Markedly elevated B-type natriuretic peptide in critically ill oncologic patients: A 10-year retrospective cohort study with characterization of a subgroup without identifiable risk factors

ABSTRACT: Markedly elevated B-type natriuretic peptide (BNP) in critically ill oncologic patients most commonly reflects cardiac dysfunction, sepsis, or renal failure, yet a rare subset exists in whom no conventional etiology can be identified. This 10-year retrospective observational study examined 8,666 admissions to a 20-bed oncologic intensive care unit (ICU) at a tertiary cancer center (January 2012-December 2022). Among 90 patients (1.0%) with BNP >3,000 pg/ml, 74 were analyzed after excluding those without echocardiographic data. Cardiac dysfunction was the predominant etiology (68%, n = 50), followed by sepsis confirmed on blood culture (20%, n = 15) and renal failure requiring renal replacement therapy (RRT) (7%, n = 5). Four patients (5%; 0.05% of all admissions) had no identifiable risk factor. All had solid tumors with preserved left ventricular ejection fraction, no active infection, and no renal failure requiring RRT. In-hospital mortality was 75%. Extreme BNP elevation in this subgroup likely reflects tumor-related inflammation and possible paraneoplastic mechanisms rather than primary cardiac pathology. Nurse practitioners managing oncologic ICU patients should systematically exclude conventional etiologies before attributing extreme BNP elevation to malignancy and should avoid cardiac-directed interventions in the absence of supporting clinical and echocardiographic evidence.