In a new study that included more than 76,000 patients, researchers from Intermountain Healthcare in Salt Lake City found that the chance of developing dementia increases when the start of anticoagulation treatment is delayed for atrial fibrillation (AFib).

Typically, when a patient is diagnosed with AFib, they delay taking anticoagulants because of a low risk of stroke or they are exploring alternative treatment options. But the new research, which was revealed May 12 at the Heart Rhythm Society’s annual conference in Chicago, shows that delaying medication, specifically warfarin, could speed up the onset of dementia.

Patients in the trial had no prior history of dementia or were treated with an antiplatelet or warfarin. Though the trial included about 76,000 patients, only 26,189 were ultimately treated with the medications. The researchers measured the time at which patients were diagnoses with AFib to the point at which they began using medication. An immediate start was considered less than 30 days from diagnosis, and a delayed start was considered after one year.

Results showed that the chances of dementia when patients delayed medication were about 30 percent higher for low-risk patients and 136 percent higher in higher risk patients, reinforcing the importance of the starting anticoagulation treatment as soon as possible.

“We saw for the first time that waiting even just 30 days to initiate anticoagulation treatment can increase a patient’s long-term risk of developing dementia,” said T. Jared Bunch, MD, the director of heart rhythm research at Intermountain Medical Center Heart Institute and the medical director for heart rhythm services at Intermountain Healthcare system, in a statement. “We want to ensure we’re doing everything possible to limit the risk of brain injury for our patients and our study not only shows the importance of early therapy but also shows the very limited role, if any, of aspirin for stroke prevention. In this study, was derived from using warfarin and we hope that newer anticoagulants that perform better than warfarin and are easier to start and use will further improve dementia risk.”

Bunch suggests that additional studies be completed to full understand how the risk of dementia increases over a longer period. However, Bunch and his team have just launched a prospective study using dabigatran versus warfarin that will examine cognitive changes over a two-year period.