title: Predicting the outcome of hip fracture patients by using N-terminal fragment of pro-B-type natriuretic peptide.
abstract: OBJECTIVE
  To examine the prognostic value of perioperative N-terminal fragment of pro-brain natriuretic peptide (NT-proBNP) in hip fracture patients.
  
  
  METHODS
  Blinded prospective cohort study.
  
  
  METHODS
  Single centre trial at Turku University Hospital in Finland.
  
  
  METHODS
  Inclusion criterion was admittance to the study hospital due to hip fracture during the trial period of October 2009--May 2010. Exclusion criteria were the patient's refusal and inadequate laboratory tests. The final study population consisted of 182 patients.
  
  
  METHODS
  NT-proBNP was assessed once during the perioperative period and later if clinically indicated, and troponin T (TnT) and ECG recordings were evaluated repeatedly. The short-term (30-day) and long-term (1000 days) mortalities were studied.
  
  
  RESULTS
  Median (IQR) follow-up time was 3.1 (0.3) years. The median (IQR) NT-proBNP level was 1260 (2298) ng/L in preoperative and 1600 (3971) ng/L in postoperative samples (p=0.001). TnT was elevated in 66 (36%) patients, and was significantly more common in patients with higher NT-proBNP. Patients with high (>2370 ng/L) and intermediate (806-2370 ng/L) NT-proBNP level had significantly higher short-term mortality compared with patients having a low (<806 ng/L) NT-proBNP level (15 vs 11 vs 2%, p=0.04), and the long-term mortality remained higher in these patients (69% vs 49% vs 27%, p<0.001). Intermediate or high NT-proBNP level (HR 7.8, 95% CI 1.03 to 59.14, p<0.05) was the only independent predictor of short-term mortality, while intermediate or high NT-proBNP level (HR 2.27, 95% CI 1.30 to 3.96, p=0.004), the presence of dementia (HR 1.74, 95% CI 1.13 to 2.66, p=0.01) and higher preoperative American Society of Anesthesiologists' (ASA) classification (HR 1.59, 95% CI 1.06 to 2.38, p=0.02) were independent predictors of long-term mortality.
  
  
  CONCLUSIONS
  An elevated perioperative NT-proBNP level is common in hip fracture patients, and it is an independent predictor of short-term and long-term mortality superior to the commonly used clinical risk scores.
  
  
  BACKGROUND
  NCT01015105; Results.
authors.affiliation: Heart Center, Turku University Hospital and Department of Clinical Medicine, University of Turku, Turku, Finland.
authors.forename: Pauliina
authors.initials: P
authors.lastname: Nordling
authors.affiliation: Heart Center, Turku University Hospital and Department of Clinical Medicine, University of Turku, Turku, Finland.
authors.forename: Tuomas
authors.initials: T
authors.lastname: Kiviniemi
authors.affiliation: Heart Center, Turku University Hospital and Department of Clinical Medicine, University of Turku, Turku, Finland.
authors.forename: Marjatta
authors.initials: M
authors.lastname: Strandberg
authors.affiliation: Department of Orthopedic Surgery, Turku University Hospital, Turku, Finland.
authors.forename: Niko
authors.initials: N
authors.lastname: Strandberg
authors.affiliation: Heart Center, Turku University Hospital and Department of Clinical Medicine, University of Turku, Turku, Finland.
authors.forename: Juhani
authors.initials: J
authors.lastname: Airaksinen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D004562:Electrocardiography; D005260:Female; D006620:Hip Fractures / Q000401:mortality* / Q000601:surgery*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D059035:Perioperative Period; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods*; D020107:Troponin T / Q000097:blood
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; D020107:Troponin T; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain