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The absorption of aspirin is reduced after coronary artery bypass grafting
Andreas Lund Hattesen1, Ivy Susanne Modrau2, Dorthe Viemose Nielsen3
1Department of Biochemistry, Centre for Haemophilia and Thrombosis, Aarhus University Hospital.
Insights
Patients undergoing coronary artery bypass grafting (CABG) show reduced aspirin absorption and effectiveness in the early postoperative period. This study investigated plasma salicylic acid (SA) levels to understand aspirin
Area of Science:
- Cardiovascular Surgery
- Pharmacology
- Clinical Medicine
Background:
- Coronary artery bypass grafting (CABG) patients may experience thromboembolic events despite aspirin treatment.
- The reduced aspirin effect post-CABG is not fully understood.
- Investigating aspirin absorption via plasma salicylic acid (SA) levels is crucial.
Purpose of the Study:
- To determine if aspirin absorption is reduced in patients after CABG.
- To measure plasma salicylic acid (SA) levels to assess aspirin absorption.
- To evaluate the antiplatelet effect of aspirin post-surgery.
Main Methods:
- 53 patients were studied between October 2015 and May 2018.
- Blood samples were collected pre-surgery, and on postoperative days 1 and 2.
- Plasma SA levels were measured using liquid chromatography-tandem-mass spectrometry; platelet aggregation was assessed using Multiplate Analyzer and VerifyNow Aspirin Test.
Main Results:
- Significantly reduced increase in plasma SA levels was observed on postoperative days 1 and 2 compared to pre-surgery.
- Aspirin's antiplatelet effect, measured by platelet aggregation, was significantly reduced on postoperative day 1.
- The reduced SA levels and aspirin effect persisted for several hours after aspirin intake post-CABG.
Conclusions:
- Aspirin absorption, indicated by plasma SA levels, is reduced in the early postoperative period after CABG.
- The antiplatelet effect of aspirin is diminished in patients immediately following CABG.
- These findings highlight a potential cause for early thromboembolic events in CABG patients.
Background:
Despite treatment with the antiplatelet drug aspirin, some patients who undergo coronary artery bypass grafting (CABG) experience a thromboembolic event in the early postoperative period. The etiology of a reduced aspirin effect after CABG is still unsolved. Hence, we investigated whether patients who undergo CABG have a reduced absorption of aspirin after surgery, measured as levels of plasma salicylic acid (SA).
Methods:
In total, 53 patients were included between October 2015 and May 2018. Blood samples where obtained at the day before surgery, and at the first (day 1) and second (day 2) postoperative day. A subgroup of 10 patients had additional blood samples obtained on day 1. Plasma SA was measured using liquid chromatography-electrospray-ionization tandem-mass spectrometry. Multiplate Analyzer (Roche, Roche Diagnostics, Mannheim, Germany) and VerifyNow Aspirin Test (Accumetrics, San Diego, Calif) were used to assess platelet aggregation as a measurement of the antiplatelet effect of aspirin.
Results:
A comparison of the difference in change of SA concentration between the day before surgery with day 1 and day 2 showed a significantly reduced increase in SA plasma levels after intake of aspirin at day 1 and day 2 after surgery (P < .0001), including a significantly reduced SA increase in the subgroup at 2, 3, and 4 hours after intake of aspirin. Corresponding with a reduced effect of aspirin, neither Multiplate Analyzer arachidonic acid, nor VerifyNow Aspirin Test showed a significant reduction in platelet aggregation 1 hour after intake of aspirin at day 1 (P < .0001). This also accounted for the subgroup 2, 3, and 4 hours after aspirin intake on day 1. At day 2 the same pattern as preoperatively was detected.
Conclusions:
After CABG, the SA level and the effect of aspirin were reduced in the immediate postoperative period.
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