[Predictors of reversion to sinus rhythm previous to electrical cardioversion in patients with persistent atrial fibrillation treated with anti-arrhythmic drugs].

BACKGROUND: Some patients with persistent atrial fibrillation treated pharmacologically revert to sinus rhythm prior to electrical cardioversion. Knowledge of factors predicting this effect may be clinically useful.

METHODOLOGY: Data were obtained from patients enrolled in the study REgistro sobre la cardioVERSión en España (REVERSE) and treated with antiarrhythmic drugs that potentially may cause pharmacological reversal. We analized by means of logistic regression predictive factors related to reversion to sinus rhythm precardioversion.

RESULTS: Of the 752 patients treated with antiarrhythmic drugs, 160 (21%) reverted to sinus rhythm without electrical cardioversion. Amiodarone was the most widely used active compound (82%) and apparently the most effective. However, differences with other antiarrhythmic drugs were not significant (amiodarone 22% versus other antiarrhythmic drugs 17%, P = .22). Lack of obesity (body mass index < 30 kg/m(2)) (odds ratio [OR] = 1.9; P = .006), duration of atrial fibrillation < 1 year (OR 3.4; P=.02) and the absence of structural heart disease (OR 1,59; P = .01) were identified as independent variables with predictive value of pharmacological reversal to sinus rhythm. Among patients treated with amiodarone who met these criteria, the frequency of successful treatment increased up to 31%.

CONCLUSION: In patients with persistent atrial fibrillation treated with anti-arrhythmic drugs, lack of obesity, duration of atrial fibrillation < 1 year and the absence of structural heart disease are predictors of reversion to sinus rhythm before electrical cardioversion.