Antiplatelet Therapy for Vascular Disease

Aka: Antiplatelet Therapy for Vascular Disease

1. See Also
   1. Preoperative Examination
   2. Angioplasty
2. Management: Guidelines
   1. Aspirin or Clopidogrel
      1. Initial Transient Ischemic Attack (TIA)
      2. Initial Ischemic Cerebrovascular Accident (CVA)
      3. Chronic stable Angina
      4. Peripheral Arterial Disease
   2. Aspirin and Clopidogrel
      1. ST segment elevation Acute Coronary Syndrome
      2. Recurrent Acute Coronary Syndrome
   3. Aspirin and Extended release Dipyridamole
      1. Recurrent Transient Ischemic Attack (TIA)
      2. Recurrent Ischemic Cerebrovascular Accident (CVA)
   4. References
      1. Tran (2004) JAMA 292:1867-74
3. Protocol: Post-Myocardial Infarction
   1. Aspirin 162 mg orally daily indefinately
   2. Clopidogrel (Plavix) added to Aspirin routinely following ST Elevation MI
      1. Dose: 75 mg orally daily (consider initial 300 mg loading dose if age <75 years)
      2. Duration following ST Elevation MI
         1. See Clopidogrel
   3. References
      1. Antman (2008) Circulation 117(2): 296-329
4. Precautions: Perioperative Stent Implications
   1. See Angioplasty
   2. Balloon Angioplasty
      1. Time since surgery <14 days: Delay non-urgent or elective surgery
      2. Time since surgery >14 days: Proceed to surgery with Aspirin
   3. Bare-Metal Stent
      1. Time since surgery <30-45 days: Delay non-urgent or elective surgery
      2. Time since surgery >45-90 days: Proceed to surgery with Aspirin
   4. Drug-eluting Stent
      1. Time since surgery <365 days: Delay non-urgent or elective surgery
      2. Time since surgery >365 days: Proceed to surgery with Aspirin
   5. Minimum dual antiplatelet time for stents
      1. Dual Antiplatelet Therapy should be continued for one year with all drug eluting stents
         1. Deviation from the one year minimum is for serious extenuating circumstances
         2. All deviations from the one year minimum should be discussed with cardiology
      2. Balloon Angioplasty: >2 weeks
      3. Bare metal stents: >1 month
      4. Sirolimus (Rapamune) eluting stents: >3 months
      5. All other Drug-eluting Stents: >6 months
5. Protocol: Duration following ST Elevation MI
   1. Continue for at least 14 days and consider one year of therapy in all post-STEMI cases
   2. Bare metal stents require minimum of 1 month of Clopidogrel
   3. Drug-eluting Stents require minimum of 3-6 months (depending on stent-type)
   4. References
      1. Antman (2008) Circulation 117(2): 296-329
6. Management: Gastrointestinal prophylaxis
   1. Proton Pump Inhibitors are often used for peptic ulcer prevention while on combined anti-platelet agents
      1. Ranitidine has been used more commonly for GI prophylaxis due to potential Cytochrome P450 2C19 drug interaction with Proton Pump Inhibitors
   2. Cytochrome P450 2C19 drug interaction with Proton Pump Inhibitors has potential to predispose to more post-stenting events
      1. Cogent study (see Bhatt below) left open that this interaction may be important
      2. Studies have not observed an increase in number of cardiovascular events
         1. Ho (2009) JAMA 301: 937-44
         2. Bhatt (2010) N Engl J Med 363:1909-17
7. Protocol: Perioperative Plavix
   1. Precautions
      1. See perioperative stenting implications above
      2. Mortality doubles in Acute Coronary Syndrome patients in first 90 days after stopping Plavix
         1. Consider tapering off by taking every other day for 2-3 weeks
         2. Conitinue Aspirin 162 after stopping Plavix
         3. Ho (2008) JAMA 299(5):532-9
   2. Timing of stopping Plavix (if no contraindications)
      1. Stop 7 days before surgery (delay surgery if too soon after cardiovascular event)
8. Protocol: Perioperative Aspirin
   1. Precautions
      1. Aspirin used for secondary prevention
         1. Stopping Aspirin before surgery resulted in a 3 fold increased risk of cardiovascular events
      2. Aspirin used after coronary stenting
         1. Stopping Aspirin before surgery resulted in a 90 fold increasd risk of cardiovascular events
   2. Protocol
      1. Consult with surgeon regarding whether Aspirin may be continued
      2. Low dose Aspirin can be continued in the perioperative period for most surgeries
         1. Avoid Aspirin prior to intracranial surgery
         2. Avoid Aspirin prior to Prostatectomy
      3. Surgical bleeding risk increases with Aspirin by 20%
         1. However, no increase in severe bleeding for most surgeries (except intracranial surgery or Prostatectomy)
   3. References
      1. Eberli (2010) J Urol 183(6): 2128-36
      2. Burger (2005) J Intern Med 257(5): 399-414
      3. Biondi-Zoccai (2006) Eur Heart J 27(22): 2667-74
9. References
   1. Dehmer (2009) Am Fam Physician 80(11): 1245-53
   2. Hannan (2008) Circulation 117(16): 2071-8
   3. Serruys (2001) N Engl J Med 344:1117-24
   4. Moses (2003) N Engl J Med 349:1315-23