Atrial fibrillation occurs commonly in heart failure; however, its importance in terms of prognosis is controversial.
We assessed the relation of atrial fibrillation on first Holter monitor to morbidity and mortality in mild to moderate heart failure in 632 patients in the Veterans Affairs Vasodilator-Heart Failure Trial (V-HeFT) I and 795 patients in V-HeFT II: Ninety-nine patients in atrial fibrillation and 533 patients in sinus rhythm were followed for a mean of 2.5 years (range, 6 months to 5.7 years) in V-HeFT I; 107 patients in atrial fibrillation and 688 patients in sinus rhythm in V-HeFT II were followed for a mean of 2.5 years (range, 6 months to 5.0 years). V-HeFT I compared treatment with prazosin, hydralazine-isosorbide dinitrate, and placebo, whereas V-HeFT II compared hydralazine-isosorbide dinitrate with enalapril. Follow-up evaluations included serial Holter monitors, serial metabolic exercise testing, hospitalization data, and clinical examinations. In V-HeFT I, cumulative mortality at 2 years was 0.34 for patients with atrial fibrillation and 0.30 for patients in sinus rhythm (p = 0.25). Overall cumulative mortality was 0.54 for atrial fibrillation patients and 0.64 for sinus rhythm patients (p = 0.86). In V-HeFT II, cumulative mortality at 2 years was 0.20 for patients with atrial fibrillation and 0.21 for patients with sinus rhythm (p = 0.68), and overall cumulative mortality was 0.46 for atrial fibrillation patients and 0.52 for those in sinus rhythm (p < 0.46). Sudden death was not increased with atrial fibrillation in V-HeFT I patients (p = 0.64) or in V-HeFT II (p = 0.68). By multivariate analysis, the relative mortality risk for atrial fibrillation was 0.95 in V-HeFT I and 0.76 in V-HeFT II: Metabolic exercise testing, showed no significant difference in mean change in peak oxygen consumption between patients with atrial fibrillation and those with sinus rhythm in V-HeFT I and a slight decrease late in V-HeFT II: Hospitalization rate for heart failure was not increased in either study. The embolic event rate was not increased for atrial fibrillation patients: 3% versus 4.9% of patients in sinus rhythm (p = 0.41) in V-HeFT I and 4.0% versus 6.0% in V-HeFT II patients (p = 0.44). A secondary analysis compared mortality of patients in atrial fibrillation with that of patients in sinus rhythm on all Holters: Mortality was not increased overall (p = 0.72 in V-HeFT I and p = 0.35 in V-HeFT II).
Atrial fibrillation does not increase major morbidity or mortality in mild to moderate heart failure.