Impact of Atrial Fibrillation with Rapid Ventricular Response in Acute Decompensated Heart Failure

BackgroundRapid atrial fibrillation (AF) is considered to be a trigger for heart failure (HF) decompensation. Few data are available on AF (particularly with a rapid ventricular response) as a trigger for HF decompensation and its effect on clinical outcomes. MethodsWe studied 11,446 patients with acute HF. Rapid AF at admission was defined as ventricular rate [&ge;]110 beats per minute, present at the first ECG performed after hospital arrival. The primary endpoint was in-hospital mortality. ResultsRapid AF (defined as ventricular rate [&ge;] 110 beats per minute) at admission was present in 609 patients (5.3%). In-hospital mortality occurred in 83 (13.6%) and 951 (8.8%) patients with and without rapid AF, respectively. In a multivariable Cox regression model, the HR for in-hospital mortality was 1.50 (95% 1.16 to 1.93, P<0.0001). With further adjustment for heart rate, the effect of rapid AF on in-hospital mortality was no longer significant (HR 1.11; 95% CI 0.83-1.50, P=0.48). From the original cohort, 419 participants with rapid AF in admission were matched on their propensity score to 419 patients with sinus tachycardia. In-hospital mortality occurred in 62 (14.8%) and 61 (14.6%) patients with and without rapid AF, respectively. Compared with the sinus tachycardia group, the HR for the in-hospital mortality in patients with rapid AF was 0.98 (95% CI 0.68 to 1.42; P=0.93). ConclusionRapid AF in ADHF patients is associated with increased mortality risk that is mediated predominantly by rapid ventricular rate. The magnitude of the AF effect is similar to that of sinus tachycardia, indicating that the underlying mechanism for the adverse outcome is not directly related to AF.