Perioperative cardiovascular management

❤️ Cardiac Risk Stratification

• Goal: Predict & mitigate Major Adverse Cardiac Events (MACE) using ACC/AHA guidelines. Integrates surgical risk, patient comorbidities via the Revised Cardiac Risk Index (RCRI), and functional capacity via Metabolic Equivalents (METs).

• RCRI Components (1 point each):

  • High-risk surgery (vascular, intraperitoneal, intrathoracic)
  • Ischemic Heart Disease (hx of MI, +stress test)
  • Congestive Heart Failure (hx of CHF, pulmonary edema)
  • Cerebrovascular Disease (hx of CVA/TIA)
  • Insulin-dependent Diabetes
  • Creatinine >2.0 mg/dL
  • MACE Risk: 0 pts ≈0.4%; 1 pt ≈1%; ≥2 pts ≈>2%.

• Functional Capacity (METs):

  • <4 METs: Poor (can't climb 1 flight of stairs).
  • ≥4 METs: Good (can proceed if RCRI is low).

⭐ In patients with good functional capacity (≥4 METs), further cardiac testing is rarely needed, regardless of RCRI score, for most elective surgeries.

💊 Management - Perioperative Drug Patrol

• Beta-blockers: CONTINUE throughout the perioperative period.
  • ⚠️ Abrupt withdrawal risks rebound tachycardia, hypertension, and ischemia.
• Statins: CONTINUE indefinitely.
  • Pleiotropic effects (plaque stabilization, anti-inflammatory) reduce MACE risk.
• ACE Inhibitors / ARBs: HOLD on the morning of surgery.
  • Prevents refractory hypotension during anesthesia induction.
  • Restart post-op once hemodynamically stable and euvolemic.
• Antiplatelets (Aspirin/DAPT):
  • Aspirin (secondary prevention): CONTINUE unless bleeding risk is very high (e.g., intracranial, spinal surgery).
  • P2Y12 Inhibitors (e.g., clopidogrel): Stop 5-7 days before surgery.

⭐ For coronary stents, DAPT discontinuation is high-risk. Delay elective surgery: >1 month post-BMS (Bare Metal Stent), >6 months post-DES (Drug-Eluting Stent).

💔 Complications - The Post-Op Heart Attack

• Perioperative MI: Myocardial infarction occurring during or within 30 days of surgery.
• MINS (Myocardial Injury after Noncardiac Surgery): Prognostically significant myocardial injury due to ischemia, detected by an elevated troponin. Often asymptomatic.
• Two Main Types:
  • Type 1 MI: Atherosclerotic plaque rupture & thrombosis. Classic ACS mechanism.
  • Type 2 MI: Oxygen supply-demand mismatch. The predominant type post-op.
    • ↓ Supply: Hypotension, anemia, hypoxemia.
    • ↑ Demand: Tachycardia, hypertension, pain, stress.
• Diagnosis & Surveillance:
  • Routine troponin surveillance in high-risk patients (pre-op and post-op days 1-3).
  • ECG may show new ischemic changes but is often non-specific or normal.

⭐ Most perioperative MIs are Type 2 and clinically silent (no chest pain). This underscores the importance of routine troponin surveillance in at-risk patients, as MINS is independently associated with increased mortality.

⚡ Biggest Takeaways

• Use the RCRI to stratify risk for major adverse cardiac events (MACE).
• Continue chronic beta-blockers and statins; do not start beta-blockers on surgery day.
• Highest risk for post-op MI is within 48-72 hours, often silent or atypical.
• For coronary stents, consult cardiology on DAPT management to prevent stent thrombosis.
• Severe symptomatic aortic stenosis is a major contraindication for elective non-cardiac surgery.
• Manage new post-op A-fib with rate control first (e.g., metoprolol, diltiazem).