Exercise capacity and prognosis in patients with chronic atrial fibrillation

Abstract

To evaluate the response of patients with chronic atrial fibrillation (AF) to exercise and to demonstrate if prognosis could be predicted, 200 male patients (64 +/- 1 years) with AF were identified retrospectively who underwent resting echocardiography and symptom-limited treadmill testing. They were classified by underlying disease into three subgroups: hypertension or no underlying disease (LONE; n = 102), ischemic heart disease (IHD; n = 45) and history of congestive heart failure or valvular disease (CHF-VD; n = 53). Maximal exercise capacities for LONE, IHD and CHF-VD were (mean +/- 1 SEM) 8.0 +/- 0.3, 6.4 +/- 0.4 and 6.0 +/- 0.3 metabolic equivalents, respectively (p < 0.01), and resting left ventricular ejection fractions were 61.7 +/- 1.6, 60.1 +/- 2.2 and 49.5 +/- 1.9%, respectively (p < 0.01). Stepwise multiple regression analysis demonstrated that, except for group classification (R2 = 0.13, p < 0.01), no clinical, exercise or morphologic variables could predict exercise capacity. After a mean 39.1-month follow-up (range 1-78), 17 of the 200 had died from cardiovascular causes. The rate of cardiac death using Kaplan-Meier survival analysis was significantly greater in CHF-VD patients (p < 0.01). However, Cox hazard function and Kaplan-Meier survival analysis demonstrated that neither echocardiographic measurements of cardiac size or function at rest, nor exercise or clinical variables were significant predictors of outcome. AF patients with a history of CHF and/or VD demonstrated a reduced exercise tolerance ad a worse prognosis than those without morphologic heart disease or those with IHD.(ABSTRACT TRUNCATED AT 250 WORDS)