Treatment and outcomes of patients with atrial fibrillation after CAR T-cell therapy

Chimeric antigen receptor (CAR) T-cell therapy has been revolutionary in the treatment of blood cancers, but has been associated with arrhythmias such as atrial fibrillation (AF). The treatment course and cardiovascular outcomes of patients who develop new or recurrent AF after CAR-T has yet to be explored.

We extracted a cohort of patients who underwent CAR T-cell therapy between 2016 and 2022. The endpoint of interest was defined as the first episode of new or recurrent AF during or after CAR-T infusion. Patients with persistent or permanent AF were not counted as events. Tocilizumab use was not counted for patients who had an AF event more than 30 days after CAR-T infusion. Chart review was used to delineate patient treatments and outcomes. Survival analyses techniques were used to define risk of new or recurrent AF.

There were 328 patients who underwent CAR T-cell therapy between 2016 and 2022, of which 41 had prior history of AF. Overall, there were 10 new and 9 recurrent AF events after CAR T-cell infusion, with a composite cumulative incidence risk of 5.8%. The majority of these events occurred within 30 days of receiving CAR-T (N=14, 73.7%). All events that occurred after 30 days were associated with significant hospitalizations unrelated to CAR-T. Rate control was the preferred method of treatment, with beta blockers being the preferred first-line therapy for both patients on and not on baseline beta blockers (Table). 2 patients were given amiodarone prophylactically prior to CAR-T infusion. Only 1 patient received cardioversion, 15 days after the AF event, but had recurrence shortly thereafter. Only 2 patients were on chronic anticoagulation, and both had history of AF prior to CAR-T. Tocilizumab was given to 9 patients (47.4%) before the onset of AF and not significantly associated to decreased risk of developing new or recurrent AF (HR 1.16, CI 0.47-2.83, P=0.75). Tocilizumab was more likely given to patients with higher cytokine release syndrome and neurotoxicity grading (Figure). There were no myocardial infarctions or strokes.

Atrial fibrillation is a rare complication of CAR T-cell therapy. Rate-control strategies remain the preferred method of treatment. Very few patients were given anticoagulation, but the incidence of subsequent stroke was negligible. More investigation will need to be undertaken to determine methods of preventing AF in the setting of CAR-T therapy.

CAR-T AF Patient Case Series