Long-term sinus rhythm maintenance after cardioversion of persistent atrial fibrillation: is the treatment's success predictable?

The aim of our study was to identify the clinical and echocardiographic predictors of long-term success of cardioversion in patients with persistent atrial fibrillation (AF). Our study comprised 104 patients (F/M 33/71; mean age 60.4 +/- 7.9 years) assigned to SR restoration and maintenance with sequentially administered antiarrhythmic drugs. Their clinical and transthoracic echocardiographic (TTE) variables were recorded prior to cardioversion and examined for correlation with sinus rhythm (SR) maintenance at 1 year. The variables under consideration included age, gender, echo parameters such as long and short left atrial (LA) axis, LA and right atrial (RA) area, fractional shortening (FS) and left ventricular end-diastolic diameter, AF duration, New York Heart Association functional class, and concomitant diseases. Generalized additive logistic regression method was used to investigate impact of the selected variables on long-term SR maintenance. At 1 year, SR was present in 63.5% of patients. Left atrium area (LA(ar)) > 28 cm (P < 0.02) and FS value >26% (P < 0.05), both measured at baseline, were significantly associated with SR maintenance after 1 year. Patients with large LA(ar) values (>28 cm(2)) presented a significant decrease (31.45 +/- 3.07 cm(2) vs 28.94 +/- 3.81 cm(2); P < 0.008) during 30 days following SR maintenance. In patients with LA(ar) >28 cm(2) we noted an atrial decrease of 2.57 +/- 3.2 cm(2) (P < 0.004) during 30 days following SR restoration, which turned out to be an independent factor related to SR presence at 1 year of follow-up (relative risk 1.83; 95% confidence interval: 1.03-2.95; P < 0.01). Of all the considered variables only LA area and FS value seem to be relatively reliable predictors of SR sustainability at 1 year after an effective cardioversion of persistent AF.