March 17, 2019 – Although nearly two-thirds of the study population did not receive all the guideline-directed medical therapies for which they were eligible, use of all therapies was linked to better outcomes in specific populations, such as patients with heart failure.
Most atrial fibrillation patients with comorbidities do not receive all the guideline-directed medical therapies (GDMT) they are eligible for, but new evidence from the DCRI suggests use of these therapies is associated with better outcomes in populations with certain comorbidities.
A study led by DCRI Fellow Zak Loring, MD, examined GDMT use for a range of conditions that are often seen in conjunction with atrial fibrillation, including coronary artery disease, diabetes, congestive heart failure, hyperlipidemia, hypertension, peripheral vascular disease, and obstructive sleep apnea. The findings were presented Sunday at the annual Scientific Sessions of American College of Cardiology in New Orleans.
After examining a population of 20,434 patients from the Outcomes for Better Informed Treatment of AF (ORBIT-AF) registry, the study team found that only about 33 percent of patients receive all the therapies for which they are eligible.
GDMT use varied widely by comorbidity type. Hyperlipidemia had a high GDMT ratio, with 75.6 percent of patients on a statin, while only 43.1 percent diabetes patients were treated with all therapies for which they were eligible.
The team was also interested in how patient outcomes were associated with both overall GDMT use and comorbidity-specific GDMT use. While the researchers did see a downward trend in all-cause mortality and major adverse cardiac or neurological events associated with GDMT use, the difference between patients who received all the therapies for which they were eligible and patients who did not was not statistically significant.
However, significant trends did emerge in specific comorbidity types. In patients with congestive heart failure, patients who used all the GDMT they were eligible for saw a 23 percent decrease in all-cause mortality compared to patients who received only some or no GDMT.
“These results are really interesting because it tells us there’s an interaction between the comorbidities and outcomes with atrial fibrillation patients,” Loring said. “For example, previous research has shown that catheter ablation as a treatment for atrial fibrillation can improve outcomes in heart failure patients. It makes us think about the interrelationship among those different conditions because treating one has an effect on the outcomes of the other.”
Not only can treatments for atrial fibrillation have an effect on comorbidities, but the team’s findings show that treatments for comorbidities can also affect the severity of atrial fibrillation. Use of continuous positive airway pressure to treat sleep apnea was associated in a reduction in the progression of atrial fibrillation.
“The associations our team found suggest that if you can get a patient on all the GDMT for which they are eligible, they are likely to experience a better outcome,” Loring said.
Other DCRI contributors to this project include Peter Shrader, MA; Rosalia Blanco, MS; Karen Pieper, MS; Eric Peterson, MD; and Jonathan Piccini, MD, MHS.