-estrés en el pronóstico de miocardiopatía hipertrófica. Materiales y métodos: Estudio retrospectivo y observacional. Se evaluaron 110 pacientes con miocardiopatía hipertrófica mediante eco-estrés con ejercicio. Fueron divididos en tres grupos; G1: OTSVI persistente (gradiente ≥30mmHg en reposo); G2: OTSVI latente (gradiente ≥50mmHg con ejercicio); G3: sin OTSVI. La mediana de seguimiento fue 2,7 años. Se definió punto final primario a muerte, muerte súbita, taquicardia ventricular sostenida o internación por insuficiencia cardíaca. Resultados: El 19,1% pertenecían a G1, 31.8% G2 y 49,1% G3. Las variables del eco-estrés asociadas al punto final primario difirieron entre los grupos (G1>G2>G3). Se evaluaron pruebas ergométricas insuficientes (57%>37%>33%; p=0,164), síntomas (57%>31%>17%; p0,6%>0%; p=0,054) e insuficiencia mitral moderada-severa al final del ejercicio (86%>71%>0,28%; p<0,01). No hubo diferencias entre grupos para cambios del segmento ST-T y comportamiento anormal de la presión arterial con el esfuerzo. Las variables predictoras independientes del punto final primario en el análisis multivariado fueron la OTSVI persistente (OR:13,2; IC:1,3-133,5); comportamiento anormal de la presión arterial durante el ejercicio (OR:6,3; IC:0,7-55,6) y los Mets alcanzados con una relación inversa (OR:0,77; IC:0,62-0,95). Conclusión: La OTSVI latente no se asoció con un mayor número de eventos en el seguimiento. La OTSVI persistente, el comportamiento anormal de la presión arterial con el esfuerzo y los Mets alcanzados se asociaron en forma independiente al punto final primario en una población con miocardiopatía hipertrófica de Argentina

Cambios en el grado de insuficiencia mitral en pacientes con enfermedad bivalvular e implante valvular aórtico percutáneo

Background: Patients undergoing double valve replacement due to severe aortic stenosis and significant mitral regurgitation present high surgical morbidity and mortality. It has been suggested that transcatheter aortic valve implantation produces an inverse left ventricular remodeling resulting in favorable changes in the loading conditions and subsequent mitral regurgitation improvement. Objective: The aim of this study was to assess the benefit of isolated transcatheter aortic valve implantation in these patients and to analyze the influence of decreased afterload and favorable left ventricular remodeling on mitral regurgitation. Methods: The study retrospectively analyzed 89 consecutive patients undergoing transcatheter aortic valve implantation at a single center between March 2009 and August 2015, due to symptomatic severe aortic stenosis and high surgical risk. Echocardiograms were analyzed before the procedure and at one-month of follow-up. Forty patients identified with significant mitral regurgitation constituted the final sample and object of this investigation. Results: Baseline mitral regurgitation was classified as severe (+4) in 5 patients (12.5%), moderate to severe (+3) in 18 patients (45%) and mild to moderate (+2) in 17 patients (42.5%). During follow-up, mitral regurgitation was identified as +4 in 1 patient (2.5%), +3 in 12 patients (30 %), +2 in 8 patients (20%), +1 in 15 patients (37.5%) and 4 patients (10%) exhibited no mitral regurgitation; all changes were statistically significant (p=0.045). Conclusion: Our results suggest that in patients with multiple valve disease, rejected for surgical treatment due to high risk, transcatheter aortic valve implantation could be the main therapeutic option, as there is a high probability of mitral regurgitation reduction after the procedure.Introducción: Ha sido descripta la morbi-mortalidad quirúrgica en pacientes sometidos a doble reemplazo valvular por presentar estenosis aórtica (EAO) severa e insuficiencia mitral (IM) significativa. El objetivo de este trabajo es evaluar el beneficio del reemplazo valvular aórtico percutáneo (TAVI) aislado en dichos pacientes, y analizar la influencia de la disminución de la poscarga y el remodelado favorable del ventrículo izquierdo (VI) sobre la IM. Materiales y métodos: Se evaluaron retrospectivamente 89 pacientes consecutivos de un único centro, sometidos a TAVI entre marzo 2009 y agosto 2015, por presentar EAO severa sintomática y alto riesgo quirúrgico. Se analizaron los ecocardiogramas antes del procedimiento y posterior al mes de seguimiento. Se identificaron un total de 40 pacientes con IM significativa que corresponden a la muestra final y objeto de nuestra investigación. Resultados: La gravedad de la IM basalmente fue clasificada en severa (+4) en 5 pacientes (12,5%), moderada a severa (+3) en 18 (45%) y leve a moderada (+2) en 17 (42,5%). En el seguimiento, se identificó IM (+4) en 1 paciente (2.5%), (+3) en 12 pacientes (30%), (+2) en 8 pacientes (20%), leves (+1) en 15 pacientes (37,5%) y 4 pacientes sin insuficiencia (10%), siendo estos cambios estadísticamente significativos (p=0.045). Conclusiones: Nuestros resultados sugieren que en aquellos pacientes con enfermedad bivalvular, descartados de tratamiento quirúrgico por alto riesgo, el TAVI podría ser la principal opción terapéutica, dado que habría una alta probabilidad de que la IM se reduzca luego del procedimient

Utilidad del Doppler tisular para identificar una subpoblación de riesgo bajo en pacientes con diagnóstico de miocardiopatía hipertrófica

Introduccion El Doppler pulsado tisular ha demostrado beneficio en la deteccion temprana de la miocardiopatia hipertrofica y en el diagnostico diferencial de esta con otras causas secundarias de hipertrofia. Objetivo Determinar el valor pronostico de las velocidades miocardicas sistolicas tisulares preservadas en pacientes con diagnostico de miocardiopatia hipertrofica. Material y metodos Se incluyeron 146 pacientes con diagnostico de miocardiopatia hipertrofica, los cuales fueron evaluados en forma prospectiva mediante un estudio de ecocardiograma Doppler. Se obtuvieron las velocidades sistolicas tisulares del promedio de las velocidades septales y laterales; se compararon los pacientes con velocidades miocardicas sistolicas tisulares preservadas (Sa . 8 cm/seg; cuartil superior) con los que presentaban velocidades disminuidas. Se definio como punto final primario a la presencia de muerte subita, accidente cerebrovascular, insuficiencia cardiaca o internacion de causa cardiovascular en el seguimiento. Resultados El 29% (n = 43) presento velocidades miocardicas sistolicas tisulares preservadas en las imagenes del Doppler tisular, con mas frecuencia de varones (76,7% vs. 53,4%; p = 0,009) y sin diferencias en la edad. Los diametros ventriculares y los espesores fueron similares, en tanto que el area auricular fue significativamente menor (23,7 ±} 6,7 cm2 vs. 28,8 ±} 8 cm2; p < 0,001). En el seguimiento (mediana de 2,7 anos), el numero de eventos aumento significativamente a medida que disminuyeron las velocidades sistolicas en el Doppler pulsado tisular. Ningun paciente del grupo velocidades miocardicas sistolicas tisulares preservadas presento el punto final combinado, con diferencias significativas con respecto al grupo control (0% vs. 21,6%; p = 0,001) y un valor predictivo negativo del 100%. Conclusiones En nuestra poblacion de pacientes portadores de miocardiopatia hipertrofica, la presencia de velocidades miocardicas sistolicas tisulares preservadas en el Doppler pulsado tisular permitio identificar a una subpoblacion de pacientes de riesgo bajo, con un escaso numero de eventos en el seguimiento, con un valor predictivo negativo elevado

An Ovine Model of Postinfarction Dilated Cardiomyopathy in Animals with Highly Variable Coronary Anatomy

Studies on cardiac regeneration require large mammalian models of dilated cardiomyopathy (DCM) after acute myocardial infarction (AMI), and pig and sheep models are increasingly used in this field of preclinical research. Given the large interindividual variability in ovine left anterior descending artery (LAD) anatomy, protocols based on the coronary arteries to be ligated often lead to significant variation in infarct sizes and hence to heterogeneous results, ranging from no ventricular remodeling to acute, lethal left ventricular (LV) failure. We designed an ovine model of postinfarction DCM based on estimated infarct size rather than on a predetermined menu of coronary artery ligatures. In seven adult sheep we induced an anterolateral AMI of approximately 25% of the LV mass by ligating the branches of the LAD that, by visual inspection, would lead to such an infarct size. In 10 to 12 weeks, LV end-diastolic volume more than doubled and LV end-systolic volume almost tripled. LV ejection fraction decreased dramatically, as did LV percent fractional shortening and LV percent wall thickening. Infarct size (planimetry) was approximately 25% of the LV endocardial surface. We conclude that in sheep, an anterolateral AMI of approximately 25% of the LV mass--regardless of the coronary branches ligated to attain that infarct size--results in a model of postinfarction DCM that may prove useful in preclinical research on myocardial regeneration.Fil: Locatelli, Paola. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro; ArgentinaFil: Olea, Fernanda Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro; ArgentinaFil: Mendiz, Oscar. Fundación Favaloro; ArgentinaFil: Salmo, Fabián. Fundación Favaloro; ArgentinaFil: Fazzi, Lucía. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fundación Favaloro; ArgentinaFil: Hnatiuk, Anna. Universidad Favaloro; ArgentinaFil: Laguens, Rubén. Fundación Favaloro; ArgentinaFil: Crottogini, Alberto Jose. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro; Argentin

Papillary fibroelastoma: retrospective analysis. Clinical presentation and surgical results

Papillary ibroelastomas are small benign intracardiac tumors known for their embolic potential. Since the introduction of echocardiography with improved resolution and transesophageal imaging techniques, they are being increasingly detected in clinical practice. In recent series, papillary fibroelastoma is considered the most frequent benign tumor of the heart. Our objective was to analyze characteristics and midterm surgical outcome of histologically-confirmed cases of papillary fibroelastoma. We conducted a retrospective study on patients with cardiac tumors submitted to surgical excision between June 1992 and February 2017. Out of 108 patients, 18 had papillary fibroelastomas. Their mean age was 58 years (22-77); 10 were men. The most frequent localizations were the aortic valve (7) and the mitral valve (5). None had significant valvular dysfunction. By transesophageal echocardiography, the tumor size (larger diameter) was 13.33 ± 5.55 mm (6.6-28.0). Two patients, both with tumor in the aortic valve, had suffered a stroke; other two had dyspnoea and atrial flutter, respectively. The remaining 14 patients were asymptomatic and their tumors were incidental findings. In 15 patients the valve was preserved. There was neither surgical mortality nor recurrence after 2.6 years of follow-up. In conclusion, most papillary fibroelastomas can be surgically removed with valve preservation and favorable clinical outcome. However, until the results of randomized trials support the decision, an aggressive surgical approach in asymptomatic patients needs to be defined in the context of surgical expertise

Minimalist Approach for Percutaneous Aortic Valve Implantation

Background: Transcatheter aortic valve implantation (TAVI) is becoming the standard procedure for high-risk patients requiringaortic valve replacement. This technique has evolved rapidly and the so-called minimalist strategy is gaining worldwide attention,while supporting evidence is still being assembled.Objective: The aim of this study was to compare 30-day outcomes of the minimalist approach (MA) versus the standard approach(SA) for TAVI performed in a single center.Methods: Between September 2009 and February 2018, 303 consecutive TAVI procedures were performed, 229 (75.6%) using theMA and 74 (24.4%) with the SA.Results: Mean age was 79.5 years and both groups had similar characteristics. There were no differences in hypertension, diabetes,smoking habits, previous percutaneous coronary intervention (PCI) or coronary artery bypass graft surgery, acute myocardial infarction(AMI), chronic obstructive pulmonary disease, atrial fibrillation and dialysis. PCI before TAVI (combined procedure) and kidneyfailure (eGFR <60 ml / min / 1.73 m2) were more common in the SA group. The STS score was similar in both groups. The totalduration of the procedure and in-hospital stay were lower in the MA group (125±26 vs. 211±48 minutes; p <0.001, and 4.1 vs. 6.3days; p=0.01, respectively). There were no differences in mortality (3.9% vs. 1.4%; p=ns), incidence of AMI, stroke, major bleedingrequiring transfusion or vascular complications at 30 days. The closure device failed in four patients (one underwent surgical repairand three required a covered stent). Moderate paravalvular leaks (PVL) were more frequent in the SA group (11.8% vs. 23%; p=0.01)but the incidence of severe PVL was similar (1.3% vs. 2.7%).Conclusion: The MA for TAVI proved to be feasible and safe, reducing the procedure duration and in-hospital stay, with 30-day outcomessimilar to those of the SA but providing better comfort for the patient.Introducción: TAVR se está convirtiendo en un procedimiento estándar para pacientes con alto riesgo quirúrgico que necesitan reemplazo de válvula aórtica. Sin embargo, la técnica ha estado evolucionando rápidamente y la llamada estrategia minimalista está ganando adeptos en todo el mundo mientras la evidencia todavía se está acumulando. Objetivo: Analizar los resultados a 30 días de la estrategia minimalista (MIN-A) en comparación con la técnica convencional (CON-A) en la experiencia de un solo centro. Material y métodos: Entre septiembre de 2009 y febrero de 2018, se realizaron 303 procedimientos consecutivos de TAVR por acceso femoral, 229 (75.6%) de ellos con MIN-A y 74 (24.4%) con CON-A. Resultados: La edad promedio fue de 79.5 años y ambos grupos tenían características similares. No hubo diferencias en hipertensión, diabetes, fumadores, PCI o CABG previa, IAM, EPOC, fibrilación auricular y diálisis. La ATC por etapas antes del TAVR (procedimiento combinado) y la insuficiencia renal (eGFR <60 ml / min / 1,73 m2) fueron más frecuentes en CON-A. El score del STS fue similar en ambos grupos. El tiempo del procedimiento fue menor en MIN-A (125±26 vs. 211±48 minutos; p<0.001) al igual que el tiempo de hospitalización (4,1 vs. 6,3 días; p = 0,01). A los 30 días no hubo diferencias en la mortalidad (3.9% frente a 1,4%; p = 0,29), IAM, accidente cerebrovascular, hemorragia, transfusión y complicaciones vasculares. Cuatro Ptes tuvieron falla del dispositivo de cierre (1 reparación quirúrgica, 3 requirieron stent-cubierto). Las fugas paravalvulares moderadas (PVL) fueron más frecuentes en CON-A (11.8% vs. 23%; p=0.01), pero las PVL severas fueron similares (1.3% vs. 2.7%). Conclusión: La estrategia minimalista en el implante percutáneo de la válvula aórtica demostró ser factible y segura disminuyendo tiempo de procedimiento y estadía en el hospital con similares resultados clínicos que la estrategia convencional a 30 días, mejorando el confort

Reference values for echocardiographic parameters and indexes of left ventricular function in healthy, young adult sheep used in translational research: comparison with standardized values in humans

Ovine models of ischemic heart disease and cardiac failure are increasingly used in translational research. However, reliable extrapolation of the results to the clinical setting requires knowing if ovine normal left ventricular (LV) function is comparable to that of humans. We thus assessed for echocardiographic LV dimensions and indexes in a large normal adult sheep population and compared them with standardized values in normal human adults. Bidimensional and tissue Doppler echocardiograms were performed in 69 young adult Corriedale sheep under light sedation. LV dimensions and indexes of systolic and diastolic function were measured. Absolute and body surface areanormalized values were compared to those for normal adult humans and their statistical distribution was assessed. Normalized dimensions (except for end diastolic diameter) as well as ejection fraction and fractional shortening fell within the ranges established by the American Society of Echocardiography and European Association of Echocardiography for normal adult humans. Normalized end diastolic diameter exceeded the upper normal limit but got close to it when correcting for the higher heart mass/body surface area ratio of sheep with respect to humans. Diastolic parameters also fell within normal human ranges except for a slightly lower mitral deceleration time. All values exhibited a Gaussian distribution. We conclude that echocardiographic parameters of systolic and diastolic LV performance in young adult sheep can be reliably extrapolated to the adult human, thus supporting the use of ovine models of human heart disease in translational research