The Kaplan-Meier therapeutic failure of antiarrhythmic drugs was 39 + / - 11 % , 42 + / - 11 % and 51 + / - 18 % at 0.5 - , 1 - and 4-year follow-up , respectively , whereas the therapeutic failure of cardiac surgery was 37 + / - 11 % , 37 + / - 11 % and 50 + / - 20 % at 0.5 , 1 and 4 years , respectively , showing no statistical difference .
