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.
aDepartment of Cardiology, National University Heart Centre
bBiostatistics Unit, National University Health System
cDepartment of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
Correspondence to Chi-Hang Lee, MD, FRCP, Department of Cardiology, National University Heart Centre Singapore, 1E Kent Ridge Road, NUHS Tower Block Level 9, Singapore 119228, Singapore Tel: +65 67 722 493; fax: +65 68 722 998; e-mail: email@example.com
Received January 26, 2014
Received in revised form February 20, 2014
Accepted February 24, 2014