In the Electrophysiologic Study Versus Electrocardiographic Monitoring (ESVEM) trial, d,l-
sotalol was associated with a lower
arrhythmia recurrence and mortality than class I
antiarrhythmic drugs. To further evaluate the relative efficacy of d,I-
sotalol compared with class I drugs, and to assess the relative importance of its class II (beta-blocking) and class III effects, 6-year
arrhythmia recurrence and mortality in patients receiving
sotalol were compared with those in patients receiving class I drugs, subdivided according to whether they also received coadministered beta blockers. Relative efficacy was also determined for
sotalol and for class I drugs as stratified by the presence/absence of prior
drug failure.
Arrhythmia recurrence was lower for the 84 patients receiving
sotalol than for patients given class I agents with (n = 28) (p = 0.008) or without (n = 184) (p = 0.001) alpha beta blocker. Mortality was lower for patients taking
sotalol than for those given a class I
drug without alpha beta blocker (p = 0.034), but similar (p = 0.835) if alpha beta blocker was also administered. In contrast to class I drugs, which had lower efficacy rates when prior
drug trials had failed,
sotalol maintained its efficacy despite prior
drug failures preceding or during the ESVEM trial. Both class II and III actions in the ESVEM trial were important to the clinical superiority of
sotalol in the treatment of
ventricular tachyarrhythmias.