Journal Article

Assessing the Impact of Prolonged Averaging of Coronary Continuous Thermodilution Traces

Rupert F. G. Simpson, Sarosh A. Khan, Emanuele Gallinoro, John R. Davies, Thabo Mahendiran, Thomas R. Keeble, Christopher M. Cook, Bernard De Bruyne, Takuya Mizukami, Samer Fawaz, Johan Svanerud, Grigoris V. Karamasis, Daniel Munhoz

2024

Overview

Continuous Thermodilution is a novel method of quantifying coronary flow (Q) in mL/min. To account for variability of Q within the cardiac cycle, the trace is smoothened with a 2 s moving average filter. This can sometimes be ineffective due to significant heart rate variability, ventricular extrasystoles, and deep inspiration, resulting in a fluctuating temperature trace and ambiguity in the location of the “steady state”. This study aims to assess whether a longer moving average filter would smoothen any fluctuations within the continuous thermodilution traces resulting in improved interpretability and reproducibility on a test–retest basis. Patients with ANOCA underwent repeat continuous thermodilution measurements. Analysis of traces were performed at averages of 10, 15, and 20 s to determine the maximum acceptable average. The maximum acceptable average was subsequently applied as a moving average filter and the traces were re-analysed to assess the practical consequences of a longer moving average. Reproducibility was then assessed and compared to a 2 s moving average. Of the averages tested, only 10 s met the criteria for acceptance. When the data was reanalysed with a 10 s moving average filter, there was no significant improvement in reproducibility, however, it resulted in a 12% diagnostic mismatch. Applying a longer moving average filter to continuous thermodilution data does not improve reproducibility. Furthermore, it results in a loss of fidelity on the traces, and a 12% diagnostic mismatch. Overall, current practice should be maintained.

• Publisher: MDPI AG
• Subject: Accuracy / Angina pectoris / Arrhythmia / Bias / Cardiovascular disease / CMD / Cmd; Coroflow; continuous thermodilution; coronary; microvascular; CMD / continuous thermodilution / Coroflow / coronary / Coronary vessels / Data smoothing / Heart beat / Medical equipment and supplies industry / Medical imaging / Medical test kit industry / Medicine (General) / microvascular / R5-920 / Reproducibility / Software / Statistical analysis / Vein & artery diseases