PO-04-005 LEFT CIRCUMFLEX ARTERY VASOSPASM DURING PULSED FIELD ABLATION AT THE MITRAL ISTHMUS: CHARACTERIZATION OF TIME-TO-RESOLUTION

Abstract

While pulsed field ablation (PFA) has emerged as a novel energy modality for ablation of atrial arrhythmias and is accompanied by a theoretically safer profile given its tissue selectivity and sparing of collateral structures, a recent study has highlighted the occurrence of subtotal coronary vasospasm during atrial fibrillation (AF) ablation on the cavo-tricuspid isthmus with PFA. While these observations were subclinical, there is at least one case report of left circumflex (LCx) coronary artery vasospasm during PFA at the mitral isthmus (MI) during AF ablation. To evaluate the natural history time-to-resolution of coronary vasospasm of the LCx artery during PFA at the MI. In a prospective, consecutively enrolled cohort of patients receiving AF ablation under deep sedation, diagnostic coronary angiography was performed via right femoral arterial access before, during, and after ablation on the MI with a multi-spline PFA catheter (Farawave, Boston Scientific Inc). LCx spasm was identified, characterized by severity, and monitored for progression and time-to-resolution. A total of 19 patients underwent PFA on the lateral MI with successful bidirectional block. Notably, 7 patients (37%) developed LCx vasospasm during ablation, of which 3 cases were mild (<50% decrease in luminal diameter), 2 were moderate (50 to 90% decrease), and 2 were severe (>90% decrease). All of the mild and moderate spasm occurrences self-resolved, with mild spasm taking on average 5.7 minutes to be relieved, and moderate spasm requiring 5 minutes. Relief of severe spasm required an average of 15 minutes, with both necessitating administration of intracoronary or intravenous nitroglycerin. Electrocardiographic ST changes were only present in one case of severe spasm (which resolved with relief of spasm), and there were no hemodynamic changes during spasm. As PFA becomes an alternative to radiofrequency and cryothermal ablation, it behooves operators to be vigilant for vasospastic effects on adjacent coronary vessels during ablation. Further investigation with larger populations is required to more fully elucidate the injurious potential of PFA-induced coronary vasospasm. This study is one of the first to elaborate on the features of LCx vasospasm during PFA on the MI.Tabled 1Patient CharacteristicsAge, mean±SD, y65.6±10.1Male, n (%)14 (74)Body mass index, mean±SD30.3±4.9Medical HistoryType of atrial fibrillationParoxysmal, n (%)4 (21)Persistent, n (%)15 (79)Duration of atrial fibrillation, mean±SD, months48.2±66.4CHA2DS2-VASc Score, mean±SD2.1±1.4Hypertension, n (%)13 (68)Diabetes, n (%)4 (21)Dyslipidemia, n (%)11 (58)Sleep apnea, n (%)1 (5)Prior stroke or transient ischemic attack, n (%)2 (11)Coronary artery disease, (%)4 (21)Congestive heart failure, n (%)1 (5)Left ventricular ejection fraction, mean±SD, %62.3±3.4Left atrium dimension, mean±SD, mm45.8±9.2MedicationsWarfarin, n (%)12 (63)Non-Warfarin oral anticoagulant, n (%)7 (37)Antiarrhythmic drugs, n (%)Class I7 (37)Class II11 (58)Class III5 (26)Class IV0 (0) Open table in a new tab