Fearon William F, Shah Maulik, Ng Martin, Brinton Todd, Wilson Andrew, Tremmel Jennifer A, Schnittger Ingela, Lee David P, Vagelos Randall H, Fitzgerald Peter J, Yock Paul G, Yeung Alan C
Division of Cardiovascular Medicine, Stanford University Medical Center, Stanford, California 94305, USA.
J Am Coll Cardiol. 2008 Feb 5;51(5):560-5. doi: 10.1016/j.jacc.2007.08.062.
The objective of this study is to evaluate the predictive value of the index of microcirculatory resistance (IMR) in patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI).
Despite adequate epicardial artery reperfusion, a number of patients with STEMI have a poor prognosis because of microvascular damage. Assessing the status of the microvasculature in this setting remains challenging.
In 29 patients after primary PCI for STEMI, IMR was measured with a pressure sensor/thermistor-tipped guidewire. The Thrombolysis In Myocardial Infarction (TIMI) myocardial perfusion grade, TIMI frame count, coronary flow reserve, and ST-segment resolution were also recorded.
The IMR correlated significantly with the peak creatinine kinase (CK) (R = 0.61, p = 0.0005) while the other measures of microvascular dysfunction did not. In patients with an IMR greater than the median value of 32 U, the peak CK was significantly higher compared with those having values <or=32 U (3,128 +/- 1,634 ng/ml vs. 1,201 +/- 911 ng/ml, p = 0.002). The IMR correlated significantly with 3-month echocardiographic wall motion score (WMS) (R = 0.59, p = 0.002) while the other measures of microvascular function did not. The WMS at 3-month follow-up was significantly worse in the group with an IMR >32 U compared with <or=32 U (28 +/- 7 vs. 20 +/- 4, p = 0.001). On multivariate analysis, IMR was the strongest predictor of peak CK and 3-month WMS. The IMR was the only significant predictor of recovery of left ventricular function on the basis of the percent change in WMS (R = 0.50, p < 0.01).
Compared to standard measures, IMR appears to be a better predictor of microvascular damage after STEMI, both acutely and in short term follow-up.
本研究旨在评估微循环阻力指数（IMR）对接受直接经皮冠状动脉介入治疗（PCI）的ST段抬高型心肌梗死（STEMI）患者的预测价值。
尽管心外膜动脉实现了充分再灌注，但仍有许多STEMI患者因微血管损伤而预后不良。在此情况下评估微血管系统的状态仍具有挑战性。
对29例接受STEMI直接PCI治疗后的患者，使用压力传感器/热敏电阻尖端导丝测量IMR。同时记录心肌梗死溶栓（TIMI）心肌灌注分级、TIMI帧计数、冠状动脉血流储备和ST段回落情况。
IMR与肌酸激酶（CK）峰值显著相关（R = 0.61，p = 0.0005），而其他微血管功能障碍指标则不然。IMR大于中位数32 U的患者，其CK峰值显著高于IMR≤32 U的患者（3,128±1,634 ng/ml对1,201±911 ng/ml，p = 0.002）。IMR与3个月时的超声心动图壁运动评分（WMS）显著相关（R = 0.59，p = 0.002），而其他微血管功能指标则无此相关性。IMR＞32 U组在3个月随访时的WMS显著差于IMR≤32 U组（28±7对20±4，p = 0.001）。多因素分析显示，IMR是CK峰值和3个月WMS的最强预测因子。基于WMS变化百分比，IMR是左心室功能恢复的唯一显著预测因子（R = 0.50，p＜0.01）。
与标准指标相比,IMR似乎能更好地预测STEMI后急性和短期随访中的微血管损伤。
