Reference values for intracoronary Doppler flow velocity-derived hyperaemic microvascular resistance index. (15th January 2023)

• Record Type: Journal Article
• Authors: Feenstra, Rutger G.T.; Seitz, Andreas; Boerhout, Coen K.M.; de Winter, Robbert J.; Ong, Peter; Beijk, Marcel A.M.; Piek, Jan J.; Sechtem, Udo; van de Hoef, Tim P.
• Is Part Of: International journal of cardiology. Volume 371(2023)
• Page Start: 16
• Page End: 20
• Publication Date: 2023-01-15
• Subjects: Hyperaemic microvascular resistance -- Reference value -- Angina -- Non-obstructive coronary artery disease -- Coronary vasomotor dysfunction; ANOCA angina with no significant epicardial coronary obstruction -- APV average peak flow velocity -- COVADIS Coronary Vasomotor Disorders International Study Group -- HMR Doppler flow velocity-derived hyperaemic microvascular resistance index calculated with distal coronary pressure -- IMR thermodilution-derived hyperaemic index of microcirculatory resistance -- Pa Aortic coronary Pressure -- Pa-HMR Doppler flow velocity-derived hyperaemic microvascular resistance index calculated with aortic pressure -- Pd Distal coronary Pressure; Cardiology -- Periodicals; Electronic journals; 616.12
• DOI: 10.1016/j.ijcard.2022.09.054
• Languages: English
• ISSNs: 0167-5273

Abstract

Abstract: Background: Invasive assessments of microvascular function are rapidly becoming an integral part of physiological assessment in chronic coronary syndromes. Objective: We aimed to establish a reference range for Doppler flow velocity-derived hyperaemic microvascular resistance index (HMR) in a cohort of angina with no significant epicardial coronary obstruction (ANOCA) patients with no structural pathophysiological alterations in the coronary circulation. Methods: The reference population consisted of ANOCA patients undergoing invasive coronary vasomotor function assessment who had a coronary flow reserve (CFR) >2.5, and had either (1) tested negatively for spasm provocation ( n = 12) or (2) tested positively with only angina at rest ( n = 29). A reference range for HMR was established using a non-parametric method and correlations with clinical characteristics were determined using a spearman rank correlation analysis. Results: In 41 patients median HMR amounted to 1.6 mmHg/cm/s [Q1, Q3: 1.3, 2.2 mmHg/cm/s]. The reference range for HMR that is applicable to 95% of the population was 0.8 mmHg/cm/s (90% CI: 0.8–1.0 mmHg/cm/s) to 2.7 mmHg/cm/s (90% CI: 2.6–2.7 mmHg/cm/s). No significant correlations were found between HMR and clinical characteristics. Conclusion: In this reference population undergoing invasive coronary vasomotor function testing, the 90% confidence interval of the HMR upper limit of normal ranges from 2.6 to 2.7 mmHg/cm/s. A > 2.5 mmHg/cm/s HMR threshold can be used to identify abnormal microvascular resistance in daily clinical practice. Central illustration: Unlabelled Image Highlights: Increased HMR in the absence of epicardial stenoses is considered a surrogate marker of coronary microvascular pathology. There was excellent correlation between HMR measurements obtained with or without a microcatheter. A >2.5 mmHg/cm/s HMR threshold can be used to identify abnormal microvascular resistance in daily clinical practice.