LONG-TERM (4-YEAR TO 6-YEAR) OUTCOME OF PALMAZ-SCHATZ STENTING - PAUCITY OF LATE CLINICAL STENT-RELATED PROBLEMS

Objectives. The purpose of this prospective single-center study was to evaluate the longer-term outcome of Palmaz-Schatz stenting in the tre atment of native coronary and saphenous vein bypass graft disease. Bac kground. The STRESS (Stent Restenosis Study) and BENESTENT (Belgian Ne therlands Stent) trials have demonstrated a decrease in both angiograp hic restenosis and the need for repeat revascularization in the Ist ye ar for vessels treated by stenting rather than balloon angioplasty. Lo nger-term (1 to 5 years) clinical results of Palmaz-Schatz stenting ar e not yet well established. Late migration of the stent, metal fatigue , endarteritis and late restenosis have all been proposed as potential late clinical complications of coronary stent implantation. Methods. The study cohort consisted of 175 consecutive patients who underwent e lective placement of 194 Palmaz-Schatz stents in 185 vessels. Clinical events (death, myocardial infarction, recurrent angina or any revascu larization) were assessed at 6 weeks, 2, 4 and 6 months, 1 year and ye arly thereafter. Clinical follow-up was available on all patients at a mean +/- SD of 54 +/- 17 months. Results. Angiographic success was ac hieved in 173 patients (98.9%); angiographic restenosis was observed a t 6 months in 26.1% of target sites. The survival rate was 86.7% at 5 years, with a 5-year event free survival rate decreasing progressively to 50.7%, reflecting primarily repeat revascularization procedures (4 1.2% at 5 years). However, the rate of repeat revascularization of the treatment site (target site revascularization [TSR]) was 14.4%, 17.7% and 19.8% at 1, 3 and 5 years, respectively, with late (>1 year) TSR driven by in-stent restenosis in only 3 patients (1.7%). Rates of both 5-year survival (70.5% vs. 93.4%) and event-free survival (21.1% vs. 63.3%) were lower for patients who underwent saphenous vein graft (SVG ) stenting than for those with native coronary artery stenting. Howeve r, 5 year TSR rates were similar for SVGs (21.9%) and native vessels ( 19.2%), indicating that the higher incidence of repeat revascularizati on for SVGs was due to an increase in non TSR, driven by progressive d isease at other sites. Conclusions. The long-term outcome of stenting shows stability of the treated lesion, with only a slight increase in TSR between 2 and 5 years (17.1% to 19.8%). The progressive increase i n repeat revascularization over that period (24% to 41%) and most ongo ing late events can be attributed to the progression of coronary disea se at other sites, rather than to late deterioration of the stent resu lt itself. Such non-TSR events account for the majority of clinical ev ents in the patients who underwent SVG stenting.