Patients taking mirabegron (Myrbetriq) for overactive bladder (OAB) did not have an increased risk of cardiovascular (CV) events compared with those taking other drugs for the condition, a population-based cohort study indicated.
The cumulative incidence of hospitalization or emergency care for tachycardia or arrhythmia was 3.6% for patients who received mirabegron and 3.8% for those who received other OAB medications at 12 months (HR 0.93, 95% CI 0.80-1.09), reported Mina Tadrous, PharmD, PhD, of Women's College Hospital in Toronto, and colleagues in .
Compared to other OAB medications, taking mirabegron was not tied to an increased risk of admission or emergency department visitation for stroke or myocardial infarction either (HR 1.06, 95% CI 0.89-1.27), the investigators found.
Similar results were seen in subgroups without prior atrial fibrillation or ventricular arrhythmia and in those ages 75 and older, the researchers added.
This data on real-world safety supports current prescribing trends, the researchers noted. "Our findings are not meant to endorse preferential use of mirabegron but to support a growing body of evidence that mirabegron is not associated with an excess risk of CV events compared with other treatments in older patients," they wrote.
Mirabegron acts on the beta-3 adrenoreceptors, which have been associated with increases in contractile force and reductions in inotropic effects, they noted. "These adverse effects have been reinforced by trials, finding a small increase in heart rate, blood pressure, and QTc intervals."
The new findings thus provide "a measure of reassurance for patients and clinicians," Tadrous told 51˶.
The researchers evaluated Ontario's provincial healthcare administrative database to find all 21,870 patients who first received OAB prescriptions and 16,948 patients first prescribed mirabegron from June 1, 2015 to March 31, 2017, matched for age, sex, index date, and propensity score. The cohort was 64.9% female and all over age 65 (median 76 years).
Limitations of the study included the investigators' inability to ascertain over-the-counter drug use or lifestyle factors as well as the potential for confounding by indication due to prescriber perceptions of mirabegron risk.
Disclosures
The study was funded by the Institute for Clinical Evaluative Sciences and Ontario Ministry of Health and Long-Term Care Health System Research Fund.
Tadrous disclosed relationships with the Ministry of Health and Long-term Care.
Primary Source
JAMA Internal Medicine
Tadrous M, et al "Association of mirabegron with the risk of arrhythmia in adult patients 66 years or older -- a population-based cohort study" JAMA Intern Med 2019; DOI: 10.1001/jamainternmed.2019.2011.