Conference Coverage

Aspirin responsiveness improved in some with OSA


Key clinical point: OSA patients with endothelial dysfunction demonstrated aspirin responsiveness after using CPAP therapy.

Major finding: The average aspirin reaction units reading for patients who had endothelial dysfunction at baseline was 520 following therapy.

Data source: A prospective cohort study of 18 patients with newly diagnosed moderate to severe OSA.

Disclosures: The study’s authors reported no conflicts of interest.



Obstructive sleep apnea patients with endothelial dysfunction gained aspirin responsiveness after using continuous positive airway pressure (CPAP) therapy, according to the findings from a small study scheduled to be presented at CHEST 2017.

“Endothelial dysfunction is an important phenomenon implicated in cardiovascular morbidity in obstructive sleep apnea (OSA) patients. While it has been demonstrated that CPAP improves endothelial function, our understanding of the pathophysiologic links between CPAP therapy and cardiovascular outcomes remain limited,” researchers wrote in the study’s abstract.

The researchers examined 18 patients’ endothelial function before and after using CPAP therapy for a median of 37 days, along with the relationship between endothelial function and aspirin responsiveness in these same patients. All study participants had been recently diagnosed with moderate to severe OSA and underwent modified peripheral artery tonometry and platelet aggregometry before and after beginning CPAP therapy. Most of the patients (14) demonstrated aspirin resistance at baseline.

Endothelial dysfunction was defined as having a reactive hyperemia index (RHI) of less than or equal to 1.67, while aspirin resistance was defined as having a reading of at least 550 aspirin reaction units (ARU).

At baseline, the average RHI of patients was 1.79 (standard deviation = 0.3), with 8 of the patients having had endothelial dysfunction. Following CPAP use, patients’ mean RHI increased to 1.94 (SD = 0.36), and endothelial dysfunction was present in just 5 of the study participants.*

After using CPAP, those patients with endothelial dysfunction at baseline were responsive to aspirin, with their average ARU reading at 520 following therapy. In contrast, those patients with normal endothelial function at baseline remained resistant to aspirin following CPAP use, based on mean ARU values before and after therapy.

Lirim Krveshi, DO, of Danbury (Conn.) Hospital, is scheduled to present this study, “A Prospective Cohort Study of Endothelial Function and its Relationship to Aspirin Responsiveness in OSA Patients,” on Sunday, Oct. 29, at 1:45 p.m. in Convention Center, room 601A. This presentation is part of the Obstructive Sleep Apnea: Insights & Management session, running from 1:30 p.m. to 3:00 p.m.

The study’s authors reported no conflicts of interest.

*This article was updated Oct. 27, 2017.

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