RCRI Calculator (Lee Revised Cardiac Risk Index before non-cardiac surgery)

Understanding the RCRI calculator — concept and principle

The Revised Cardiac Risk Index (RCRI, Lee index) estimates the risk of major cardiac complications after non-cardiac surgery from six simple factors. Anaesthetists, surgeons and physicians use it in pre-operative assessment to decide whether further heart testing or other precautions are needed.

One point per factor: with the default inputs the result is 2 → Class III (6.6% in validation).

How it is calculated

RCRI (0–6) = one point each for:

High-risk surgery: inside the abdomen or chest, or vascular surgery above the groin
Ischaemic heart disease
History of heart failure
History of stroke or TIA
Diabetes treated with insulin
Pre-operative creatinine above 2.0 mg/dL (177 µmol/L)

Classes I–IV = 0, 1, 2 and 3 or more points.

The principle

Lee and colleagues (1999) studied 2,893 patients undergoing major non-cardiac surgery and found six factors that independently predicted heart attack, pulmonary oedema, ventricular fibrillation or cardiac arrest, and complete heart block. Each received equal weight, which keeps the score easy to use. They then validated it in 1,422 further patients.

Worked example

Default inputs: high-risk surgery yes, ischaemic heart disease yes, all others no.

Points = 1 + 1 = 2.
2 points → Class III.
Major cardiac complications: 6.6% in the validation cohort, 3.6% in the derivation cohort.

How to read the result

Where does your result fall?

Rates in the original study were 0.4%, 0.9%, 6.6% and 11.0% for classes I–IV in the validation cohort. Later studies with routine troponin testing found higher event rates, so the percentages are best read as relative risk. Higher classes, combined with poor functional capacity, may prompt further assessment, but many patients proceed without extra tests.

Common mistakes

Counting low-risk procedures such as most limb operations as high-risk surgery.
Counting diabetes treated with tablets only.
Using the score for heart surgery.

Keep in mind: This is a decision aid for clinicians, not a diagnosis. Pre-operative decisions are made by the anaesthetic and surgical team.

Frequently asked questions

What RCRI score is high risk?

Three or more points (class IV) carries the highest risk.

Does a high score cancel surgery?

Not usually; it helps the team plan monitoring and optimise treatment.

Is there a newer tool?

Yes, tools such as the NSQIP calculator, but RCRI remains widely used for its simplicity.

Sources: Lee TH, Marcantonio ER, Mangione CM, et al., "Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery", Circulation 1999;100:1043–1049

Checked 9 Nov 2026. Lee TH, Marcantonio ER, Mangione CM, et al., “Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery”, Circulation 1999;100:1043–1049 (Table 1 risk factors and definitions; Table 3 complication rates by class, derivation n = 2,893 and validation n = 1,422).

Your numbers