Cardiac safety of ribociclib evaluated with 24-hour rhythm Holter electrocardiogram

Objective We aimed to evaluate cardiac safety profile of ribociclib with 24-h rhythm Holter ECG. Material and method Forty-two female metastatic breast cancer patients were included in the study. Rhythm Holter ECG was performed before starting treatment with ribociclib and after 3 months of the treatment initiation. Results The mean age of the patients was 56.36 ± 12.73. 52.4% ( n = 22) of the patients were using ribociclib in combination with fulvestrant and 47.6% ( n = 20) with aromatase inhibitors. None of the patients developed cardiotoxicity. When the rhythm Holter results before and in third month of the treatment were compared, there was no statistically significant difference. Conclusion This is the first study evaluating effects of ribociclib treatment on cardiac rhythm with Holter ECG. The findings suggested ribociclib has a low risk of causing early cardiotoxicity.