Continued review of outcomes of people who suffer from non-valvular atrial fibrillation treated with rivaroxaban have shown that the likelihood of a major bleeding event, a known side effect of this treatment, increases with age, said a researcher at Baylor College of Medicine.

Non-valvular atrial fibrillation is the most common cardiac arrhythmia. It can cause heart failure, stroke, poor mental health, reduced quality of life and even death.

A group of researchers, including Dr. W. Frank Peacock, professor of emergency medicine and research director at Ben Taub Hospital, used an algorithm to review nearly 10 million electronic medical records from the Department of Defense healthcare system.

Those who had been hospitalized for a major bleeding event related to rivaroxaban were identified. They found more than 31,000 rivaroxaban users, and out of those, 622 experienced major bleeding events. Although the overall risk of bleeding was low, it increased with advancing age, Peacock said.

Gastrointestinal bleeding rates increased from 1.67 events per 100 patient years of rivaroxaban exposure to 3.56 per 100 patient years of exposure if older than 85 years of age. Further, while intracranial hemorrhage occurred even less often, virtually zero if under 65 years of age, it increased directly with advancing age, to a rate 0.2 per100 patient years of rivaroxaban exposure if older than 85 years of age. The results were similar to the findings from the ROCKET trial, said Peacock.

Continued review of patient outcomes helps doctors weigh the benefits of certain types of treatments, learn who is most at risk for side effects, and allows them to educate the patient on all options, said Peacock.

Others who took part in the study include CDR Sally Tamayo, Naval Medical Center, Portsmouth, VA; Manesh Patel, Duke University Health System and Duke Clinical Research Institute, Durham, NC; Zhong Yuan, Janssen Research & Development, LLC, Titusville, NJ; Nicholas Sicignano and Kathleen Hopf, both with Health ResearchTx, Trevose, PA.