Many studies of patients with heart failure (HF) have shown that development of atrial fibrillation (AF) is associated with poorer patient prognosis. As Dr Mario Talajic states, however, “what is not known is if the poorer prognosis is due to AF itself or whether the occurrence of AF is simply a marker of a sicker patient.” The AF-CHF trial investigators found that the type of AF therapy (rhythm control versus rate control) had no effect on cardiovascular mortality. However, 15% of the patients crossed over from one therapeutic strategy to another in this trial, which may have impacted on the results. The study investigators have now assessed their data in more detail.

All patients in the AF-CHF trial had severe systolic dysfunction and symptomatic HF, as well as recent AF. Mean follow-up was 37 ± 19 months. For the 1,168 patients who remained on their originally assigned therapy for the study duration (538 on rhythm-control medication and 630 on rate-control drugs), the type of AF therapy had no effect on cardiovascular mortality. In a time-dependent, on-treatment, efficacy analysis of the entire 1,376 patient population, the type of AF therapy did not impact on cardiovascular mortality, total mortality, or worsening of HF. Furthermore, the proportion of time in sinus rhythm whilst on assigned antiarrhythmia therapy did not effect these outcomes in the 1,316 patients for whom electrocardiograms were available.

On the basis of their findings, Dr Talajic believes that “a lot of current practice, which targets this arrhythmia in an aggressive (and costly) fashion, may, in fact, not be warranted.”