Acute myocardial infarction

The goal of reperfusion during the early phases of myocardial infarction is limitation of the extent of infarction, which should be reflected by low mortality. Over the past 10 years, 701 patients underwent coronary bypass graft surgery as treatment for myocardial infarction within 24 hr of peak symptoms. This included 440 patients with transmural myocardial infarction as well as 261 patients with nontransmural myocardial infarction. The presence of one-, two-, or three-vessel disease in the transmural vs the nontransmural group was significantly different. Nevertheless, the mortality was low in both groups, 5.2% (23/440) in the transmural group and 3.0% (8/261) in the nontransmural group. Over the 10 year study period, mortality of the transmural group rose to 12.5% (55/440) while the nontransmural group, which was followed-up for 8 years, had a total mortality of 6.5% (17/261). The major predictor of in-hospital mortality in the transmural group was presurgical cardiogenic shock, while left main coronary artery disease was the major factor associated with mortality in the nontransmural group. Likewise, presence of three-vessel disease in the transmural group was associated with higher mortality than one- or two-vessel disease. The transmural group was further divided into subgroups receiving early (i.e., within 6 hr from symptom onset) or late (longer than 6 hr) reperfusion, and the mortality differences were striking. In the group receiving early reperfusion the short-term mortality was significantly lower than that in the group receiving late reperfusion (1 1/291, 3.8%; 12/ 149, 8.0%; p =.05 by chi square). A similar trend was noted in the long-term mortality, with a difference between the groups that was statistically significant (24/291, 8.2%; 31/149, 21.0%; p <.01 by chi square). We conclude that (1) early reperfusion is associated with significantly lower short- and long-term mortality than late reperfusion, (2) nontransmural myocardial infarction treated with surgical reperfusion is associated with extremely low short- and long-term mortality relative to published reports, and (3) three-vessel disease is a relatively high-risk situation in transmural myocardial infarction, especially in conjunction with clinical class IV.