Immediate assessment of coronary microcirculation during treatment of ST elevation myocardial infarction (STEMI) may facilitate patient stratification for targeted treatment algorithms. Use of pressure-wire to measure the index of microcirculatory resistance (IMR) is possible but has inevitable practical restrictions. We aimed to develop and validate angiography-derived index of microcirculatory resistance (IMRangio) as a novel and pressure-wire-free index to facilitate assessment of the coronary microcirculation. 45 STEMI patients treated with primary percutaneous coronary intervention (pPCI) were enrolled. Immediately before stenting and at completion of pPCI, IMR was measured within the infarct related artery (IRA). At the same time points, 2 angiographic views were acquired during hyperaemia to measure quantitative flow ratio (QFR) from which IMRangio was derived. In a subset of 15 patients both IMR and IMRangio were also measured in the non-IRA. Patients underwent cardiovascular magnetic resonance imaging (CMR) at 48 h for assessment of microvascular obstruction (MVO). IMRangio and IMR were significantly correlated (ρ: 0.85, p < 0.001). Both IMR and IMRangio were higher in the IRA rather than in the non-IRA (p = 0.01 and p = 0.006, respectively) and were higher in patients with evidence of clinically significant MVO (> 1.55% of left ventricular mass) (p = 0.03 and p = 0.005, respectively). Post-pPCI IMRangio presented and area under the curve (AUC) of 0.96 (CI95% 0.92-1.00, p < 0.001) for prediction of post-pPCI IMR > 40U and of 0.81 (CI95% 0.65-0.97, p < 0.001) for MVO > 1.55%. IMRangio is a promising tool for the assessment of coronary microcirculation. Assessment of IMR without the use of a pressure-wire may enable more rapid, convenient and cost-effective assessment of coronary microvascular function.

中文翻译：

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血管造影衍生的微循环阻力指数作为评估 ST 段抬高心肌梗死冠状动脉微循环的新型无压力线工具。

在治疗 ST 段抬高型心肌梗死 (STEMI) 期间立即评估冠状动脉微循环可能有助于针对靶向治疗算法进行患者分层。使用压力线测量微循环阻力 (IMR) 指数是可能的，但不可避免地存在实际限制。我们旨在开发和验证血管造影衍生的微循环阻力指数 (IMRangio) 作为一种新颖的无压力线指数，以促进冠状动脉微循环的评估。45 名接受直接经皮冠状动脉介入治疗 (pPCI) 治疗的 STEMI 患者入组。在支架植入前和 pPCI 完成时，测量梗死相关动脉 (IRA) 内的 IMR。同时点，在充血期间获得了 2 个血管造影视图，以测量定量流量比 (QFR)，从中得出 IMRangio。在 15 名患者的子集中，IMR 和 IMRangio 也在非 IRA 中进行了测量。患者在 48 小时接受心血管磁共振成像 (CMR) 以评估微血管阻塞 (MVO)。IMRangio 和 IMR 显着相关（ρ：0.85，p < 0.001）。IMR 和 IMRangio 在 IRA 中高于非 IRA（分别为 p = 0.01 和 p = 0.006），并且在有临床显着 MVO 证据（> 左心室质量的 1.55%）的患者中更高（p = 0.03 和 p = 0.005，分别）。pPCI 后 IMRangio 呈现和曲线下面积 (AUC) 为 0.96（CI95% 0.92-1.00，p < 0.001），用于预测 pPCI 后 IMR > 40U 和 0.81（CI95% 0.65-0.97，p < 0。001) 对于 MVO > 1.55%。IMRangio 是一种很有前景的评估冠状动脉微循环的工具。不使用压力线评估 IMR 可以更快速、方便和经济地评估冠状动脉微血管功能。