THE INFLUENCE OF ATRIAL-FIBRILLATION ON PROGNOSIS IN MILD-TO-MODERATEHEART-FAILURE - THE V-HEFT STUDIES

Background. Atrial fibrillation occurs commonly in heart failure; howe ver, its importance in terms of prognosis is controversial. Methods an d Results. We assessed the relation of atrial fibrillation on first Ho lter monitor to morbidity and mortality in mild to moderate heart fail ure in 632 patients in the Veterans Affairs Vasodilator-Heart Failure Trial (V-HeFT) I and 795 patients in V-HeFT II. Ninety-nine patients i n atrial fibrillation and 533 patients in sinus rhythm were followed f or 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-isosor bide dinitrate, and placebo, whereas V-HeFT II compared hydralazine-is osorbide dinitrate with enalapril. Follow-up evaluations included seri al 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 p atients in sinus rhythm (p=0.25). Overall cumulative mortality was 0.5 4 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 p atients with atrial fibrillation and 0.21 for patients with sinus rhyt hm (p=0.68), and overall cumulative mortality was 0.46 for atrial fibr illation 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 relat ive 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 dif ference in mean change in peak oxygen consumption between patients wit h atrial fibrillation and those with sinus rhythm in V-HeFT I and a sl ight decrease late in V-HeFT II. Hospitalization rate for heart failur e was not increased in either study. The embolic event rate was not in creased for atrial fibrillation patients: 3% versus 4.9% of patients i n 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 H olters: Mortality was not increased overall (p=0.72 in V-HeFT I and p= 0.35 in V-HeFT II). Conclusions. Atrial fibrillation does not increase major morbidity or mortality in mild to moderate heart failure.