Risk factor analysis of microvascular obstruction after percutaneous coronary intervention for ST-segment elevation myocardial infarction

OBJECTIVE: This study aimed to explore the risk factors of microvascular obstruction (MVO) after percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI). METHODS: A retrospective analysis was performed on 165 patients with STEMI who successfully underwent emergency PCI and completed cardiac magnetic resonance (CMR) within 1 week after PCI. Total ischemia time (symptom onset to wire, S2W), first medical contact to wire (FMC2W), and door to wire (D2W) were compared with the recommended critical time nodes for STEMI treatment. Left ventricular function was evaluated by CMR cine, and myocardial infarction characteristics and MVO were evaluated by late-gadolinium enhancement (LGE). Binary logistic regression analysis was used to evaluate the effect of delay in treatment of STEMI on the occurrence of MVO after PCI. RESULTS: In this study, 89 (53.9%) patients with STEMI presented with MVO after emergency PCI. The FMC2W time and S2W time in the MVO (+) group were significantly longer than those in the MVO (-) group (P < 0.05). Compared with the MVO (-) group, the MVO (+) group had larger myocardial infarction size (IS) and lower left ventricular ejection fraction (LVEF) (P < 0.05). Patients with FMC2W time >120 min and S2W time >300 min had greater myocardial IS and MVO than the FMC2W ≤ 120 min and S2W time ≤300 min group, respectively. Logistic regression analysis showed that S2W time >300 min (P = 0.039, OR = 2.756, 95% CI = 1.053-7.213) was an independent predictor of MVO after PCI in patients with STEMI. CONCLUSION: Shortening the total time of myocardial ischemia and increasing the proportion of early reperfusion therapy can prevent or reduce MVO after PCI.