Sorbonne Université, ACTION Study Group, INSERM UMRS 1166, ICAN, Institut de Cardiologie, Hôpital Pitié-Salpêtrière (AP-HP), Paris, France.
Unité de Recherche Clinique, CHU Lariboisière, Paris, France.
EuroIntervention. 2024 Aug 19;20(16):1008-1017. doi: 10.4244/EIJ-D-24-00247.
Whether saline-induced hyperaemia captures exercise-induced coronary flow regulation remains unknown.
Through this study, we aimed to describe absolute coronary flow (Q) and microvascular resistance (Rμ) adaptation during exercise in participants with angina with non-obstructive coronary artery disease (ANOCA) and to explore the correlations between saline- and exercise-derived coronary flow reserve (CFR) and microvascular resistance reserve (MRR).
Rμ, Q, CFR and MRR were assessed in the left anterior descending artery using continuous thermodilution with saline infusion at 10 mL/min (rest), 20 mL/min (hyperaemia) and finally at a 10 mL/min infusion rate during stress testing with a dedicated supine cycling ergometer. An incremental workload of 30 watts every two minutes was applied. A saline-derived CFR (CFR) cutoff <2.5 was used to identify coronary microvascular dysfunction (CMD).
CFR-defined CMD was observed in 53.3% of the participants (16/30). While cycling, these patients less of an ability to increase Q (7 [interquartile range [IQR] 30.5-103.0] vs 21 [IQR 5.8-45.0] mL/min/30 watts; p=0.01) due to a smaller decrease of Rμ (109 {IQR 32-286} vs 202 [IQR 102-379] Wood units [WU]/30 watts; p<0.01) as compared with the group with normal CFR. In the overall population, CFR and exercise-derived CFR (CFR) were 2.70±0.90 and 2.85±1.54, respectively, with an agreement classification of 83.3%. A good correlation between saline and exercise techniques for both CFR (r=0.73; p<0.0001) and MRR (r=0.76; p<0.0001) was observed. Among participants with normal CFR, 28.7% (4/14) had an impaired CFR <2.5 at the peak of exercise due to a moderate and late decrease of Rμ.
Saline-induced hyperaemia provided a valid surrogate for exercise physiology independently of the absolute level of CFR and MRR, although exercise provided more granularity to evaluate adaptation among participants with exercise-related CMD.
盐水诱导充血是否能捕捉到运动引起的冠状动脉血流调节尚不清楚。
通过本研究，我们旨在描述心绞痛伴非阻塞性冠状动脉疾病（ANOCA）患者在运动过程中绝对冠状动脉血流（Q）和微血管阻力（Rμ）的适应性，并探讨盐水和运动衍生的冠状动脉血流储备（CFR）和微血管阻力储备（MRR）之间的相关性。
使用连续热稀释法，以 10mL/min（休息时）、20mL/min（充血时）的速度输注盐水，并在专用的仰卧式自行车测力计上进行递增 30 瓦/两分钟的负荷测试，评估左前降支的 Rμ、Q、CFR 和 MRR。使用<2.5 的 CFR 截断值来识别冠状动脉微血管功能障碍（CMD）。
30 名参与者中有 53.3%（16/30）存在 CFR 定义的 CMD。在骑自行车时，这些患者由于 Rμ（109 [IQR 32-286] vs 202 [IQR 102-379] Wood 单位[WU]/30 瓦；p<0.01）的降低幅度较小，因此增加 Q 的能力降低（7 [IQR 30.5-103.0] vs 21 [IQR 5.8-45.0] mL/min/30 瓦；p=0.01）。与正常 CFR 组相比。在整个人群中，CFR 和运动衍生的 CFR（CFR）分别为 2.70±0.90 和 2.85±1.54，分类一致性为 83.3%。盐水和运动技术对 CFR（r=0.73；p<0.0001）和 MRR（r=0.76；p<0.0001）均具有良好的相关性。在正常 CFR 的参与者中，由于 Rμ 的中度和延迟降低，有 28.7%（4/14）在运动峰值时出现 CFR<2.5 的受损情况。
盐水诱导充血可以作为运动生理学的有效替代方法，与绝对 CFR 和 MRR 水平无关，尽管运动提供了更多的粒度来评估与运动相关的 CMD 患者的适应性。
