We studied the relation between angioplasty-related time delay and the effectiveness of the intervention in decreasing death compared with fibrinolysis in patients who had acute myocardial infarction. The absolute survival benefit of angioplasty compared with fibrinolysis decreased by 0.24% for every additional 10-minute delay. Regression analysis showed that percutaneous coronary intervention remained superior to fibrinolysis when a time delay related to percutaneous coronary intervention extended to 110 minutes.