Cardiovascular complications and their association with short‐ and long‐term outcomes in patients with multiple myeloma undergoing chimeric antigen receptor T‐cell therapy

Studies of cardiovascular (CV) events after chimeric antigen receptor T-cell (CAR-T) therapy have mostly focused on patients with lymphoma. We evaluated the incidence, timing and prognostic significance of in-hospital and post-discharge CV events in patients with multiple myeloma (MM) receiving CAR-T therapy. We conducted a retrospective analysis of MM patients treated with CAR-T between 2018 and 2024. CV events (heart failure, arrhythmias, myocardial infarction and stroke) and all-cause mortality were assessed separately during hospitalization and post-discharge. Time-dependent Cox regression was used to evaluate associations with mortality. Among 256 patients, 11.7% (n = 30) experienced in-hospital CV events, most commonly atrial arrhythmias (5.5%) and new left ventricular (LV) dysfunction (3.9%), with a median onset of 8 (Q1, Q3: 5, 11) days. Ninety percent of those with LV dysfunction recovered function. Independent predictors of in-hospital CV events included age >65, prior atrial fibrillation, antiplatelet use, cytokine release syndrome grade ≥2 and higher immune effector cell-associated neurotoxicity syndrome grade. Post-discharge CV events were less common (7.8%), occurring at a median of 13 (Q1, Q3: 7, 22) months. Only post-discharge CV events were associated with higher post-discharge all-cause mortality. There were no in-hospital CV deaths and one post-discharge CV death. In this large MM CAR-T cohort, in-hospital CV events were relatively uncommon, reversible and not linked to mortality. In contrast, post-discharge CV events, while rare, predicted worse survival.