Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA.
Am J Cardiol. 2010 Sep 1;106(5):635-40. doi: 10.1016/j.amjcard.2010.04.012.
The goal of this analysis was to determine the relation between myocardial infarct size and left ventricular (LV) ejection fraction (EF) in patients with ST-segment elevation myocardial infarction (STEMI) after primary percutaneous coronary intervention (pPCI) using cardiovascular magnetic resonance imaging (CMR). After STEMI, LVEF and infarct size correlate with prognosis, but the relation between infarct size and LVEF is incompletely known. Consecutive subjects presenting to a single center with STEMI treated with pPCI were enrolled, and cine functional and late gadolinium enhancement CMR was performed 3 months after presentation. From cine images, LVEF was calculated using volumetric summation of disks method. Infarct size was measured as percent LV myocardial volume with late gadolinium enhancement. In the 78 patients enrolled (mean age 54.5 years, range 42 to 82), median LVEF was 56% (interquartile range 49 to 62) and median infarct size was 11% (interquartile range 5 to 18). Of the 53 patients with infarct size <15%, all had LVEF >40%, and there was no significant relation between infarct size and LVEF (slope -0.43, R(2) = 0.045, p = 0.13). In patients with infarct size > or =15%, there was a significant negative linear association between infarct size and LVEF (slope -1.21, R(2) = 0.66, p <0.001), such that for every 5% increase in infarct size, there was a 6.1% decrease in LVEF. In conclusion, there is a negative linear relation between infarct size and LVEF for moderate to large infarcts. For small infarcts there is no significant relation between infarct size and LVEF. Up to 15% of LV myocardial volume may be infarcted before there is any appreciable decrease in LVEF.
本分析旨在使用心血管磁共振成像（CMR）确定接受直接经皮冠状动脉介入治疗（pPCI）后的 ST 段抬高型心肌梗死（STEMI）患者心肌梗死面积与左心室射血分数（LVEF）之间的关系。在 STEMI 后，LVEF 和梗死面积与预后相关，但梗死面积与 LVEF 之间的关系尚不完全清楚。连续入组在单一中心接受 pPCI 治疗的 STEMI 患者，在发病后 3 个月行电影功能和晚期钆增强 CMR。从电影图像中，使用圆盘体积求和法计算 LVEF。梗死面积以晚期钆增强的 LV 心肌体积百分比表示。在纳入的 78 例患者中（平均年龄 54.5 岁，范围 42 至 82 岁），中位 LVEF 为 56%（四分位间距 49 至 62），中位梗死面积为 11%（四分位间距 5 至 18）。在梗死面积<15%的 53 例患者中，所有患者的 LVEF>40%，且梗死面积与 LVEF 之间无显著相关性（斜率 -0.43，R(2) = 0.045，p = 0.13）。在梗死面积≥15%的患者中，梗死面积与 LVEF 之间呈显著负线性相关（斜率-1.21，R(2) = 0.66，p<0.001），即梗死面积每增加 5%，LVEF 降低 6.1%。总之，中等至大面积梗死的梗死面积与 LVEF 之间存在负线性关系。对于小面积梗死，梗死面积与 LVEF 之间无显著相关性。在 LVEF 出现明显下降之前，可能有高达 15%的 LV 心肌发生梗死。
