What is the approach to preoperative (pre-op) risk stratification?

Preoperative Risk Stratification Approach

Preoperative risk stratification should follow a stepwise approach using validated tools like the Revised Cardiac Risk Index (RCRI) to assess cardiac risk, with further testing based on risk level, functional capacity, and surgery-specific factors. 1

Step 1: Initial Assessment

• Urgency evaluation: Determine if surgery is emergent (cannot delay), urgent, time-sensitive, or elective 2, 1

• Prior cardiac interventions: Check if patient has undergone coronary revascularization in past 5 years or coronary evaluation in past 2 years 2

• Clinical risk factors: Identify major, intermediate, and minor predictors:

  Major Predictors	Intermediate Predictors	Minor Predictors
  Unstable coronary syndromes	Prior MI/pathologic Q waves	Advanced age
  Decompensated heart failure	Mild angina pectoris	Abnormal ECG
  Significant arrhythmias	Compensated/prior heart failure	Non-sinus rhythm
  Severe valvular disease	Diabetes mellitus	Low functional capacity
  	Renal insufficiency	History of stroke
  	Uncontrolled hypertension

Step 2: Risk Calculation

• Validated risk scores:

  • Revised Cardiac Risk Index (RCRI)
  • American College of Surgeons NSQIP risk calculator
  • EuroSCORE (for cardiac surgery)
  • Mayo Surgical Risk Score 1

• Surgery-specific risk:

  • Low risk (<1% cardiac events): Endoscopy, superficial procedures, cataract, breast
  • Intermediate risk (1-5% cardiac events): Carotid endarterectomy, head and neck, intraperitoneal, orthopedic
  • High risk (>5% cardiac events): Aortic, major vascular, prolonged procedures with large fluid shifts 2

Step 3: Functional Capacity Assessment

• Evaluate using:
  • Duke Activity Status Index (DASI)
  • Two-flight stairs test
  • Poor functional capacity: <4 METs or DASI <34
  • Good functional capacity: ≥4 METs or DASI ≥34 1

Step 4: Testing Strategy Based on Risk

• Low risk (RCRI 0 points) + good functional capacity:

  • Proceed to surgery without further cardiac testing 1

• Intermediate risk (RCRI 1-2 points):

  • If good functional capacity: Usually no further testing
  • If poor functional capacity: Consider non-invasive testing for high-risk surgery 2, 1

• High risk (RCRI ≥3 points):

  • Consider non-invasive stress testing regardless of functional capacity
  • Consider biomarker assessment (BNP/NT-proBNP and troponin) 1, 3

• Special populations:

  • Age ≥70 years: Add frailty assessment using validated tools 1
  • Patients with congenital heart disease: Consult ACHD specialist 2
  • LVAD patients: Coordinate with LVAD care team 2

Step 5: Perioperative Management

• Beta-blockers:

  • Continue in patients already on therapy
  • Consider initiating in high-risk patients (≥3 RCRI factors) >1 day before surgery
  • Avoid starting on day of surgery (Class III: Harm) 1

• Statins:

  • Continue in patients already taking them
  • Consider initiating for vascular surgery or elevated-risk procedures 1

• Antiplatelet therapy:

  • Continue dual antiplatelet therapy for urgent surgery within 4-6 weeks of stent placement
  • Avoid elective surgery within 30 days of BMS or 12 months of DES if DAPT must be discontinued 1

Common Pitfalls to Avoid

• Ordering routine tests without clinical indication
• Starting beta-blockers on day of surgery (increases stroke and mortality risk)
• Performing elective surgery too soon after coronary stent placement
• Overlooking poor functional capacity as a significant risk factor
• Failing to use validated risk prediction tools 1, 3

By following this structured approach to preoperative risk stratification, clinicians can identify patients at increased risk for perioperative cardiovascular complications and implement appropriate risk-reduction strategies to improve outcomes.