Prognostic importance of collateral flow and residual coronary stenosis of the myocardial infarct artery after anterior wall Q-wave acute myocardial infarction

Abstract

Residual high-grade coronary stenosis and collateral flow are frequent findings in the chronic phase after a Q-wave acute myocardial infarction (AMI). The prognostic importance of a residual stenosis of the infarct artery and of collateral flow to the infarct area was analyzed in a group of 102 young patients (mean age 35 years, range 22 to 39) who had survived an anterior wall Q-wave AML Patients whose only significant lesion (>50% luminal diameter reduction) was in the proximal portion of the left anterior descending artery were enrolled in the study. A 50 to 74% diameter stenosis was present in 33 of 102 patients (32%), 43 (42% had a 75 to 99% stenosis and 26% had a total occlusion of the infarct vessel. Collateral vessels, which were evaluated by a scoring system, were present in 52 of 102 patients (51%). Four percent had only faint (score 1), 17 of 102 patients (17%) had moderate and 32 patients (31%) had good collateral flow (score >4). The 8-year cumulative mortality was 15.2%—an eightfold increase compared with the age-matched general population. No patient with <75% stenosis died during follow-up, whereas the cumulative 8-year mortality was 23 and 17% in patients with a 75 to 99% stenosis or total occlusion, respectively (p <0.01). Patients with at least moderate collateral flow had a mortality rate of 21%, versus 8% for patients without or with faint collateral flow (p <0.05). Thus, a >75% residual stenosis after anterior wall AMI is associated with less favorable survival, compared with a less severe stenosis. Collateral vessels after an anterior wall Q-wave AMI do not protect against adverse events. These results suggest that restoration of anterograde flow could have a favorable influence on long-term prognosis in these patients.