II. Indications
- Cardiac Ischemia
- Myocardial Infarction
III. Precautions: Perioperative Stent Implications
- See Antiplatelet Therapy for Vascular Disease
- PTCA required to stabilize acute cardiovascular status prior to surgery
- Surgery with low risk of bleeding: Stent and continue dual-Antiplatelet Therapy
- Time to surgery 14 to 29 days: Balloon Angioplasty
- Time to surgery 30 to 365 days: Bare-Metal Stent
- Time to surgery >365 days: Drug-eluting Stent
IV. Efficacy
- Initial: 95% effective in coronary ischemia
- Balloon Angioplasty without stent
- Overall restenosis rate: 40% in first 6-9 months
- Procedure mortality rate: 1 to 2.5%
- Emergency CABG rate: 1.9 to 5.8%
- Angioplasty with bare metal stent
- Overall restenosis rate: 30% in first 6-9 months
- Procedure mortality rate: <0.25%
- Emergency CABG rate: <0.3 to 0.6%
- Angioplasty with drug eluting stent
- Overall restenosis rate: <10% in first 6-9 months
- Procedure mortality rate: <0.25%
- Emergency CABG rate: <0.3 to 0.6%
- Drug eluting stents have a higher rate of thrombus formation in first 6-12 months
- Hence the use of dual antiplatelet agents for the first 6-12 months
- See adverse effects below
- Initial studies: 6.9% re-stenosis at 9 months
V. Adverse Effects: Thrombosis at drug eluting stent site
- See Antiplatelet Therapy for Vascular Disease (includes Gastrointestinal Prophylaxis)
- May be related to polymer used to bind the drugs to the stent
-
Platelet ADP Receptor Antagonist with Aspirin 81 mg for at least 6-12 months (depending on stent-type)
- Minimizing Aspirin dose decreases serious bleeding events
- Significantly reduces cardiovascular events
- Benefit of Ticagrelor, Prasugrel over Clopidogrel, but at higher bleeding risk and 30x cost
- However, Clopidogrel may offer similar efficacy after the first week post-stenting
- Dual therapy beyond one year does not appear to lower cardiovascular event risk in most patients
- Dual Antiplatelet Therapy does increase bleeding risk
- Consult with cardiology to switch back to Aspirin alone at 81 mg orally daily
- Lee (2014) Circulation 129: 304-12 [PubMed]
- Peri-operative management within one year of drug eluting stent placement
- See Antiplatelet Therapy for Vascular Disease
- Delay elective surgeries for >6-12 months from PTCA placement
- Less invasive procedures (e.g. endoscopy) can be performed without stopping dual agents
- Protocol for more invasive urgent procedures
- Continue Aspirin 81 mg throughout perioperative period
- Stop Clopidogrel 5 days before surgery and restart on same day of surgery postoperatively
- First dose on restarting Clopidogrel should be loading dose of 300 mg
- References
- Kopacky (2008) Mayo Selected Topics in Internal Medicine, Lecture
- Mehta (2001) Lancet 358:527-33 [PubMed]
VI. Preparations: Drug-eluting Stents
- Stainless steel stents
- Cypher (Sirolimus-eluting stent)
- Taxus (Paclitaxel-eluting stent)
- Cobalt-chromium stents
- Endeavor (Zotarolimus-eluting stent)
- Xience (Everolimus-eluting stent)
- Promus (Everolimus-eluting stent)