Improved Aspirin Responsiveness in Obesity With Bariatric Surgery

HealthDay News — The effects of aspirin on platelet inhibition may be more potent after bariatric surgery, according to a study published online in Cardiovascular Therapeutics.

Nicholas B. Norgard, PharmD, from the University at Buffalo in New York, and colleagues administered two seven-day courses of 81 mg aspirin in 15 patients scheduled to undergo bariatric surgery. The courses were administered before surgery and 3 months after surgery. Before and after each aspirin course, they measured platelet aggregation. The change in on-treatment aspirin reactive units (ARUs) pre- and post-surgery was measured as the primary end point.

The researchers found that off-treatment ARU was significantly reduced post-bariatric surgery vs pre-surgery levels (602±59 vs 531±78; P =.035). After surgery there was also a significant reduction in on-aspirin platelet reactivity (469±60 vs 432±143; P =.03). The extent of weight loss was significantly correlated with the degree of improvement in on-aspirin platelet reactivity (r² = 0.49; P =.024). Compared with normal-weighted subjects, obese patients had significantly higher pre-surgery on-aspirin platelet reactivity (469±60 vs 419±52; P =.016), which was reduced to baseline after surgery (432±63 vs 419±52; P =.54).

“Aspirin-induced platelet inhibition may be more potent following bariatric surgery,” the authors write. “The mechanisms behind this improvement require further investigation.”

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Norgard NB, Monte SV, Fernandez SF, Ma Q. Aspirin responsiveness changes in obese patients following bariatric surgery [published online July 14, 2017]. Cardiovasc Ther. doi:10.1111/1755-5922.12268