Exercise-induced Reduction in Left Ventricular Ejection Fraction in the Absence of Coronary Artery Disease: Clinical Characteristics and Outcomes

Abstract

During exercise stress echocardiography (ESE) there are patients with normal left ventricular ejection fraction (LVEF) who paradoxically develop reduced LVEF during exercise despite absence of coronary artery disease (CAD) and a significant hypertensive response. This study sought to describe the clinical features and outcomes of this population. Among ESE performed between 2003 and 2022, patients without CAD by angiogram within 90 days of ESE, resting LVEF ≥50% with a ≥5% LVEF decrease during ESE were included. Outcomes assessed were all-cause mortality, heart failure (HF) hospitalization, and atrial fibrillation (AF). Kaplan-Meier and Cox regression methods were used to analyze time-to-event outcomes. Among 213,643 ESE, 134 patients met eligibility criteria. The mean age of the population was 66±10 years, 76% were women, and 16% had AF at baseline. Mean LVEF was 58±4% at rest and 43±4% at peak stress. Stress ECG met criteria for ischemia in 14% of these patients. The 10-year estimated incidence of HF hospitalization was 17.6% (95% CI 9.0-26.2). Among the subgroup without AF at baseline, the 10-year estimated incidence of developing AF was 23.4% (95% CI 13.4-33.4). The 10-year estimated incidence of all-cause mortality was 12.9% (95% CI 5.5-20.3), with 89% of deaths occurring due to non-cardiovascular causes. Patients with exercise-induced reduction in LVEF in the absence of obstructive CAD have a high incidence of HF hospitalizations and AF. The underlying pathophysiology of this disease process needs to be further investigated.