B-type natriuretic peptide predicts long-term prognosis in a cohort of critically Ill patients

Abstract

B-type natriuretic peptide is an important prognostic marker in heart failure. However, there are limited data for its value in non-cardiac intensive care unit patients, namely regarding long-term prognosis. We investigated the long-term prognostic value of BNP in a cohort of critically ill patients. This was a prospective and observational study, conducted in a tertiary university hospital 20-bed intensive care unit. We included 103 mechanically- ventilated patients admitted for a noncardiac primary diagnosis; B-type natriuretic peptide samples were obtained on admission. A mean 14 (3-30) month follow up was available in 96.1% of patients who were discharged from hospital. Mean age was 60.7±19.0 years and mean APACHE II score was 16.2±7.2. APACHE II score and renal dysfunction increased with rising B-type natriuretic peptide, with more than 60% of patients having Btype natriuretic peptide levels of 100 pg/mL or over; echocardiography-derived left ventricular ejection fraction was lower in patients with higher B-type natriuretic peptide (P < 0.001). Long-term survivors had lower median B-type natriuretic peptide values (117.5[2-1668] pg/mL) compared with intensive care unit non-survivors (191.0[5-4945] pg/mL), P<0.001. After adjustment to APACHE II score, B-type natriuretic peptide levels of 300 pg/mL or over were independently associated with long-term mortality (odds-ratio 4.1 [95% CI 1.45-11.5], P=0.008). We conclude that in an unselected cohort of intensive care unit patients, admission B-type natriuretic peptide is frequently elevated, even without clinically apparent acute heart disease, and is a strong independent predictor of long-term mortality.