Determination of the severity of underlying lesions in acute myocardial infarction on the basis of collateral vessel development.

BACKGROUND: We aimed to address the conflict over whether the underlying lesion that leads to acute myocardial infarction (AMI) is representative of low-grade or high-grade stenosis. Because the development of collateral vessels is an indication of ischemia, their presence was used as a surrogate marker for the existence of a high-grade lesion.
METHODS: Coronary angiography was used to assess 159 patients, divided into two groups, with (Rentrop 1-3) and without (Rentrop 0) collateral vessels, who had AMI with ST-segment elevation for which they underwent a percutaneous coronary intervention with the implantation of a coronary stent and had baseline thrombolysis in myocardial infarction 0/1 flow.
RESULTS: Of the 159 patients recruited, the presence of collateral vessels was detected in 95 (collateral group; 60%), indicating that the causal lesion was representative of a high-grade stenosis. Among these 95 patients, the Rentrop scores were 1, 2, and 3 in 57 (60%), 33 (34.7%), and six (5.3%) patients, respectively. Logistic regression analysis showed that a baseline thrombolysis in myocardial infarction 0 flow (hazard ratio, 4.6; 95% confidence interval, 1.4-14.6; P=0.01) and a culprit right coronary artery (hazard ratio, 3.0; 95% confidence interval, 1.4-6.2; P=0.007) were independent predictors of the development of collateral vessels.
CONCLUSION: The majority of AMI cases can be attributed to a severe stenosis, as demonstrated by the presence of collateral vessels in 60% of the patients in this study.