title: [NT-proBNP for risk stratification of pulmonary embolism].
abstract: BACKGROUND
  Pulmonary embolism (PE) is an entity with high mortality and morbidity, in which risk stratification for adverse events is essential. N-terminal brain natriuretic peptide (NT-proBNP), a right ventricular dysfunction marker, may be useful in assessing the short-term prognosis of patients with PE.
  
  
  OBJECTIVE
  To characterize a sample of patients hospitalized with PE according to NT-proBNP level at hospital admission and to assess the impact of this biomarker on short-term evolution.
  
  
  METHODS
  We performed a retrospective analysis of consecutive patients admitted with PE over a period of 3.5 years. Based on the median NT-proBNP at hospital admission, patients were divided into two groups (Group 1: NT-proBNP<median and Group 2: NT-proBNP ≥ median). The two groups were compared in terms of demographic characteristics, personal history, clinical presentation, laboratory, electrocardiographic and echocardiographic data, drug therapy, in-hospital course (catecholamine support, invasive ventilation and in-hospital death and the combined endpoint of these events) and 30-day all-cause mortality. A receiver operating characteristic (ROC) curve was constructed to determine the discriminatory power and cut-off value of NT-proBNP for 30-day all-cause mortality.
  
  
  RESULTS
  Ninety-one patients, mean age 69±16.4 years (51.6% aged ≥75 years), 53.8% male, were analyzed. Of the total sample, 41.8% had no etiological or predisposing factors for PE and most (84.6%) were stratified as intermediate-risk PE. Median NT-proBNP was 2440 pg/ml. Patients in Group 2 were significantly older (74.8±13.2 vs. 62.8±17.2 years, p=0.003) and more had a history of heart failure (35.5% vs. 3.3%, p=0.002) and chronic kidney disease (32.3% vs. 6.7%, p=0.012). They had more tachypnea on initial clinical evaluation (74.2% vs. 44.8, p=0.02), less chest pain (16.1% vs. 46.7%, p=0.01) and higher creatininemia (1.7±0.9 vs. 1.1±0.5mg/dl, p=0.004). Group 2 also more frequently had right chamber dilatation (85.7% vs. 56.7%, p=0.015) and lower left ventricular ejection fraction (56.4±17.6% vs. 66.2±13.5%, p=0.036) on echocardiography. There were no significant differences in drug therapy between the two groups. Regarding the studied endpoints, Group 2 patients needed more catecholamine support (25.8% vs. 6.7%, p=0.044), had higher in-hospital mortality (16.1% vs. 0.0%, p=0.022) and more frequently had the combined endpoint (32.3% vs. 10.0%, p=0.034). All-cause mortality at 30 days was seen only in Group 2 patients (24.1% vs. 0.0%, p=0.034). By ROC curve analysis, NT-proBNP had excellent discriminatory power for this event, with an area under the curve of 0.848. The best NT-proBNP cut-off value was 4740 pg/ml.
  
  
  CONCLUSIONS
  Elevated NT-proBNP levels identified PE patients with worse short-term prognosis, and showed excellent power to predict 30-day all-cause mortality. The results of this study may have important clinical implications. The inclusion of NT-proBNP measurement in the initial evaluation of patients with PE can add valuable prognostic information.
authors.affiliation: UNICARD, Serviço de Cardiologia, Hospital de São Francisco Xavier - Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal. heldores@hotmail.com
authors.forename: Hélder
authors.initials: H
authors.lastname: Dores
authors.forename: Cândida
authors.initials: C
authors.lastname: Fonseca
authors.forename: Sílvio
authors.initials: S
authors.lastname: Leal
authors.forename: Ingrid
authors.initials: I
authors.lastname: Rosário
authors.forename: João
authors.initials: J
authors.lastname: Abecasis
authors.forename: José
authors.initials: J
authors.lastname: Monge
authors.forename: Maria João
authors.initials: MJ
authors.lastname: Correia
authors.forename: Luís
authors.initials: L
authors.lastname: Bronze
authors.forename: Ana
authors.initials: A
authors.lastname: Leitão
authors.forename: Isabel
authors.initials: I
authors.lastname: Arroja
authors.forename: Ana
authors.initials: A
authors.lastname: Aleixo
authors.forename: Aniceto
authors.initials: A
authors.lastname: Silva
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011655:Pulmonary Embolism / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain