A recent comprehensive study, led by the Department of Health Policy at Vanderbilt University School of Medicine in Nashville, Tennessee, has brought to the forefront a significant concern in the realm of atrial fibrillation (AF) treatment. Collaborating with researchers from the University of Miami and the Miami VA Healthcare System, this groundbreaking research delves into an area of critical importance for patients and healthcare providers alike.

The study, published recently in JAMA Online First emphasises the potential risks associated with using diltiazem in combination with apixaban or rivaroxaban, two common anticoagulant medications.

Atrial fibrillation, a condition characterised by irregular heartbeats, often requires medication to control the heart rate and prevent blood clots. Diltiazem is frequently prescribed for this purpose. However, the study reveals that diltiazem may inhibit the elimination of apixaban and rivaroxaban from the body, leading to over anticoagulation and an increased risk of serious bleeding events.

The retrospective cohort study analysed data from Medicare beneficiaries aged 65 years or older who initiated treatment with either apixaban or rivaroxaban between January 1, 2012, and November 29, 2020. The researchers compared patients who also began treatment with either diltiazem or metoprolol, another commonly prescribed medication for heart rate control. The study followed patients for up to 365 days, examining outcomes such as bleeding-related hospitalisation, death with recent evidence of bleeding, ischemic stroke, and major ischemic or hemorrhagic events.

The findings revealed that patients receiving diltiazem treatment had a significantly higher risk of experiencing bleeding-related hospitalization and death with recent evidence of bleeding compared to those receiving metoprolol. Moreover, the risk of serious bleeding was even greater for patients receiving higher doses of diltiazem, particularly doses exceeding 120 mg per day.

While the study did not find a significant increase in the risk of ischemic stroke or systemic embolism associated with diltiazem use, the heightened risk of serious bleeding underscores the importance of cautious medication management in patients with atrial fibrillation.

The study's lead author stressed the need for healthcare providers to carefully consider the potential risks and benefits when prescribing diltiazem in combination with apixaban or rivaroxaban. While these anticoagulant medications play a crucial role in preventing strokes and other complications in AF patients, the risk of serious bleeding must be carefully weighed, especially in patients receiving higher doses of diltiazem.

Overall, the study highlights the importance of individualised treatment approaches and close monitoring of patients with atrial fibrillation to minimise the risk of adverse events while maximising the benefits of anticoagulant therapy. Further research and clinical guidelines are needed to inform healthcare providers and improve patient outcomes in this population.