New-onset atrial fibrillation after multivessel PCI or CABG: a nationwide study

Abstract Background New-onset atrial fibrillation (NOAF) is a well-recognized complication after CABG, affecting 15–40% of patients and increasing the risk of stroke and mortality.(1) Given the increasing use of multivessel percutaneous coronary intervention (MV PCI) as an alternative to CABG, understanding the frequency and clinical implications of NOAF in PCI-treated patients is of significant clinical relevance.(2) Unlike single-vessel PCI, MV PCI involves longer procedural times, greater hemodynamic stress, and increased contrast load—all factors that may predispose patients to NOAF. However, data on NOAF incidence in this population are limited, often constrained by short-term monitoring and incomplete detection. Purpose We determined the incidence of NOAF following MV PCI compared to CABG. Methods This nationwide observational study utilized data from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR). SCAAR includes all patients undergoing PCI or angiography in Sweden and provides extensive information on patient characteristics, angiographic findings and treatment strategies. We combined SCAAR with the Swedish National Prescription Registry which captures all dispensed prescriptions in Sweden. Patients who underwent MV PCI or CABG in Sweden between 11 June 2013 and 17 January 2021 were identified and formed two groups. Patients with prior atrial fibrillation, OAC use or revascularization were excluded. To assess the incidence of clinically significant post-discharge NOAF, we evaluate the dispensed prescription of OAC within three months after revascularisation. Continuation at six months later was confirmed, as treatment for thromboembolic event is typically reduced or discontinued after this period. Secondary outcomes included stroke, myocardial infarction, and all-cause mortality. Kaplan-Meier estimates and an adjusted Cox proportional hazard model were used to assess outcome after 90 days. Results Among patients undergoing MV PCI the incidence of NOAF, indicated by new OAC prescriptions, was 0.5%, compared to 6.6% in CABG patients (adjusted hazard ratio: 19.07; 95% confidence interval: 9.98-36.43; p≤0.001). PCI patients were older, had more angina, heart failure, renal dysfunction, and higher CHA₂DS₂-VASc scores, while CABG patients had more diabetes and extensive coronary artery disease. No differences were observed for stroke, myocardial infarction, or all-cause mortality. Conclusion NOAF is significantly less common after MV PCI compared to CABG, suggesting that the revascularization strategy influences arrhythmic risk. Since NOAF predicts adverse cardiovascular events, even its lower incidence in PCI-treated patients remains clinically relevant. Enhanced risk assessment strategies may help identify high-risk PCI patients who could benefit from closer monitoring and preventive measures. Future research should explore NOAF mechanisms in PCI patients and evaluate its long-term impact on cardiovascular outcomes.