Baseline longitudinal strain predicts recovery of left ventricular ejection fraction in hospitalized patients with nonischemic cardiomyopathy

Abstract

Background-—Heart failure (HF) with “recovered” ejection fraction (HFrecEF) is an emerging phenotype, but no tools exist to predict ejection fraction (EF) recovery in acute HF. We hypothesized that indices of baseline cardiac structure and function predict HFrecEF in nonischemic cardiomyopathy and reduced EF. Methods and Results-—We identified a nonischemic cardiomyopathy cohort with EF<40% during the first HF hospitalization (n=166). We performed speckle-tracking echocardiography to measure longitudinal, circumferential, and radial strain, and the average of these measures (myocardial systolic performance). HFrecEF was defined as follow-up EF ≥40% and ≥10% improvement from baseline EF. Fifty-nine patients (36%) achieved HFrecEF (baseline EF 26±7%; follow-up EF 51±7%) within a median of 135 (interquartile range 58-239) days after the first HF hospitalization. Baseline demographics, biomarker profiles, and comorbid conditions (except lower chronic kidney disease in HFrecEF) were similar between HFrecEF and persistent reduced-EF groups. HFrecEF patients had smaller baseline left ventricular end-systolic dimension (3.6 versus 4.8 cm; P<0.01), higher baseline myocardial systolic performance (9.2% versus 8.1%; P=0.02), and improved survival (adjusted hazard ratio 0.27, 95% confidence interval 0.11, 0.62). We found a significant interaction between baseline left ventricular end-systolic dimension and absolute longitudinal strain. Among patients with left ventricular end-systolic dimension >4.35 cm, higher absolute longitudinal strain (≥8%) was associated with HFrecEF (unadjusted odds ratio=3.9, 95% CI)confidence interval 1.2, 12.8). Incorporation of baseline indices of cardiac mechanics with clinical variables resulted in a predictive model for HFrecEF with c-statistic=0.85. Conclusions-—Factors associated with achieving HFrecEF were specific to cardiac structure and indices of cardiac mechanics. Higher baseline absolute longitudinal strain is associated with HFrecEF among nonischemic cardiomyopathy patients with reduced EF and larger left ventricular dimensions.