Abstract 4307: Diabetes Mellitus is Associated With Inadequate Platelet Inhibition After Clopidogrel and With Poorer Peri-procedural Outcome in Patients Undergoing Percutaneous Coronary Intervention
Background. Diabetes mellitus (DM) is associated with high platelet reactivity and impaired response to clopidogrel. A threshold of platelet reactivity ≥240 P2Y12 reaction units (PRU) after clopidogrel loading, as measured by the VerifyNow assay, is associated with a significantly higher risk of peri-procedural myocardial infarction (MI) in patients undergoing percutaneous coronary intervention (PCI). In this study we prospectively evaluated the influence of diabetes mellitus on residual platelet reactivity after clopidogrel administration and peri-procedural outcome after PCI.
Methods. A total of 285 patients (104 diabetics, 36%) receiving clopidogrel and undergoing PCI were prospectively enrolled. Platelet reactivity was measured before intervention and after 8 and 24 hours by the VerifyNow P2Y12 assay. Cardiac biomarkers levels also were measured at the same time-points.
Results. Diabetic patients showed higher platelet reactivity by PRU values (214±83 vs. 193±68 in patients without DM; p=0.02). A PRU value ≥240 was more frequently observed in patients with DM than in non-diabetic patients (36% vs. 22%; p=0.01). Patients with pre-procedural PRU levels in the fourth quartile had a higher prevalence of DM (47% vs. 33% in quartiles 1 to 3; p=0.04). Peri-procedural MI incidence was higher in diabetic patients (11% vs 4% in those without DM; p=0.04). Among patients with DM, a PRU value ≥240 was associated with higher incidence of peri-procedural MI (22% vs 5% in those with PRU <240; p=0.10). Considering the presence of DM and a PRU value <240 in the whole population, patients presenting both these factors showed the highest incidence of peri-pricedural MI (p for trend <0.01).
Conclusions. DM is associated with impaired platelet response to clopidogrel, as assessed by a point-of-care assay, and poorer peri-procedural outcome in patients undergoing PCI. In patients with DM more aggressive antithrombotic strategies may be indicated in order to reduce peri-procedural complications in the setting of PCI.