Background and Importance Ibrutinib is a Bruton’s tyrosine kinase (BTK) inhibitor used for the treatment of chronic lymphocytic leukaemia (CLL). Ibrutinib has been associated with an increased incidence of atrial fibrillation (AF) in trials ranging from 5% to 16% (1).

Aim and Objectives To analyse the appearance of AF and the time of its debut, as well as the possible risk factors in patients being treated with ibrutinib in a tertiary hospital.

Material and Methods Observational, cross-sectional, retrospective, multicentre study. Patients with CLL treated with ibrutinib from July 2016 to September 23 for at least 2 months were included. Diraya®, FarmaTools® and Prisma® databases were consulted. Variables were collected: age, sex, cardiovascular risk factors: arterial hypertension (AHT), diabetes mellitus (DM) and obesity. Duration of treatment with ibrutinib, serum creatinine at the start of treatment, drugs prescribed after ibrutinib, appearance of AF, time to AF and whether hospitalisation was required.

Results Forty-six patients with CLL in the last 7 years were included (16 women, 35%); the median age was 63 years [45–88]. 22 patients (48%) had AHT, eight patients (17%) had DM and five patients (11%) were obese. The mean creatinine value was 0.97 [1.91–0]. Anticoagulation was prescribed to seven patients (15%) and renin angiotensin system blockers to five patients (11%). Thirty-one patients (67%) continue to be treated with ibrutinib. The mean duration of treatment in the 13 patients (28%) who discontinued treatment was 546 days. Of these, two patients (4%) developed AF on days 21 and 594. In the first case, hospitalisation was required and treatment was suspended. In the second, it was not related to ibrutinib because too much time had elapsed since onset, did not require hospitalisation and the drug was not discontinued. Two patients (4%) with previous chronic AF did not develop any new event. One patient (2%) with no risk factors developed ventricular extrasystoles.

Conclusion and Relevance According to our cohort, a considerable number of cases appeared after treatment with ibrutinib that can be extrapolated to the results obtained in previous studies¹ without appearing to be related to cardiovascular risk factors prior to treatment. Those responsible for these patients should be aware that this is a serious adverse effect that should be monitored.

References and/or Acknowledgements 1. https://pubmed.ncbi.nlm.nih.gov/31250562/

Conflict of Interest No conflict of interest.