Department of Cardiology, St Vincent's Hospital, Fitzroy, Victoria, Australia.
Heart. 2012 Oct;98(20):1492-7. doi: 10.1136/heartjnl-2012-302252. Epub 2012 Aug 15.
This study was designed to assess whether measurement of the index of microvascular resistance (IMR) could help prospectively identify patients who develop periprocedural myocardial infarction (PPMI).
IMR was measured in 54 patients before and following percutaneous coronary intervention (PCI) in a culprit vessel with a PressureWire using the equation IMR = Pa(Hyp) × Tmn(Hyp) (Pd(Hyp)-Pw/Pa(Hyp)-Pw). IMR was also measured in an angiographically normal reference vessel. The relative pre-IMR ratio (rPIMR) defined as IMR Culprit divided by IMR Non-Culprit was also calculated. Troponin was sequentially sampled up to 24 h following PCI. Mean troponin post-PCI was 0.37±0.8 ng/ml. 33 (61%) patients fulfilled the criteria for PPMI. IMR pre-PCI was the most significant correlate of post-PCI troponin (r=0.43 p=0.001), however, the number of balloon inflations (r=0.3, p=0.02) and rPIMR (r=0.33 p=0.017) were also correlated. IMR pre-PCI was higher in patients with periprocedural myocardial infarction compared with patients without PPMI (IMR pre-PCI 21.2±2.1 PPMI vs 15.6±1.8 No PPMI, p=0.02). The strongest predictor of troponin post-PCI was IMR pre-PCI (β 0.7, p=0.02). Both IMR pre- and rPIMR were predictive of PPMI (OR 11 (1.3 to 90.5) p=0.026, OR 1.09 (1 to 1.19) p=0.03, respectively).
Microvascular function prior to PCI is an important determinant of PPMI. Measuring IMR pre-PCI and rPIMR may allow prospective identification of patients at risk of periprocedural myocardial infarction. Future studies in a larger cohort are required to establish the predictive ability of IMR in PPMI.
本研究旨在评估测量微血管阻力指数（IMR）是否有助于前瞻性识别发生围手术期心肌梗死（PPMI）的患者。
在经皮冠状动脉介入治疗（PCI）前，使用压力导丝在罪犯血管中测量 54 例患者的 IMR，计算公式为 IMR = Pa（Hyp）×Tmn（Hyp）（Pd（Hyp）-Pw/Pa（Hyp）-Pw）。还在血管造影正常的参考血管中测量 IMR。也计算了相对术前 IMR 比值（rPIMR），定义为 IMR 罪犯血管/IMR 非罪犯血管。在 PCI 后 24 小时内连续取样肌钙蛋白。PCI 后平均肌钙蛋白为 0.37±0.8ng/ml。33 例（61%）患者符合 PPMI 的标准。PCI 前的 IMR 是 PCI 后肌钙蛋白的最显著相关因素（r=0.43，p=0.001），但球囊扩张次数（r=0.3，p=0.02）和 rPIMR（r=0.33，p=0.017）也与肌钙蛋白相关。与无 PPMI 的患者相比，发生围手术期心肌梗死的患者 PCI 前的 IMR 更高（IMR 术前 21.2±2.1 PPMI 与无 PPMI 15.6±1.8，p=0.02）。预测 PCI 后肌钙蛋白的最强因素是 IMR 术前（β 0.7，p=0.02）。IMR 术前和 rPIMR 均能预测 PPMI（OR 11（1.3 至 90.5），p=0.026，OR 1.09（1 至 1.19），p=0.03）。
PCI 前微血管功能是 PPMI 的重要决定因素。测量 PCI 前的 IMR 和 rPIMR 可能有助于前瞻性识别发生围手术期心肌梗死的高危患者。需要更大样本量的未来研究来确定 IMR 在 PPMI 中的预测能力。
