What are the risks and management strategies for a patient with right coronary artery disease undergoing non-cardiac surgery?

Risk Assessment for Right Coronary Artery Disease in Non-Cardiac Surgery

Patients with right coronary artery disease undergoing non-cardiac surgery face perioperative cardiac risk that depends primarily on their functional capacity, clinical risk factors, and the type of surgery being performed, rather than the specific coronary anatomy itself. 1

Risk Stratification Framework

The presence of coronary artery disease (CAD) alone does not automatically confer high risk. The key determinants are:

Functional Capacity Assessment

• Patients with excellent functional capacity (>10 METs) can proceed directly to surgery without further cardiac testing, even with known CAD 1
• Good functional capacity is defined as the ability to achieve 6-8 METs of activity without significant dyspnea 2
• If functional capacity is poor (<4 METs), symptomatic, or unknown, then clinical risk factors become critical 1

Clinical Risk Factors (Revised Lee Index)

The number of clinical risk factors determines perioperative cardiac risk 1, 3:

• High-risk surgery (vascular, intraperitoneal, intrathoracic)
• History of ischemic heart disease
• History of heart failure
• Cerebrovascular disease
• Insulin-dependent diabetes mellitus
• Renal insufficiency (creatinine >2 mg/dL)

With 0-1 risk factors: proceed to surgery without further testing 1 With 2 risk factors: either proceed to surgery with beta-blocker therapy or consider testing if it will change management 1 With ≥3 risk factors: consider stress testing if surgery can be delayed, to identify patients who may benefit from 30 days of medical optimization 3

Surgery-Specific Risk

• Vascular surgery: cardiac risk often >5% 1
• Intermediate-risk procedures (intraperitoneal, intrathoracic, orthopedic, prostate): cardiac risk 1-5% 1
• Low-risk procedures (endoscopic, superficial, cataract, breast, ambulatory): cardiac risk <1% 1

Critical Management Principles

What NOT to Do

Routine coronary revascularization before non-cardiac surgery is NOT recommended solely to reduce perioperative cardiac events 1. The CARP trial demonstrated no benefit from preoperative revascularization except in patients with left main disease 1.

Routine stress testing is not predictive of MI or death and should not be performed routinely 3. Stress testing only helps identify patients who may benefit from medical optimization when surgery can be delayed 3.

Perioperative Medical Management

Beta-blocker therapy:

• Continue in patients already on chronic beta-blockers 1
• For patients with ≥1 risk factor not on beta-blockers, consider starting low-dose beta-blocker (bisoprolol 2.5-5 mg daily) ideally 1 month before surgery, titrated to heart rate <70 bpm and systolic BP ≥120 mmHg 3
• Improper timing and dosing can increase stroke and death risk 3

Statin therapy:

• Should be started ideally 30 days before surgery in all patients with CAD 3, 4
• Sharply decreases MI, stroke, and death perioperatively and long-term 3

Antiplatelet therapy:

• Continue aspirin perioperatively in patients with established CAD unless bleeding risk is prohibitive 4
• If patient has coronary stents, timing is critical (see below) 1

Special Consideration: Prior Coronary Stent

This represents a major perioperative hazard requiring specific timing:

Mandatory delays for elective surgery:

• 14 days after balloon angioplasty 1
• 30 days after bare-metal stent (BMS) 1
• Optimally 365 days after drug-eluting stent (DES) 1
• Minimum 180 days after DES may be considered if delay risk exceeds stent thrombosis risk 1

Elective surgery should NOT be performed if dual antiplatelet therapy must be discontinued within 30 days of BMS or 12 months of DES 1. This carries Class III: Harm designation.

Common Pitfalls to Avoid

1. Do not order routine coronary angiography 1 - indications are the same as in non-operative settings
2. Do not assume all CAD patients need stress testing 3 - functional capacity assessment is more important
3. Do not perform prophylactic revascularization 1 - it does not reduce perioperative events except in left main disease
4. Do not start beta-blockers acutely perioperatively without titration 3 - this increases stroke risk
5. Do not proceed with elective surgery in patients with recent stents within the mandatory waiting periods 1

Bottom Line Algorithm

For a patient with right coronary artery disease:

1. Assess functional capacity - if >10 METs, proceed to surgery 1
2. Count clinical risk factors using Lee index 1, 3
3. Classify surgery risk (low/intermediate/high) 1
4. If ≥3 risk factors and intermediate/high-risk surgery with poor functional capacity, consider stress testing only if surgery can be delayed for medical optimization 3
5. Ensure on statin therapy (start 30 days prior if possible) 3
6. Consider beta-blocker if ≥1 risk factor (start 1 month prior, titrate carefully) 3
7. Continue aspirin unless prohibitive bleeding risk 4
8. Verify no recent coronary stent within mandatory waiting periods 1