Revised Cardiac Risk Index Calculation
The Revised Cardiac Risk Index (RCRI) assigns 1 point for each of six independent risk factors: history of ischemic heart disease, history of congestive heart failure, history of cerebrovascular disease (stroke or TIA), preoperative insulin treatment for diabetes mellitus, preoperative creatinine >2 mg/dL (or GFR <30 mL/min), and high-risk surgery (intraperitoneal, intrathoracic, or suprainguinal vascular procedures). 1
Calculating the RCRI Score
Assign 1 point for each of the following six criteria present:
Ischemic heart disease: History of myocardial infarction, positive stress test, current angina, use of nitrates, or ECG with pathological Q waves 1
Congestive heart failure: History of heart failure, pulmonary edema, paroxysmal nocturnal dyspnea, bilateral rales, S3 gallop, or chest X-ray showing pulmonary vascular redistribution 1
Cerebrovascular disease: History of transient ischemic attack or stroke 1
High-risk surgery: Intraperitoneal, intrathoracic, or suprainguinal vascular procedures (including abdominal aortic aneurysm repair, other vascular surgery, thoracic surgery, abdominal surgery, or orthopedic surgery) 1
Preoperative insulin-dependent diabetes mellitus: Diabetes requiring insulin treatment 1
Preoperative renal dysfunction: Serum creatinine >2 mg/dL 1
Risk Stratification Based on Total Score
The total RCRI score predicts the risk of major adverse cardiac events (cardiac death, myocardial infarction, cardiac arrest, complete heart block, or pulmonary edema):
Class I (0 points): Low risk with 0.4-0.5% incidence of major cardiac complications 1, 2, 3
Class II (1 point): Low to moderate risk with 0.9-2.9% incidence of major cardiac complications 1, 2, 3
Class III (2 points): Moderate risk with 4.6-7.4% incidence of major cardiac complications 1, 2, 3
Class IV (≥3 points): High risk with 9.7-17.0% incidence of major cardiac complications 1, 2, 3
Clinical Application and Management
For patients with RCRI 0-1 (low risk), proceed directly to surgery without additional cardiac testing. 2, 4
For patients with RCRI ≥2 (elevated risk), assess functional capacity using the Duke Activity Status Index (DASI) or ability to achieve 4 METs. 2, 4
If functional capacity is good (≥4 METs or DASI ≥34), proceed to surgery without further testing 2, 4
If functional capacity is poor (<4 METs) or unknown, consider pharmacological stress testing only if results would change management 2, 4
Important Caveats and Limitations
The RCRI substantially underestimates cardiac risk in vascular surgery patients, particularly for lower extremity bypass, endovascular AAA repair, and open AAA repair. 5 For vascular surgery, consider using the Vascular Study Group Cardiac Risk Index (VSG-CRI) instead, which demonstrates superior discrimination (ROC 0.71 vs 0.62) 5
For thoracic surgery patients undergoing lobectomy or pneumonectomy, use the recalibrated Thoracic RCRI (ThRCRI), which includes only four variables: cerebrovascular disease (1.5 points), cardiac ischemia (1.5 points), renal disease (1 point), and pneumonectomy (1.5 points). 6 This recalibrated score shows better discrimination than the standard RCRI (c-index 0.72 vs 0.62) 6
Modern validation studies show that preoperative insulin treatment and creatinine >2 mg/dL may not independently improve predictive ability. 3 A simplified 5-factor model using GFR <30 mL/min instead of creatinine >2 mg/dL demonstrates superior prediction with identical discrimination 3
Continue beta-blockers and statins in patients already taking these medications perioperatively. 2, 4 For patients with RCRI ≥2 not on beta-blockers, initiating therapy may be reasonable if started >1 day before surgery to assess tolerability 4
Emergency surgery increases cardiac risk regardless of RCRI score and necessitates proceeding with limited evaluation while implementing intensive perioperative monitoring. 1, 7