Abstract 371: High On-Treatment Residual Platelet Reactivity Post--Percutaneous Coronary Intervention in Patients Loaded with High-Dose Clopidogrel: Impact of Diabetes, Age, African-American Race and Presentation Acuity on Antiplatelet Hyporesponse
Background: High residual platelet reactivity (HRPR) on clopidogrel is variably defined and linked with factors such as age, race, genetics and diabetes (DM). We investigated the prevalence of HRPR and validated its link to reported risk factors in a high-risk PCI population using published definitions.
Methods: 127 PCI pts had prospective platelet inhibition testing via the Accumetrics VerifyNow P2Y12 platform, 24 hrs post-600 mg clopidogrel po. Inhibition of platelet aggregation (IPA) and residual platelet reactivity (P2Y12-reactivity units, PRU) were analyzed on continuous and dichotomous scales with varying data-supported cutoff values: PRU<230, <208; IPA<10%. Predictors of HRPR were analyzed.
Results: In 127 pts (age 64 ± 11, DM 50.4%, male 63.7%) mean PRU was 198.0 ± 107 (39.3% ± 30.2% IPA). Using cutoffs of PRU > 230, PRU > 208 and IPA < 10%, HRPR was seen in 42.5%, 48.0% and 24.4% of pts respectively. (Fig 1) DM (220 +/-114.3 vs 177+/-97, P=0.022) and age > 65 yrs (177+ 107 vs 219 + 106, P=0.028) were predictive of high residual platelet reactivity (HRPR) and increasing age was continuously correlated with HRPR (r=0.184, p=0.038). 70.1% of pts were African American (AA) and 34.6% presented with STEMI/ACS but neither factor correlated with HRPR.
Conclusions: HRPR on clopidogrel was highly prevalent post-PCI but with great variability based on definition. DM and older age were linked with HRPR but several other risk factors. These data suggest limited predictability of HRPR based on published metrics of risk.
- © 2012 by American Heart Association, Inc.