Clinical and angiographic outcome of NIR stent implantation in small vessels with unfavorable lesion morphology.

Background: Coronary artery stents are used for the treatment of acute or threatened vessel occlusion complicating coronary angioplasty or for the prevention of restenosis after angioplasty. Improvements in stent design made the stenting of complex and small vessels feasible. We prospectively evaluated the safety, efficacy and long-term patency of NIR stent (Boston Scientific, Maple Grove, Minnesota) implantation in small vessels with complex lesion morphology.

Methods: The study population consisted of patients with complex (type OCO) lesions under 3 mm vessel diameter who were undergoing coronary angioplasty for symptomatic coronary artery disease followed by high-pressure NIR stent implantation and antiplatelet therapy only. Follow-up angiography was performed six months after the initial procedure.

Results: Of 143 patients fulfilling the angiographic criteria and undergoing stent implantation between October 1995 and November 1997, 67 patients (46.9%) received NIR stents. In 58 patients (86.6%), angiographic 6-month follow-up was available. In one patient (1.7%), stent implantation was unsuccessful. Procedural success of the NIR stent implantation was 98.2%. Implantation of other stents failed in 12 cases. NIR stent implantation was successful in all of them. No patient required urgent bypass surgery. No patient died. Restenosis occurred 5.8 +/- 1.3 months after the initial procedure in 21 patients (36.2%).

Conclusions: Coronary high-pressure stenting of small (< 3 mm) type OCO (AHA/ACC) lesions in patients with symptomatic coronary heart disease is a feasible treatment option with a high procedural success rate and low complication rate. The new flexible NIR stent showed an acceptable restenosis rate. The implantation was successful even in vessels in which previous attempts of Palmaz-Schatz stent placement had failed.