Palmer Sonny, Layland Jamie, Carrick David, Williams Paul D, Judkins Christopher, Gong Fei Fei, Burns Andrew T, Whitbourn Robert J, MacIsaac Andrew I, Wilson Andrew M
Department of Cardiology, St Vincent's Hospital, Fitzroy, Victoria, Australia.
Department of Cardiology, Golden Jubilee National Hospital, Glasgow, United Kingdom.
J Interv Cardiol. 2016 Apr;29(2):146-54. doi: 10.1111/joic.12271. Epub 2016 Jan 29.
The index of microcirculatory resistance (IMR), an invasive measure of microvascular function, has been shown to correlate with clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI). The aim of this study is to evaluate the predictive value of IMR on left ventricular recovery in patients undergoing a pharmacoinvasive strategy for STEMI.
The index of microcirculatory resistance was assessed following percutaneous coronary intervention (PCI) in 31 patients with STEMI who were initially managed with thrombolysis. Other markers of microvascular function such as coronary flow reserve (CFR), TIMI flow grade, corrected TIMI frame count (cTFC), and ST-segment resolution were also recorded. All indices were evaluated against measures of left ventricular function and recovery 3 months postindex event.
The IMR correlated with left ventricular function, as assessed by wall motion score and ejection fraction at 3-month follow-up (r = 0.652, P = 0.005; r = -0.452, P = 0.011, respectively). The traditional methods of assessing microvascular function, such as CFR, TIMI flow grade, cTFC, and ST-segment resolution did not correlate with wall motion score and ejection fraction at 3 months. Post-PCI IMR was significantly lower in those patients with left ventricular recovery at 3 months (18 U vs 39 U, P < 0.001). The optimal cut-off value for post-PCI IMR and left ventricular recovery was 32 U. In patients in whom the IMR was greater than 32 U, the percent change in ejection fraction was significantly lower than in those patients in whom the IMR was less than 32 U (2 ± 11 vs 12 ± 8, P = 0.012).
In patients presenting with STEMI initially managed with thrombolysis and subsequently undergoing PCI, IMR correlates with measures of left ventricular function and has the potential to predict left ventricular recovery at 3 months.
微循环阻力指数（IMR）是一种评估微血管功能的侵入性指标，已被证明与ST段抬高型心肌梗死（STEMI）患者的临床预后相关。本研究旨在评估IMR对接受药物介入治疗策略的STEMI患者左心室恢复情况的预测价值。
对31例最初接受溶栓治疗的STEMI患者在经皮冠状动脉介入治疗（PCI）后评估微循环阻力指数。还记录了其他微血管功能指标，如冠状动脉血流储备（CFR）、TIMI血流分级、校正TIMI帧数（cTFC）和ST段回落情况。所有指标均与索引事件后3个月的左心室功能和恢复情况进行评估。
3个月随访时，IMR与左心室功能相关，通过室壁运动评分和射血分数评估（r分别为0.652，P = 0.005；r为 -0.452，P = 0.011）。评估微血管功能的传统方法，如CFR、TIMI血流分级、cTFC和ST段回落情况，与3个月时的室壁运动评分和射血分数无关。3个月时左心室恢复的患者PCI术后IMR显著更低（18 U对39 U，P < 0.001）。PCI术后IMR与左心室恢复的最佳截断值为32 U。IMR大于32 U的患者，其射血分数的变化百分比显著低于IMR小于32 U的患者（2±11对12±8，P = 0.012）。
对于最初接受溶栓治疗并随后接受PCI的STEMI患者，IMR与左心室功能指标相关，并且有可能预测3个月时的左心室恢复情况。
