Use of stents for small coronary arteries. Results of the Multi-Link 2.5 Portuguese Registry.

INTRODUCTION: Stents are being used with increasing frequency in percutaneous transluminal coronary angioplasty (PTCA) but their use in small vessels is still controversial, due to the possibility of excessively high rates of adverse events and restenosis.

OBJECTIVE: To assess the safety and clinical efficacy of ACS RX Multi-Link (ML) 2.5 mm stents, in "de novo" coronary stenosis.

DESIGN: Prospective Registry, with 6 months clinical follow-up, involving all Portuguese centers of Interventional Cardiology.

POPULATION: Between April 7 and November 20 1998, 102 patients were enrolled, 82 male and with ages ranging from 30 to 86 years (average 58 +/- 11). Clinical presentation for PTCA was stable angina in 53%, unstable angina in 36% and silent ischemia in 11%. There was a history of previous myocardial infarction in 29% of patients. The main risk factors were hypertension (58%), hyperlipidemia (57%), smoking (25%) and diabetes (20%). Multivessel coronary artery disease was present in 46% of patients and left ventricular function was normal in 89%. Of the 217 existing lesions, 188 (87%) were treated: 35 with balloon angioplasty and 153 with stent implantation, 114 of which were ML 2.5 mm: 79 of 15 mm in length and 35 of 25 mm.

METHODS: Angiographic success with ML stent implantation and major adverse cardiac events (MACE)--myocardial infarction (MI), coronary artery bypass graft (CABG), new target vessel revascularizations and death--were evaluated during hospital stay, and at 1 and 6 months clinical follow-up.

RESULTS: Angiographic success was 97.4%. In one patient it was not possible to cross the lesion, in another there was stent migration and in a third distal coronary flow after stenting was TIMI grade 1. Clinical success was 96.1% and there were no cases of death, Q-wave MI or urgent CABG. Two patients had non-Q wave MI and two required urgent repeat angioplasty. Subacute stent thrombosis occurred in 1 patient. There were no additional MACE at 1 month follow-up. At 6-month follow-up (in 97% of patients) MACE had occurred in 14.1%: 2 deaths (one non-cardiac), 3 MI (one non-Q) and 14 new PTCA (one in a non-ML stent). There was no need for CABG in any patient. Six-month survival rate was 97.9%, 94.9% were free of infarction and 84.8% were free of infarction and new revascularization.

CONCLUSIONS: Multi-Link 2.5 mm stent implantation appears to be safe and efficient with a low incidence of immediate and 6-month adverse events in the range of centers and operators of the Registry.