Revised Cardiac Risk Index (RCRI) Calculator
Score perioperative cardiac risk before non-cardiac surgery with the Revised Cardiac Risk Index (Lee index) — six factors, one point each.
Tick each risk factor that applies:
What is the Revised Cardiac Risk Index?
The Revised Cardiac Risk Index (RCRI), often called the Lee index after Thomas Lee and colleagues who published it in 1999, is a simple bedside tool that estimates the chance of a serious cardiac complication after non-cardiac surgery. It refined the older Goldman index into six easy, equally weighted risk factors — no arithmetic, just count how many apply.
"Major cardiac complications" here means the events that change outcomes: myocardial infarction, pulmonary oedema, ventricular fibrillation or cardiac arrest, and complete heart block. Because it takes seconds and needs only the history and one lab value, the RCRI remains one of the most widely used preoperative risk scores in the world, and it is embedded in major perioperative guidelines.
The six RCRI risk factors
Each factor below scores one point. Tick the ones that apply in the calculator above.
- High-risk surgery — intraperitoneal, intrathoracic, or suprainguinal vascular procedures. These operations carry the largest fluid shifts and physiological stress.
- Ischaemic heart disease — a history of myocardial infarction, a positive stress test, current angina, use of nitrate therapy, or Q waves on the ECG.
- Congestive heart failure — a history of heart failure, pulmonary oedema, paroxysmal nocturnal dyspnoea, an S3 gallop, or bilateral crackles / vascular redistribution on chest X-ray.
- Cerebrovascular disease — a prior stroke or transient ischaemic attack.
- Insulin-treated diabetes — diabetes managed with insulin (diet- or tablet-controlled diabetes does not score).
- Renal impairment — a preoperative serum creatinine above 2.0 mg/dL (177 µmol/L).
RCRI score and estimated risk
Add the points and read across. The percentages are the commonly quoted major-adverse-cardiac-event (MACE) rates:
| Score | Class | Est. major cardiac event risk |
|---|---|---|
| 0 | I | ~0.4% |
| 1 | II | ~0.9% |
| 2 | III | ~6.6% |
| ≥ 3 | IV | ~11% |
Original event rates are from Lee et al. (1999). Later cohorts using more sensitive troponin assays report somewhat higher absolute rates, so treat these figures as a risk stratum rather than an exact probability.
How to interpret and use the score
The RCRI sorts patients into broad risk bands rather than giving a precise percentage. In practice, a score of 0–1 marks a low-risk patient who can usually proceed to surgery without extra cardiac testing, while a score of 2 or more flags elevated risk that deserves a closer look.
Crucially, a high score is not a reason to cancel surgery by itself. Current perioperative guidelines pair the RCRI with functional capacity (can the patient climb two flights of stairs, roughly 4 METs?) and ask a simple question: would further testing actually change management? If the answer is no, additional stress tests or imaging rarely help and may delay needed surgery. If the answer is yes — for example, poor functional capacity plus an elevated RCRI before major vascular surgery — further evaluation and medical optimisation may be warranted.
RCRI vs newer risk tools
The RCRI wins on simplicity and decades of validation, but it is not the only option. The ACS NSQIP Surgical Risk Calculator and the Gupta MICA model use larger datasets and procedure-specific data, and they often discriminate risk a little better — at the cost of needing an online tool and more inputs. Many clinicians use the RCRI for a fast first pass and reach for a NSQIP-based estimate when a more granular number will change the plan.
Limitations
- It was derived in stable patients undergoing elective, major non-cardiac surgery — it performs less well for emergency operations and for isolated vascular surgery.
- The original MACE rates predate high-sensitivity troponin, so true event rates today are often higher.
- It does not capture frailty, anaemia, or functional capacity, which independently affect outcomes.
For the physiology behind these risk factors, see our hemodynamics guide and the ejection fraction explainer, and test yourself in the free hemodynamics question bank.
References
- Lee TH, et al. Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery. Circulation. 1999;100(10):1043–1049. Original study.
- American College of Cardiology / American Heart Association perioperative cardiovascular evaluation guidelines. ACC · AHA.
Educational reference only — not a substitute for clinical judgement or institutional protocols.
Frequently asked questions
What is the Revised Cardiac Risk Index?
The RCRI (Lee index) estimates the risk of major cardiac complications — myocardial infarction, pulmonary oedema, ventricular fibrillation or arrest, and complete heart block — after non-cardiac surgery, using six equally weighted risk factors.
What are the six RCRI risk factors?
High-risk surgery, ischaemic heart disease, congestive heart failure, cerebrovascular disease (stroke or TIA), insulin-treated diabetes, and a preoperative serum creatinine over 2.0 mg/dL.
How is the RCRI scored?
Each of the six factors scores one point; the total (0 to 6) maps to a risk class, with higher scores indicating higher perioperative cardiac risk. There is no weighting — every factor counts equally.
What RCRI score is considered high risk?
A score of 2 or more marks elevated perioperative cardiac risk (about 6.6% at 2 points and roughly 11% at 3 or more), whereas 0–1 is low risk. The exact threshold for further action depends on the surgery and the patient's functional capacity.
Does a high RCRI mean surgery should be cancelled?
No. A high score flags the need for a closer look, not automatic cancellation. Guidelines combine the RCRI with functional capacity and ask whether further testing would actually change management before deciding.
Is the RCRI still used today?
Yes — it remains one of the most widely used and validated preoperative risk tools because it is fast and needs only the history and a creatinine. Newer models such as the ACS NSQIP calculator may discriminate risk slightly better when a more precise estimate is needed.
Does diet-controlled diabetes score a point on the RCRI?
No. Only diabetes treated with insulin scores a point. Diet- or tablet-controlled diabetes does not count toward the RCRI.