Abstract

Although left ventricular (LV) hypertrophy has been proposed as a factor predisposing to atrial fibrillation (AF), its relevance to prognosis and selection of therapeutic strategies is unclear. We identified 2,105 patients with echocardiographic data on LV mass enrolled in the Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial. LV hypertrophy was defined as increased LV mass, stratified by American Society of Echocardiography criteria. The primary end point was all-cause mortality, secondary end point was as per AFFIRM trial definition, and tertiary end point was cardiovascular hospitalizations. We compared "strict" versus "lenient" rate control in patients with increased LV mass, and studied association of heart failure (HF) with preserved and decreased systolic function in patients with increased LV mass. Over 6 years, 332 deaths (15.7%) were reported. Adjusted hazard ratio (HR) of severely increased LV mass for all-cause mortality was 1.34 (95% confidence interval [CI] 1.01 to 1.79, p=0.045) for the overall population and 1.61 (95% CI 1.09 to 2.37, p=0.016) for the rhythm-control arm. Increased LV mass was a predictor of cardiovascular hospitalizations in the lenient rate-control group (HR 1.72, 95% CI 1.05 to 2.82, p=0.03) but not in the strict rate-control group. Severely increased LV mass was predictive of cardiovascular hospitalizations in patients with HF with preserved (HR 1.8, 95% CI 1.0 to 3.2, p=0.03) and decreased LV systolic function (HR 2.4, 95% CI 1.1 to 5.2, p=0.02). Thus, LV hypertrophy is a significant independent predictor of mortality in patients with AF, especially those managed with rhythm control. In patients with LV hypertrophy, strict rate control may be associated with better outcomes than lenient rate control. LV hypertrophy portends higher cardiovascular morbidity in patients with AF and HF.