Prevention of Supraventricular Tachyarrhythmias After Open Heart Operation by Low-Dose Sotalol: A Prospective, Double-Blind, Randomized, Placebo-Controlled Study

Background. The aim of this prospective, double-blind, placebo-controlled trial was to assess the preventive effect and safety of low-dose sotalol after heart operation. Methods. Two hundred fifty-five consecutive patients referred for elective coronary artery bypass grafting (n = 220) or aortic valve operation (n = 35) were randomized to receive either 80 mg of sotalol twice daily (n = 126) or matching placebo (n = 129) for 3 months, with the first dose given 2 hours before operation. Results. There were no significant baseline differences between the groups. Overall, supraventricular tachyarrhythmias occurred in 36% of patients (82% atrial fibrillation). Hospital stay was 11.6 ± 5 days in patients with supraventricular arrhythmias, versus 9.5 ± 2.4 days in patients without it (p < 0.0001). Low-dose sotalol reduced the rate of supraventricular arrhythmias from 46% (placebo) to 26% (sotalol; p = 0.0012), or by 43%. On the fourth postoperative day, heart rate was lower in the sotalol group (74 ± 12 beats/min versus 85 ± 15 beats/min; p < 0.0001) but the QT interval corrected for the heart rate was not prolonged (sotalol group, 0.44 ± 0.03 second; placebo group, 0.43 ± 0.03 second; p = not significant). Study medication had to be discontinued because of side effects in 5.6% of sotalol and 3.9% of placebo patients (p = not significant), with one possible proarrhythmic event occurring in a patient receiving sotalol. Conclusions. Because more than 90% of supraventricular arrhythmic episodes occurred within 9 days after operation and 70% of all possibly sotalol related side effects occurred after day 9, the findings in this study imply that prophylactic treatment with sotalol may be limited to the first 9 postoperative days.