Thosar Saurabh S, Taqui Sahar, Davidson Brian, Belcik Todd, Hodovan James, Rice Sean P M, Lindner Jonathan R
Oregon Institute of Occupational Health Sciences, Portland, OR, United States.
OHSU Knight Cardiovascular Institute, School of Medicine, Portland, OR, United States.
Front Cardiovasc Med. 2023 Jan 25;10:1057692. doi: 10.3389/fcvm.2023.1057692. eCollection 2023.
Ischemia with no obstructive coronary artery disease (INOCA) is a risk factor for major adverse cardiovascular events and is characterized by abnormal coronary microvascular tone. In patients with INOCA, adverse cardiovascular events most commonly occur in the morning compared to other times of the day and night.
We tested whether coronary microvascular function varies diurnally with attenuation in the morning in patients with symptomatic coronary artery disease without significant (>50%) epicardial stenosis. We evaluated data from 17 patients studied in the AM (700-1159 h) and 11 patients in the PM (1200-1800 h). Coronary microvascular function was measured using perfusion contrast imaging at rest and after infusion of intravenous regadenoson. We calculated microvascular flow reserve as the ratio of hyperemic to resting flow. Along with independent sample -tests, we performed bootstrapping procedures to test mean differences between AM and PM groups, using the bias-corrected and accelerated method with 5,000 bootstrapped samples.
The AM and PM groups were matched for demographic and existing risk factors. Coronary microvascular flow reserve was ∼33% higher in the AM compared to the PM ( = 0.025, BCa 95% CI [0.25, 1.64]; Hedge's = 0.89, 95% CI [0.11, 1.66]) as a result of significantly lower resting flow (∼50%) in the AM compared to the PM ( = 0.03, = -56.65, BCa 95% CI [-118.59, -2.12]; Hedge's = -0.86, 95% CI [-1.60, -0.06]). Our observations are of clinical value and can influence diagnosis and treatment in the clinic based on the time of day of measurements.
无阻塞性冠状动脉疾病的心肌缺血（INOCA）是主要不良心血管事件的危险因素，其特征是冠状动脉微血管张力异常。在INOCA患者中，与白天和夜间的其他时间相比，不良心血管事件最常发生在早晨。
我们测试了有症状的冠状动脉疾病且无明显（>50%）心外膜狭窄的患者中，冠状动脉微血管功能是否会在早晨随着衰减而昼夜变化。我们评估了17例上午（7:00 - 11:59）研究的患者和11例下午（12:00 - 18:00）研究的患者的数据。使用灌注对比成像在静息状态下以及静脉注射瑞加诺生后测量冠状动脉微血管功能。我们将微血管血流储备计算为充血血流与静息血流的比值。除了独立样本检验外，我们还使用偏差校正和加速方法以及5000个自抽样样本进行自抽样程序，以测试上午组和下午组之间的均值差异。
上午组和下午组在人口统计学和现有危险因素方面相匹配。与下午相比，上午的冠状动脉微血管血流储备高约33%（P = 0.025，BCa 95% CI [0.25, 1.64]；Hedge's g = 0.89，95% CI [0.11, 1.66]），这是因为与下午相比，上午的静息血流显著降低（约50%）（P = 0.03，t = -56.65，BCa 95% CI [-118.59, -2.12]；Hedge's g = -0.86，95% CI [-1.60, -0.06]）。我们的观察结果具有临床价值，并且可以根据测量的时间来影响临床诊断和治疗。
