The Revised Cardiac Risk Index (RCRI) is a clinical calculator used to estimate the risk of cardiac complications during the perioperative period in patients undergoing non-cardiac surgery. It is particularly useful for stratifying patients into different risk categories based on six identified risk factors: high-risk surgery, history of ischemic heart disease, history of congestive heart failure, history of cerebrovascular disease, insulin therapy for diabetes, and preoperative serum creatinine >2.0 mg/dL. 

The RCRI is not applicable to patients undergoing cardiac surgery, as it was specifically designed for non-cardiac surgical procedures. It also may not be as accurate in populations not represented in the original study, such as those with less common comorbidities or undergoing less common surgical procedures.

Revised Cardiac Risk Index for perioperative risks (RCRI)

# Criteria
 A. High-risk surgery (intraperitoneal, intrathoracic, or suprainguinal vascular surgery) (+1)
B. History of ischemic heart disease (history of myocardial infarction/positive exercise test, ECG with pathological Q waves, current ischemic chest pain, or use of nitrate) (+1)
C. History of congestive heart failure (pulmonary edema, bilateral rales or S3 gallop, paroxysmal nocturnal dyspnea, pulmonary vascular redistribution on chest X-ray) (+1)
D. History of cerebrovascular disease (transient ischemic attack or stroke) (+1)
E. Use of insulin for diabetes (+1)
F. Preoperative creatinine > 2 mg/dL [> 178 mcmol/L] (+1)

# Conditions
- score == 0
- score == 1
- score == 2
- score >= 3