Coronary artery disease potentiates response to dofetilide for rhythm control of atrial fibrillation

Dofetilide, a class III antiarrhythmic, is one of the few alternatives to amiodarone in patients with atrial fibrillation (AF) and heart failure or coronary artery disease (CAD). While amiodarone has been extensively studied, little is known about predictors of response to dofetilide. We sought to identify clinical parameters associated with dofetilide success in a large cohort of patients with AF.

A total of 287 patients with AF started on dofetilide between 2001 and 2008 were included. Dofetilide was deemed "completely effective" if the patient remained on dofetilide at follow-up and had no recurrences of AF clinically or by electrocardiogram. Dofetilide efficacy was analyzed in relation to clinical variables relevant to AF and AF recurrence. After a follow-up of 10.2 ± 7.7 months, 54.7% of the patients remained on dofetilide and it was completely effective in 26.8%. The discontinuation rate during initial hospitalization was 13.3% from excessive QT prolongation and one patient with torsades de pointes (successfully treated). A history of CAD was the only univariate predictor of efficacy (odds ratio [OR] 2.27, 95% confidence interval [CI] 1.29-4.01, P < 0.05). CAD remained the only significant factor associated with efficacy of dofetilide in a multivariate regression model (OR 2.01, 95% CI 1.11-3.70, P < 0.05, n = 270). The overall efficacy of dofetilide in patients with CAD was 41.1%, compared to 23.5% in those without CAD (P < 0.05).

In this large cohort of patients with AF, underlying coronary disease was significantly associated with dofetilide success. This finding may have utility for clinical decisions regarding initiation of dofetilide.