Abstract 12780: Impact of Atrial Fibrillation on Exercise Intolerance in Patients With Preserved Left Ventricular Ejection Fraction

Abstract

Introduction: When atrial fibrillation (AF) develops, there is loss of the atrial kick, with consequent decrease of cardiac output. Therefore, AF is recognized as an exacerbating factor for heart failure in patients with heart disease. However, the relationship between permanent AF and exercise intolerance in this population has been incompletely understood. Accordingly, we examined whether the presence of AF exacerbates exercise tolerance in patients with preserved left ventricular ejection fraction (LVEF). Methods: We studied 402 patients (age 68.0±9.6 years; male 67.5%) with 370 in sinus rhythm (SR) and with 32 in permanent AF. All patients had preserved LVEF (>50%) and were 40 years old or more. Patients underwent cardio-pulmonary exercise testing (CPX) including an analysis for oxygen uptake at peak exercise (peak VO 2 ). Before CPX, comprehensive Doppler echocardiography was carried out. Early diastolic transmitral velocity (E) and mitral annular velocity during early diastole (e’) were measured. Results: No significant difference was found in age, body mass index, or the E/e’ ratio (9.0±3.2vs9.9±3.8, p=0.12) between the patients with SR and those with AF. Patients with SR had significantly higher LVEF (70.9±7.9vs66.2±8.7%, p=0.001) and higher proportion of female gender (34.9vs6.3%, p=0.001) than in those who with AF. Peak VO 2 did not differ between patients with AF and those with SR (19.2±5.2vs20.4±5.8ml/kg/min, p=0.28). In multiple logistic regression analysis, age (OR 3.7, 95%CI2.4-5.9, p<0.001) and female gender (OR 4.0, 95%CI 2.4-6.7, p<0.001) significantly contributed to exercise intolerance. However, the presence of AF (p=0.12) and higher LVEF (p=0.45) were not selected. Conclusions: Similar exercise tolerance was observed between patients with SR and those with permanent AF. These data suggest that permanent AF does not affect the exercise intolerance in patients with preserved LVEF.