Preventive effect of an antiallergic drug,pemirolast potassium,on restenosis after stent placement: quantitative coronary angiography and intravascular ultrasound studies

OBJECTIVES: The preventive effect of pemirolast against restenosis after coronary stent placement was evaluated. METHODS: Eighty-four patients with 89 de novo lesions who underwent successful coronary stenting were assigned to the pemirolast group(40 patients, 45 lesions) and the control group(44 patients, 44 lesions). Administration of pemirolast(20 mg/day) was initiated from the next morning after stenting and continued for 6 months of follow-up. Quantitative coronary angiography was performed immediately after stenting and at follow-up. Angiographic restenosis was defined as diameter stenosis > or = 50% at follow-up. Intravascular ultrasound study conducted at follow-up angiography was used to measure vessel cross-sectional area(CSA), stent CSA, lumen CSA, neointima CSA(stent CSA--lumen CSA), and percentage neointima CSA(neointima CSA/stent CSA x 100%) at the minimal lumen site. RESULTS: There were no significant differences in baseline characteristics between the two groups. Restenosis rate was significantly lower in the pemirolast group than in the control group(15.0% vs 34.1% of patients, 13.3% vs 34.1% of lesions, p < 0.05, respectively). The intravascular ultrasound study at follow-up(36 lesions in the pemirolast group, 33 in the control group) found no significant differences in vessel CSA and stent CSA between the two groups(17.3 +/- 2.2 vs 16.8 +/- 2.4 mm2, 8.6 +/- 1.9 vs 8.4 +/- 1.7 mm2, respectively). However, lumen CSA was significantly larger in the pemirolast group than in the control group(5.5 +/- 1.3 vs 4.4 +/- 1.1 mm2, p < 0.05). Moreover, neointima CSA and percentage neointima CSA were significantly smaller in the pemirolast group(3.1 +/- 1.1 vs 4.0 +/- 1.2 mm2, p < 0.05 and 36.2 +/- 15.9% vs 47.4 +/- 15.6%, p < 0.01). CONCLUSIONS: Pemirolast has a preventive effect against restenosis after stent placement, possibly by inhibiting neointimal hyperplasia.