Platelet Inhibition with Ticagrelor versus Clopidogrel in Diabetic Patients after Percutaneous Coronary Intervention for Chronic Coronary Syndromes.

Background:  Clopidogrel is currently the only P2Y inhibitor with class I recommendation in patients after percutaneous coronary intervention (PCI) for chronic coronary syndromes (CCS). Diabetic patients have reduced therapeutic response to clopidogrel.

Purpose:  This study assessed the antiplatelet effect of ticagrelor versus clopidogrel in diabetic patients after recent PCI for CCS.

Methods:  Eligible patients were randomly assigned to receive ticagrelor 90 mg twice daily or clopidogrel 75 mg once daily, in addition to aspirin 100 mg once daily for 15 days. P2Y reaction unit (PRU) and percent inhibition were measured by VerifyNow P2Y assay. High on-treatment platelet reactivity (HOPR) was defined as PRU > 208. Bleeding was assessed by the Platelet Inhibition and Patient Outcomes criteria. Cardiac ischemic events were evaluated as adverse events.

Results:  The baseline characteristics of the patients ( = 39) were well balanced between the two groups. Both before and 2 to 4 hours after the final study dose on day 15, PRU was lower (41.3 ± 35.8 vs. 192.6 ± 49.5,  < 0.001; 36.6 ± 25.8 vs. 187.6 ± 70.9,  < 0.001), percent inhibition was higher (83.0% [70.5%, 96.0%] vs. 16.0% [0%, 25.0%],  < 0.001; 85.0% [76.0%, 96.5%] vs. 25.0% [0%, 39.0%],  < 0.001), and HOPR occurred less frequently (0% [0/20] vs. 26.3% [5/19],  = 0.020; 0% [0/20] vs. 31.6% [6/19],  = 0.008) in the ticagrelor group ( = 20) compared with the clopidogrel group ( = 19). No major or minor bleeding, or serious adverse events occurred in both groups.

Conclusion:  Ticagrelor achieved greater peak and trough platelet inhibition than did clopidogrel in diabetic patients after recent PCI for CCS, which suggests the potential use of ticagrelor in this clinical setting.