The revised cardiac risk index (RCRI) holds a central role in preoperative cardiac risk stratification in noncardiac surgery. Its performance in unselected populations, including different age groups, has, however, not been systematically investigated. We assessed the relationship of RCRI with major adverse cardiovascular events in an unselected cohort of patients undergoing elective, noncardiac surgery overall and in different age groups.
We followed up all individuals = 25 years who underwent major elective noncardiac surgery in Denmark (January 1, 2005, to November 30, 2011) for the 30-day risk of major adverse cardiovascular events (ischemic stroke, myocardial infarction, or cardiovascular death). There were 742 of 357,396 (0.2%), 755 of 74.889 (1.0%), 521 of 11,921 (4%), and 257 of 3146 (8%) major adverse cardiovascular events occurring in RCRI classes I, II, III, and IV. Multivariable odds ratio estimates were as follows: ischemic heart disease 3.30 (95% confidence interval, 2.96-3.69), high-risk surgery 2.70 (2.46-2.96), congestive heart failure 2.65 (2.29-3.06), cerebrovascular disease 10.02 (9.08-11.05), insulin therapy 1.62 (1.37-1.93), and kidney disease 1.45 (1.33-1.59). Modeling RCRI classes as a continuous variable, C statistic was highest among age group 56 to 65 years (0.772) and lowest for those aged >85 years (0.683). Sensitivity of RCRI class >I (ie, having = 1 risk factor) for capturing major adverse cardiovascular events was 59%, 71%, 64%, 66%, and 67% in patients aged = 55, 56 to 65, 66 to 75, 76 to 85, and >85 years, respectively; the negative predictive values were >98% across all age groups.
In a nationwide unselected cohort, the performance of the RCRI was similar to that of the original cohort. Having = 1 risk factor was of moderate sensitivity, but high negative predictive value for all ages.