Antiplatelet Agents

Effective management of antiplatelet agents requires balancing:

Aspirin

For primary prevention:

  • Should be discontinued at least 3 days prior
    Reduces rate of major bleeding.

For secondary prevention:

  • Consider discontinuation at least 3 days prior
  • Important to restart when the risk of bleeding has passed

Antiplatelets for Coronary Artery Stents

  • Premature cessation of DAPT is the greatest contributor to stent thrombosis
    • Cessation ↑ risk
    • Surgery ↑ risk
      Proinflammatory states.
  • Stent thrombosis risk is higher if ACS was the initial indication for PCI (compared with stable CAD)

Stent types:

  • Bare-metal stent (BMS)
    High rates of early stent thrombosis, but low rates of late and very-late stent thrombosis.
    • Require DAPT for minimum of 4 weeks and ideally 6 months
      Risk of progressive stent narrowing with early DAPT withdrawal.
    • Elective surgery can be considered one month after insertion, provided aspirin is continued
  • Drug-eluting stent (DES)
    Incorporate an anti-proliferative drug which delays endothelialisation.
    • Two generations of DES exist:
      • First-generation:
        • Include sirolimus and paclitaxel
        • Higher rate of late and very-late stent thrombosis
      • Second-generation
        • Include everolimus and zotarolimus-eluting stents
        • Improved risk profile
        • Very low rates of early, late, and very-late ST
          Appropriate to use if surgery is expected within 4 weeks of PCI.
    • Require DAPT for minimum of 6 months
      High risk of cardiac death due to complete stent thrombosis with early DAPT withdrawal.
    • Elective surgery should be performed:
      • Ideally after 6 months
      • Can be considered after 3-6 months
  • Bioresorbable vascular scaffold (BVS)
    • Potential ↑ risk of thrombosis
    • Ceasing DAPT within 3 years of insertion should be discussed with cardiology

Perioperative Management

  • Assess thrombosis risk
    • Cardiac history
      • Low EF
    • Non-cardiac history
      • CKD
        eGFR <60ml/min.
      • DM
    • Coronary & stent anatomy
      • ACS as indication
      • Prior stent thrombosis
      • Left mainstem or diffuse multivessel disease
      • ⩾3 stents
      • ⩾3 lesions
      • Bifurcation with 2 stents
      • Total stent length >60mm
      • All vessels stented
  • Assess bleeding risk
    High-risk surgeries include:
    • Bronchoscopy
    • Intra-cranial surgery
    • Spine surgery
    • Retinal surgery
    • Prostatectomy
  • Adjust medications
    • Cease P2Y12 inhibitor:
      • In high or intermediate risk surgery
      • Restart and reload after 24-72 hours
    • Continue aspirin if at all possible
      If ceasing aspirin, discuss with cardiology.
Drug When to cease pre-operatively Re-loading dose Indications Other
Clopidogrel 5 days 300-600mg Intracranial stents (others are off label), or cardiac stents with high-bleeding risk Clopidogrel resistance in ~30% of patients due to pharmacogenetic variation
Prasugrel 7 days 60mg Recommended for patients at high risk of recurrent ischaemia Greater risk of bleeding than clopidogrel, fastest time to onset
Ticagrelor 3-5 days 180mg Preferred to clopidogrel in patients at low risk of ischaemia More effective than clopidogrel with similar rate of bleeding

Urgent Surgery

  • Discussion with cardiology and haematology
  • Consider platelet transfusion

References

  1. Carruthers J, Shaw J, Tran H, Kusre S. Guideline: Perioperative Management of Antiplatelet Therapy in Patients with Coronary Artery Stents. The Alfred Hospital, Melbourne. May 2019.
  2. Indraratna P, Cao C. New antiplatelet drugs for acute coronary syndrome. Aust Prescr. 2014. doi:10.18773/austprescr.2014.074