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c_stents

intracoronary stents

introduction

1st generation bare metal stents

  • the first generation Palmaz-Schatz bare metal (BMS) coronary stents were evaluated in two major trials in 1994 (STRESS and Benestent):
    • angiographic restenosis rates at 6months were ~1/3rd less than for PTCA alone.

2nd generation bare metal stents

  • pooled analysis of six major clinical trials in 2002 assessed second generation coronary stents with long term aspirin and 4 weeks ticlodipine:
    • Clinically relevant restenosis occurred in only about one-half of patients with angiographic restenosis (defined as ≥50 percent diameter stenosis).
    • The predictors of both clinical and angiographic restenosis were the same (smaller posttreatment lumen diameter, stent length, and diabetes).
    • at 1 year, target lesion revascularisation was performed in 12% and target vessel revascularisation in 14.1% which were higher than at 6 months demonstrating a higher than expected delayed presentation.
    • most clinically significant restenosis with second generation stents become clinically evident within the first 6-12 months.
    • after one year, recurrent ischemia is more likely to be due to new or progressive disease at another site rather than restenosis.
      • the annual hazard rate was 1.7 percent for target lesion events compared to 6.3 percent for non-target lesion events

drug-eluting stents

  • multiple trials have demonstrated that the sirolimus and paclitaxel drug-eluting stents markedly reduced the incidence of in-stent restenosis and the rate of target lesion revascularization by about 75 percent.
  • A 2006 meta-analysis included 19 trials with 7060 patients comparing DES to BMS:
    • No effect on all-cause mortality
    • A significant reduction in angiographic restenosis (10.5 versus 31.7 percent)
    • A significant reduction in target lesion revascularization (6.2 versus 16.6 percent)
    • A significant reduction in major adverse cardiac events (10.1 versus 19.9 percent), which was entirely due to a reduction in target lesion revascularization.
  • BUT there are safety concerns, cost issues and the need for patients to received long-term dual antiplatelet therapy is an issue
    • premature cessation of dual antiplatelt Rx (aspirin with clopidogrel) risks death or MI.

references and resources

c_stents.txt · Last modified: 2009/03/03 04:42 (external edit)