Ticagrelor enhances the cardioprotective effects of ischemic preconditioning in stable patients undergoing percutaneous coronary intervention: the TAPER-S randomized study

Background: Ticagrelor improves clinical outcomes in patients with acute coronary syndromes compared with clopidogrel. Ticagrelor also inhibits cell uptake of adenosine and has been associated with cardioprotective effects in animal models. We sought to investigate the potential cardioprotective effects of ticagrelor, as compared with clopidogrel, in stable patients undergoing percutaneous coronary intervention (PCI). Methods and results: This was a Prospective Randomized Open Blinded End-points (PROBE) trial enrolling stable patients with coronary artery disease (CAD) requiring fractional flow reserve-guided PCI of intermediate epicardial coronary lesions. ST-segment elevation at intracoronary electrocardiogram (IC-ECG) during a two-step sequential coronary balloon inflations in the reference vessel during PCI was used as an indirect marker of cardioprotection induced by ischemic preconditioning (IPC). The primary endpoint of the study was the comparison of the delta (Δ) (difference) ST-segment elevation measured by IC-ECG during two-step sequential coronary balloon inflations. Results: Fifty-three patients were randomized to either clopidogrel or ticagrelor. The study was stopped earlier because the primary endpoint was met at a pre-specified interim analysis. ΔST-segment elevation was significantly higher in ticagrelor as compared to clopidogrel arms (P < 0.0001). Ticagrelor was associated with lower angina score during coronary balloon inflations. There was no difference in coronary microvascular resistance between groups. Adenosine serum concentrations were increased in patients treated with ticagrelor as compared to those treated with clopidogrel. Conclusions: Ticagrelor enhances the cardioprotective effects of IPC compared with clopidogrel in stable patients with CAD undergoing PCI. Further studies are warranted to fully elucidate the mechanisms through which ticagrelor may exert cardioprotective effects in humans.