Late Clinical Outcome after Intracoronary Palmaz-Schatz Stenting with High Pressure Balloon Dilatation without Anticoagulation

ABSTRACT

BACKGROUND: The intracoronary stent implantation is accepted as the treatment modality to reduce restenosis in comparison with balloon angioplasty in patients with coronary artery disease. In recent studies, the technique of high pressure balloon dilation for stent optimization has been shown to improve procedural success and to reduce the subacute closure after stenting. The late clinical outcome, however, is still uncertain after stenting with high pressure balloon dilation. Therefore, we evaluated the effect of high pressure balloon dilation on subsequent clinical courses after intracoronary stenting. METHOD: One hundred sixty nine patients with 176 lesions were treated with Palmaz-Schatz stent implantation. Intracoronary stenting without high pressure balloon dilation was perforned in 55 patients with 55 lesions(phase 1), whereas intracoronary stenting with high pressure balloon dilation was done in 114 patients with 121 lesions(phase 2). We compared the angiographic and clinical results immediately and at late follow-up period after atenting between phase 1 and phase 2. RESULTS: Coronary angiography was repeated at 6 months in 135 patients, 138 lesions(78%). The overall incidence of restenosis was 25%(31% in phase 1 and 22% in phase 2). The restenosis occurred in 18% of elective stenting on de novo lesions(23% in phase 1 and 15% in phase 2). The restenosis rate was significantly reduced after using high pressure balloon dilation in infarct-related artery, final luminal diameter>/=4.0 mm after stenting and bail-out procedure(p<0.05). In phase 2, the restenosis rate was significantly higher in the lesions that had been previously dilated(43% in restenotic lesion vs 15% in de novo lesion, p<0.05) and in type C lesion compared with the others(type A, type B1, type B2 and type C ; 22%, 22%, 15% and 57%, respectively, p<0.05). According to the final luminal diameter, the restenosis rate was 7% in case of final luminal diameter greater than 4.0 mm which was significantly lower than that of final luminal diameter less than 3.5mm(p<0.05). At univariate anaysis, factors affecting restnosis were post-stent minimal luminal diameter, balloon-to-vessel ratio, acute gain and restenotic lesion. However multivariate analysis showed post-stent minimal luminal diameter was the only factor affecting restenosis. CONCLUSION: As intracoronary stenting using high pressure balloon dilation technique without anticoagulation has a good immediate results, negligible stent thrombosis and has a tendency of lower rate of restenosis.