Predictors of atrial fibrillation in ibrutinib-treated CLL patients: a prospective study

Ibrutinib is an oral irreversible inhibitor of Bruton’s tyrosine kinase, indicated for the treatment of chronic lymphocytic leukaemia. The drug is generally well tolerated; however, not infrequent side effects are reported, with the major two being bleeding and ibrutinib-related atrial fibrillation. Atrial fibrillation pathogenesis in this setting is not completely clear, and no prospective studies have evaluated the impact of previous cardiologic history and baseline characteristics.

We prospectively performed cardiologic assessment in 43 CLL patients before starting ibrutinib therapy. Cardiologic workup included comorbidity collection and electrocardiographic and echocardiographic baseline evaluation.

After a median observation of 8 months, seven patients developed atrial fibrillation (16.3%). Cases developing atrial fibrillation were all elderly males (p = 0.04), and mostly with a history of previous arterial hypertension (p = 0.009). Atrial fibrillation occurrence also correlated with the presence of one or more pre-existent cardiologic comorbidities (p = 0.03), with a higher atrial fibrillation risk score (calculated with comorbidities and cardiologic risk factor evaluation p < 0.001), and with higher left atrial diameter (p = 0.02) and area (p = 0.03) by echocardiography. The occurrence of atrial fibrillation was managed after an integrated cardio-oncologic evaluation: anticoagulation was started in 4 (57.1%) patients and beta-blockers or amiodarone in 5 (71.4%). One patient underwent electric cardioversion and another patient pacemaker positioning to normalise heart rate in order to continue ibrutinib.

Our data show that echocardiography is a highly informative and reproducible tool that should be included in pre-treatment workup for patients who are candidates for ibrutinib therapy.