Center Variation in Use of Preoperative Dual Antiplatelet Therapy and Platelet Function Testing at the Time of Coronary Artery Bypass Grafting in Maryland

Abstract

BACKGROUND: Patients presenting with acute coronary syndrome are administered a P2Y 12 inhibitor and aspirin before coronary catheterization to prevent further myocardial injury from thrombosis. Guidelines recommend a standard waiting period between the time patients are administered dual antiplatelet therapy (DAPT) and elective cardiac surgery. Since 25% to 30% of the population may be considered nonresponders to clopidogrel, platelet function testing can be utilized for timing of surgery and to assess bleeding risks. The extent to which a standard waiting period or platelet function testing is used across centers is not established, representing an important opportunity to standardize practice. METHODS: We conducted a retrospective cohort study from 2011 to 2020 using data from the Maryland Cardiac Surgical Quality Initiative, a consortium of all 10 hospitals in the state performing cardiac surgery. The proportion of patients administered DAPT within 5 days of surgery was examined by hospital over the time period. Mixed-effects multivariable logistic regressions were used to examine the association of preoperative DAPT with ischemic and bleeding outcomes. Centers were surveyed on use or nonuse of preoperative platelet function testing, and bleeding outcomes were compared. RESULTS: There was significant heterogeneity of preoperative DAPT usage across centers ranging from 2% to 54% (P < .001). DAPT within 5 days of isolated coronary artery bypass grafting (CABG) was associated with higher odds of reoperation for bleeding (odds ratio [OR], 1.55; 95% confidence interval [CI], 1.19-2.01; P = .001), >2 units of red blood cells (RBCs) transfused (OR, 1.62; 95% CI, 1.44-1.81; P < .001), and >2 units of non-RBCs transfused (OR, 1.79; 95% CI, 1.60-2.00; P < .001). In the 5 hospitals using preoperative platelet function testing to guide timing of surgery, there were greater odds for DAPT within 5 days (OR, 1.33; 95% CI, 1.22-1.45; P < .001), fewer RBCs >2 units transfusions (22% vs 33%; P < .001), and non-RBCs >2 units (17% vs 28%; P < .001) transfusions within DAPT patients. CONCLUSIONS: There is significant variability in DAPT usage within 5 days of CABG between hospital centers. Preoperative platelet function testing may allow for earlier timing of surgery for those on DAPT without increased bleeding risks.

In Response

“…W e thank Butt et al 1 for their comments regarding our manuscript. 2 We concur as to the limitations of the Society of Thoracic Surgeons classification of preoperative P2Y12 use, both regarding the lack of data on specific drug used and the exact timing of drug. Understanding both of these exposures are key next steps to advancing this line of inquiry.…”

What Is the Best Monitoring Strategy for Platelet Function: Aggregability Count or Elasticity?

“…Finally, Hensley et al 4 recently reported the association between preoperative platelet function testing and reduced blood product usage in cardiac surgery. Although adenosine diphosphate (ADP) aggregometry is not widely used intraoperatively, multimodal blood conservation is as important as preoperative platelet function testing in high-risk patients on P2Y 12 inhibitors.…”

In Response

“…5. The authors quote a study from Hensley et al 6 demonstrating an association between the preoperative use of PFT and reduced blood product usage in cardiac surgery. Although interesting, this study has little to do with our study: it is confirmative of the concept that, whenever feasible and appropriate, preoperative PFT may be useful (a concept already included in many existing guidelines).…”