Absence of differential effect of ticagrelor versus prasugrel maintenance dose on endothelial function in patients with stable coronary artery disease.

Endothelial function may be improved by ticagrelor, through adenosine-mediated mechanisms. We aimed to assess the effect of ticagrelor vs prasugrel on endothelial function in patients with stable coronary artery disease (CAD).In a prospective, randomized, crossover study, 22 stable CAD patients under prasugrel 10mg once daily maintenance dose (MD) for at least 3 months, were randomized to either ticagrelor 90 mg twice daily or prasugrel 10 mg once daily for 15 days with a direct treatment-crossover for another 15 days. Endothelial function was assessed by peripheral arterial tonometry (EndoPAT 2000 system, Itamar Medical, Caesarea, Israel) at Day 0 (randomization), Day 15 and Day 30. Reactive Hyperemia Index (RHI) was calculated by automated software and endothelial dysfunction (ED) was defined as RHI<1.67. RHI at the end of the 2 treatment periods did not differ between ticagrelor and prasugrel: Least squares estimates (95% confidence interval) 1.78 (1.58-1.99) vs 1.88 (1.67-2.08), with a fixed estimate of -0.099 (95% CI -0.45 to 0.25) for the difference between them, p=0.5. ED rate did not differ significantly between ticagrelor and prasugrel: 45.5% vs 45.5%, p=0.6.In CAD patients we have failed to find evidence of alteration of endothelial function following ticagrelor compared to prasugrel MD treatment, as assessed with peripheral arterial tonometry. CLINICALTRIALS.NCT01957540.