Background: The optimal antiplatelet regimen in elective patients undergoing complex percutaneous coronary interventions (PCIs) is uncertain. We aimed to assess the impact of glycoprotein IIb/IIIa (GpIIb/IIIa) inhibition with eptifibatide in clinically stable subjects with diffuse coronary lesions.
Methods: Patients with stable coronary artery disease undergoing PCI by means of implantation of >33 mm of drug-eluting stent were single-blindedly randomized to heparin plus eptifibatide versus heparin alone. The primary end point was the rate of abnormal post-PCI creatine kinase-MB mass values. Secondary end points were major adverse cardiovascular events (MACEs) (ie, cardiac death, myocardial infarction, or urgent revascularization) and MACE plus bailout GpIIb/IIIa inhibitor use.
Results: The study was stopped for slow enrollment and funding issues after including a total of 91 patients: 44 were randomized to heparin plus eptifibatide, and 47, to heparin alone. Analysis for the primary end point showed a trend toward lower rates of abnormal post-PCI creatine kinase-MB mass values in the heparin-plus-eptifibatide group (18 [41%]) versus the heparin-alone group (26 [55%], relative risk 0.74 [95% CI 0.48-1.15], P = .169). Similar nonstatistically significant trends were found for rates of MACE, their components, or MACE plus bailout GpIIb/IIIa inhibitors (all P > .05). Notably, heparin plus eptifibatide proved remarkably safe because major bleedings or minor bleeding was uncommon and nonsignificantly different in both groups (all P > .05).
Conclusions: Given its lack of statistical power, the INSTANT study cannot definitively provide evidence against or in favor of routine eptifibatide administration in stable patients undergoing implantation of multiple drug-eluting stent for diffuse coronary disease. However, the favorable trend evident for the primary end point warrants further larger randomized studies.
Trial registration: ClinicalTrials.gov NCT01454440.
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