Department of Cardiology, Hokkaido Ohno Memorial Hospital, Sapporo, Japan.
Department of Cardiovascular Medicine, Hokkaido University, Graduate School of Medicine, Sapporo, Japan.
J Cardiol. 2022 Feb;79(2):247-256. doi: 10.1016/j.jjcc.2021.09.001. Epub 2021 Sep 15.
Vasodilator capacity of coronary circulation is an important diagnostic and prognostic tool in patients with coronary artery disease (CAD). We aimed to clarify the incidence of coronary microvascular dysfunction (CMD), defined as impaired modified coronary flow capacity (mCFC) proposed by Johnson and Gould and measured by N-ammonia myocardial perfusion positron emission tomography (PET), in patients without obstructive CAD and to evaluate the risk of future cardiovascular events.
This retrospective study recruited 407 consecutive CAD-suspected patients who underwent both pharmacological stress/rest N-ammonia PET and coronary angiography. Of the 407 patients, 137 patients (median age, 70 years; 63 women) were eligible and followed up (median, 19.8 months). Endpoints were defined as cardiovascular death or major adverse cardiovascular events (MACEs), such as cardiovascular death, nonfatal myocardial infarction, unplanned hospitalization for any cardiac reasons, and unplanned coronary revascularization. The impaired mCFC group included patients with mildly to severely reduced regional CFC in, at least, one vascular territory (n=34), while the remaining patients (n=103) were categorized as having preserved mCFC.
Overall, cardiovascular death and MACEs occurred in five (4%) patients. The Kaplan-Meier curve showed a significant reduction in event-free survival for cardiovascular death (p=0.004) and MACEs (p<0.0001) in the impaired mCFC group, compared to the preserved mCFC group. Impaired mCFC was independently associated with the incidence of both cardiovascular death and MACEs after propensity-score adjustments [hazard ratio (HR), 10.7; 95% confidence interval (CI), 1.0-106.0; p=0.04 and HR, 9.5; 95% CI, 2.5-36.2; p<0.001, respectively].
In CAD-suspected patients without obstructive coronary arteries, impaired mCFC was observed in approximately 25% and was associated with a higher risk of cardiovascular death and MACEs. The mCFC concept can help identify patients who would benefit from specific therapies or lifestyle modifications to prevent future MACEs and can clarify potential mechanisms of CMD.
冠状动脉循环的血管扩张能力是冠心病（CAD）患者重要的诊断和预后工具。我们旨在明确冠状动脉微血管功能障碍（CMD）的发生率，CMD 定义为 Johnson 和 Gould 提出的改良冠状动脉血流储备能力（mCFC）受损，并通过 N-氨心肌灌注正电子发射断层扫描（PET）测量。我们在无阻塞性 CAD 的患者中评估了未来心血管事件的风险。
本回顾性研究纳入了 407 例连续疑似 CAD 患者，这些患者均接受了药物应激/静息 N-氨 PET 和冠状动脉造影检查。在这 407 例患者中，有 137 例（中位年龄 70 岁；63 例女性）符合条件并接受了随访（中位随访时间为 19.8 个月）。终点定义为心血管死亡或主要不良心血管事件（MACEs），如心血管死亡、非致死性心肌梗死、因任何心脏原因计划外住院和计划外冠状动脉血运重建。mCFC 受损组包括至少一个血管区域存在区域性 CFC 轻至重度降低的患者（n=34），而其余患者（n=103）归类为 mCFC 正常。
总体而言，有 5 例（4%）患者发生心血管死亡和 MACEs。Kaplan-Meier 曲线显示，与 mCFC 正常组相比，mCFC 受损组心血管死亡（p=0.004）和 MACEs（p<0.0001）的无事件生存明显降低。在倾向评分调整后，mCFC 受损与心血管死亡和 MACEs 的发生率独立相关[风险比（HR），10.7；95%置信区间（CI），1.0-106.0；p=0.04 和 HR，9.5；95% CI，2.5-36.2；p<0.001]。
在无阻塞性冠状动脉的疑似 CAD 患者中，约 25%的患者存在 mCFC 受损，且与心血管死亡和 MACEs 的风险增加相关。mCFC 概念有助于识别可能从特定治疗或生活方式改变中获益以预防未来 MACEs 的患者，并阐明 CMD 的潜在机制。
