RESUMO
BACKGROUND AND AIMS: Though widely used to classify heart failure (HF) patients, the prognostic role of left ventricular ejection fraction (LVEF) is debated. We hypothesized that the echocardiographic measures of forward LV output, being more representative of cardiac hemodynamics, may improve risk prediction in a large cohort of HF patients with systolic dysfunction. METHODS: Consecutive stable HF patients with LVEF <50% on guideline-recommended therapies undergoing an echocardiography including the evaluation of forward LV output (i.e., LV outflow tract velocity-time integral [LVOT-VTI], stroke volume index [SVi], and cardiac index [CI]) over a 6-year period, were selected and followed-up for the endpoint of cardiac and all-cause death. RESULTS: Among the 1,509 patients analyzed (71±12 years, 75% males, LVEF 35±9%), 328 (22%) died during a median 28-month (14-40) follow-up, 165 (11%) of which for cardiac causes. At multivariable regression analysis, LVOT-VTI (<0.001), SVi (p<0.001), and CI (p<0.001), but not LVEF (p>0.05), predicted cardiac and all-cause death. The optimal prognostic cut-offs for LVOT-VTI, SVi, and CI were 15 cm, 38 mL/m2, and 2 L/min/m2, respectively. Adding each of these measures to a multivariable risk model (including clinical, biohumoral, and echocardiographic markers) improved risk prediction (p<0.001). Among the different measures of forward LV output, CI was less accurate than LVOT-VTI and SVi. CONCLUSION: The echocardiographic evaluation of forward LV output improves risk prediction in HF patients across a wide LVEF spectrum over other well-established clinical, biohumoral, and echocardiographic prognostic markers.
RESUMO
AIMS: Left ventricular outflow velocity-time integral (LVOT-VTI) has been shown to improve outcome prediction in different patients' subsets, with or without heart failure (HF). Nevertheless, the prognostic value of LVOT-VTI in patients with HF and secondary mitral regurgitation (MR) has never been investigated so far. Therefore, in the present study, we aimed to assess the prognostic value different metrics of LV forward output, including LVOT-VTI, in HF patients with secondary MR. METHODS AND RESULTS: Consecutive patients with HF and moderate-to-severe/severe secondary MR and systolic dysfunction (i.e., left ventricular ejection fraction [LVEF] <50%) were retrospectively selected and followed-up for the primary endpoint of cardiac death. Out of the 287 patients analyzed (aged 74 ± 11 years, 70% men, 46% ischemic etiology, mean LVEF 30 ± 9%, mean LVOT-VTI 20 ± 5 cm), 71 met the primary endpoint over a 33-month median follow-up (16-47 months). Patients with an LVOT-VTI ≤17 cm (n = 96, 32%) showed the greatest risk of cardiac death (Log Rank 44.3, p < 0.001) and all-cause mortality (Log rank 8.6, p = 0.003). At multivariable regression analysis, all the measures of LV forward volume (namely LVOT-VTI, stroke volume index, cardiac output, and cardiac index) were predictors of poor outcomes. Among these, LVOT-VTI was the most accurate in risk prediction (univariable C-statistics 0.70 [95%CI 0.64-0.77]). CONCLUSION: Left ventricular forward output, noninvasively estimated through LVOT-VTI, improves outcome prediction in HF patients with low LVEF and secondary MR.