Display Settings:


Send to:

Choose Destination
Circulation. 2011 Sep 6;124(10):1132-7. doi: 10.1161/CIRCULATIONAHA.111.029165. Epub 2011 Aug 29.

Platelet reactivity and cardiovascular outcomes after percutaneous coronary intervention: a time-dependent analysis of the Gauging Responsiveness with a VerifyNow P2Y12 assay: Impact on Thrombosis and Safety (GRAVITAS) trial.

Author information

  • 1Scripps Clinic and Scripps Translational Science Institute, La Jolla, CA, USA. price.matthew@scrippshealth.org



In the Gauging Responsiveness With A VerifyNow P2Y12 Assay: Impact on Thrombosis and Safety (GRAVITAS) trial, 6 months of high-dose clopidogrel did not reduce cardiovascular events compared with standard-dose clopidogrel in patients with high on-treatment platelet reactivity (OTR) after percutaneous coronary intervention, defined as OTR ≥230 P2Y12 reaction units according to the VerifyNow P2Y12 platelet function test. The aim of this analysis was to examine the relationship between outcomes and OTR over the course of the trial.


OTR was measured at 12 to 24 hours and 30±7 days after percutaneous coronary intervention. Cox proportional hazards models with OTR as a time-varying covariate were used to determine the association between OTR and the primary end point of cardiovascular death, myocardial infarction, and stent thrombosis. Of the 2800 enrolled patients, 2796 (99.98%) had evaluable platelet function data. OTR <208 P2Y12 reaction units was significantly associated with a lower risk of the primary end point at 60 days (hazard ratio, 0.18; 95% confidence interval, 0.04 to 0.79; P=0.02) and at 6 months (hazard ratio, 0.43; 95% confidence interval, 0.23 to 0.82; P=0.01). After adjustment for other significant predictors of outcome, OTR <208 P2Y12 reaction units remained independently associated with the primary end point at 60 days (hazard ratio, 0.23; 95% confidence interval, 0.05 to 0.98; P=0.047) and tended to be associated at 6 months (adjusted hazard ratio, 0.54; 95% confidence interval, 0.28 to 1.04; P=0.065).


In the GRAVITAS trial, achievement of on-clopidogrel reactivity <208 P2Y12 reaction units at 12 to 24 hours after percutaneous coronary intervention or during follow-up was associated with a lower risk for cardiovascular events. The efficacy of an individualized strategy to target a level of OTR below this threshold merits investigation. Clinical Trial Registration- http://www.clinicaltrials.gov. Unique identifier: NCT00645918.

Comment in

[PubMed - indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Write to the Help Desk