NT-proBNP in young healthy adults undergoing non-cardiac surgery

Objectives: N-terminal pro-brain natriuretic peptide (NT-proBNP), a standard marker for diagnosis and treatment guidance of heart failure, has previously been investigated in high-risk patients undergoing cardiac and non-cardiac surgery. However, the kinetics of NT-proBNP in healthy patients undergoing non-cardiac surgery are unknown.

Design & methods: A secondary analysis of a prospective cohort study was conducted. NT-proBNP plasma concentrations were measured preoperatively, 2-6 h, and 18-30 h after surgery in 120 patients, 18-35 years, undergoing elective non-cardiac surgery. Reasons for non-inclusion: history or symptoms of cardiac disease, kidney disease, pulmonary embolism, thrombosis, stroke, diabetes, head or chest trauma, pregnancy, incomplete panel of perioperative NT-proBNP plasma samples. Absolute and relative change of NT-proBNP plasma concentration were calculated. Changes between preoperative, 2-6 h, and 18-30 h (POD 1) NT-proBNP values, and of within-patient change in NT-proBNP were analyzed.

Results: In 95 patients, NT-proBNP plasma concentrations (median [IQR]) were 8 [5-26] pg/mL at baseline, 17 [5-53] pg/mL 2-6 h, and 42 [11-86] pg/mL 18-30 h after surgery. Absolute and relative NT-proBNP increase after surgery was 32 [5-74] pg/mL and 196% [61 - 592%] compared to baseline. NT-proBNP elevation above the age- and sex-specific reference range was observed in 6/95 (6%) patients prior to surgery and in 39/95 (41%) patients after surgery.

Conclusions: Even after uncomplicated surgery and postoperative period, NT-proBNP concentrations markedly increase in otherwise healthy adult patients. The aetiology of postoperative NT-proBNP increase is currently unknown and may be multifactorial.