TY - JOUR JO - EuroIntervention TI - Normal values of thermodilution-derived absolute coronary blood flow and microvascular resistance in humans AB - <p><strong>Background: </strong>Absolute hyperaemic coronary blood flow (Q, in mL/min) and resistance (R, in Wood units [WU]) can be measured invasively by continuous thermodilution.</p> <p><strong>Aims:</strong> The aim of this study was to assess normal reference values of Q and R.</p> <p><strong>Methods:</strong> 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 (Rtot, Repi, and Rmicro) 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.</p> <p><strong>Results:</strong> Whole heart hyperaemic Q tended to be higher in controls compared to patients (668&plusmn;185 vs 582&plusmn;138 mL/min, p=0.068). In the left anterior descending coronary artery (LAD), hyperaemic Q was significantly higher (293&plusmn;102 mL/min versus 228&plusmn;71 mL/min, p=0.004) in controls than in patients. This was driven mainly by a difference in Repi (43&plusmn;23 vs 83&plusmn;41 WU, p=0.048), without significant differences in Rmicro. After adjustment for vessel-specific myocardial mass, hyperaemic Q was similar in the three vascular territories (5.9&plusmn;1.9, 4.9&plusmn;1.7, and 5.3&plusmn;2.1 mL/min/g, p=0.44, in the LAD, left circumflex and right coronary artery, respectively).</p> <p><strong>Conclusions:</strong> 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.</p> AU - Fournier Stephane AU - Keulards C.J. Daniƫlle AU - van 't Veer Marcel AU - Colaiori Iginio AU - Di Gioia Giuseppe AU - Zimmermann M. Frederick AU - Mizukami Takuya AU - Nagumo Sakura AU - Kodeboina Monika AU - El Farissi Mohamed AU - Zelis M. Jo AU - Sonck Jeroen AU - Collet Carlos AU - Pijls H. J. Nico AU - De Bruyne Bernard VL - 17 IS - 4 Y1 - 20/07/2021 Y1 - 2021 DOI - 10.4244/EIJ-D-20-00684 SP - e309 EP - e316 KW - clinical research KW - fractional flow reserve KW - other technique KW - microvascular resistance KW - coronary circulation KW - absolute coronary resistance KW - absolute coronary blood flow PB - Europa Digital & Publishing SE - Coronary interventions - Mini focus on coronary physiology UR - https://eurointervention.pcronline.com/article/normal-values-of-thermodilution-derived-absolute-coronary-blood-flowand-microvascular-resistance-in-humans SN - 1774-024X ER -