Coronary Thermodilution to Assess Flow Reserve

Abstract

Background-Guide wire-based simultaneous measurement of fractional flow reserve (FFR) and coronary flow reserve (CFR) is important to understand microvascular disease of the heart. The aim of this study was to investigate the feasibility of simultaneous measurement of FFR and CFR by one pressure-temperature sensor-tipped guide wire with the use of coronary thermodilution and to compare CFR by thermodilution (CFR thermo ) with simultaneously measured Doppler CFR (CFR Doppl ). Methods and Results-In 103 coronary arteries in 50 patients, a pressure-temperature sensor-tipped 0.014-inch floppy guide wire and a 0.014-inch Doppler guide wire were introduced. Both normal vessels and a wide range of stenotic vessels were included. With 3 mL of saline at room temperature used as an indicator, by hand-injection, thermodilution curves in the coronary artery were obtained in triplicate, both at baseline and at intravenous adenosine-induced maximum hyperemia. After adequate curve-fitting, CFR thermo was calculated from the ratio of inverse mean transit times and compared with CFR Doppl calculated by velocities at hyperemia and baseline. Adequate sets of thermodilution curves and corresponding CFR thermo could be obtained in 87% of the arteries versus 91% for Doppler CFR and 100% for FFR. CFR thermo correlated fairly well to CFR Doppl (CFR thermo ϭ0.84 CFR Doppl ϩ0.17; rϭ0.80; PϽ0.001), although individual differences of Ͼ20% between both indexes were seen in a quarter of all arteries. Conclusions-This study shows the feasibility of simultaneous measurement of FFR (by coronary pressure) and CFR (by coronary thermodilution) in humans by one single guide wire in a practical and straightforward way and will facilitate assessment of microvascular disease.

Novel Index for Invasively Assessing the Coronary Microcirculation

“…9 Recent technological advances have made it feasible to measure coronary artery pressure invasively and to estimate coronary artery flow with a single coronary pressure wire. 10,11 Modified software allows the pressure sensor of the wire to act also as a distal thermistor, while the shaft of the wire serves as a proximal thermistor. In this manner, the mean transit time of saline injected down a coronary artery can be derived from a coronary thermodilution curve.…”

Impact of Coronary Plaque Burden and Composition on Periprocedural Myocardial Infarction and Coronary Flow Reserve After Percutaneous Coronary Intervention

“…CFR was defined as the ratio of Tmn Hyp to Tmn Bas. 21,22) Statistical analyses: Continuous variables are presented as the mean ± SD. Statistical analyses were performed using JMP 9 software (SAS Institute Inc., Cary, NC, USA).…”

Intracoronary and Intravenous Adenosine 5′-Triphosphate, Adenosine, Papaverine, and Contrast Medium to Assess Fractional Flow Reserve in Humans

“…In the catheterization laboratory, CFR is defined as maximal flow divided by baseline flow 1 and can be derived from flow velocity or thermodilution. 2,3 FFR is defined as the ratio of maximal flow in the stenotic territory to maximal flow in the same territory but without stenosis and can be calculated from coronary pressure measurements. 4,5 A less than maximal vasodilation would underestimate CFR and overestimate FFR and might lead to erroneous clinical decision-making.…”