title: [Value of plasma NT-proBNP for diagnosing heart failure in patients with previous myocardial infarction].
abstract: OBJECTIVE
  The study aimed to evaluate the value of plasma NT-proBNP in diagnosing heart failure in patients with previous myocardial infarction.
  
  
  METHODS
  Plasma concentration of NT-proBNP was measured in patients with previous myocardial infarction by ELISA method at admission. Patients were divided into non heart failure group (NYHA class I) and heart failure group (NYHA class II-IV). The NT-proBNP levels were compared between NYHA class I, II, III and IV, and between heart failure group and non heart failure group. ROC analyses were performed to evaluate the diagnosing value of plasma NT-proBNP for heart failure and to identify the optimal cut-off point for diagnosing heart failure patients.
  
  
  RESULTS
  Total 586 patients [aged from 25 - 83 (58 ± 11) years, 80% male] with previous myocardial infarction were enrolled in his study (n = 374 of NYHA class I, n = 99 of NYHA classes II, n = 82 of NYHA class III, n = 31 of NYHA class IV). Plasma NT-proBNP levels in these four NYHA classes were 484.7 (381.6, 647.8) pmol/L, 907.6 (516.6, 1290.3) pmol/L, 1420.2 (879.5, 2336.2) pmol/L, 2442.6 (1695.4, 3670.7) pmol/L, respectively (P < 0.01). The plasma NT-proBNP level in heart failure group was significantly higher than in non heart failure group [1148.2 (707.9, 2145.3) pmol/L vs. 484.7 (381.6, 647.8) pmol/L, P < 0.01]. Plasma NT-proBNP level in patients with age ≥ 60 years was significantly higher than patients with age < 60 years [702.3 (472.4, 1208.5) pmol/L vs. 526.6 (392.1, 855.6) pmol/L, P < 0.01]. ROC analysis showed that the area under the curve (AUC) for diagnosing heart failure was 0.844 (95%CI: 0.809 - 0.880, P < 0.01), the optimal plasma NT-proBNP cut-off point for diagnosing heart failure was 700 pmol/L with a sensitivity of 75.9%, a specificity of 79.9%, an accuracy of 78.3%, a positive predictive value of 67.9% and a negative predictive value of 85.3%. The optimal plasma NT-proBNP cut-off point was 600 pmol/L for patients ≥ 60 years old and 800 pmol/L for patients < 60 years old.
  
  
  CONCLUSIONS
  Plasma NT-proBNP level is a valuable parameter for diagnosing heart failure in patients with previous myocardial infarction.
authors.affiliation: Chinese Academy of Medical Sciences, Beijing, China.
authors.forename: Bing-qi
authors.initials: BQ
authors.lastname: Wei
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Yue-jin
authors.initials: YJ
authors.lastname: Yang
authors.forename: Rong
authors.initials: R
authors.lastname: Lü
authors.forename: Yu-hui
authors.initials: YH
authors.lastname: Zhang
authors.forename: Qiong
authors.initials: Q
authors.lastname: Zhou
authors.forename: Run-lin
authors.initials: RL
authors.lastname: Gao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006333:Heart Failure / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
chemical_list: D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain