Monitoring Platelet Reactivity in Patients Treated with Prasugrel or Ticagrelor Prior to an Urgent Coronary Artery Bypass Surgery in Order to Shorten Operation Delay

Background: Prasugrel and ticagrelor are potent platelet ADP receptor inhibitors indicated for the treatment of acute myocardial infarction (AMI). Some of the patients pre-treated with these drugs may require urgent coronary artery bypass grafting (CABG). We hypothesized that by sequential platelet reactivity monitoring the operation delay may be shortened from the guideline-recommended 5-7 days, without increasing the risk of bleeding.

Aim: To monitor pre-operative platelet function in patients with AMI pre-treated with prasugrel or ticagrelor.

Methods: We performed pre-operative platelet function tests in 37 patients with AMI (ST elevation and non-ST elevation MI) on prasugrel (59.5%) or ticagrelor (40.5%) who were planned to undergo urgent CABG. When the level of platelet inhibition, as measured by the VerifyNow test, was reduced to ≤40% inhibition, surgery was endorsed. Bleeding associated parameters were collected.

Results: Platelet function test results are presented in Figure 1. Based on platelet function results, a shorter operation delay than guideline- recommended was employed in 21 (56.7%) patients with an average time of 2.6±1.0 days for ticagrelor and 3.8±1.5 days for prasugrel. There were no significant differences in the bleeding parameters (including lowest Hg count, Hg drop, 24 hours chest tube output and average number of packed RBC per patient-Table 1) between patients with short washout period and those with the recommended washout period. However, more patients required packed RBC transfusion in the shortened washout group (61.9% vs 28.6% respectively, P=0.05). None of the patients required re-operation due to bleeding complications.

Conclusions: A strategy of preoperative point-of-care assay for platelet function can identify subjects who may recover platelet function prior to 5-7 days after discontinuation of prasugrel or ticagrelor and may allow to perform CABG at an earlier interval than recommended with reasonable bleeding risk. Further larger studies are required to establish these findings.