Whole heart hyperaemic coronary blood flow assessed by continuous thermodilution tended to be higher in controls compared to patients with mild atherosclerosis (668 vs 582 mL/min, p=0.068).
Observational (n=69)
Yes
What are the normal reference values of absolute coronary hyperaemic blood flow and microvascular resistance measured by continuous thermodilution in humans?
While continuous thermodilution can measure absolute coronary hyperaemic flow and resistance, the wide range of normal values limits its utility for inter-patient comparisons in clinical practice.
Absolute Event Rate: 582% vs 668%
p-value: p=0.068
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 (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. 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 Repi (43±23 vs 83±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±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.
Fournier et al. (Thu,) conducted a observational in Mild, non-obstructive coronary atherosclerosis (n=69). Continuous thermodilution vs. Normal coronary arteries (controls) was evaluated on Whole heart hyperaemic coronary blood flow (mL/min) (p=0.068). Whole heart hyperaemic coronary blood flow assessed by continuous thermodilution tended to be higher in controls compared to patients with mild atherosclerosis (668 vs 582 mL/min, p=0.068).