Intracoronary ECG ST-Segment Shift Remission Time During Reactive Myocardial Hyperemia (Τ-icECG): A New Method to Assess Hemodynamic Coronary Stenosis Severity

• Published in: American journal of physiology. Heart and circulatory physiology Vol. 327; no. 4; pp. H1124 - H1131
• Main Authors: Bigler, Marius Reto, Kieninger-Gräfitsch, Andrea, Rohla, Miklos, Corpataux, Noé, Waldmann, Frédéric, Wildhaber, Reto, Häner, Jonas, Seiler, Christian
• Format: Journal Article
• Language: English
• Published: United States American Physiological Society 01.10.2024
• Series: Vascular Biology and Microcirculation
• Subjects: Algorithms; Balloon treatment; Coronary artery; Coronary vessels; Hemodynamics; Hyperemia; Ischemia; Myocardial ischemia; Myocardium; Observational studies; Occlusion; Remission; Segments; Short Report; Stenosis; intracoronary electrocardiogram; myocardial ischemia; Autonomous algorithm; fractional flow reserve; ECG-analysing system
• ISSN: 0363-6135; 1522-1539; 1522-1539
• DOI: 10.1152/ajpheart.00481.2024

Background-Fractional flow reserve (FFR) measurements are recommended for assessing hemodynamic coronary stenosis severity. Intracoronary ECG (icECG) is easily obtainable and highly sensitive in detecting myocardial ischemia due to its close vicinity to the myocardium. We hypothesized that the remission time of myocardial ischemia on icECG after a controlled coronary occlusion accurately detects hemodynamically relevant coronary stenosis. Methods-This retrospective, observational study included patients with chronic coronary syndrome undergoing hemodynamic coronary stenosis assessment immediately following a strictly 1-minute proximal coronary artery balloon occlusion with simultaneous icECG recording. IcECG was used for a beat-to-beat analysis of the ST-segment shift during reactive hyperemia immediately following balloon deflation. The time from coronary balloon deflation until the ST-segment shift reached 37% of its maximum level, i.e., icECG ST-segment shift remission time( -icECG in seconds,s) was obtained by an automatic algorithm. -icECG was tested against the simultaneously obtained reactive hyperemia FFR at a threshold of 0.80 as reference parameter. Results-One hundred and thirty-nine icECGs from 120 patients (age 68±10 years) were analysed. Receiver operating characteristic (ROC) analysis of -icECG for the detection of hemodynamically relevant coronary stenosis at an FFR of ≤0.80 was performed. The area under the ROC curve was equal to 0.621(p=0.0363) at an optimal -icECG threshold of 8s(sensitivity 61%, specificity 67%). -icECG correlated inversely and linearly with FFR(p=0.0327). Conclusion-This first proof-of-concept study demonstrates that τ-icECG, a measure of icECG ST segment-shift remission after a 1-minute coronary artery balloon occlusion accurately detects hemodynamically relevant coronary artery stenosis according to FFR at a threshold of ≥8seconds.