1. Normal Values of Thermodilution-Derived Absolute Coronary Blood Flow and Microvascular Resistance in Humans
- Author
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Giuseppe Di Gioia, Jo M. Zelis, Marcel van 't Veer, Daniëlle C J Keulards, Jeroen Sonck, M Kodeboina, Mohamed El Farissi, Takuya Mizukami, Stephane Fournier, Iginio Colaiori, Sakura Nagumo, Bernard De Bruyne, Carlos Collet, Frederik M. Zimmermann, Nico H.J. Pijls, Cardiovascular Biomechanics, and Eindhoven MedTech Innovation Center
- Subjects
medicine.medical_specialty ,Fractional flow reserve ,030204 cardiovascular system & hematology ,Anterior Descending Coronary Artery ,Clinical research ,03 medical and health sciences ,Coronary circulation ,0302 clinical medicine ,Absolute coronary blood flow ,medicine.artery ,Internal medicine ,Medicine ,030212 general & internal medicine ,Coronary atherosclerosis ,Other technique ,business.industry ,Absolute coronary resistance ,Blood flow ,Coronary arteries ,medicine.anatomical_structure ,Right coronary artery ,Vascular resistance ,Cardiology ,Microvascular resistance ,Cardiology and Cardiovascular Medicine ,business - Abstract
Background: Absolute hyperaemic coronary blood flow (Q, in mL/min) and resistance (R, in Wood units [WU]) can be measured invasively by continuous thermodilution. Aims: The aim of this study was to assess normal reference values of Q and R. Methods: In 177 arteries (69 patients: 25 controls, i.e., without identifiable coronary atherosclerosis; 44 patients with mild, non-obstructive atherosclerosis), thermodilution-derived hyperaemic Q and total, epicardial, and microvascular absolute resistances (R tot, R epi, and R micro) were measured. In 20 controls and 29 patients, measurements were obtained in all three major coronary arteries, thus allowing calculations of Q and R for the whole heart. In 15 controls (41 vessels) and 25 patients (71 vessels), vessel-specific myocardial mass was derived from coronary computed tomography angiography. Results: Whole heart hyperaemic Q tended to be higher in controls compared to patients (668±185 vs 582±138 mL/min, p=0.068). In the left anterior descending coronary artery (LAD), hyperaemic Q was significantly higher (293±102 mL/min versus 228±71 mL/min, p=0.004) in controls than in patients. This was driven mainly by a difference in R epi (43±23 vs 83±41 WU, p=0.048), without significant differences in R micro. After adjustment for vessel-specific myocardial mass, hyperaemic Q was similar in the three vascular territories (5.9±1.9, 4.9±1.7, and 5.3±2.1 mL/min/g, p=0.44, in the LAD, left circumflex and right coronary artery, respectively). Conclusions: The present report provides reference values of absolute coronary hyperaemic Q and R. Q was homogeneously distributed in the three major myocardial territories but the large ranges of observed hyperaemic values of flow and of microvascular resistance preclude their clinical use for inter-patient comparison.
- Published
- 2021