Systematic Review: Prediction of Perioperative Cardiac Complications and Mortality by the Revised Cardiac Risk Index

BACKGROUND: The Revised Cardiac Risk Index (RCRI) is widely used to predict perioperative cardiac complications. PURPOSE: To evaluate the ability of the RCRI to predict cardiac complications and death after noncardiac surgery. DATA SOURCES: MEDLINE, EMBASE, and ISI Web of Science (1966 to 31 December 2008). STUDY SELECTION: Cohort studies that reported the association of the RCRI with major cardiac complications (cardiac death, myocardial infarction, and nonfatal cardiac arrest) or death in the hospital or within 30 days of surgery. DATA EXTRACTION: Two reviewers independently extracted study characteristics, documented outcome data, and evaluated study quality. DATA SYNTHESIS: Of 24 studies (792 740 patients), 18 reported cardiac complications; 6 of the 18 studies were prospective and had uniform outcome surveillance and blinded outcome adjudication. The RCRI discriminated moderately well between patients at low versus high risk for cardiac events after mixed noncardiac surgery (area under the receiver-operating characteristic curve AUC, 0.75 95% CI, 0.72 to 0.79); sensitivity, 0.65 CI, 0.46 to 0.81; specificity, 0.76 CI, 0.58 to 0.88; positive likelihood ratio, 2.78 CI, 1.74 to 4.45; negative likelihood ratio, 0.45 CI, 0.31 to 0.67). Prediction of cardiac events after vascular noncardiac surgery was less accurate (AUC, 0.64 CI, 0.61 to 0.66; sensitivity, 0.70 CI, 0.53 to 0.82; specificity, 0.55 CI, 0.45 to 0.66; positive likelihood ratio, 1.56 CI, 1.42 to 1.73; negative likelihood ratio, 0.55 CI, 0.40 to 0.76). Six studies reported death, with a median AUC of 0.62 (range, 0.54 to 0.78). A pooled AUC for predicting death could not be calculated because of very high heterogeneity (I(2) = 95%). LIMITATION: Studies generally were of low methodological quality, had varied definitions of cardiac events, and were statistically and clinically heterogeneous. CONCLUSION: The RCRI discriminated moderately well between patients at low versus high risk for cardiac events after mixed noncardiac surgery. It did not perform well at predicting cardiac events after vascular noncardiac surgery or at predicting death. High-quality research is needed in this area of perioperative medicine.