We investigated whether patients who do not undergo coronary angiography and therefore any form of revascularization after a myocardial infarction derive greater benefit from chronic β-blocker therapy than patients who undergo coronary angiography. With multivariate analyses, treatment with β-blockers was a much stronger predictor of survival in patients who did not undergo coronary angiography (relative risk = 0.38, p = 0.005) than in those patients who did undergo catheterization ( p < 0.05 for interaction). Our findings provide direct support for the recommendation by the American College of Cardiology/American Heart Association task force that β-blocker therapy should be initiated for all infarct survivors who do not undergo revascularization and who have no contraindications. (Am Heart J 1997;134:608-13.)