Revised Cardiac Risk Index (RCRI)

RCRI explained

This Revised Cardiac Risk Index (RCRI) helps in the evaluation of patients undergoing cardiac surgery.

It estimates the likelihood of perioperative cardiac events and therefore can support clinical decision making as to the benefits and risks surgery has over other treatment options that might be available for individual cases.

The criteria considered in the RCRI is discussed below:

1. High-Risk Surgery

- Intraperitoneal;

- Intrathoracic;

- Suprainguinal vascular.

The first criteria checks whether the patient is undergoing any of the above types of surgery, which are considered to have a higher risk of subsequent perioperative cardiac complications.

2. History of ischemic heart disease

Patient history which is proven through history positive test, diagnosed MI, the patient under nitrate therapy, current chest pain suspicion of myocardial ischemia or evidence of pathological Q waves on electrocardiogram.

3. History of congestive heart failure

- Pulmonary edema, bilateral rales or S3 gallop;

- Paroxysmal nocturnal dyspnea;

- CXR showing pulmonary vascular redistribution.

The presence of any of the above three symptoms indicates history of CHF.

4. History of cerebrovascular disease

- Prior TIA or stroke.

5. Pre-operative insulin treatment.

6. Pre-operative creatinine more than 2 mg/dL.

This signals presence of chronic kidney disease.

The RCRI refers to the following conditions as major cardiac events or complications:

■ Myocardial infarction;

■ Ventricular fibrillation;

■ Primary cardiac arrest;

■ Pulmonary edema;

■ Complete heart block.

The RCRI and programs such as the National Surgical Quality Improvement Program (NSQIP) cater for cardiac surgery complications, but there are other evaluations that deal with cardiac risk arising from noncardiac surgery.

Myocardial infarction and heart failure are common causes of morbidity and mortality in any type of serious surgery.

Similarly, the spectrum of peri and post-operative complications does not end with cardiac events, as other complications such as coagulopathy, cerebrovascular disease or anemia can occur.

Result interpretation

The RCRI is simple and straightforward to calculate: the presence of either of the criteria counts as 1 point towards the final score which varies between 0 and 6.

The higher the score, the higher the risk of post operative cardiac events.

The scores are assigned to four risk classes, as follows:

About the study

The score was created by Lee et al. in 1999 as a revision of the original cardiac risk evaluation by Goldman (from 1977).

Every criteria in the RCRI was found to have independent predictive value and the index is part of the American Heart Association and American College of Cardiology.

By comparison to the original study, the revised version, the RCRI is easier to administer and more accurate in clinical settings.

The RCRI was created following a study that involved a cohort of 4315 patients of age 50 and above who were to undergo an elective major noncardiac procedure in a tertiary-care teaching hospital.

The main outcome measure considered was major cardiac complications, which occurred in 2% of the 2893 patients from the derivation cohort.

The score was found to accurately identify patients at higher risk for complications.

Original source

Lee TH, Marcantonio ER, Mangione CM, Thomas EJ, Polanczyk CA, Cook EF, Sugarbaker DJ, Donaldson MC, Poss R, Ho KK, Ludwig LE, Pedan A, Goldman L. Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery. Circulation. 1999; 100(10):1043-9.

Original index study

Goldman L, Caldera DL, Nussbaum SR, Southwick FS, Krogstad D, Murray B, Burke DS, O'Malley TA, Goroll AH, Caplan CH, Nolan J, Carabello B, Slater EE. Multifactorial index of cardiac risk in noncardiac surgical procedures. N Engl J Med. 1977; 297(16):845-50.