Sleep Apnea Associated with Worse Outcomes in Atrial Fibrillation

New data from the ORBIT-AF registry indicate that obstructive sleep apnea (OSA) increases the chance of hospitalization and major bleeding for people with atrial fibrillation (AF).

Researchers from Duke University’s Clinical Research Institute, whose findings were published in the Journal of the American College of Cardiology, studied 10,132 AF patients, comparing the 18% percent of patients who had OSA with the 82% who did not.

“OSA has been shown to be associated with the risk of developing AF,” the authors wrote. “However, the impact of OSA on outcomes for patients with AF in clinical practice in not well described.”

The researchers sought to remedy that by analyzing material from the Outcomes Registry for Better Informed Treatment of Atrial Fibrillation (ORBIT-AF), a US-based ambulatory AF registry that is funded by Janssen Scientific Affairs, LLC.

Of those with OSA, 641 were hospitalized at least once during the study period compared to 2,322 of the AF patients who did not have OSA.

That translates into 51 hospitalizations per 100 patient years in the OSA group vs. 40 hospitalizations per 100 patient years in the non-OSA group. The adjusted hazard ratio indicates a 15% greater hospitalization risk in the OSA group (95% CI: 1.05-1.26).

Patients with OSA suffered an even greater elevation of bleeding risk: the adjusted hazard ratio was 33% higher (95% CI: 1.03-1.72). Overall, the study period saw 85 major bleeds (or 5.5 per 100 patient years) in the OSA group and 273 (or 4.0 per 100 patient years) in the non-OSA group.

Despite the differences in hospitalization and bleeding, comparison of the OSA group and the non-OSA group found similar rates of death, AF progression and major adverse events aside from bleeding.

There were, however, other very significant differences between the groups — differences that researchers had to control for when calculating the risk of hospitalization and bleeding.

OSA patients were younger (69 vs. 76) and more likely to be male (69% vs. 55%) than their counterparts. They were also more likely to have co-morbidities such as heart failure (40% vs. 31%), hypertension (87% vs. 82%), and diabetes (42% vs. 27%). They were, moreover, more symptomatic and more likely to be on rhythm control (35% vs. 31%) and anticoagulation (79% vs. 75%) despite similar CHAD2 scores.

Further analysis of 1,624 OSA patients, which was orally presented at the American College of Cardiology’s recent annual meeting, showed that 937 (58%) used continuous positive airway pressure (CPAP) during a treatment for OSA.

Those patients had a 34% relative drop in the rate of AF progression compared to counterparts who did not use CPAP.

On other fronts — death, hospitalization, major bleeding and cardiovascular events — CPAP use was not associated with better outcomes, said the presenter, Duke University’s Jonathan P. Piccini, MD, MHS, FACC, FHRS.

Still, Piccini said, the findings on AF progression alone highlight the need for the further study of CPAP use and, quite probably, the need to screen AF patients more aggressively for signs of OSA and to encourage those with apnea to use CPAP as a tool for reducing total AF burden.