Division of Cardiology, Cardiac and Vascular Center, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 50, Irwon-dong, Gangnam-gu, Seoul 135-710, Republic of Korea.
Int J Cardiovasc Imaging. 2012 Aug;28(6):1487-97. doi: 10.1007/s10554-011-9975-2. Epub 2011 Nov 10.
To define causes and pathological mechanisms underlying differences in clinical outcomes, we compared the findings of contrast-enhanced magnetic resonance imaging (CE-MRI) between ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI). In 168 patients undergoing early invasive intervention for STEMI (n = 113) and NSTEMI (n = 55), CE-MRI was performed a median of 6 days after the index event. Infarct size was measured on delayed-enhancement imaging, and area at risk (AAR) was quantified on T2-weighted images. The median infarct size was significantly smaller in the NSTEMI group than in the STEMI group (10.7% [5.6-18.1] vs. 19.2% [10.3-30.7], P < 0.001). Although there was a trend toward a greater myocardial salvage index ([AAR - infarct size] × 100/AAR) in the NSTEMI group compared to the STEMI group (48.2 [30.4-66.8] vs. 40.5 [24.8-53.5], P = 0.056), myocardial salvage index was similar between the groups in patients with anterior infarction (39.6 [20.0-54.9] vs. 35.5 [23.2-53.4], P = 0.96). The NSTEMI group also had a significantly lower extent of microvascular obstruction and a smaller number of segments with >75% of infarct transmurality relative to the STEMI group (0% [0-0.6] vs. 0.9% [0-2.3], P < 0.001 and 3.0 ± 2.3 vs. 4.6 ± 2.9, P = 0.001, respectively). Myocardial hemorrhage was detected less frequently in the NSTEMI group than the STEMI group (22.6% vs. 43.8%, P = 0.029). In the multivariate analysis, baseline Thrombolysis In Myocardial Infarction flow grade 3 and hemorrhagic infarction were closely associated with ST-segment elevation (OR 0.32, 95% CI 0.13-0.81, P = 0.017; OR 5.66, 95% CI 1.77-18.12, P = 0.003, respectively). In conclusion, in vivo pathophysiological differences revealed by CE-MRI assessment include more favorable infarct size, AAR, myocardial salvage and reperfusion injury in patients with NSTEMI compared to those with STEMI undergoing early invasive intervention.
为了明确导致 STEMI 和 NSTEMI 临床结局差异的原因和病理机制，我们比较了 STEMI（n=113）和 NSTEMI（n=55）患者早期侵入性干预后行对比增强磁共振成像（CE-MRI）的结果。CE-MRI 检查在指数事件后中位数 6 天进行。通过延迟增强成像测量梗死面积，通过 T2 加权图像定量测量危险区（AAR）。与 STEMI 组相比，NSTEMI 组的梗死面积明显较小（10.7%[5.6-18.1] vs. 19.2%[10.3-30.7]，P<0.001）。尽管 NSTEMI 组的心肌挽救指数（[AAR-梗死面积]×100/AAR）较 STEMI 组有增加的趋势（48.2[30.4-66.8] vs. 40.5[24.8-53.5]，P=0.056），但在前壁梗死患者中，两组的心肌挽救指数相似（39.6[20.0-54.9] vs. 35.5[23.2-53.4]，P=0.96）。与 STEMI 组相比，NSTEMI 组的微血管阻塞程度显著较低，>75%梗死透壁节段的数量也较少（0%[0-0.6] vs. 0.9%[0-2.3]，P<0.001和 3.0±2.3 vs. 4.6±2.9，P=0.001）。与 STEMI 组相比，NSTEMI 组较少出现心肌出血（22.6% vs. 43.8%，P=0.029）。多变量分析显示，基线溶栓治疗心肌梗死血流分级 3 和出血性梗死与 ST 段抬高密切相关（OR 0.32，95%CI 0.13-0.81，P=0.017；OR 5.66，95%CI 1.77-18.12，P=0.003）。总之，CE-MRI 评估显示的体内病理生理差异包括与 STEMI 相比，接受早期侵入性干预的 NSTEMI 患者的梗死面积、AAR、心肌挽救和再灌注损伤更有利。
