Increased Clopidogrel May Lower Events Post-PCI in Low Responders 

Key Points:

• VASP index could be useful marker for assessing risk for cardiac events after intervention.
By TCT Daily Staff

Repeated clopidogrel doses prior to PCI may safely and effectively lower the risk of adverse events after stenting in patients who are poor responders to the thienopyridine.

Laurent Bonello, MD, of Hopital Universitaire Nord, Marseille, France, said Monday that use of the vasodilator-stimulated phosphoprotein (VASP) index helped guide clinicians in increasing the loading dose of clopidogrel up to 2,400 mg, which resulted in a decreased rate of major adverse events without increased bleeding rates.

In their study, Bonello and colleagues randomized 162 patients with a VASP index >50% following an initial 600-mg clopidogrel loading dose to a treatment group that received up to three additional 600-mg doses, based on need, every 24 hours until the VASP index was lowered below the 50% threshold, or to a control group that received no additional antiplatelet therapy.

 At 30 days, the researchers reported no CV deaths, stent thromboses or revascularizations among the 78 patients receiving additional clopidogrel doses. In the control group, there was an increased risk for any event, which included two cardiovascular deaths (2%), four stent thromboses (5%), and two revascularizations (2%) — a total incident rate of 10% among the 84 patients in that group (P=.007).

In addition, each additional dose of clopidogrel lowered the number of patients with low response from 49% to 35%, Bonello reported. Eleven patients remained low responders despite a 2,400 mg dose of clopidogrel.

There was one major thrombolysis in myocardial infarction (TIMI) event in both groups. Two minor TIMI events (3%) were reported in the increased-loading dose group and three (4%) in the control group.

VASP-guided loading dose
Several studies have associated a VASP index lower than 50% with a high negative predictive value for stent thrombosis and MACE, said Bonello.