Atrial Fibrillation Following Autologous Stem Cell Transplantation in Multiple Myeloma

BACKGROUND: Atrial fibrillation (AF) is a common and clinically significant complication in cancer patients, but data on its incidence and impact among multiple myeloma (MM) patients undergoing autologous stem cell transplantation (ASCT) remain limited. OBJECTIVES: The aim of this study was to characterize the incidence, predictors, and prognostic implications of AF following ASCT in MM patients. METHODS: A total of 801 MM patients who underwent ASCT between 2016 and 2022 were retrospectively analyzed. Pretransplantation evaluation included electrocardiography and echocardiography within 180 days of conditioning. Patients with AF at baseline were excluded. Post-transplantation AF was defined as electrocardiography-confirmed AF occurring after stem cell infusion. RESULTS: Over a median follow-up period of 36.2 months, 70 patients (8.7%) developed post-transplantation AF. The cumulative incidence was 5.5% at 90 days and 9.0% at 3 years, with a median onset of 13 days. Independent predictors included age >65 years (HR: 1.88; 95% CI: 1.16-3.07), prior paroxysmal AF (HR: 6.19; 95% CI: 3.63-10.5), and obesity (HR: 2.00; 95% CI: 1.10-3.63). Left atrial volume index >34 mL/m2 (HR: 1.67; 95% CI: 0.99-2.80) and corrected QT interval >480 ms (HR: 1.69; 95% CI: 0.91-3.12) were associated with AF but not statistically significant after adjustment. Among patients without prior AF, corrected QT interval >480 ms remained a significant predictor. In multivariable analysis, post-transplantation AF conferred a 5-fold higher risk for all-cause mortality and a 4.5-fold higher risk for nonrelapse mortality. CONCLUSIONS: AF is a frequent and high-risk complication among MM patients undergoing ASCT. Routinely available clinical factors enable risk stratification, underscoring the importance of cardiovascular evaluation and vigilant post-transplantation monitoring in this vulnerable population.