Total occlusion of the infarct-related coronary artery correlates with brachial artery flow-mediated dilation in patients with ST-elevation myocardial infarction

BACKGROUND: Occlusion of the coronary artery is the main cause of ST-elevation myocardial infarction (STEMI). In some patients, it is followed by early spontaneous thrombolysis. In this study, we tried to determine whether spontaneous thrombolysis in the infarct-related artery (IRA) correlates with the state of the endothelium, which we assessed using the brachial artery flow-mediated dilation (FMD) test. METHODS: 52 patients with STEMI were included in the study. Based on the results of coronary angiography performed during the first three days of STEMI, the patients were divided into two groups: Group I (n=33), consisting of patients with remaining total occlusion of the IRA, and Group II (n=19), consisting of patients with spontaneous thrombolysis. We assessed the endothelial function, using the brachial artery FMD test. RESULTS: In Group I, during the first three days of STEMI, brachial artery FMD results were significantly lower than those in Group II: 5.41+/- (3.23-7.41)% versus 10.81+/-(8.00-14.89)%, respectively; P=0.000036. After 7-14 days, this difference disappeared because of significant elevation of the FMD levels in the first group. Group I was characterized by higher levels of high sensitive C-reactive protein (CRP), cholesterol, and cholesterol-LDL and lower usage of angiotensin-converting enzyme (ACE) inhibitors before STEMI. CONCLUSION: The data presented above reveal that spontaneous coronary thrombolysis in patients with acute STEMI is associated with a preserved endothelium-dependent vasodilator response in the brachial artery. It can depend on the levels of hs-CRP, of fasting glucose, and of ACE-inhibitors from previous treatment.