Impact of initial heart failure emergence on clinical outcomes of atrial fibrillation patients in the AFFIRM trial.

BACKGROUND: Heart failure (HF) emergence in atrial fibrillation (AF) patients undergoing different treatment strategies has not been studied.

METHODS: AFFIRM trial subjects with no history of HF, without clinical HF and normal left ventricular ejection fraction at enrollment were identified. The principal outcome was time to development of a composite of New York Heart Association class ≥II HF and/or cardiovascular (CV) death. It was compared for rate and rhythm strategies and correlated with electrocardiographic parameters on follow-up (FU).

RESULTS: A total of 1,771 patients (880 rate, 891 rhythm) were evaluated. The principal outcome occurred in 21.4% of rate and 16.8% of rhythm subjects at 5 years (hazard ratio [HR] 1.32, 95% CI 1.04-1.69, P = .024). HF increment by 2 classes increased total mortality (HR 2.83, 95% CI 1.91-4.18, P < .0001), cardiac mortality, (HR 4.27, 95% CI 2.03-9.04, P = .0001), and CV hospitalizations (HR 3.04, 95% CI 2.15-4.29, P < .0001). HF emergence during FU was associated with AF (P = .0004), ventricular rate >80 beats/min (P = .0106), and higher frequency of recorded AF in the rhythm arm (25%-75% vs <25%, HR 1.69, 95% CI 1.09-2.64, P = .020; >75% vs <25%, HR 3.15, 95% CI 1.87-5.34, P =< .001).

CONCLUSIONS: (1) In AF patients without HF, symptomatic HF emergence was more frequent with rate control than with rhythm control. (2) HF appearance presages increased mortality risk. (3) Delaying HF emergence is associated with effective rhythm control with documented sinus rhythm during >75% of FU visits as well as ventricular rate control.