What pre-operative evaluation scoring guides, such as American Society of Anesthesiologists (ASA) Physical Status classification system or Revised Cardiac Risk Index (RCRI), are recommended for assessing risk of complications in adult patients with cardiovascular disease or diabetes?

Preoperative Evaluation Scoring Guides

For adult patients with cardiovascular disease or diabetes undergoing noncardiac surgery, use the Revised Cardiac Risk Index (RCRI) as your primary risk stratification tool, supplemented by the American Society of Anesthesiologists Physical Status (ASA-PS) classification and functional capacity assessment using the Duke Activity Status Index (DASI). 1, 2, 3

Primary Risk Stratification Tools

Revised Cardiac Risk Index (RCRI)

The RCRI is the most widely validated and ACC/AHA-endorsed tool for initial cardiac risk assessment. 1, 2, 3, 4

• Calculate the RCRI by assigning 1 point for each of 6 risk factors: ischemic heart disease, heart failure, cerebrovascular disease, high-risk surgery (intraperitoneal, intrathoracic, or suprainguinal vascular), insulin-dependent diabetes, and chronic renal dysfunction (creatinine >2 mg/dL). 2, 3, 4

• Risk stratification based on total score:

  • 0-1 points = Low risk (<1% MACE rate): proceed directly to surgery without additional cardiac testing 2, 3
  • 2 points = Moderate risk: assess functional capacity; additional testing only if capacity is poor or unknown and results would change management 3
  • ≥3 points = High risk: implement comprehensive cardiac monitoring, assess functional capacity, and consider pharmacological stress testing if it would alter management 2, 3

American Society of Anesthesiologists Physical Status (ASA-PS)

The ASA-PS classification independently predicts postoperative complications and mortality across all surgical procedures. 1, 5, 6

• ASA-PS demonstrates strong predictive power with odds ratios ranging from 2.05 to 63.25 for complications and 5.77 to 2011.92 for mortality as classification increases from 2 to 5. 5

• ASA-PS classification correlates with delirium risk: ASA 3 shows OR 1.76 (95% CI 1.05-2.95) and ASA 4 shows OR 2.43 (95% CI 1.42-4.14) compared to ASA 1. 1

• A critical limitation is poor inter-rater reliability even among anesthesiologists, which may reduce its precision in individual cases. 1

Functional Capacity Assessment

Functional capacity is a reliable predictor of perioperative cardiac events and should be assessed using the Duke Activity Status Index (DASI). 1, 2, 3

• Patients unable to perform 4 METs of activity during daily life have increased perioperative and long-term cardiac risk. 1

• Activities <4 METs include: slow ballroom dancing, golfing with a cart, playing a musical instrument, walking at 2-3 mph. 1

• Activities >4 METs include: climbing a flight of stairs, walking uphill, walking on level ground at 4 mph, performing heavy housework. 1

• Good functional capacity (≥4 METs) allows patients to proceed to surgery even with elevated RCRI scores, while poor capacity (<4 METs) warrants consideration of pharmacological stress testing if results would change management. 3

Advanced Risk Calculators

American College of Surgeons NSQIP Surgical Risk Calculator

The NSQIP calculator may offer superior discrimination compared to RCRI, particularly for procedure-specific risk assessment. 1, 3

• This calculator uses 21 patient-specific variables (age, sex, BMI, dyspnea, previous MI, functional status) plus the specific CPT code to calculate percentage risk of MACE, death, and 8 other outcomes. 1

• The NSQIP MICA calculator shows a median delta c-statistic of 0.11 higher than RCRI for predicting myocardial infarction and cardiac arrest. 3

• Access the calculator at www.riskcalculator.facs.org for procedure-specific risk estimation. 1

• Key limitation: has not been validated outside the NSQIP population and defines MI narrowly (only ST-elevation MI or troponin >3× normal in symptomatic patients). 1

Thoracic Revised Cardiac Risk Index (ThRCRI)

For thoracic surgery patients specifically, use the ThRCRI instead of standard RCRI. 2, 3, 4

• ThRCRI uses weighted factors including ischemic heart disease, cerebrovascular disease, serum creatinine, and whether pneumonectomy is planned. 3

• This tool has been externally validated specifically for lung resection cohorts and provides more accurate risk assessment than RCRI in thoracic surgery populations. 3

Biomarker-Enhanced Risk Stratification

For patients with RCRI ≥2, measure preoperative NT-proBNP and/or troponin to enhance risk prediction. 3

• The combination of NT-proBNP and troponin provides a median delta c-statistic improvement of 0.12 over RCRI alone. 3

• BNP alone shows a median delta c-statistic of 0.15 higher than RCRI for MACE prediction. 3

• However, no data demonstrate that targeting these biomarkers for treatment reduces postoperative risk, limiting their clinical utility beyond risk stratification. 1

Additional Preoperative Testing Based on Risk Scores

12-Lead ECG Indications

Obtain a 12-lead ECG for: 1

• Recent chest pain or ischemic equivalent in intermediate- or high-risk patients scheduled for intermediate- or high-risk procedures (Class I) 1
• Asymptomatic patients with diabetes mellitus (Class IIa) 1
• Patients with prior coronary revascularization (Class IIb) 1

Do not routinely obtain ECG in asymptomatic subjects undergoing low-risk procedures (Class III). 1

Left Ventricular Function Assessment

Assess resting left ventricular function in: 1

• Patients with current or poorly controlled heart failure (Class I) 1
• Patients with prior heart failure or dyspnea of unknown origin (Class IIa) 1

Do not routinely assess left ventricular function in patients without prior heart failure (Class III). 1

Age-Specific Risk Considerations

Age is a powerful independent predictor of postoperative complications: 1

• Age 66-85 years: OR 2.67 (95% CI 2.16-3.29) for delirium compared to ≤65 years 1
• Age >85 years: OR 6.24 (95% CI 4.65-8.37) for delirium compared to ≤65 years 1

Clinical Pitfalls and Caveats

RCRI performs poorly in vascular surgery populations; consider using the Gupta score or NSQIP calculator instead for these patients. 3

Emergency surgery increases cardiac risk regardless of RCRI score; focus on immediate perioperative medical optimization rather than extensive testing in these cases. 3

Combining ASA-PS with surgeon-generated risk estimates improves prediction accuracy (AUC 0.84) to match clinical data-based models. 6

For patients with BMI <18.5, the risk of delirium increases substantially (OR 2.25,95% CI 1.64-3.09). 1

Male sex independently increases risk (OR 1.28,95% CI 1.08-1.5) compared to female sex. 1