PF394 RHYTHM AND CONDUCTION DISORDERS IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA RECEIVING TREATMENT WITH IBRUTINIB
Authors: E. Emelina, G. Gendlin, I. Nikitin
Journal: HemaSphere (2019)

Background: During treatment with ibrutinib (Ib), atrial fibrillation (AF), supraventricular tachycardia (SVT), atrioventricular blocks (AV‐blockade), pauses of sinus rhythm, and marked bradycardia may develop. Early detection and correction of rhythm and conduction disturbances allows the continuation of ibrutinib therapy in these patients. Aims: Early diagnosis and treatment of rhythm and conduction disorders in patients taking ibrutinib. Methods: We examined and observe 197 patients with chronic lymphocytic leukemia (CLL), receiving Ib at a dose 420 mg per day as a 1,2,3 and 4 lines of therapy from 5 months to 56 months. All patients underwent electrocardiography, echocardiography and 24‐hour ECG monitoring. Results: Included patients with CLL aged from 32 to 91 years (66.0 (59.0–72.0) years), of which 70 women aged from 39 to 83 years (64.0 (54.0 ‐ 71.0) years) and 127 men aged from 32 to 91 years (66.0 (60.0–72.0) years). AF was registered in 25 patients (13.97%) in periods ranging from 1 month to 41 months of Ib therapy. The age of patients with AF identified during the treatment of Ib is 68.0 (62.0 ‐ 74.0) years. In 20 of 25 patients (80%), only paroxysm of AF was registered. In 2 patients, AF was converted to a permanent form. Indications for the prescribing of new oral anticoagulants had 72.7% of patients with AF, currently receiving apixaban, rivaroxaban and dabigatran. 2 patients had severe grade 2 AV‐blockade, which required the installation of a pacemaker. A 67‐year‐old patient who had received Ib for 13 months had AV degree II blockade, with Wenckebach periods and a 2: 1 transition to AV blockade with HR of 37 beats per minute, accompanied by Morgagni‐ Adams‐Stokes attacks. A 80 year old patient developed AV degree 2 blockage with HR of 36 beats per minute, in combination with SVT with HR of 135 beats per minute, was asymptomatic and was detected by chance after 14 months of taking Ib. In 2 patients, 53 and 56 years old, who did not have any cardiovascular and thyroid diseases, during the treatment of Ib, the development of recurrent severe paroxysms of SVT with a rhythm frequency of up to 188–285 beats per minute, registered after 2 and 15 months of Ib therapy. Medical correction is carried out and therapy Ib continues. Severe bradycardia with HR from 21 beats per minute to 44 beats per minute during wakefulness was detected in 5 patients (4 women and 1 man) aged 55 to 72 years, receiving Ib from 13 to 34 months. All 5 patients had no symptoms. During the routine examination, rhythm pauses were detected in 2 patients with a constant form of AF. A 71‐year‐old patient with asymptomatic pauses of sinus rhythm up to 3.6 msec with HR up to 21 beats per minute in combination with a tachysystoly of up to 160 beats per minute required the installation of a pacemaker. A 57‐year‐old patient with asymptomatic pauses of sinus rhythm up to 2.8 msec with HR of 37 beats per minute, tachysystole of up to 180 beats per minute is planned to install an pacemaker. Summary/Conclusion: Asymptomatic conduction disorders need for screening ECG monitoring within 24 hours, especially for patients who receive Ib for more than 1 year. Provided early diagnosis and detection of rhythm and conduction disturbances, rapid correction, both medication and when indicated, cardiac surgery allow patients to continue treatment of Ib without reducing its dose.