This article is more than 5 years old. Information may no longer be current.
Late ischemic events post-stenting tied to clopidogrel response
High platelet reactivity on clopidogrel after successful drug-eluting stent implantation was associated with increased rates of stent thrombosis and MI and reduced bleeding at 2 years, while high platelet reactivity on aspirin was infrequent and not associated with any ischemic or bleeding events, according to new 2-year data from the ADAPT-DES registry.
Of all 8,582 patients treated with dual antiplatelet therapy for at least 1 year, 42.7% had high platelet reactivity on clopidogrel, defined as P2Y12 reaction units (PRU) greater than 208, and 5.6% had high platelet reactivity on aspirin, defined as aspirin reactivity units (ARU) greater than 550. Platelet reactivity was measured using the VerifyNow P2Y12 and Aspirin assays (Accumetrics).
In the entire ADAPT-DES registry population, within 2 years, stent thrombosis occurred in 1.07%, MI in 4.8%, clinically relevant bleeding in 8.6% and all-cause mortality in 3.9%.
In unadjusted and propensity-adjusted models, high platelet reactivity was associated with increased 2-year risk for definite or probable stent thrombosis (adjusted HR = 1.87; 95% CI, 1.19-2.96) and MI (adjusted HR = 1.33; 95% CI, 1.06-1.66) and was inversely associated with clinically relevant bleeding (adjusted HR = 0.79; 95% CI, 0.67-0.93). The researchers also noted a nonsignificant trend toward increased all-cause mortality with high platelet reactivity on clopidogrel.
Additionally, in high-risk patients who continued on DAPT to 2 years or until an event occurred, results from a propensity-adjusted multivariable model showed that high platelet reactivity on clopidogrel was independently linked to increased risks for definite or probable stent thrombosis (adjusted HR = 2.16; 95% CI, 1.27-3.67), MI (adjusted HR = 1.35; 95% CI, 1.05-1.74), all-cause mortality (adjusted HR = 1.36; 95% CI, 1.01-1.85) and MACE, defined as a cumulative incidence of cardiac death, MI or definite or probable stent thrombosis (adjusted HR = 1.38; 95% CI, 1.06-1.63). High platelet reactivity on clopidogrel was also inversely associated with freedom from clinically relevant bleeding (adjusted HR = 0.74; 95% CI, 0.62-0.9).
However, in patients who continued on DAPT to 2 years or until an event occurred, “the majority of adverse events in patients on continuous DAPT through 2 years occurred in the first year, and stent thrombosis, MI, clinically relevant bleeding and death between years 1 and 2 were not significantly associated with high platelet reactivity on clopidogrel,” Thomas D. Stuckey, MD, from LeBauer Cardiovascular Research Foundation/Cone Health, Greensboro, North Carolina, and colleagues wrote in JACC: Cardiovascular Interventions.
High platelet reactivity on aspirin was rare and did not correlate with early, late or very late stent thrombosis or ischemic or bleeding events.
“Further studies are required to establish whether a long-term relationship exists between [high platelet reactivity] on clopidogrel, individualized patient selection for DAPT, and all-cause mortality, and whether further information might be provided by repeat platelet function testing at 1 year,” the researchers wrote. The overall low rate of events between years 1 and 2 in this large-scale registry in which long-term DAPT decisions were made based on clinical risk features and other real-world variables supports an individualized strategy to long-term DAPT decision-making.”– by Melissa Foster
Disclosures: The ADAPT-DES study was sponsored by the Cardiovascular Research Foundation, with funding provided by Abbott Vascular, Accumetrics, Biosensors, Boston Scientific, Cordis, Daiichi Sankyo, Eli Lilly, Medtronic, The Medicines Company and Volcano. Please see the full study for a list of the authors’ relevant financial disclosures.