There has been increasing application of coronary angioplasty to patients with chronic total occlusions. The acute and long-term outcome in 271 patients after coronary angioplasty (142 single and 129 multiple stenoses) of a total occlusion was compared with 1,429 patients undergoing angioplasty of subtotal (less than or equal to 99% stenosis) occlusions (885 single and 544 multilesion) participating in the 1985-1986 National Heart, Lung, and Blood Institute Percutaneous Transluminal Coronary Angioplasty Registry. Baseline characteristics were similar for each lesion group except for a higher incidence of prior myocardial infarction and left ventricular dysfunction (ejection fraction less than 50%) in patients with total occlusion. Major complications (death, myocardial infarction or emergency bypass surgery) were similar (p = not significant) between patients with total and subtotal occlusions for single (6 vs 7%) and multilesion angioplasty (9 vs 6%). At 2 years, after making adjustments for baseline variables, patients with a total occlusion had a significantly increased risk of death compared with those with subtotal occlusion. There were no significant differences in cumulative event rates for myocardial infarction or bypass surgery. Approximately three-fourths of patients in each group were free of angina at 2 years. In conclusion, angioplasty of chronic total occlusions is associated with a similar acute complication rate. Despite similar relief of anginal symptoms, patients in the total occlusion group have a higher 2-year mortality.