School of Cardiovascular Medicine and Sciences, British Heart Foundation Centre of Excellence and National Institute for Health Research Biomedical Research Centre, King's College London, London, United Kingdom.
School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom.
JACC Cardiovasc Imaging. 2021 May;14(5):978-986. doi: 10.1016/j.jcmg.2020.10.015. Epub 2020 Nov 25.
This study assessed the ability to identify coronary microvascular dysfunction (CMD) in patients with angina and nonobstructive coronary artery disease (NOCAD) using high-resolution cardiac magnetic resonance (CMR) and hypothesized that quantitative perfusion techniques would have greater accuracy than visual analysis.
Half of all patients with angina are found to have NOCAD, while the presence of CMD portends greater morbidity and mortality, it now represents a modifiable therapeutic target. Diagnosis currently requires invasive assessment of coronary blood flow during angiography. With greater reliance on computed tomography coronary angiography as a first-line tool to investigate angina, noninvasive tests for diagnosing CMD warrant validation.
Consecutive patients with angina and NOCAD were enrolled. Intracoronary pressure and flow measurements were acquired during rest and vasodilator-mediated hyperemia. CMR (3-T) was performed and analyzed by visual and quantitative techniques, including calculation of myocardial blood flow (MBF) during hyperemia (stress MBF), transmural myocardial perfusion reserve (MPR: MBF / MBF), and subendocardial MPR (MPR). CMD was defined dichotomously as an invasive coronary flow reserve <2.5, with CMR readers blinded to this classification.
A total of 75 patients were enrolled (57 ± 10 years of age, 81% women). Among the quantitative perfusion indices, MPR and MPR had the highest accuracy (area under the curve [AUC]: 0.90 and 0.88) with high sensitivity and specificity, respectively, both superior to visual assessment (both p < 0.001). Visual assessment identified CMD with 58% accuracy (41% sensitivity and 83% specificity). Quantitative stress MBF performed similarly to visual analysis (AUC: 0.64 vs. 0.60; p = 0.69).
High-resolution CMR has good accuracy at detecting CMD but only when analyzed quantitatively. Although omission of rest imaging and stress-only protocols make for quicker scans, this is at the cost of accuracy compared with integrating rest and stress perfusion. Quantitative perfusion CMR has an increasingly important role in the management of patients frequently encountered with angina and NOCAD.
本研究旨在评估高分辨率心脏磁共振（CMR）在心绞痛和非阻塞性冠状动脉疾病（NOCAD）患者中识别冠状动脉微血管功能障碍（CMD）的能力，并假设定量灌注技术比视觉分析具有更高的准确性。
一半的心绞痛患者被发现存在 NOCAD，而 CMD 的存在预示着更高的发病率和死亡率，它现在代表了一个可治疗的治疗靶点。目前，CMD 的诊断需要在血管造影期间对冠状动脉血流进行有创评估。随着对计算机断层扫描冠状动脉造影作为一线工具来研究心绞痛的依赖程度增加，用于诊断 CMD 的非侵入性测试需要验证。
连续纳入心绞痛和 NOCAD 的患者。在休息和血管扩张剂介导的充血期间获取冠状动脉内压力和流量测量值。进行 CMR（3-T）检查，并通过视觉和定量技术进行分析，包括计算充血期间的心肌血流（MBF）（应激 MBF）、心肌灌注储备的透壁性（MPR：MBF/MBF）和心内膜下 MPR（MPR）。CMD 定义为有创冠状动脉血流储备<2.5，CMR 读者对此分类不知情。
共纳入 75 例患者（57±10 岁，81%为女性）。在定量灌注指数中，MPR 和 MPR 具有最高的准确性（曲线下面积[AUC]：0.90 和 0.88），具有较高的敏感性和特异性，均优于视觉评估（均 p<0.001）。视觉评估识别 CMD 的准确性为 58%（敏感性为 41%，特异性为 83%）。定量应激 MBF 的表现与视觉分析相似（AUC：0.64 对 0.60；p=0.69）。
高分辨率 CMR 具有良好的准确性，可检测 CMD，但仅在进行定量分析时如此。尽管省略静息成像和仅应激方案可使扫描更快，但与整合静息和应激灌注相比，这是以准确性为代价的。定量灌注 CMR 在经常遇到心绞痛和 NOCAD 的患者的管理中具有越来越重要的作用。
