Effects of cigarette smoking on platelet reactivity during P2Y12 inhibition in patients with myocardial infarction undergoing drug-eluting stent implantation: results from the prospective cigarette smoking on platelet reactivity (COPTER) study.

Interaction between cigarette smoking and efficacy of oral antiplatelet drugs is not definitely elucidated. We evaluated the effects of cigarette smoking on platelet reactivity in patients receiving different oral P2Y12 antagonists after myocardial infarction (MI) and drug-eluting stent (DES) implantation. Two-hundred-five consecutive current smokers receiving DES implantation after ST-segment elevation MI were enrolled. All patients were aspirin-treated and were on chronic therapy with clopidogrel (N = 59), prasugrel (N = 71) or ticagrelor (N = 75); by protocol, all patients at baseline had no high on-treatment platelet reactivity by the VerifyNow P2Y12 assay. Platelet reactivity, expressed by P2Y12 reaction units (PRU), was measured in all patients at baseline (T0), after a 15-day period of smoking cessation (T1) and after further 15 days of smoking resumption (T2). In the overall population there was a modest, albeit significant, reduction of PRU values from T0 to T1 (from 173 ± 14 to 165 ± 17, P < 0.0001); resumption of cigarette smoking was associated with re-increase of platelet reactivity (from 165 ± 17 at T1 to 170 ± 17 at T2, P = 0.0002). These variations were consistent in the subgroups receiving clopidogrel, prasugrel or ticagrelor and were irrespective of the number of cigarettes smoked. In conclusion, cigarette smoking weakly influences antiplatelet effects of oral P2Y12 inhibition and this was irrespective of the type of antiplatelet agent; thus, interaction between cigarette smoking and efficacy of oral antiplatelet drugs is modest and unlikely translates into clinical effects (ClinicalTrials.gov Identifier: NCT02026713).