Clinical outcomes in heart failure with reduced left ventricular ejection fraction and good functional capacity: The illusion of stability.

ABSTRACT

BACKGROUND: Heart failure (HF) remains a prevalent syndrome with significant morbidity and mortality. Optimal drug and device therapies are crucial to reduce the risk of death or HF admission. Yet, less symptomatic patients with good functional capacity are often perceived as having a low risk of adverse events and their attending physicians may suffer from prescription inertia or refrain from performing therapy optimization. Maximum or peak oxygen consumption (pVO2) assessed during cardiopulmonary exercise testing (CPET) is often used as a prognosis indicator and surrogate marker for functional capacity. Our goal was to assess clinical outcomes in a seemingly low risk HF population in Weber class A (pVO2>20 mL/kg/min) with reduced left ventricular ejection fraction (LVEF). METHODS: Single-center retrospective observational study enrolling consecutive HF patients with LVEF<40% (HFrEF) performing CPET between 2003 and 2018. Those with pVO2 >20 mL/kg/min were included. The primary endpoint was a composite of all-cause death or HF hospitalizations at two years after CPET. We also assessed the rates of N-terminal pro b-type natriuretic peptide (NT-proBNP) elevations at baseline. RESULTS: Seventy-two patients were included (mean age of 53±10 years; 86% male; 90% NYHA I-II; median LVEF 32%; median pVO2 24 mL/kg/min). At baseline, 93% had an NT-proBNP level >125 pg/mL (median NT-proBNP 388 [201-684] pg/mL). Overall, seven patients (10%) met the primary endpoint three died (4%) and five (7%) had at least one HF admission. Among those who died, only one patient had an HF admission during follow up. CONCLUSION: In a clinically stable HFrEF population with good functional capacity, persistent neurohormonal activation was present in the majority, and one in ten patients died or had a HF admission at two years' follow-up. These findings support the urgent need to motivate clinicians to pursue optimal drug uptitration even in less symptomatic patients.