What is the best preoperative calculator for assessing cardiac risk in patients undergoing non-cardiac surgery?

From the Guidelines

The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) perioperative MI and cardiac arrest (MICA) risk calculator is the best preoperative calculator for assessing cardiac risk in patients undergoing non-cardiac surgery. This calculator, which can be found at http://www.surgicalriskcalculator.com/miorcardiacarrest, uses five predictors of perioperative myocardial infarction/cardiac arrest: type of surgery, functional status, elevated creatinine, American Society of Anesthesiologists (ASA) class, and age 1. The NSQIP MICA model has been shown to perform better than the Lee risk index, with some reduction in performance in vascular patients, although it was still superior 1. The calculator provides a model-based estimate of the probability of myocardial infarction/cardiac arrest for an individual patient, allowing for accurate and simple risk calculation at the bedside or clinic.

When using the NSQIP MICA risk calculator in practice, it's essential to remember that it should be part of a comprehensive evaluation that includes functional capacity assessment and consideration of surgery-specific risks. The calculator helps guide decisions about additional cardiac testing, perioperative beta-blocker use, and the level of postoperative monitoring required, ultimately improving resource allocation and patient outcomes through targeted interventions for higher-risk individuals. According to the 2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM guideline for perioperative cardiovascular management for noncardiac surgery, the NSQIP MICA risk calculator is a useful tool for assessing perioperative cardiovascular risk 1.

Some key points to consider when using the NSQIP MICA risk calculator include:

• The calculator is based on data from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database
• The calculator uses five predictors of perioperative myocardial infarction/cardiac arrest
• The calculator provides a model-based estimate of the probability of myocardial infarction/cardiac arrest for an individual patient
• The calculator should be used as part of a comprehensive evaluation that includes functional capacity assessment and consideration of surgery-specific risks.

Overall, the NSQIP MICA risk calculator is a valuable tool for assessing cardiac risk in patients undergoing non-cardiac surgery, and its use can help improve patient outcomes and reduce morbidity and mortality.

From the Research

Preoperative Calculators for Cardiac Risk Assessment

Several studies have investigated the use of preoperative calculators for assessing cardiac risk in patients undergoing non-cardiac surgery. The Revised Cardiac Risk Index (RCRI) is a widely used index that predicts major cardiac outcomes from five independent clinical determinants: history of ischemic heart disease, history of cardiovascular disease, heart failure, insulin-dependent diabetes mellitus, and chronic renal failure 2, 3, 4.

Available Preoperative Calculators

Some of the available preoperative calculators include:

• Revised Cardiac Risk Index (RCRI) 2, 3, 4
• National Surgical Quality Improvement Program (NSQIP) index 3
• Vascular events In noncardiac Surgery patIents cOhort evaluatioN (VISION) 3
• Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity (POSSUM) 3
• Preoperative Score to Predict Postoperative Mortality (POSPOM) 3
• Orion score 3
• Alternative and optimized carotid-RCRI (CtRCRI) 5

Comparison of Preoperative Calculators

Studies have compared the performance of these calculators, with some showing that the RCRI has high negative predictive value but suboptimal accuracy in many clinical settings 2, 3. Other studies have found that alternative calculators, such as the CtRCRI, may have better predictive value for long-term cardiovascular events 5.

Factors to Consider

When selecting a preoperative calculator, factors to consider include:

• The type of surgery being performed
• The patient's medical history, including history of ischemic heart disease, congestive heart failure, and cerebrovascular disease
• The patient's renal function, including glomerular filtration rate (GFR)
• The patient's diabetes status and insulin treatment
• The patient's functional capacity and surgical procedural category 2, 6, 4

Limitations and Future Directions

While several preoperative calculators are available, their use in clinical practice is still scarce, and there is a need for a new "best standard" cardiovascular risk prediction model to supersede the RCRI 2, 3. Further research is needed to develop and validate new calculators that can accurately predict cardiac risk in patients undergoing non-cardiac surgery.