Reduced collateral circulation to the infarct-related artery in elderly patients with acute myocardial infarction

The purpose of this study was to investigate the hypothesis that circulation via collateral vessels to an infarct-related artery (IRA) is impaired with aging in patients with acute myocardial infarction (AMI).

Animal experiments have shown that advanced age blunts the development of new vessels in response to angiogenic cytokines.

Of 3,573 consecutive patients with AMI, 1,934 patients who fulfilled the following criteria were enrolled in this study: 1) coronary angiograms were obtained within 72 h after the onset of AMI; and 2) IRA showed complete occlusion (Thrombolysis In Myocardial Infarction [TIMI] flow grade 0 or 1). Collaterals to the IRA were angiographically evaluated using the Rentrop score. Rentrop scores 1 to 3 were defined as demonstrating significant collaterals.

The prevalence of collaterals decreased with age, from 47.9%, 45.8%, 43.4%, to 34.0% in patients <50 years, 50 to 59 years, 60 to 69 years, > or =70 years, respectively (p < 0.001). Advanced age was an independent factor predicting the absence of collateral circulation to the IRA. In contrast, time to catheterization, history of angina pectoris, and preinfarction angina were independent predictors for the presence of collaterals. Multivariate analysis showed that the absence of collaterals was an independent predictor of in-hospital mortality in elderly patients > or =70 years (odds ratio, 15.6; 95% confidence interval, 3.5 to 69.6), although this finding was not significant in patients <70 years.

Advanced age is associated with decreased angiographic presence of collaterals to the IRA in patients with AMI. This abnormality may contribute to the poor prognosis of elderly patients with AMI.