What is the best risk score for predicting major adverse cardiac events (MACE) post-operatively?

Best Risk Score for Predicting Major Adverse Cardiac Events (MACE) Post-Operatively

The Revised Cardiac Risk Index (RCRI) is the most widely validated and recommended risk score for predicting major adverse cardiac events (MACE) post-operatively, though no single risk score has been definitively proven superior to others. 1

Major Risk Prediction Tools

• The RCRI is a simple, validated, and commonly used tool that assigns 1 point for each of 6 predictors to assess perioperative risk of major cardiac complications 1
• The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) perioperative MI and cardiac arrest (MICA) risk calculator may provide superior predictive discrimination in some populations 1
• The universal American College of Surgeons NSQIP surgical risk calculator is another option with potentially better discrimination in certain populations 1
• The AUB-HAS2 cardiovascular risk index is an easily calculated tool to assess 30-day event risk 1

RCRI Components and Risk Stratification

• RCRI includes six independent predictors: history of ischemic heart disease, history of heart failure, history of cerebrovascular disease, preoperative insulin treatment for diabetes, preoperative creatinine >2 mg/dL, and high-risk surgery 1, 2
• Patients can be classified by RCRI score: 0 factors (low risk), 1 factor (low to moderate risk), 2 factors (moderate risk), and ≥3 factors (high risk) for major cardiac complications 3, 4
• Rates of major cardiac complications with 0,1,2, ≥3 RCRI factors were found to be 0.5%, 2.6%, 7.2%, and 14.4%, respectively, in a large validation cohort 2

Limitations of Risk Scores

• Risk scores have poorer discrimination in patients undergoing vascular surgery, likely due to underestimation of MI risk 1, 5
• The 2024 AHA/ACC guidelines note that "although many risk scores exist, data are lacking to support the use of one risk index over another" 1
• The performance of risk scores may vary by age group, with C-statistic highest among patients aged 56-65 years (0.772) and lowest for those aged >85 years (0.683) 6
• A modified version of RCRI using GFR <30 mL/min instead of creatinine >176.8 μmol/L may provide better prediction 2

Complementary Assessment Tools

• Functional capacity assessment using the Duke Activity Status Index (DASI) should be combined with risk scores for better stratification 1, 7
• Poor functional capacity (inability to achieve 4 METs) indicates increased risk of perioperative adverse cardiovascular events 1, 3
• B-type natriuretic peptide (BNP) levels can provide additional risk stratification beyond standard risk scores 3, 4

Practical Application

• For low-risk patients (RCRI 0-1), proceeding with standard monitoring during surgery is recommended 4, 7
• For intermediate-risk patients (RCRI 2), consider enhanced monitoring during and after the procedure 4
• For high-risk patients (RCRI ≥3), implement comprehensive cardiac monitoring and consider surveillance for myocardial injury after noncardiac surgery (MINS) 3, 7
• Emergency surgery increases cardiac risk regardless of RCRI score 4, 7

Common Pitfalls

• Avoid relying solely on age as a risk factor; focus on cardiac, pulmonary, and renal disease status 7
• Risk scores may have limited predictive ability in certain populations, such as the oldest-old patients (≥80 years) 8
• Consider that the addition of factors such as age, atrial fibrillation, and trauma surgery may improve risk prediction in elderly patients 8