Randomized Angiographic and Intravascular Ultrasound Comparison of Dual-Antiplatelet Therapy vs Triple-Antiplatelet Therapy to Reduce Neointimal Tissue Proliferation in Diabetic Patients

Abstract

Background: Previous studies have suggested a benefit of cilostazol in addition to standard dual-antiplatelet therapy (DAPT), reducing in-stent late luminal loss and restenosis after percutaneous coronary intervention (PCI) with bare-metal and drug-eluting stent (DES) implantation. However, there is a paucity of intravascular ultrasound (IVUS) assessment of neointimal tissue hyperplasia (NIH) after triple-antiplatelet therapy (TAPT), especially in diabetic patients treated with DES.

Methods: This prospective, placebo-controlled trial was conducted in diabetic patients randomized (1:1) to receive either standard DAPT (aspirin and clopidogrel) vs TAPT with cilostazol for a minimum of 12 months after PCI with Endeavor zotarolimus-eluting stent (E-ZES). The primary endpoint was the 9-month comparison of percentage of NIH in both groups. Additionally, we compared in-stent late lumen loss, binary restenosis, major adverse cardiac event (MACE; cardiac death, non-fatal myocardial infarction, and restenosis) rates, and the incidence of vascular/bleeding complications.

Results: In total, 133 diabetic patients were enrolled (cilostazol cohort = 65 patients) with 56.4% male and mean age of 60.8 years. Overall, the two cohorts were comparable in terms of baseline clinical and angiographic characteristics, except for the reference vessel diameter, which was smaller among patients randomized to cilostazol (2.48 ± 0.46 mm vs 2.69 ± 0.48 mm; P=.01). At 9 months, there was a non-significant trend toward less percentage of NIH obstruction in the TAPT cohort (33.2 ± 8.29% vs 35.1 ± 8.45%; P=.07). However, this finding did not impact angiographic late-lumen loss (0.60 ± 0.46 mm cilostazol group vs 0.64 ± 0.48 mm control group; P=.30) and binary restenosis (9.8% vs 6.8%; P=.99). MACE rate also did not significantly differ between the cohorts (13.8% cilostazol group vs 8.8% control group; P=.81). Of note, the addition of a third antiplatelet agent did not increase vascular and bleeding complications.

Conclusion: In diabetic patients treated with E-ZES, TAPT with cilostazol did not add any significant benefit in terms of NIH suppression or MACE reduction.