Maurice Enriquez-Sarano

Determinants of pulmonary hypertension in left ventricular dysfunction.

OBJECTIVESnThis study sought to analyze the determinants of pulmonary hypertension in patients with left ventricular dysfunction.nnnBACKGROUNDnPulmonary hypertension in patients with left ventricular dysfunction is a predictor of poor outcome. The independent role of cardiac functional abnormalities in the genesis of pulmonary hypertension is unclear.nnnMETHODSnIn 102 consecutive patients with primary left ventricular dysfunction (ejection fraction < 50%), systolic pulmonary artery pressure was prospectively measured by Doppler echocardiography (using tricuspid regurgitant velocity), and left ventricular systolic and diastolic function, functional mitral regurgitation, cardiac output and left atrial volume were quantified.nnnRESULTSnSystolic pulmonary artery pressure was elevated in patients with left ventricular dysfunction (51 +/- 14 mm Hg [mean +/- SD]), but the range was wide (23 to 87 mm Hg). Of the numerous variables correlating significantly with systolic pulmonary artery pressure, the strongest were mitral deceleration time (r = -0.61, p = 0.0001; odds ratio of pulmonary pressure > or = 50 mm Hg [95% confidence interval] if < 150 ms, 48.8 [14.8 to 161]) and mitral effective regurgitant orifice (r = 0.50, p = 0.0001; odds ratio [95% confidence interval] if > or = 20 mm2, 5.9 [2.3 to 15.5]). In multivariate analysis, these two variables were the strongest predictors of systolic pulmonary artery pressure in association with age (p = 0.005). Ejection fraction or end-systolic volume was not an independent predictor of pulmonary artery pressure.nnnCONCLUSIONSnPulmonary hypertension is frequent and highly variable in patients with left ventricular dysfunction. It is not independently related to the degree of left ventricular systolic dysfunction but is strongly associated with diastolic dysfunction (shorter mitral deceleration time) and the degree of functional mitral regurgitation (larger effective regurgitant orifice). These results emphasize the importance of assessing diastolic function and quantifying mitral regurgitation in patients with left ventricular dysfunction.

Clinical Context and Mechanism of Functional Tricuspid Regurgitation in Patients With and Without Pulmonary Hypertension

Background— Functional tricuspid regurgitation (FTR) with structurally normal valve is of poorly defined mechanisms. Prevalence and clinical context of idiopathic FTR (Id-FTR) (without overt TR cause) are unknown. Methods and Results— To investigate prevalence, clinical context, and mechanisms specific to FTR types, Id-FTR versus pulmonary hypertension-related (PHTN-FTR, systolic pulmonary pressure ≥50 mm Hg), we analyzed 1161 patients with prospectively quantified TR. Id-FTR (prevalence 12%) was associated with aging and atrial fibrillation. For mechanistic purposes, we measured valvular and right ventricular (RV) remodeling in 141 Id-FTR matched to 140 PHTN-FTR and to 99 controls with trivial TR for age, sex, atrial fibrillation, and ejection fraction. PHTN-FTR and Id-FTR were also matched for TR effective-regurgitant-orifice (ERO). Id-FTR valvular alterations (versus controls) were largest annular area (3.53±0.6 versus 2.74±0.4 cm2, P<0.0001) and lowest valvular/annular coverage ratio (1.06±0.1 versus 1.45±0.2, P<0.0001) but normal valve tenting height. PHTN-FTR had mild annular enlargement but excessive valve tenting height (0.8±0.3 versus 0.35±0.1 cm, P<0.0001). Valvular changes were linked to specific RV changes, largest basal dilatation, and normal length (RV conical deformation) in Id-FTR versus longest RV with elliptical/spherical deformation in PHTN-FTR. With increasing FTR severity (ERO ≥40 mm2), changes specific to each FTR type were accentuated, and RV function (index of myocardial performance) was consistently reduced. Conclusions— Id-FTR is frequent, linked to aging and atrial fibrillation, can be severe, and is of unique mechanism. In Id-FTR, excess annular and RV-basal enlargement exhausts valvular/annular coverage reserve, and RV conical deformation does not cause notable valvular tenting. Conversely, PHTN-FTR is determined by valvular tethering with tenting linked to RV elongation and elliptical/spherical deformation. These specific FTR-mechanisms may be important in considering surgical correction in FTR.

Rapid Estimation of Regurgitant Volume by the Proximal Isovelocity Surface Area Method in Mitral Regurgitation: Can Continuous-Wave Doppler Echocardiography Be Omitted?

The proximal isovelocity surface area (PISA) method is accurate for quantitating mitral regurgitation but requires recording both mitral maximal and integrated jet velocities using the same continuous-wave Doppler jet signal. In 272 consecutive patients with isolated mitral regurgitation, the mean ratio of maximal to integral of velocity had a narrow range of variation (mean +/- SD, 3.25 +/- 0.47). The estimated regurgitant volume, calculated as regurgitant flow/3.25, showed an excellent correlation with reference regurgitant volumes (r = 0.96 and r = 0.97; standard error of the estimate, 11 ml; both p < 0.0001), with limited overestimation and high sensitivity and specificity for severe mitral regurgitation. The estimated regurgitant volume is a useful measurement in patients in whom the continuous-wave Doppler signal of mitral regurgitation cannot be obtained.

The Conundrum of Functional Mitral Regurgitation in Chronic Heart Failure

Heart failure begets mitral regurgitation (MR); MR begets heart failure. This incestuous and insidious relationship has long been known to contribute to the positive feedback loop that underlies progressive, pathologic ventricular remodeling in chronic heart failure (CHF). Yet, despite decades of

When to Intervene for Asymptomatic Mitral Valve Regurgitation

Mitral regurgitation (MR), currently the most frequent valvular heart disease, is mostly degenerative, linked to aging and of increasing prevalence. Indications of mitral surgery, the only current approved treatment of MR, are disputed. Coherent cumulative evidence obtained worldwide show that early surgery in asymptomatic patients is the preferred approach. Waiting for symptoms or left ventricular dysfunction is a failed strategy in that these characteristics are insensitive markers of risk, are often unrecognized in a timely manner and, even after successful surgery, are associated with poor outcome. Furthermore, in patients with severe organic MR, surgery is almost unavoidable and early mitral repair before the appearance of symptoms or overt LV dysfunction may restore life expectancy as long as valve repair is performed. New objective markers of adverse outcome under medical management have recently been described, allowing selection of patients for performance of restorative surgery that reestablishes life expectancy. This approach of early surgery provides improved outcomes in observational studies and is conceivable in centers that provide low risk, high repair rates, high quality of repairs and of Doppler-Echocardiographic assessment.

Progress in the Treatment of Severe Mitral Regurgitation

Organic mitral regurgitation (MR) is prevalent in the general population. Disease progression, involving potentially irreversible left ventricular dysfunction, implies a poor prognosis for patients who do not receive appropriate treatment. Immediate rescue surgery is indicated in those with severe MR in whom subclinical left ventricular dysfunction is suggested by echocardiographic measurements or the presence of symptoms, however minor. Patients whose symptomatology is unclear should be evaluated by exercise testing. Not all forms of severe organic MR are the same: the presence of risk factors in patients with severe asymptomatic MR and preserved ventricular function indicates a suboptimal prognosis over the medium-to-long term and should prompt early mitral repair if there is a low surgical risk and the probability of a successful repair is >90-95%. The patient should be referred to a specialized surgical center if necessary. Appropriate training of surgeons in mitral repair is essential. Ischemic MR carries a worse prognosis and the risk of surgery is higher. Consequently, treatment decisions must be patient-specific and take into account the possibility of repair, the risk of surgery, and the need for concomitant surgical revascularization. New percutaneous approaches to mitral repair are being developed for selected patient groups.

Avances en el tratamiento de la insuficiencia mitral grave

La insuficiencia mitral (IM) organica es prevalente en la poblacion. Su progresion, con deterioro potencialmente irreversible de la funcion ventricular izquierda, pone de manifiesto el grave pronostico de los pacientes que no reciben tratamiento oportunamente. La deteccion de disfuncion subclinica del ventriculo izquierdo a traves de parametros ecocardiograficos o la presencia de sintomas, asi sean minimos, indican cirugia de rescate inmediata en la IM grave. Los pacientes con sintomatologia incierta deben ser evaluados con prueba de esfuerzo. No todas las IM organicas graves son iguales: la presencia de factores de riesgo en la IM grave asintomatica con funcion ventricular normal indica peor pronostico a medio y largo plazo, lo cual debe estimular la cirugia temprana con reparacion si el riesgo quirurgico es bajo y la posibilidad de reparacion es > 90-95%. Si es necesario, se debe referir al paciente a centros especializados. El entrenamiento adecuado de cirujanos en la reparacion mitral es critico. La IM isquemica acarrea un peor pronostico, con mayor riesgo quirurgico, y las decisiones sobre el tratamiento deben ser especificas para cada paciente, teniendo en cuenta la posibilidad de reparacion, el riesgo quirurgico y la necesidad de revascularizacion quirurgica concomitante. Se esta estudiando nuevos procedimientos percutaneos para pacientes seleccionados.