PREVENTION OF SUDDEN CARDIAC DEATH AFTER A 1ST MYOCARDIAL-INFARCTION BY PHARMACOLOGICAL OR SURGICAL ANTIADRENERGIC INTERVENTIONS

Introduction: Growing evidence points to sympathetic hyperactivity as one critical trigger for life-threatening arrhythmias among postmyocardial infarction patients. Methods and Results: We have evaluated, in a placebo-controlled multicenter study, the efficacy of a beta-adrenergic blocking agent (oxprenolol 160 mg) and of a selective left cardiac sympathetic denervation in preventing sudden death in patients with a first and anterior myocardial infarction. Two patient groups were studied. The high-risk group included 144 patients who survived a myocardial infarction complicated by either ventricular tachycardia or fibrillation. The relatively low-risk group included 869 patients whose myocardial infarction did not have these complications; they were allocated only to placebo or oxprenolol. Randomization took place 30 days postmyocardial infarction; mean follow-up was 22 months. In the high-risk group the sudden cardiac death (crude rate) in the placebo subgroup was indeed high (21.3%), and was strikingly reduced to 2.7% and to 3.6% by oxprenolol and by left cardiac sympathetic denervation, respectively (P < 0.05). In the low-risk group the sudden cardiac death (crude rate) in the placebo subgroup was 5.2% and was still reduced by oxprenolol to 1.6% (P < 0.05). The results for total mortality were quite similar to those for sudden death in both groups. Conclusion: This study, unique for the populations studied and for one of the treatments used, demonstrates that pharmacologic and surgical antiadrenergic interventions significantly reduce sudden cardiac death in postmyocardial infarction patients at high and at low risk. With due consideration to the relatively small size of the high-risk group, it seems reasonable to suggest that left cardiac sympathetic denervation may be considered as a possible alternative for high-risk patients with contraindications to beta blockers.