Is hospital admission for initiation of antiarrhythmic therapy with sotalol for atrial arrhythmias required?: yield of in-hospital monitoring and prediction of risk for significant arrhythmi complications

Objectives. We sought to determine the yield of in-hospital monitoring for detection of significant arrhythmi complications in patients starting sotalol therapy for atrial arrhythmias and to identify factors that might predict safe outpatient initiation. Background. The need for hospital admission during initiation of antiarrhythmic therapy has been questioned, particularly for sotalol, with which proarrhythmi may be dose related. Methods. The records of 120 patients admitted to the hospital for initiation of sotalol therapy were retrospectively reviewed to determine the incidence of significant arrhythmi complications, defined as new or increased ventricular arrhythmias, significant bradycardi or excessive corrected QT (QTc) interval prolongation. Results. Twenty-five patients (20.8%) experienced 35 complications, triggering therapy changes during the hospital period in 21 (17.5%). New or increased ventricular arrhythmias developed in 7 patients (5.8%) (torsade de pointes in 2), significant bradycardi in 20 (16.7%) (rate <40 beats/min in 13, pause >3.0 s in 4, third-degree atrioventricular block in 1, permanent pacemaker implantation in 3) and excessively prolonged QTc intervals in 8 (6.7%) (dosage reduced or discontinued in 6). Time to the earliest detection of complications was 2.1 ± 2.5 (mean ± SD) days after initiation of sotalol, with 22 of 25 patients meeting criteri for complications within 3 days of monitoring. Baseline electrocardiographic intervals or absence of heart disease failed to distinguish low risk group. Multivariate analysis identified absence of pacemaker as the only significant predictor of arrhythmi complications (p = 0.022). Conclusions. Because clinically significant complications can be detected with in-hospital monitoring in one of five patients starting sotalol therapy, hospital admission is warranted for initiation of sotalol. Patients without pacemakers are at higher risk for these complications.