II. Indications

  1. Cardiac Ischemia
  2. Myocardial Infarction

III. Precautions: Perioperative Stent Implications

  1. See Antiplatelet Therapy for Vascular Disease
  2. PTCA required to stabilize acute cardiovascular status prior to surgery
    1. Surgery with low risk of bleeding: Stent and continue dual-Antiplatelet Therapy
    2. Time to surgery 14 to 29 days: Balloon Angioplasty
    3. Time to surgery 30 to 365 days: Bare-Metal Stent
    4. Time to surgery >365 days: Drug-eluting Stent

IV. Efficacy

  1. Initial: 95% effective in coronary ischemia
  2. Balloon Angioplasty without stent
    1. Overall restenosis rate: 40% in first 6-9 months
    2. Procedure mortality rate: 1 to 2.5%
    3. Emergency CABG rate: 1.9 to 5.8%
  3. Angioplasty with bare metal stent
    1. Overall restenosis rate: 30% in first 6-9 months
    2. Procedure mortality rate: <0.25%
    3. Emergency CABG rate: <0.3 to 0.6%
  4. Angioplasty with drug eluting stent
    1. Overall restenosis rate: <10% in first 6-9 months
    2. Procedure mortality rate: <0.25%
    3. Emergency CABG rate: <0.3 to 0.6%
    4. Drug eluting stents have a higher rate of thrombus formation in first 6-12 months
      1. Hence the use of dual antiplatelet agents for the first 6-12 months
      2. See adverse effects below
    5. Initial studies: 6.9% re-stenosis at 9 months

V. Adverse Effects: Thrombosis at drug eluting stent site

  1. See Antiplatelet Therapy for Vascular Disease (includes Gastrointestinal Prophylaxis)
  2. May be related to polymer used to bind the drugs to the stent
  3. Platelet ADP Receptor Antagonist with Aspirin 81 mg for at least 6-12 months (depending on stent-type)
    1. Minimizing Aspirin dose decreases serious bleeding events
    2. Significantly reduces cardiovascular events
    3. Benefit of Ticagrelor, Prasugrel over Clopidogrel, but at higher bleeding risk and 30x cost
      1. Rezaei (2017) Int J Cardiol 235:61-66 [PubMed]
    4. However, Clopidogrel may offer similar efficacy after the first week post-stenting
      1. Sibbing (2017) Lancet 390(10104):1747-57 [PubMed]
  4. Dual therapy beyond one year does not appear to lower cardiovascular event risk in most patients
    1. Dual Antiplatelet Therapy does increase bleeding risk
    2. Consult with cardiology to switch back to Aspirin alone at 81 mg orally daily
    3. Lee (2014) Circulation 129: 304-12 [PubMed]
  5. Peri-operative management within one year of drug eluting stent placement
    1. See Antiplatelet Therapy for Vascular Disease
    2. Delay elective surgeries for >6-12 months from PTCA placement
    3. Less invasive procedures (e.g. endoscopy) can be performed without stopping dual agents
    4. Protocol for more invasive urgent procedures
      1. Continue Aspirin 81 mg throughout perioperative period
      2. Stop Clopidogrel 5 days before surgery and restart on same day of surgery postoperatively
        1. First dose on restarting Clopidogrel should be loading dose of 300 mg
  6. References
    1. Kopacky (2008) Mayo Selected Topics in Internal Medicine, Lecture
    2. Mehta (2001) Lancet 358:527-33 [PubMed]

VI. Preparations: Drug-eluting Stents

  1. Stainless steel stents
    1. Cypher (Sirolimus-eluting stent)
    2. Taxus (Paclitaxel-eluting stent)
  2. Cobalt-chromium stents
    1. Endeavor (Zotarolimus-eluting stent)
    2. Xience (Everolimus-eluting stent)
    3. Promus (Everolimus-eluting stent)

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