Revised Cardiac Risk Index for non-cardiac surgery.

What it is and when to use it

The Revised Cardiac Risk Index (RCRI), also known as the Lee index, estimates the risk of major cardiac complications (myocardial infarction, pulmonary edema, ventricular fibrillation or cardiac arrest, and complete heart block) associated with major noncardiac surgery. It assigns one point to each of six independent predictors: high-risk surgery (intraperitoneal, intrathoracic, or suprainguinal vascular), history of ischemic heart disease, history of heart failure, history of cerebrovascular disease, insulin-treated diabetes, and preoperative serum creatinine above 2.0 mg/dL. It is one of the preoperative risk-assessment tools endorsed by the ESC and ACC/AHA guidelines for noncardiac surgery.

How to interpret it

The score ranges from 0 to 6 points based on the number of factors present. In the original validation cohort (Lee 1999), the risk of major cardiac complications rises with the number of factors: 0 factors carries the lowest risk, 1 factor low risk, 2 factors intermediate risk, and 3 or more factors the highest risk, with approximate estimated rates of about 0.4%, 0.9%, 7%, and 11% respectively; later pooled validated estimates place the 0, 1, 2, and ≥3 factor groups at roughly 3.9%, 6.0%, 10.1%, and 15% for major cardiovascular complications. In practice, a score of 0–1 is interpreted as low risk and a score of ≥2 as elevated risk that may warrant medical optimization or further testing.

Limitations and when not to use it

The RCRI was developed and validated in patients aged 50 years or older undergoing elective major noncardiac surgery with hospital admission; it is not validated for urgent or emergent surgery, cardiac surgery, or low-risk or ambulatory procedures. It does not assess overall mortality risk, noncardiac complications, or functional capacity, and it tends to underestimate risk in vascular surgery. It does not replace clinical judgment or functional-capacity assessment (METs) and should not be used in isolation to decide on preoperative cardiac testing.

Frequently asked questions

What are the six factors in the Lee index (RCRI)?

High-risk surgery, ischemic heart disease, heart failure, cerebrovascular disease, insulin-treated diabetes, and serum creatinine above 2.0 mg/dL. Each factor is worth one point.

What RCRI score is considered high risk?

A score of 2 or more points is associated with substantially elevated cardiac risk and often prompts medical optimization or further evaluation; 0–1 point is considered low risk.

Is the RCRI valid for cardiac or emergency surgery?

No. It was validated in elective noncardiac surgery in patients aged 50 or older and is not validated for cardiac, emergency, or low-risk procedures.