Association of preoperative NT-proBNP with 30-day and five-year mortality after cardiac surgery

Elevated levels of N-terminal prohormone of brain natriuretic peptide (NT-proBNP) reflect cardiac status in heart failure patients and are independently associated with mortality and adverse cardiovascular outcomes in elective patients undergoing non-cardiac surgery. However, there is scarce evidence about the association between NT-proBNP and outcome after cardiac surgery in large patient populations.

The aim of this study was to analyze the association of preoperative NT-pro-BNP levels with 30-day and five-year mortality after cardiac surgery.

A consecutive cohort of 6938 patients undergoing cardiac surgery was analyzed retrospectively. The relationship between preoperative NT-proBNP and 30-day and five-year mortality adjusted for EuroSCORE II was explored using a Cox proportional hazards model. The dynamics of preoperative NT-proBNP were analyzed by comparing the values at the time of diagnosis or assignment to surgery with the values on the day before surgery (n= 4739). Results were validated in an external cohort from the SWEDEHEART registry (n=3415).

Median preoperative NT-proBNP was 552 ng/l. Death within 30 days occurred in 2.1% of the patients.

High preoperative NT-proBNP levels were associated with a higher 30-dayand 5-yearmortality. Preoperative NT-proBNP thresholds to identify patients at high-risk (>4000 ng/l), intermediate-risk (2000-4000 ng/l) and low-risk (<2000 ng/l) for 30-day mortality were determined. Patients in the intermediate or high-risk category had a higher risk for prolonged ICU stay (OR 2.52), ultrafiltration (OR 3.68), ECMO (OR 3.63), 30-day mortality (HR 2.79), and 5-year mortality (HR 2.41) (p-value all <0.001). Patients who improved in the preoperative NT-proBNP risk had a significant 30-day and five-year survival benefit.

Preoperative NT-proBNP levels are independently associated with 30-day and five-year mortality after cardiac surgery. NT-proBNP reduction prior to surgery might decrease 30-day and five-year mortality after cardiac surgery.

NTproBNP is associated with outcome