BACKGROUND Coronary microvascular dysfunction (CMD) is a common cause of angina with no obstructive coronary artery disease (ANOCA), and effective treatment options are limited. OBJECTIVES This study aims to assess the safety and efficacy of the coronary sinus (CS) Reducer (Neovasc, Inc/Shockwave Medical) for treatment of angina in patients with CMD. METHODS This Phase II trial enrolled 30 patients with ANOCA, invasively diagnosed CMD, and Canadian Cardiovascular Society (CCS) class 3 to 4 angina despite medical therapy. CMD was defined by coronary flow reserve (CFR) ≤2.5 and/or ≤50% increase in coronary blood flow (CBF) in response to intracoronary infusion of acetylcholine. Invasive coronary microvascular function testing was performed before and at 120 days postimplantation. The primary endpoint was change in microvascular function at 120 days. Secondary endpoints were changes in CCS angina class and Seattle Angina Questionnaire (SAQ) scores. RESULTS Mean age was 54.8 ± 11.0 years; 67% (20/30) were women. In patients with low baseline CFR (endothelium-independent CMD), CFR increased significantly from 2.1 (1.95-2.30) to 2.7 (2.45-2.95) (n = 19; P = 0.0011). Patients with abnormal CBF response to acetylcholine at baseline (endothelium-dependent CMD) had an increase in CBF response to acetylcholine: -11.0% (-20.15% to 5.85%) to 11.5% (-4.82% to 39.29%) (n = 11; P = 0.042). There was a significant improvement in CCS angina class from 4.0 (3.25-4.0) to 2.0 (2.0-3.0) (P < 0.001) and increase in each domain of the SAQ questionnaire (P < 0.006 for all). CONCLUSIONS This study demonstrates that the CS Reducer is associated with significant improvement in angina, quality of life, and coronary microvascular function in patients with CMD and may emerge as a novel therapy for patients with ANOCA.

中文翻译：

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冠状窦复位剂可改善微血管功能障碍患者的心绞痛、生活质量和冠状动脉血流储备。


背景 冠状动脉微血管功能障碍 （CMD） 是心绞痛的常见原因，无阻塞性冠状动脉疾病 （ANOCA），有效的治疗选择有限。目的 本研究旨在评估冠状窦 （CS） 复位剂 （Neovasc， Inc/Shockwave Medical） 治疗 CMD 患者心绞痛的安全性和有效性。方法 该 II 期试验招募了 30 名 ANOCA 患者，侵袭性诊断为 CMD 和加拿大心血管学会 （CCS） 3 至 4 级心绞痛患者尽管接受了药物治疗。CMD 定义为冠状动脉内输注乙酰胆碱后冠状动脉血流储备 （CFR） ≤ 2.5 和/或 ≤ 50% 冠状动脉血流量 （CBF） 增加。在植入前和植入后 120 天进行侵入性冠状动脉微血管功能测试。主要终点是 120 天时微血管功能的变化。次要终点是 CCS 心绞痛分级和西雅图心绞痛问卷 （SAQ） 评分的变化。结果 平均年龄 54.8 ± 11.0 岁;67% （20/30） 是女性。在低基线 CFR （内皮非依赖性 CMD） 患者中，CFR 从 2.1 （1.95-2.30） 显著增加到 2.7 （2.45-2.95） （n = 19;P = 0.0011）。基线时 CBF 对乙酰胆碱反应异常的患者（内皮依赖性 CMD）对乙酰胆碱的 CBF 反应增加：-11.0%（-20.15% 至 5.85%）至 11.5%（-4.82% 至 39.29%）（n = 11;P = 0.042）。CCS 心绞痛分级从 4.0 （3.25-4.0） 显著改善至 2.0 （2.0-3.0） （P < 0.001），SAQ 问卷各领域均有所增加 （P < 0.006）。 结论 本研究表明，CS Reducer 与 CMD 患者心绞痛、生活质量和冠状动脉微血管功能的显着改善相关，并可能成为 ANOCA 患者的一种新疗法。