CARDIOVASCULAR MEDICINE

Reliability of N-terminal proBNP assay in diagnosis of left ventricular systolic dysfunction within representative and high risk populations

F D R Hobbs¹, R C Davis¹, A K Roalfe¹, R Hare¹ and M K Davies²

¹ Department of Primary Care and General Practice, University of Birmingham, Birmingham, UK
² Department of Cardiology, Selly Oak Hospital, Birmingham

Correspondence to:
Correspondence to:
Professor Richard Hobbs
Department of Primary Care and General Practice, Primary Care Clinical Sciences Building, University of Birmingham, Birmingham B15 2TT, UK; f.d.r.hobbs{at}bham.ac.uk

Objective: To determine the performance of a new NT-proBNP assay in comparison with brain natriuretic peptide (BNP) in identifying left ventricular systolic dysfunction (LVSD) in randomly selected community populations.

Methods: Blood samples were taken prospectively in the community from 591 randomly sampled individuals over the age of 45 years, stratified for age and socioeconomic status and divided into four cohorts (general population; clinically diagnosed heart failure; patients on diuretics; and patients deemed at high risk of heart failure). Definite heart failure (left ventricular ejection fraction (LVEF) < 40%) was identified in 33 people. Samples were handled as though in routine clinical practice. The laboratories undertaking the assays were blinded.

Results: Using NT-proBNP to diagnose LVEF < 40% in the general population, a level of > 40 pmol/l had 80% sensitivity, 73% specificity, 5% positive predictive value (PPV), 100% negative predictive value (NPV), and an area under the receiver-operator characteristic curve (AUC) of 76% (95% confidence interval (CI) 46% to 100%). For BNP to diagnose LVSD, a cut off level of > 33 pmol/l had 80% sensitivity, 88% specificity, 10% PPV, 100% NPV, and AUC of 88% (95% CI 75% to 100%). Similar NPVs were found for patients randomly screened from the three other populations.

Conclusions: Both NT-proBNP and BNP have value in diagnosing LVSD in a community setting, with similar sensitivities and specificities. Using a high cut off for positivity will confirm the diagnosis of LVSD but will miss cases. At lower cut off values, positive results will require cardiac imaging to confirm LVSD.

Abbreviations: AUC, area under receiver-operator characteristic curve; BNP, brain natriuretic peptide; ECHOES, echocardiographic Heart of England screening study; LR, likelihood ratio; LVEF, left ventricular ejection fraction; LVSD, left ventricular systolic dysfunction; NPV, negative predictive value; PPV, positive predictive value

Keywords: natriuretic peptides; left ventricular systolic dysfunction; heart failure

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

• Hobbs, F.D.R. (2009). Clinical burden and health service challenges of chronic heart failure. Eur J Heart Fail Suppl 8: i1-i4 [Full Text]  
• Goode, K. M., Clark, A. L., Bristow, J. A., Sykes, K. B., Cleland, J. G.F. (2007). Screening for left ventricular systolic dysfunction in high-risk patients in primary-care: A cost-benefit analysis. Eur J Heart Fail 9: 1186-1195 [Abstract] [Full Text]  
• Emdin, M., Passino, C., Prontera, C., Fontana, M., Poletti, R., Gabutti, A., Mammini, C., Giannoni, A., Zyw, L., Zucchelli, G., Clerico, A. (2007). Comparison of Brain Natriuretic Peptide (BNP) and Amino-Terminal ProBNP for Early Diagnosis of Heart Failure. Clin. Chem. 53: 1289-1297 [Abstract] [Full Text]  
• Clerico, A., Fontana, M., Zyw, L., Passino, C., Emdin, M. (2007). Comparison of the Diagnostic Accuracy of Brain Natriuretic Peptide (BNP) and the N-Terminal Part of the Propeptide of BNP Immunoassays in Chronic and Acute Heart Failure: A Systematic Review. Clin. Chem. 53: 813-822 [Abstract] [Full Text]  
• Herrmann, M., Taban-Shoma, O., Hubner, U., Pexa, A., Kilter, H., Umanskaya, N., Hans Straub, R., Bohm, M., Herrmann, W. (2007). Hyperhomocysteinemia and Myocardial Expression of Brain Natriuretic Peptide in Rats. Clin. Chem. 53: 773-780 [Abstract] [Full Text]  
• Costello-Boerrigter, L. C., Boerrigter, G., Redfield, M. M., Rodeheffer, R. J., Urban, L. H., Mahoney, D. W., Jacobsen, S. J., Heublein, D. M., Burnett, J. C. Jr (2006). Amino-Terminal Pro-B-Type Natriuretic Peptide and B-Type Natriuretic Peptide in the General Community: Determinants and Detection of Left Ventricular Dysfunction. J Am Coll Cardiol 47: 345-353 [Abstract] [Full Text]  
• Herrmann, M., Kindermann, I., Muller, S., Georg, T., Kindermann, M., Bohm, M., Herrmann, W. (2005). Relationship of Plasma Homocysteine with the Severity of Chronic Heart Failure. Clin. Chem. 51: 1512-1515 [Full Text]