Revised Cardiac Risk Index Calculator (Lee Index for Pre-operative Risk)
Calculate the Revised Cardiac Risk Index (Lee index) before non-cardiac surgery — six risk factors, class I–IV and the estimated risk of major cardiac complications, original and updated (CCS 2017).
How it works
RCRI = 1 point each for: high-risk surgery, ischemic heart disease, heart failure, cerebrovascular disease, insulin-treated diabetes, creatinine > 2 mg/dL. Class I = 0, II = 1, III = 2, IV ≥ 3. Risk of major cardiac complications (Lee 1999): 0.4%, 0.9%, 6.6%, 11.0%; updated 30-day risk (Duceppe 2017): 3.9%, 6.0%, 10.1%, 15.0%.
The Revised Cardiac Risk Index (Lee et al., Circulation 1999) is the most widely used tool for estimating the risk of a major cardiac complication — myocardial infarction, pulmonary oedema, ventricular fibrillation, cardiac arrest or complete heart block — after non-cardiac surgery. Later validation with modern troponin surveillance found higher event rates, so the Canadian Cardiovascular Society (Duceppe 2017) published updated risks. CCS advises measuring BNP or NT-proBNP before surgery in patients with an RCRI of 1 or more, age 65 or over, or age 45–64 with significant cardiovascular disease.
Worked example
A patient with angina history (ischemic heart disease) booked for open abdominal surgery (high-risk surgery) and no other factors scores RCRI = 2 / 6 — class III, with a 6.6% risk of major cardiac complications in the original study and 10.1% 30-day risk in the updated estimates.
Sources: Lee TH et al. Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery. Circulation 1999 · Duceppe E et al. Canadian Cardiovascular Society guidelines on perioperative cardiac risk assessment. Can J Cardiol 2017
Frequently asked questions
What does an RCRI score of 0 mean?
Class I — the lowest risk group, with about 0.4% major cardiac complications in the original study (3.9% for the broader updated outcome). Further cardiac testing is rarely needed for that reason alone.
What is high-risk surgery in the RCRI?
Intraperitoneal (e.g. bowel resection), intrathoracic (e.g. lung resection) or suprainguinal vascular surgery (e.g. aortic surgery).
Why are there two risk percentages?
The original 1999 figures came from one centre; a later systematic review and the Canadian guideline found higher event rates when patients were monitored with troponins, so both are shown.
Does a high RCRI mean surgery is unsafe?
Not by itself. It guides further assessment (functional capacity, biomarkers, cardiology input) and peri-operative monitoring; the decision balances surgical benefit against risk.
Related calculators
Clinical decision tool for education and for use by trained clinicians alongside clinical judgement — not a diagnosis and not a substitute for medical assessment. Scores validated in specific populations may not apply to every patient.