The most common major vascular complication after noncardiac surgery is myocardial injury, which is associated with perioperative death. Several guidelines recommend using the Revised Cardiac Risk Index to predict perioperative cardiac risk. However, although this tool is easy to use, its accuracy is limited. As part of an international prospective cohort study, researchers evaluated whether the measurement of preoperative N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels has predictive value beyond the Revised Cardiac Risk Index for the composite of vascular death and myocardial injury 30 days after noncardiac surgery.

The study included 10,402 adults age 45 or older who had inpatient noncardiac surgery. NT-proBNP levels were measured before surgery, and troponin levels were measured for three days after surgery. The Revised Cardiac Risk Index was calculated after study completion; researchers were blinded to the results.

The primary composite outcome of vascular death and myocardial injury after noncardiac surgery occurred in 1,269 (12.2%) patients within 30 days of surgery. Compared with the reference group (NT-proBNP, less than 100 pg/mL), patients with NT-proBNP levels of 100 to less than 200 pg/mL, 200 to less than 1,500 pg/mL, and 1,500 pg/mL or more had adjusted hazard ratios of 2.27, 3.63, and 5.82, respectively, according to multivariable analyses. Corresponding incidences of the primary outcome were 12.3%, 20.8%, and 37.5%, respectively. NT-proBNP levels also independently predicted secondary outcomes, including myocardial infarction and all-cause mortality. Preoperative NT-proBNP levels, in addition to the Revised Cardiac Risk Index, substantially improved prediction of postoperative risk.

In noting the study's limitations, the authors point out that they identified new NT-proBNP ranges for this study that were derived from the sample population and weren't externally validated. They advise that clinicians should consider using information about preoperative NT-proBNP levels to improve preoperative cardiac risk stratification in patients having noncardiac surgery.