Pre-Surgical Cardiac Risk Assessment
A stepwise approach to pre-surgical cardiac risk assessment is recommended, beginning with evaluation of surgery urgency, patient's cardiac risk factors, and functional capacity, followed by appropriate testing only when results would change management. 1
Step 1: Determine Urgency of Surgery
- Emergency surgery: Proceed to surgery without cardiac testing
- Urgent/time-sensitive surgery: Limited evaluation (6-24 hours)
- Elective surgery: Complete evaluation possible 1
Step 2: Evaluate Prior Cardiac Evaluation/Treatment
- If coronary revascularization within past 5 years with stable symptoms, further testing usually unnecessary
- If cardiac evaluation within past 2 years with favorable findings and stable symptoms, repeat testing usually unnecessary 2
Step 3: Identify Major Clinical Risk Factors
Major risk factors requiring management before elective surgery:
- Unstable coronary syndromes
- Decompensated heart failure
- Significant arrhythmias (high-grade AV block, symptomatic ventricular arrhythmias, SVT with uncontrolled rate)
- Severe valvular disease 2
Step 4: Assess Intermediate Clinical Risk Factors
Intermediate risk factors:
- Prior MI (history or pathologic Q waves)
- Angina pectoris (stable)
- Compensated/prior heart failure
- Diabetes mellitus (particularly type 1)
- Renal insufficiency
- Uncontrolled hypertension 2
Step 5: Evaluate Functional Capacity
- Good functional capacity (≥4 METs): Can climb a flight of stairs or walk on level ground at 6.4 km/h
- Poor functional capacity (<4 METs): Cannot climb a flight of stairs 1
Step 6: Determine Surgery-Specific Risk
Surgery risk categories:
- High-risk (>5%): Vascular, major thoracic/abdominal, head and neck procedures
- Intermediate-risk (1-5%): Intraperitoneal, intrathoracic, carotid, prostate procedures
- Low-risk (<1%): Superficial, cataract, breast surgeries 1
Step 7: Determine Need for Further Testing
Testing recommendations:
- Low-risk surgery: No cardiac testing needed regardless of risk factors 2, 1
- Intermediate/high-risk surgery with good functional capacity: Proceed to surgery without testing 1
- Intermediate/high-risk surgery with poor functional capacity AND ≥2 intermediate risk factors: Consider non-invasive stress testing 2, 3
Stress testing indications:
- High-risk surgery with 3 or more clinical risk factors (Class I recommendation)
- High-risk surgery with 2 clinical risk factors (Class IIb recommendation) 2
Step 8: Perioperative Management
For patients with valvular heart disease:
- In severe VHD, clinical and echocardiographic evaluation is recommended before non-cardiac surgery 2
- For severe aortic stenosis:
- Symptomatic patients: Consider valve replacement before elective surgery
- Asymptomatic patients: Low/intermediate-risk surgery can proceed; high-risk surgery requires further assessment 2
Medication management:
- Beta-blockers: Avoid high-dose initiation within 24 hours before surgery (increases stroke and mortality risk) 3, 4
- Statins: Consider in patients with atherosclerotic disease undergoing vascular surgery 3
- ACE inhibitors/ARBs: Withhold starting 24 hours before surgery 4
- Aspirin: Not recommended for routine perioperative cardiac risk reduction 3, 4
Step 9: Postoperative Monitoring
- Consider troponin monitoring for 48-72 hours after surgery in high-risk patients 4
- For patients ≥65 years or 45-64 years with significant cardiovascular disease, or Revised Cardiac Risk Index score ≥1 4
Common Pitfalls to Avoid
- Ordering tests that won't change management
- Routine stress testing in low-risk patients
- Routine coronary revascularization before non-cardiac surgery
- Initiating high-dose beta-blockers immediately before surgery
- Providing "medical clearance" rather than risk assessment and recommendations 1, 3
Remember that the goal of pre-surgical cardiac risk assessment is not to give "medical clearance" but to evaluate current medical status and make recommendations for perioperative management to reduce morbidity and mortality.