Also known as RCRI, Revised Cardiac Risk Index, Lee Index
Cardiac complication rate after noncardiac surgery — preoperative reference.
Clinically reviewed bySamira Bahrainy, MDNot an endorsement of any individual result, and no substitute for the treating clinician’s judgement.
Reviewed Oct 21, 2026Version 1.0.0Next review Oct 21, 2028
Applies to / doesn’t apply to7
Applies to: Adults aged 50 or older undergoing nonemergent major noncardiac surgery with an expected hospital stay of at least two days. The abstract calls this “elective major noncardiac procedures”; the Methods operationalise it as nonemergent plus the expected-stay requirement. Day-case and ambulatory surgery fall outside the derivation cohort.
- Emergency surgery. The index has no role there: urgency comes first, and these patients proceed without formal risk testing.
- Cardiac surgery — the index is for noncardiac surgery only.
- Minor, ambulatory or day-case surgery, or an expected hospital stay under two days — outside the derivation cohort’s entry criteria.
- Patients under 50 — outside the entry criteria.
- Vascular surgery, and abdominal aortic aneurysm repair in particular. The derivation paper’s own AAA subgroup found no relationship between risk class and major cardiac complications (ROC 0.543 ± 0.092), and pooled vascular discrimination is 0.64 (0.61–0.66) against 0.75 (0.72–0.79) in mixed noncardiac surgery (Ford 2010).
- Chronic dialysis or kidney transplant. A validation across 38,541 surgeries in kidney failure found the index over-predicts, with AUC 0.64 (0.62–0.65) (Harrison 2022), and no source gives a rule for interpreting the creatinine item in an anuric patient.
- Patients with active unstable disease poorly represented in the cohort — unstable angina, class IV heart failure, an active transient ischaemic attack, or critical aortic stenosis.
Intraperitoneal, intrathoracic, or suprainguinal vascular surgery. Carotid endarterectomy and infrainguinal vascular procedures do not count.
Any one of: history of myocardial infarction; history of a positive exercise test; current chest pain considered due to myocardial ischaemia; current nitrate therapy; ECG with pathological Q waves. A prior coronary bypass or angioplasty on its own does not count.
Any one of: history of congestive heart failure, pulmonary oedema, or paroxysmal nocturnal dyspnoea; bilateral rales or an S3 gallop on examination; chest radiograph showing pulmonary vascular redistribution.
Prior transient ischaemic attack or stroke. Carotid stenosis without a prior TIA or stroke does not count.
Receiving insulin for diabetes before surgery. Diabetes managed by diet or oral agents alone does not count.
Scores only above 2.0 mg/dL (176.8 µmol/L). Entered as measured; a value of exactly 2.0 does not score.
Optional, and scores no points — the index has no dialysis item. Recorded because the creatinine criterion was not derived for patients on dialysis or with a kidney transplant.
What this score estimates
Counts how many of six preoperative predictors are present before nonemergent major noncardiac surgery, and reports the rate of major cardiac complications observed during the index hospital admission in patients with that many predictors. The endpoint is exactly four events — myocardial infarction, pulmonary oedema, ventricular fibrillation or primary cardiac arrest, and complete heart block; cardiac death is not part of it. Each predictor is worth one point, so the score is an integer from 0 to 6, grouped into Class I–IV at 0, 1, 2 and 3 or more. It is an observed group rate for a defined composite endpoint, not an individual probability.
Pearls & pitfalls
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- The displayed rates come from a cohort operated on between 1989 and 1994, in which myocardial infarction was identified by CK-MB rather than troponin. They are lower than the rates observed in contemporary, troponin-surveilled cohorts, which is why CCS 2017 recalibrated its risk communication around later studies rather than these figures.
- The rate attached to a score depends on which endpoint is being counted and in which population, so the same score carries very different published figures across sources: from the in-hospital four-event composite shown here up to VISION’s 30-day figures, which reach 8.2% at a score of 0 once myocardial injury after noncardiac surgery is included (Roshanov 2021). Other widely used calculators show higher rates for this same score for that reason, not because either number is wrong.
- This calculator applies no elevated-risk threshold. ACC/AHA 2024 defines elevated risk as a predicted risk of major adverse cardiovascular events of 1% or more and notes that an RCRI above 1 has traditionally been used as the threshold. The score and the estimate are not interchangeable: the rates shown here count a different endpoint, in a different era.
- Discrimination is modest and does not support reading a rate as a precise individual estimate: AUC 0.759 in the derivation cohort and 0.806 in the validation cohort for the in-hospital composite (Lee 1999), and C 0.69 for 30-day myocardial infarction, nonfatal arrest or cardiac death — 0.65 once myocardial injury is included — across 35,815 patients in VISION (Roshanov 2021).
- The 95% confidence intervals for the displayed validation-cohort rates are 0.05–1.5% (Class I), 0.3–2.1% (Class II), 3.9–10.3% (Class III) and 5.8–18.4% (Class IV) (Lee 1999).
- The derivation cohort of the same paper gives 0.5%, 1.3%, 3.6% and 9.1% on the identical endpoint. Validation Class III (6.6%) sits above derivation Class III (3.6%) while Class II sits below it; with 109–567 patients per class and heavily overlapping confidence intervals, that is cohort noise and should not be smoothed away.
- Class IV covers every score from 3 to 6 and reports one rate. No primary source publishes a distinct rate above a score of 2, so a per-score figure for 4, 5 or 6 would be fabricated.
- Equal weighting is the paper’s explicit choice, not a later simplification: the authors fitted variable weights and found no demonstrated discrimination advantage (ROC 0.765 ± 0.032 weighted against 0.759 ± 0.032 equal, P = 0.28). P = 0.28 means no advantage was demonstrated — it is not evidence that the two are equivalent.
- In most settings the error is under-prediction: across 10,081 nonemergent vascular procedures the index underestimated an in-hospital composite by 1.7- to 7.4-fold (Bertges 2010). The documented exception is kidney failure, where it over-predicts (Harrison 2022).
- It does not predict mortality. Across 24 studies and 792,740 patients, median AUC for death was 0.62, range 0.54–0.78 (Ford 2010).
- Lee found that advanced age, critical aortic stenosis and rhythm abnormalities were not retained by the model, and warned that this could reflect cohort selection. Their absence from the score is not evidence that they do not matter clinically.
Not captured by the score:
- Age beyond the ≥50 entry criterion
- Functional capacity or exercise tolerance (METs, DASI)
- Valvular disease, including critical aortic stenosis
- Pulmonary hypertension
- Arrhythmia
- Frailty
- Anaemia
- Emergency status
- Gradations of surgical severity beyond the three listed categories
- Intraoperative haemodynamics
- Biomarkers — BNP, NT-proBNP, troponin
What the guidelines say
4
States that its panel favoured the RCRI among available indices, and recalibrated its risk communication around later troponin-surveilled studies rather than the 1999 rates.
View guideline source ↗Lists the RCRI alongside NSQIP MICA, ACS-NSQIP, SORT and AUB-HAS2, and records that the Task Force decided against recommending one specific risk score.
View guideline source ↗Describes the RCRI as six equal-point variables, restates the creatinine criterion as 2.0 mg/dL or above, and attaches 30-day percentages drawn from later pooled validation material rather than the derivation paper’s in-hospital composite.
View guideline source ↗Lists the RCRI among perioperative risk scores and calculators, defines elevated risk as a predicted risk of major adverse cardiovascular events of 1% or more, and notes that determining elevated risk depends on the calculator used — traditionally an RCRI above 1, or a calculated risk above 1% on any calculator.
View guideline source ↗Guideline positions are stated as published. Curie.MD Calc does not publish treatment direction.
Where this comes from
8
How it’s scored
What was observed
References
- Lee TH, Marcantonio ER, Mangione CM, et al. Circulation. 1999;100(10):1043-9. View source ↗
- Ford MK, Beattie WS, Wijeysundera DN. Ann Intern Med. 2010;152(1):26-35. View source ↗
- Bertges DJ, Goodney PP, Zhao Y, et al. J Vasc Surg. 2010;52(3):674-83. View source ↗
- Roshanov PS, Sessler DI, Chow CK, et al. Can J Cardiol. 2021;37(8):1215-24. View source ↗
- Harrison TG, Ruzycki SM, James MT, et al. CJC Open. 2022;4(10):905-13. View source ↗
- Duceppe E, Parlow J, MacDonald P, et al. Canadian Cardiovascular Society guidelines on perioperative cardiac risk assessment and management for patients who undergo noncardiac surgery. Can J Cardiol. 2017;33(1):17-32. View source ↗
- 2022 ESC Guidelines on cardiovascular assessment and management of patients undergoing non-cardiac surgery. Eur Heart J. 2022;43(39):3826-924. View source ↗
- ACC/AHA 2024 multisociety perioperative guideline. Circulation. 2024;150:e351-e442. View source ↗