Arrhythmia control and other factors related to sudden death in coronary disease patients at intermediate risk

Thirty-three patients with coronary artery disease and frequent, complex ventricular arrhythmias (VA) were followed long-term to evaluate factors related to sudden death (SD). Patients with malignant VA (sustained ventricular tachycardia (VT), resuscitated SD, or acute myocardial infarction) were excluded. Baseline data included angiographic ejection fraction (EF), segmental wall motion, and Holter evidence of frequent (>30/hr) and complex (repetitive) ventricular premature beats (VPBs). Control of VA was attempted with conventional or experimental agents and was defined as ≥70% reduction in VPBs, ≥90% reduction in couplets, and abolition of nonsustained VT on two consecutive Holter tapes. After 24 ± 15 months of follow-up on the single most effective agent, 18 patients survived while 15 patients died suddenly. There was no difference between these groups with respect to age, sex, or baseline VA. Survivors had a higher EF (51% vs 34%, p < 0.001), fewer dyskinetic segments (0.05 vs 1.0, p < 0.01), and better VA control (83% vs 40%, p < 0.01) than nonsurvivors. By analysis of variance, VA control was not independent of EF (F = 6.98, p < 0.01). The 1-, 2-, and 3-year survival rates were 90%, 90%, and 82% for patients with EF ≥ 40% and 22%, 11%, and 11% for those with EF < 40% and uncontrolled VA. We conclude that left ventricular function and VA control are dependent determinants of sudden death, and this “intermediate” risk group consists of (1) low risk patients with EF ≥ 40% in whom a multicenter placebo-controlled trial may be justified and (2) high risk patients with EF <40% for whom no effective agent can be identified by noninvasive means and in whom a more aggressive approach may be needed.