Objective: To evaluate the utility of N terminal pro brain natriuretic peptide (NT-proBNP) as a diagnostic marker for diastolic dysfunction or failure, systolic dysfunction, and significant valve disorders in patients over 75 years.
Design: Cohort study.
Setting: Outpatient echocardiography service in a district general hospital.
Participants: 100 consecutive patients.
Main outcome measures: Sensitivity, specificity, positive predictive values, negative predictive values, and area under receiver operating characteristic curve for NT-proBNP assay in the diagnosis of left ventricular diastolic dysfunction or failure, systolic dysfunction, and significant valve disorders.
Results: For diagnosis of systolic dysfunction NT-proBNP level of 424 pg/ml had a sensitivity of 96%, specificity of 45%, positive predictive value of 36%, and negative predictive value of 96%. The area under the curve was 0.71 (95% confidence intervals: 0.69 to 0.89). In valve heart disease, level of 227 pg/ml had sensitivity of 91%, specificity of 43%, positive predictive value of 40%, and negative predictive value of 92%. Patients with diastolic dysfunction/failure had lower plasma concentrations.
Conclusions: This study showed that NT-proBNP had excellent negative predictive value for systolic dysfunction and significant valve disorders in very elderly patients. It increased significantly in systolic dysfunction, valve heart disease, and atrial fibrillation. NT-proBNP is not useful in the diagnosis of diastolic dysfunction or diastolic heart failure using standard echocardiography criteria.
- NT-proBNP, N terminal pro brain natriuretic peptide
- AUC, area under curve
- LV, left ventricular
- LA, left atrial
- DT, deceleration time
- IVRT, isovolumetric relaxation time
- ROC, receiver operating characteristic curve
- heart failure
- diastolic failure
- valve heart disease
- NT pro-BNP
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Funding: the study was funded by clinical audit and research department of East and North Hertfordshire NHS trust.
Conflicts of interest: none declared.