Background and Aims The microvascular resistance reserve (MRR) is a novel invasive index of the microcirculation, which is independent of epicardial stenoses, and MRR has both diagnostic and prognostic implications. This study investigates whether MRR is associated with health status outcomes by revascularization in patients with moderate coronary stenoses. Methods Consecutive patients with stable chest pain and moderate (30-90% diameter) stenoses on invasive coronary angiography (n=222) underwent invasive physiology assessment. Revascularization was performed by guideline recommendations. At baseline and follow-up, health status and myocardial perfusion were assessed by Seattle Angina Questionnaire (SAQ) and positron emission tomography. The primary endpoint was freedom from angina at follow-up with secondary endpoints including changes in health status by SAQ domains and myocardial perfusion by MRR and revascularization status. Low MRR was defined as ≤3.0. Results Freedom from angina occurred in 38/173 patients. In multivariate analyses, MRR was associated with freedom from angina at follow-up (odds ratio 0.860, 95% confidence interval 0.740-0.987). By MRR and revascularization groups, patients with normal MRR who did not undergo revascularization, and patients with abnormal MRR who underwent revascularization, improved health status of angina frequency (mean difference SAQ angina frequency score 8.5 [3.07-13.11] and 13.5 [2.82-23.16], respectively). For both groups, health status of physical limitation (mean difference in SAQ physical limitation score 9.7 [4.79-11.93] and 8.7 [0.53-13.88], respectively) and general health status (mean difference in SAQ summary score 9.3 [5.18-12.50] and 10.8 [2.51-17.28], respectively) also improved. Only patients with abnormal MRR who underwent revascularization improved myocardial perfusion. Conclusions In patients with moderate coronary stenoses, MRR seems to predict symptomatic and perfusion benefit of revascularization.

中文翻译：

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微血管阻力储备：慢性冠脉综合征血运重建后对健康状况和心肌灌注的影响


背景和目的 微血管阻力储备 （MRR） 是一种新的微循环侵入性指标，独立于心外膜狭窄，MRR 具有诊断和预后意义。本研究通过血运重建调查 MRR 是否与中度冠状动脉狭窄患者的健康状况结果相关。方法 对有创冠状动脉造影 （n=222） 上稳定胸痛和中度 （30-90% 直径） 狭窄的连续患者进行侵入性生理学评估。根据指南建议进行血运重建。在基线和随访时，通过西雅图心绞痛问卷 （SAQ） 和正电子发射断层扫描评估健康状况和心肌灌注。主要终点是随访时无心绞痛，次要终点包括 SAQ 结构域和心肌灌注的健康状况变化，MRR 和血运重建状态。低 MRR 定义为 ≤3.0。结果 38/173 例患者无心绞痛。在多变量分析中，MRR 与随访时无心绞痛相关 （比值比 0.860,95% 置信区间 0.740-0.987）。在 MRR 和血运重建组中，MRR 正常但未进行血运重建的患者和接受血运重建的 MRR 异常患者改善了心绞痛频率的健康状况 （平均差 SAQ 心绞痛频率评分分别为 8.5 [3.07-13.11] 和 13.5 [2.82-23.16]）。对于两组，身体限制的健康状况 （SAQ 身体限制评分的平均差异分别为 9.7 [4.79-11.93] 和 8.7 [0.53-13.88]）和一般健康状况 （SAQ 总分的平均差异分别为 9.3 [5.18-12.50] 和 10.8 [2.51-17.28]）也有所改善。 只有接受血运重建的 MRR 异常患者才改善了心肌灌注。结论 在中度冠状动脉狭窄患者中，MRR 似乎可以预测血运重建的症状和灌注益处。