Poster Presentation ANZBMS-MEPSA-ANZORS 2022

Objective: Bisphosphonates are the first-line treatment for several bone and mineral disorders. Randomised trials and cohort studies have reported increased rates of atrial fibrillation in patients receiving bisphosphonates. However, uncertainty remains as to whether other electrical disturbances are precipitated by bisphosphonates. We reviewed the literature for studies reporting ECG findings in patients receiving intravenous bisphosphonates for any indication.

Methods: We retrieved studies (June 2022) reporting ECG parameters following administration of intravenous bisphosphonates. We excluded studies that only reported atrial fibrillation, case reports and non-human studies. Continuous data were meta-analysed if reported in at least two studies. Random-effects models were fitted and reported as standardized mean difference (SMD) with 95%CI.

Results: 1123 records were retrieved. Six met our inclusion criteria, of which five had data for meta-analysis. Studies were of low to moderate quality. Five studies used zoledronic acid while one study used pamidronate. Most studies [n=4] were conducted in postmenopausal women with osteoporosis, one study was conducted in patients with bone metastases and one study was conducted in children with cerebral palsy and osteoporosis. Most studies [n=4] reported outcomes in the subacute (>24 h) phase. Study populations ranged from n=15 to n=116. There was a significant difference in QTc dispersion (SMD=-0.456 milliseconds [95%CI: -0.800 to -0.113]; I2=0%; n=67 patients; k=2 studies) but no differences in heart rate, P wave (maximum), P wave (minimum), P wave dispersion, PR interval, QRS duration QTc (maximum), QTc (minimum), or QTc. The correlation between pre- and post-infusion QTc dispersion was rho=0.981 (p=0.866). Results were unchanged when analysing studies reporting acute or subacute phase ECG changes.

Conclusion: Overall, there is insufficient and low-quality evidence to support an association between intravenous bisphosphonate administration and acute phase dysrhythmias. These data underscore the importance of performing a pre-infusion ECG to evaluate potentially unreported conduction abnormalities.