Zoledronic acid and atrial fibrillation in cancer patients with bone metastases

Abstract

e20591 Background: Treatment with a bisphosphonate was linked with a significantly increased risk for atrial fibrillation (AF) in a few studies. Once-yearly infusions of intravenous zoledronic acid (ZA) was also significantly increased serious AF in postmenopausal women with osteoporosis. This study was conducted to determine the frequency of atrial fibrillation among cancer patients receiving the standard treatment of ZA. Methods: One hundred and twenty-four cancer patients who had bone metastasis receiving ZA were included in this study. All patients have been receiving 4 mg ZA at 4-week intervals; with each dose administered over 15 minutes. Patients who presented outpatient clinic for any reason (routine control, chemotherapy, ZA administration) a short survey completed and standard 12-lead ECG recordings were obtained. Results: One hundred and twenty-four cancer patients with documented bone metastases were evaluated. Mean age of the patients was 55 ± 13.0 years, 60% of the patients were female. Forty-one percent of the patients had breast cancer and 17% non-small cell lung cancer and the remainder had other solid tumors. Mean duration of ZA administration was 13.4 ± 15.0 months/patients. Mean total cumulative dose was 54 ± 15.0 mg per patients. 60 (48%) of the patients were treated with antracycline including regimens, and 37 (30%) were treated with mediastinal radiotherapy that might effect the heart. Twenty-three percent of the patients had hypertension, 10% diabetes mellitus, 7% currently smoker and 32% exsmoker, 3.7% myocardial infarction history, 1.9% congestive heart failure, and 1% valvular disease. On ECG evaluation; we observed sinus rhythm in 58%, sinus tachycardia in 15%, sinus bradicardia in 3.2%, ventricular exracystole in 5.7% of the patients. There were no AF. Conclusions: Although most of the patients were also having potentially cardiotoxic treatment, there was no increase in AF frequency in cancer patients who were treated with intravenous ZA. We believe that the risk of AF is small and may increase with age and comorbidity. No significant financial relationships to disclose.