Ragosta M, Camarano G, Kaul S, Powers E R, Sarembock I J, Gimple L W
Cardiovascular Division, University of Virginia School of Medicine, Charlottesville.
Circulation. 1994 Jun;89(6):2562-9. doi: 10.1161/01.cir.89.6.2562.
Patency of the infarct-related artery (IRA) after acute myocardial infarction (AMI) may not reflect the magnitude of tissue perfusion. In animal models of AMI, myocardial cellular necrosis has been associated with extensive capillary damage. Because myocardial contrast echocardiography (MCE) can define the spatial distribution of microvascular perfusion, we hypothesized that it could be used in patients after recent AMI to distinguish myocardial regions that have an intact microvasculature and thus are viable from those without an intact microvasculature and thus are not viable.
One hundred five patients with a recent AMI (range, 1 day to 4 weeks; median, 8 days) who were undergoing cardiac catheterization were included in the study. Two-dimensional echocardiography was performed at baseline and repeated 1 month later to assess regional function within the infarct zone (scores of 1 to 5 indicating normal to dyskinetic segments, respectively). MCE was performed in the cardiac catheterization laboratory to assess microvascular perfusion within the infarct bed. A contrast score index was derived by assigning scores to individual segments within the infarct zone (0, 0.5, and 1 denoting no, intermediate, and homogeneous contrast effect, respectively) and deriving the average score within the infarct bed. Revascularization was performed as clinically indicated. Although the baseline wall motion score and the contrast score index were similar in the 90 patients with a patent IRA and the 15 patients with an occluded IRA (median +/- 1 interquartile range, 3 +/- 1 versus 3.5 +/- 1; P = .41), wall motion score 1 month later was significantly better in those with open IRAs compared with those with closed IRAs (2 +/- 2 versus 3 +/- 2, P = .05). In the 90 patients with an open IRA, a strong correlation was noted between wall motion score 1 month later and the contrast score index (rho = -.64, P < .001). On multivariate analysis, the best correlate of the 1-month wall motion score was the contrast score index.
In patients studied in the cardiac catheterization laboratory between 1 day and 4 weeks after AMI, an intact microvasculature as identified by MCE indicates myocardial regions that improve function 1 month later. This study demonstrates that microvascular patency is closely associated with myocardial cellular viability after AMI in humans.
急性心肌梗死（AMI）后梗死相关动脉（IRA）的通畅情况可能无法反映组织灌注的程度。在AMI动物模型中，心肌细胞坏死与广泛的毛细血管损伤有关。由于心肌对比超声心动图（MCE）能够确定微血管灌注的空间分布，我们推测它可用于近期发生AMI的患者，以区分微血管系统完整因而存活的心肌区域和微血管系统不完整因而无法存活的心肌区域。
本研究纳入了105例近期发生AMI（病程1天至4周；中位数为8天）且正在接受心导管检查的患者。在基线时进行二维超声心动图检查，并在1个月后重复检查，以评估梗死区域内的局部功能（评分1至5分别表示节段运动正常至运动障碍）。在心导管检查实验室进行MCE，以评估梗死心肌床内的微血管灌注情况。通过对梗死区域内的各个节段进行评分（0、0.5和1分别表示无、中等和均匀的对比效果）并计算梗死心肌床内的平均评分得出对比评分指数。根据临床指征进行血运重建。尽管在IRA通畅的90例患者和IRA闭塞的15例患者中，基线壁运动评分和对比评分指数相似（中位数±1四分位数间距，3±1对3.5±1；P = 0.41），但1个月后，IRA开放患者的壁运动评分明显优于IRA闭塞患者（2±2对3±2，P = 0.05）。在90例IRA开放的患者中，1个月后的壁运动评分与对比评分指数之间存在强烈相关性（rho = -0.64，P < 0.001）。多因素分析显示，1个月壁运动评分的最佳相关因素是对比评分指数。
在AMI后1天至4周于心导管检查实验室研究的患者中，MCE确定的微血管系统完整表明心肌区域在1个月后功能改善。本研究表明，微血管通畅与人类AMI后心肌细胞存活密切相关。
