Management of non ST-elevation acute coronary syndrome (NSTEACS) patients in New Zealand (NZ): A longitudinal analysis. Results from the NZACS national audits of 2002, 2007 and 2012

Background: Current guidelines recommend ceasing ticagrelor 5 days pre-operatively. A half-life of 14 hours and a twice-daily dosing regimen suggests this is longer than necessary for resumption of platelet function.We report the time course of platelet function following ticagrelor cessation in patients presenting with acute coronary syndrome (ACS) referred for surgical revascularisation. Methods: A prospective pilot study of ACS patients at Waikato Hospital who were commenced on ticagrelor and referred for coronary artery bypass graft surgery post angiography. Ticagrelor was discontinued immediately after angiography and platelet function was assessed immediately and then daily with the VERIFY-NOW assay. Percentage (%) platelet inhibition was assessed and the time to return to normal (<20%) was plotted. Results: 10 patients who received aspirin and ticagrelor were recruited. The mean patient age was 60 years (50-64) with 70% male. 60% of patients were diabetic. The indication for angiography was Non ST-elevation MI in 80% and Unstable angina in 20%. Indication for surgical revascularisation was triple vessel disease in 90% and extensive LADdisease in 10%. The time course of platelet function is shown for all. The majority had high platelet inhibition prior to discontinuation with platelet function normalising by day 2 (p < 0.0001). 90% of patients had less than 20% residual platelet inhibition at 48 hours with no significant rebound noted at 5 days. Conclusions: This pilot study demonstrates that discontinuation of ticagrelor results in recovery of platelet function within 2 days. Larger confirmation studies may result in shorter surgical waiting times for ACS patients.