What the RCRI does
Before noncardiac surgery, the anesthesia and surgical team needs to know how likely a major cardiac complication is: a heart attack, pulmonary edema, ventricular fibrillation or cardiac arrest, or complete heart block. The Revised Cardiac Risk Index (RCRI), published by Thomas Lee and colleagues in 1999, estimates that risk from six simple factors. It is still the most widely used preoperative cardiac risk tool.
The six criteria
| Criterion | Points |
|---|---|
| High-risk surgery: intraperitoneal, intrathoracic or suprainguinal vascular | 1 |
| Ischemic heart disease: past heart attack, positive stress test, angina, nitrate use or pathological Q waves | 1 |
| History of heart failure | 1 |
| History of stroke or transient ischemic attack | 1 |
| Diabetes treated with insulin | 1 |
| Preoperative creatinine above 2 mg/dL (177 µmol/L) | 1 |
Risk by score
| Score | Class | Lee 1999 | Updated 2017 estimate |
|---|---|---|---|
| 0 | I | 0.4% | 3.9% |
| 1 | II | 0.9% | 6.0% |
| 2 | III | 6.6% | 10.1% |
| 3 or more | IV | 11% | 15.0% |
The updated estimates come from a 2017 meta-analysis used by the Canadian Cardiovascular Society. They measure a broader outcome, death, heart attack or cardiac arrest within 30 days, and were derived from more recent and more routinely screened patients, which explains the higher rates.
Worked example
A patient with insulin-treated diabetes is scheduled for open bowel surgery. The surgery counts 1 point and insulin 1 point, for a score of 2, class III: a risk of about 6.6% in the original study and 10.1% in the updated estimate.
How the score is used
- Low risk (0 points) and good exercise capacity: surgery can usually proceed without further cardiac testing.
- Elevated risk: guidelines suggest assessing functional capacity (for example, can the patient climb two flights of stairs?) and, in some guidelines, measuring BNP or NT-proBNP before surgery, or troponin after it.
- Stress testing or coronary angiography is reserved for patients who would need it anyway, regardless of the surgery.
Limits
The RCRI does not account for age, the urgency of surgery or the patient’s fitness. Emergency surgery, frailty and poor functional capacity all add risk. Other tools, such as the American College of Surgeons NSQIP calculator, use many more variables.
This calculator is for general information and education. It is not medical advice and does not replace the judgment of a doctor, nurse or pharmacist who knows the full clinical picture.