Nt-proBNP in Pediatric Cardiac Surgery: A Correlation Study with the Postoperative Course and Morbidity

INTRODUCTION: B-type natriuretic peptides, synthesized by cardiac myocytes in response to increased ventricular wall stress, are secreted as prohormones and cleaved into biologically active hormone (BNP) and the inactive N-terminal fragment, known as Nt-proBNP. They possess diuretic, natriuretic, and vasodilatory effects. Recently, B-type natriuretic peptides have been identified as valuable param-eters in detecting acute and chronic left ventricular dysfunction. This study aims to investigate the relationship between preoperative and postoperative Nt-proBNP levels, the postoperative course, and morbidity in congenital cardiac surgery patients.
METHODS: Thirty-one patients, aged between 3 months and 16 years, undergoing open-heart surgery with cardiopulmonary bypass due to congenital heart disease, were examined. The patients had left-to-right shunt lesions or stenosis in the ventricular outflow tract. Patients were divided into two groups based on the need for high-dose (>5mcg/kg/min) inotropic therapy during the postoperative period: those requiring high-dose inotropic support and those requiring low-dose or no inotropic support. Nt-proBNP levels were measured preoperatively (T0), at 2 hours postoperatively (T1), and 24 hours postoperatively (T2). Additionally, postoperative inotropic support, cardiopulmonary bypass, cross-clamp, and mechanical ventilation durations were recorded.
RESULTS: There was a statistically significant difference in cross-clamp durations between the groups. Statistically significant differences were also observed in the duration of inotropic therapy, mechanical ventilation, and length of stay in the intensive care unit. Our study revealed a correlation between the dose and duration of inotropic therapy administered during the postoperative period and Nt-proBNP levels, with patients requiring high-dose inotropic support showing a mean serum level of 1009.10±1345.43 pg/ml. This finding suggests an association between elevated Nt-proBNP levels and increased postoperative inotropic requirements.
DISCUSSION AND CONCLUSION: In the context of adult heart illnesses and cardiac surgery, serum Nt-proBNP levels are a biochemical marker that can effectively assess low functional capability and prognosis. Elevated levels of preoperative serum Nt-proBNP in individuals having cardiac surgery for congenital heart abnormali-ties offer crucial insights into myocardial function and the efficacy of medicinal interventions.