LATE SURVIVAL AFTER PERIOPERATIVE MYOCARDIAL-INFARCTION COMPLICATING VASCULAR-SURGERY

Purpose: Although early death from perioperative myocardial infarction (PMI) after vascular surgery is well established, long-term outcome i n patients surviving PMI is unknown. This prospective study was design ed to determine cardiac outcome and survival rates in patients with sy mptomatic and asymptomatic nonfatal PMI associated with peripheral vas cular surgery. Methods: During a 36-month period for 1989 to 1992, all patients undergoing vascular surgery at our institution were monitore d for PMI with serial creatine kinase and myocardial band isoenzymes a nd electrocardiography. PMIs were classified as symptomatic (associate d with chest pain, arrhythmia, congestive heart failure, or hypotensio n) or asymptomatic (electrocardiographic changes and/or elevated creat ine kinase and myocardial band isoenzymes). Patients with PMI were the n prospectively monitored and compared for late survival, with control patients undergoing vascular surgery without PMI during the same inte rval. Results: During the study period 1561 major peripheral vascular procedures were performed. There were 47 PMIs (3.0%). Eleven (0.7%) PM Is were fatal, 31 were nonfatal, and five other patients with PMI died during operation of non-heart-related causes. Eight of 31 patients wi th nonfatal PMI had a ''chemical PMI'' with creatine kinase and myocar dial band isoenzyme elevation as the sole indicator of PMI. During fol low-up (mean 27.7 months), there was a higher incidence of both subseq uent myocardial infarction and coronary artery revascularization among the patients with nonfatal PMI compared with control subjects (p < 0. 05); however, survival for patients with nonfatal PMI at 1 and 4 years (80% and 51%) did not differ from that of control patients (90% and 6 0%) (P > 0.05). Patients with ''chemical PMI'' had similar patterns of subsequent myocardial infarction and coronary intervention as control patients. Conclusions: Patients surviving nonfatal PMI after peripher al vascular surgery have a higher incidence of subsequent adverse card iac events and coronary artery revascularization than patients undergo ing vascular surgery without PMI, but they have similar survival rates at I and 4 years. Patients in the enzyme-only PMI group have a simila r outcome compared with control subjects suggesting that a perioperati ve ''chemical MI'' may not be a significant clinical event.