II. Precautions

  1. Aspirin is lifelong therapy for known cardiovascular disease (secondary prevention)
    1. Should not be interrupted for surgery following stroke, Acute Coronary Syndrome, or coronary revascularization
    2. This is regardless of time since vascular event or procedure
    3. See risks below regarding stopping Aspirin in the perioperative period
  2. Clopidogrel (Plavix) in combination with Aspirin
    1. Should be continued at least until endothelialization of the stent or lesion can reasonably be expected
    2. For Drug-eluting Stents this duration is for a minimum of 1 year
      1. May extend 2-3 years especially in high risk patients (see below)

III. Physiology: Antiplatelet agents and bleeding risk

  1. Plavix, Aspirin poison platelets for full 21 day life
  2. Agents stopped 7 days before surgery allows 33% of platelets to regenerate (50,000)
  3. Adequate platelet aggregation returns within 5 days of stopping antiplatelet agents

IV. Physiology: Stent and coronary lesion endothelialization

  1. Stents and coronary lesions act as unstable Plaque until fully covered by a cellular layer
    1. Bare metal stents are completely covered by smooth muscle within 6 weeks and by endothelium within 3 months
    2. Drug eluting stents require 1-3 years for endothelialization
    3. Stent thrombosis is a catastrophic event (up to 45% mortality)

V. Physiology: Antiplatelet agent cessation and thrombosis risk

  1. Aspirin cessation: 3.1 Odds Ratio of cardiac complication (peak at 10 days)
  2. Aspirin cessation after coronary stent: 90 Odds Ratio
    1. Even 2 years after Drug-eluting Stent placement, Aspirin cessation may result in stent stenosis
  3. Clopidogrel cessation after drug eluting stent: Up to 57 Odds Ratio in first 18 months
  4. Risk of stent closure increases in the perioperative period due to increased platelet aggregation activity

VI. Evaluation: Surgical Bleeding Risk

  1. Low surgical bleeding risk (transfusion not required)
    1. Minor otolaryngology surgery
    2. Minor orthopedic surgery
    3. Endoscopy without biopsy
    4. Anterior chamber eye surgery
    5. Dentistry
  2. Intermediate surgical bleeding risk (transfusion may be required)
    1. Visceral surgery
    2. Vascular surgery
    3. Major otolaryngology surgery
    4. Major orthopedic surgery
    5. Endoscopy with biopsy
  3. High surgical bleeding risk (transfusion required)
    1. Cardiac surgery
    2. Surgery with massive bleeding (e.g. transurethral Prostatectomy)
    3. Surgery in a closed space
      1. Intracranial surgery
      2. Major spinal surgery
      3. Bone Intramedullary canal procedures
      4. Posterior eye chamber

VII. Evaluation: Cardiac Risk for perioperative events in known coronary disease

  1. Low Cardiac Risk
    1. Bare metal stents, Angioplasty, or CABG >3 months prior
    2. Acute Coronary Syndrome >6 months prior
    3. Drug-eluting Stent >12 months prior
  2. Intermediate Cardiac Risk
    1. Bare metal stents, Angioplasty, or CABG 6 weeks to 3 months prior
    2. Acute Coronary Syndrome 6 weeks to 6 months prior
    3. High Risk Drug-eluting Stent >12 months prior
      1. Stent in dominant, proximal, ostial or bifurcated position or
      2. High risk patient with advanced age, Diabetes Mellitus, low ejection fraction or Renal Failure
  3. High Cardiac Risk
    1. Bare metal stents, Angioplasty, or CABG, Acute Coronary Syndrome <6 weeks prior (<3 months if complications)
    2. Drug-eluting Stent <12 months prior (longer if high risk drug eluting stent)

VIII. Protocol: ACC/AHA Guidelines 2016

  1. No known cardiovascular disease (primary prevention)
    1. If significant risk of cardiovascular event (Revised Cardiac Risk Index)
      1. Follow guidelines for secondary prevention as below
    2. Stop Aspirin 7-10 days prior to surgery
    3. Restarting Aspirin
      1. Restart Aspirin 24 hours after low bleeding risk procedures
      2. Restart Aspirin 48-72 hours after higher bleeding risk procedures
  2. Known cardiovascular disease (secondary prevention)
    1. Aspirin
      1. Continue without stopping through perioperative period
      2. Only stop Aspirin if high risk of bleeding (see above)
    2. Platelet ADP Receptor Antagonist (e.g. Clopidogrel, dual Antiplatelet Therapy)
      1. Continue Aspirin perioperatively if possible while off Platelet ADP Receptor Antagonist
      2. Elective surgery
        1. Postpone surgery for 30 days after bare metal stent, 6 months after Drug-eluting Stent
        2. Postpone surgery for 1 year after Acute Coronary Syndrome
        3. Hold Platelet ADP Receptor Antagonist perioperatively
      3. Important surgery to be done as soon as possible (risk of delay)
        1. Postpone surgery for >3 months after Drug-eluting Stent (or use dual antiplatelets periop)
        2. Postpone surgery for 1 year after Acute Coronary Syndrome (or use dual antiplatelets periop)
        3. Hold Platelet ADP Receptor Antagonist perioperatively
      4. Urgent or emergent surgery
        1. Continue dual antiplatelet agents unless major bleeding risk (e.g. active bleeding, intracranial surgery)
  3. References
    1. Levine (2016) Circulation 134(10): e123-55 [PubMed]

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