PB0876 - Platelet function testing and timing of bypass surgery - A platelet function sub-study from the RAPID CABG randomized trial

Monday, July 11, 2022

6:30 PM – 7:30 PM

Location: Exhibition

Presentation Format: In-Person

Presenting Author(s)

Marie Lordkipanidzé, B.Pharm, PhD

Associate professor
Faculty of pharmacy, University of Montreal
Montreal, Quebec, Canada

Co-Author(s)

GW

George Wells

Director of Cardiovascular Methods Centre
University of Ottawa Heart Institute
Ottawa, Ontario, Canada
ML

Michel Le May

Co-investigator
University of Ottawa Heart Institute
Ottawa, Ontario, Canada
FR

Fraser Rubens

Co-investigator
University of Ottawa Heart Institute
Ottawa, Ontario, Canada
LC

Li Chen

Co-investigator
University of Ottawa Heart Institute
Ottawa, Ontario, Canada
MR

Marc Ruel

Co-investigator
University of Ottawa Heart Institute
Ottawa, Ontario, Canada
AC

Aun Yeong Chong

Co-investigator
University of Ottawa Heart Institute
Ottawa, Ontario, Canada
MW

Mélanie Welman

Research associate
Montreal Heart Institute
Montreal, Quebec, Canada
LP

Louis Perrault

Co-investigator
Montreal Heart Institute
Montreal, Quebec, Canada
VC

Vincent Chan

Co-investigator
University of Ottawa Heart Institute
Ottawa, Ontario, Canada
JT

Jean-François Tanguay

Co-PI
Montreal Heart Institute
Montreal, Quebec, Canada
DS

Derek So

Co-PI
University of Ottawa Heart Institute
Ottawa, Ontario, Canada

Background: The RAPID CABG (NCT02668562) randomized trial demonstrated early coronary artery bypass surgery (CABG), 2-3 days after ticagrelor cessation, was non-inferior in incurring perioperative bleeding compared to waiting 5-7 days. Platelet function testing has been proposed as a tool to guide timing to surgery. In this pre-specified platelet function sub-study, we evaluate perioperative platelet function as a determinant of bleeding.

Aims: To assess whether pharmacodyamic measurement of platelet function following ticagrelor cessation is a predictor of bleeding and ischemic outcomes.

Methods: Patients with acute coronary syndromes and requiring CABG were randomly assigned to early surgery, 2-3 days after ticagrelor cessation, vs standard delay of 5-7 days. Platelet function was measured using the VerifyNow P2Y12 assay before, immediately after and at 24, 48 and 72 hours post-CABG. The primary outcome was bleeding, defined as class 3 or 4 (severe and massive) universal definition of peri-operative bleeding (UDPB). Secondary outcomes included: other bleeding outcomes (BARC type 4, TIMI CABG-related bleeding, cardiac tamponade) and ischemic outcomes (CV death, stroke, myocardial infarction, refractory ischemia, urgent unplanned revascularization).

Results: In the per-protocol population, platelet function measures were available in 60/65 patients in the early group and 54/58 in the delayed group. At all perioperative time points, the delayed group had significantly higher platelet reactivity (Figure A). Proportion of patients with low platelet reactivity (LPR - defined by PRU < 85, a correlate to increased bleeding risk), was similar in the early (5%) vs. delayed (1.9%) groups (p=0.62). A higher proportion had high platelet reactivity (HPR, defined as PRU>208) in the delayed (89%) vs. the early (45%) group at time of surgery (p < 0.001). Preoperative platelet reactivity was not associated with blood loss (Figure B). Correlation to other bleeding and ischemic outcomes will be presented.

Conclusion(s): Platelet function recovery after ticagrelor cessation followed expected pharmacokinetics, but did not predict perioperative bleeding.