Delayed diffuse coronary artery spasm following pulsed field ablation for atrial fibrillation: A case series review
J Chiong, P Calvert, M Mills, S Modi, D Gupta, V LutherAbstract
Background
Pulsed field ablation (PFA) has emerged as a promising energy source for atrial fibrillation (AF) ablation due to its ease of use, cardioselectivity, and safety profile (1). Immediate focal coronary spasm during ablation near the cavotricuspid or mitral isthmus is well recognised (2–3). However, delayed and diffuse coronary spasm, occurring remote from ablation sites following completion of the procedure has been recently reported. This represents a distinct, life-threatening complication that remains poorly characterised.
Purpose
To review and analyse all current published cases of delayed diffuse coronary artery spasm following PFA for atrial fibrillation occurring remote from coronary arteries, identifying common risk factors and shared mechanistic pathways.
Methods
A comprehensive literature review was performed (4–6). Extracted data included patient demographics, PFA systems, procedural details, spatial relation to coronary vessels, haemolysis markers, treatment response, and outcomes.
Results
Three cases (2 males, 1 female; age 53–77 years) involving three different PFA platforms (Sphere 9, PulseSelect, Farapulse) were identified. All procedures were performed under general anaesthesia and included pulmonary vein isolation plus posterior wall ablation (56–68 total PFA applications). No PFA was delivered in proximity to coronary arteries. Protamine was administered for heparin reversal in all cases. Diffuse coronary vasospasm occurred 30–78 minutes post procedure, >30 mm from pulmonary veins, manifesting with acute inferior ST elevation, and each resulting in cardiac arrest. Intracoronary nitrates were used in all cases, with two undergoing mechanical intervention (drug-eluting balloon or stent) for haemodynamic instability. Two cases showed biochemical evidence of haemolysis (haemoglobin decrease 15–58 g/L, raised bilirubin, LDH), and was not specified in one case. All patients achieved full neurological recovery. Two were discharged on calcium channel blockers, with no recurrence over a mean 12 week follow up.
Conclusions
Delayed and diffuse coronary artery spasm is a rare but increasingly recognised life threatening complication associated with pulsed field AF ablation, which can occur remote from the site of ablation, and across different catheter platforms. There are several similarities between cases, which may suggest shared underlying mechanisms. Firstly, the presence of haemolysis may implicate nitric oxide depletion mediated vasoconstriction in this process. Secondly, extended applications to the posterior wall may cause autonomic disruption due to proximity to sympathetic ganglia. Further research is needed to better characterise this important phenomenon.