Comparison of Metoprolol and Sotalol in Prevention of Ventricular Tachyarrhythmias After the Implantation of a Cardioverter Defibrillator - Metoprolol and Sotalol in Prevention of Ventricular Tachycardia

Jan 23, 2005
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Date Published:
01/01/1998
Date Updated:
01/23/2005
Original Posted Date:
01/23/2005
References

Description:

The goal of this trial was to evaluate the efficacy of d,l-sotalol versus metoprolol for prevention of ventricular tachyarrhythmias (VT/VF) in patients receiving implantable cardioverter defibrillators (ICDs).

Hypothesis:

Therapy with metoprolol, as compared with sotalol, will be associated with a reduction in the incidence of VT/VF.

Study Design

Study Design:

Patients Enrolled: 70
Mean Follow Up: 26 ± 16 months
Mean Patient Age: Mean age 62 years
Female: 13%
Mean Ejection Fraction: 40 ± 10%

Patient Populations:

Patients were included if they had a clinical indication for an ICD:
1) Age >18 years,
2) A history of ≥1 unsuccessful previous trial of suppressive antiarrhythmic therapy by serial drug testing with programmed stimulation in patients with clinically documented VT/VF and induction of clinical VT/VF, and
3) Patients with VT/VF not inducible during programmed electrical stimulation.

Exclusions:

Any of the following:
1) Acute myocardial infarction within one week,
2) Contraindications for β-blockers,
3) History of proarrhythmia caused by sotalol, and
4) Prophylactic use of an ICD.

Primary Endpoints:

Appropriate ICD intervention

Secondary Endpoints:

Total mortality

Drug/Procedures Used:

Subjects fitted with ICDs for life-threatening VT/VF were recruited. Immediately following device implantation, subjects were randomized in an open fashion to receive either metoprolol (n=35) or d,l-sotalol (n=35).

Initial metoprolol dose was 50 mg/day and initial sotalol dose was 80 mg/day. The dose was subsequently increased in individual subjects to the highest well-tolerated dose.

Ventricular tachyarrhythmias treated with antitachycardia pacing were defined as VT; those treated with an ICD shock were defined as fast VT/VF.

Patients were followed-up every three months, during which time their symptoms were assessed, and ICD interrogation was performed.

Principal Findings:

Mean follow-up time was 26 ± 16 months. Mean medication dose was 104 ± 37 mg for metoprolol and 242 ± 109 mg for sotalol. Seventeen percent of patients receiving metoprolol and 28% of those receiving sotalol had to have their medication discontinued.

By the end of follow-up, 34% of patients had VT treated by antitachycardia pacing. Actuarial rates for absence of VT recurrence at one and two years were significantly higher in the metoprolol group compared with the d,l-sotalol group (83% and 80% vs. 57% and 51%, respectively, p=0.016).

Thirty-seven percent of patients experienced a fast VT/VF episode by the end of follow-up. Actuarial rates for absence of recurrence of a fast VT or VF were 88% and 80% at one and two years, respectively, compared with 54% and 46% of the patients in the sotalol group (p=0.002).

Combined endpoint of symptomatic recurrence of a fast VT/VF or death was also reduced with metoprolol as compared with sotalol. Probability of event-free survival at one and two years were 83% and 74%, respectively with metoprolol versus 47% and 38%, respectively with sotalol (p=0.004).

Interpretation:

Among patients with ICDs implanted for life-threatening VT or VF, treatment with metoprolol was associated with a reduction in recurrent ventricular tachyarrhythymia compared with treatment with sotalol. The sample size in this study was small.

The authors also acknowledge that etiology of VT/VF was not controlled for. Finally, older ICD models in the study did not record intracardiac electrograms; therefore, incidence of true VT/VF may have been overestimated.

The larger, multicenter VT-MASS trial also compared metoprolol with sotalol.

References:

Seidl K, Hauer B, Schwick NG, Zahn R, Senges J. Comparison of metoprolol and sotalol in preventing ventricular tachyarrhythmias after the implantation of a cardioverter/defibrillator. Am J Cardiol 1998;82:744-8.

Keywords: Tachycardia, Ventricular, Follow-Up Studies, Electric Stimulation, Ventricular Fibrillation, Sotalol, Probability, Metoprolol, Defibrillators, Implantable


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