Platelet inhibition with ticagrelor versus clopidogrel in Hispanic patients with stable coronary artery disease with or without diabetes mellitus

BACKGROUND/PURPOSE: Diabetes mellitus (DM) disproportionately affects Hispanic patients. DM patients have enhanced platelet reactivity and reduced sensitivity to clopidogrel. Ticagrelor demonstrated a more rapid onset and greater magnitude of platelet inhibition than clopidogrel in Hispanic patients with stable coronary artery disease (CAD). This subgroup analysis examined the onset and level of platelet inhibition of ticagrelor and clopidogrel in Hispanic patients with DM. METHODS/MATERIALS: This was a subgroup analysis of a randomized, open-label, crossover study in which 40 Hispanic patients with stable CAD received ticagrelor 180 mg loading dose (LD)/90 mg twice-daily maintenance dose (MD) then clopidogrel 600 mg LD/75 mg once-daily MD, or vice versa. The primary end point was on-treatment platelet reactivity at 2 hours post-LD using the VerifyNow™ P2Y12 test. RESULTS: 21 patients had DM and 19 were non-diabetic. At 2 hours post-LD, mean platelet reactivity in the diabetic group was 34.5 PRU with ticagrelor versus 219.3 PRU with clopidogrel (P<0.001), and in the non-diabetic group was 33.7 PRU with ticagrelor versus 181.0 PRU with clopidogrel (P<0.001). In both diabetic and non-diabetic subgroups, mean platelet reactivity declined to a significantly greater extent with ticagrelor than clopidogrel at all time points evaluated (0.5, 2, and 8 hours post LD and after 7-9 days of MD). Patients were significantly more likely to have high on-treatment platelet reactivity (≥208 PRU) during treatment with clopidogrel compared with ticagrelor, regardless of diabetic status. CONCLUSIONS: Among Hispanic patients with stable CAD, ticagrelor achieves a faster onset and greater magnitude of platelet inhibition compared with clopidogrel, irrespective of diabetic status.