Clinical predictors of improvement in left ventricular ejection fraction in U.S. veterans with heart failure.

Background: Our understanding of the factors associated with improvement of LVEF and a heart failure with improved EF (HFimpEF) phenotype remains incomplete. Methods: We conducted a retrospective study using a national database of patients followed in the Veterans Affairs (VA) health system with serial assessment of left ventricular ejection fraction (LVEF) by echocardiography. We identified US veterans with a new diagnosis of heart failure with: (i) LVEF of <40 % in the 12 months prior to diagnosis, and (ii) follow-up LVEF assessment at least 6 months after their diagnosis. We defined HFimpEF as a final LVEF of ≥40 %. Results: Among the 106,414 US veterans with an initial LVEF of <40 % in this analysis, 39,994 (37.6 %) had a final EF of >40 % after a median follow up of 5 years. Multivariate regression analysis identified several factors that were independently associated with LVEF improvement including female sex, younger age, higher BMI, and a history of specific comorbid conditions such as hypertension, valve disease, atrial fibrillation, connective tissue disease, liver disease, and malignancy (p < 0.001). Conversely, a history of ischemic heart disease and peripheral arterial disease, as well as specific racial backgrounds (Black and Hispanic) were associated with lower rates of LVEF improvement. The model c-statistic for predicting LVEF improvement was 0.70. Conclusions: This large, detailed dataset facilitated an analysis of a large number of variables that significantly associated with HFimpEF; however, their combined discriminatory value for LVEF improvement remained modest, underscoring the complexity of the gene-environment-treatment interactions that govern LV function.