Predictive Value of Stress Testing, Revised Cardiac Risk Index, and Functional Status in Patients Undergoing Noncardiac Surgery

Abstract

Objective: Patients undergoing noncardiac surgery are at risk for postoperative cardiovascular complications. Literature regarding the ability of the Revised Cardiac Risk Index (RCRI), functional capacity, and stress testing to predict perioperative cardiac events is scarce. The authors examined the association of these parameters with perioperative cardiac events and their additive ability to predict these outcomes.

Design: This was a single-center retrospective study conducted at the Cleveland Clinic.

Setting: Hospital.

Participants: Patients undergoing noncardiac surgery.

Intervention: Patients underwent stress testing.

Measurements and main results: The primary outcome of interest was major adverse cardiac events (MACE). The study cohort included 509 patients with a predominantly good functional status, as defined by estimated metabolic equivalents (METSe), which was ≥4 in 83% of the patients. The addition of preoperative stress testing, when indicated based on the RCRI and functional class limitation, only modestly improved discrimination of risk for postoperative outcomes (METSe + RCRI + positive stress test-C statistic 0.77 for MACE; 0.84 for 1-year mortality) compared with the combination of functional capacity (METSe) and RCRI (C statistic 0.70 for MACE; 0.79 for 1-year mortality). A surprisingly high prevalence of false negative stress tests (negative stress tests in patients who later had presence of obstructive coronary disease on angiography) was noted, but the C statistic for MACE remained unchanged, even when no false negative results were assumed.

Conclusions: In a cohort of patients with predominantly good functional status and intermediate-to-high RCRI scores, addition of a preoperative stress test was of only moderate value in predicting postoperative cardiovascular outcomes compared with a combination of functional class and RCRI.

Keywords: cardiovascular outcomes; non cardiac surgery; stress test.