Continuous thermodilution to assess absolute flow and microvascular resistance: validation in humans using [15O]H2O positron emission tomography. (25th April 2019)

• Record Type: Journal Article
• Authors: Everaars, Henk; de Waard, Guus A; Schumacher, Stefan P; Zimmermann, Frederik M; Bom, Michiel J; van de Ven, Peter M; Raijmakers, Pieter G; Lammertsma, Adriaan A; Götte, Marco J; van Rossum, Albert C; Kurata, Akira; Marques, Koen M J; Pijls, Nico H J; van Royen, Niels; Knaapen, Paul
• Is Part Of: European heart journal. Volume 40:Number 28(2019)
• Page Start: 2350
• Page End: 2359
• Publication Date: 2019-04-25
• Subjects: Absolute coronary flow -- Microvascular resistance -- Microcirculation -- Thermodilution -- Positron emission tomography; Cardiology -- Periodicals; Heart -- Diseases -- Periodicals; 616.12005
• DOI: 10.1093/eurheartj/ehz245
• Languages: English
• ISSNs: 0195-668X

Abstract

Abstract: Aims: Continuous thermodilution is a novel technique to quantify absolute coronary flow and microvascular resistance (MVR). Notably, intracoronary infusion of saline elicits maximal hyperaemia, obviating the need for adenosine. The primary aim of this study was to validate continuous thermodilution in humans by comparing invasive measurements to [ 15 O]H2 O positron emission tomography (PET). As a secondary goal, absolute flow and MVR were compared between invasive measurements obtained with and without adenosine. Methods and results: Twenty-five patients underwent coronary computed tomography angiography (CCTA), [ 15 O]H2 O PET, and invasive assessment. Absolute coronary flow and MVR were measured in the left anterior descending and left circumflex artery using a dedicated infusion catheter and a temperature/pressure sensor-tipped guidewire. Invasive measurements were performed with and without adenosine. In order to compare invasive flow measurements with PET perfusion, subtending myocardial mass of the investigated vessels was derived from CCTA using the Voronoi algorithm. Invasive and non-invasive measurements of adenosine-induced hyperaemic flow and MVR showed strong correlation ( r = 0.91; P < 0.001 for flow and r = 0.85; P < 0.001 for MVR) and good agreement [intraclass correlation coefficient (ICC) = 0.90; P < 0.001 for flow and ICC = 0.79; P < 0.001 for MVR]. Absolute flow and MVR also correlated well between measurements with and without adenosine ( r = 0.97; P < 0.001 for flow and r = 0.98; P < 0.001 for MVR) and showed good agreement (ICC = 0.96; P < 0.001 for flow and ICC = 0.98; P < 0.001 for MVR). Conclusions: Continuous thermodilution is an accurate method to measure absolute coronary flow and MVR, which is evidenced by strong agreement with [ 15 O]H2 O PET derived flow and resistance. Absolute flow and MVR correlate highly between invasive measurements obtained with and without adenosine, which confirms that intracoronary infusion of room temperature saline elicits steady-state maximal hyperaemia.