Examining Risk: A Systematic Review of Perioperative Cardiac Risk Prediction Indices

To conduct a systematic review of published cardiac risk indices relevant to patients undergoing noncardiac surgery and to provide clinically meaningful recommendations to physicians regarding the use of these indices.

A literature search of articles published from January 1, 1999, through December 28, 2018, was conducted in Ovid (MEDLINE), PubMed, Embase, CINAHL, and Web of Science. Publications describing models predicting risk of cardiac complications after noncardiac surgery were included and citation chaining was used to identify additional studies for inclusion.

Eleven risk indices involving 2,910,297 adult patients were included in this analysis. Studies varied in size, population, quality, risk of bias, outcome event definitions, risk factors identified, index outputs, accuracy, and clinical usefulness. Studies considered 6 to 83 variables to develop their models. Among the identified models, the factors with the highest predictiveness for adverse cardiac outcomes included congestive heart failure, type of surgery, creatinine, diabetes, history of stroke or transient ischemic attack, and emergency surgery. Substantial data from the large studies also supports advancing age, American Society of Anesthesiology physical status classification, functional status, and hypertension as additional risks.

The risk indices identified generally fell into two groups - those with higher accuracy for predicting a narrow range of cardiac outcomes and those with lower accuracy for predicting a broader range of cardiac outcomes. Using one index from each group may be the most clinically useful approach. Risk factors identified varied widely among studies. In addition to judicious use of predictive indices, reasoned clinical judgment remains indispensable in assessing perioperative cardiac risk.