Determinants of impaired microcirculatory resistance in patients with ST segment elevation myocardial infarction

초록

Determinants of impaired microcirculatory resistance in patients with ST-Segment Elevation Myocardial Infarction Aims We sought to find differences of clinical and angiographic characteristic in STEMI patients with or without coronary microvascular dysfunction by index of microcirculatory resistance (IMR). Methods STEMI patients who underwent primary percutaneous coronary intervention (PCI) were enrolled. Baseline characteristics including clinical and angiographic characteristic were investigated in all patients. The IMR, parameter of hyperemic microvascular resistance, was measured with a pressure sensor/thermistor-tipped guidewire after primary percutaneous coronary intervention (PCI). Results 113 STEMI patients (age=56±11 years, M:F=95:18) were enrolled and 113 culprit lesions of coronary artery were analysed. The patients were divided into three groups based on following the value of IMR: Low-IMR (n=38, IMR=12.9±2.6 U), Mid-IMR (n=38; IMR=23.9±4.0 U) and High-IMR group (n=37; IMR=48.1±17.1 U). Mean age of Low-IMR was significantly younger than Mid-IMR and High-IMR. Mean door-to-balloon times were under 90 minutes in all IMR groups, and there were no significant differences among each IMR groups. However, symptom-onset-to-balloon time was significantly longer in High-IMR than Mid-IMR and Low-IMR (p<0.001). The high IMR group included the more frequent proximal location of culprit lesion than non-proximal location (p=0.008). In multivariate regression analysis, age and symptom-onset-to-balloon time were independent determinants of higher IMR (p=0.013 for age, p=0.003 for symptom-onset-to-balloon time). Conclusions Our data suggests that in STEMI patients with mean door-to-balloon time under 90minutes, age and symptom-onset-to-balloon time may be the main determinants of impaired microcirculatory resistance in STEMI