We read with interest the report by Quadros et al “Identifying Patients at Risk for Premature Discontinuation of Thienopyridine After Coronary Stent Implantation.” In their elegant study, the investigators identified risk factors for nonadherence to thienopyridine after coronary stenting and confirmed previous studies showing the negative impact of poor socioeconomic conditions on patient adherence. Indeed, nonadherence is a major pitfall of coronary intervention, and premature discontinuation of antiplatelet therapy has been identified as the greatest risk factor for stent thrombosis. In their study, the investigators used a self-reported measure of adherence based on face-to-face interviews with physicians, which may tend to overestimate true adherence to treatment because of social desirability bias. In effect, in a previous study using platelet function test and controlled intake to identify nonadherent patients, it was shown that self-reported adherence on the basis of interviews is not sensitive enough to detect nonadherence behaviors. Indeed, self-reported adherence through face-to-face interviews identified as nonadherent 6% patients in the study sample, whereas 14% patients were “screened” as nonadherent using platelet testing and controlled intake. Previous studies of “resistance” used also verbal confirmation that patients were actually taking aspirin. Therefore, platelet testing might be a helpful tool for the early detection of patient adherence to antiplatelet therapy. This assessment is linearly related to adherence levels in case of a homogenous degree of response, such as aspirin response as assessed with aggregometry, but it is inadequate with drug such as clopidogrel, characterized by a large variability of response even in adherent patients. Therefore, it could not be used in this study. It is noteworthy that the forthcoming advent of P2Y ₁₂ blockers will allow the use of platelet testing as a sensitive measure to detect less adherent patients. We completely agree with Quadros et al about “the need that health professionals recognize adherence problems” and appropriately detect them as early as possible, especially with this new class of drugs, which is likely to cause more nuisance bleeding and potentially increase the risk for nonadherence.