Plasma cardiac natriuretic peptide determination as a screening test for the detection of patients with mild left ventricular impairment

Objective - To determine the usefulness of measuring the cardiac natriuretic peptides, atrial natriuretic factor, N-terminal pro-atrial natriuretic factor, and brain natriuretic peptide, as screening tests for identifying patients with mild left ventricular impairment. Design - Cross-sectional evaluation of the diagnostic accuracy of the cardiac natriuretic peptides. Setting - Cardiac catheterisation unit, Norwegian central hospital. Patients - A consecutive series of 254 patients undergoing diagnostic left-sided cardiac catheterisation. One hundred and twenty eight of these patients had a history of previous myocardial infarction. Main outcome measures - The presence of normal and impaired left ventricular function, as evaluated by logistic regression analysis and estimation of the area under the receiver operating characteristic (ROC) curve (an index of overall diagnostic accuracy). Ventricular function was assessed by the measurement of left ventricular end diastolic pressure and angiographically determined left ventricular ejection fraction. Results - Logistic regression analysis showed that plasma brain natriuretic peptide was the best predictor of increased left ventricular end diastolic pressure (greater than or equal to 15 mm Hg) (P < 0.001), decreased left ventricular ejection fraction (less than or equal to 45%) (P < 0.001), and the combination of left ventricular ejection fraction less than or equal to 45% and left ventricular end diastolic pressure greater than or equal to 15 mm Hg (P < 0.001). The areas under the ROC function for the detection of left ventricular dysfunction were 0.789 for brain natriuretic peptide, 0.665 for atrial natriuretic factor, and 0.610 for N-terminal pro-atrial natriuretic factor. Conclusions - Plasma brain natriuretic peptide seemed to be a better indicator of left ventricular function than plasma atrial natriuretic factor or N-terminal pro-atrial natriuretic factor. However, the overall diagnostic accuracy of circulating atrial natriuretic factor, N-terminal pro-atrial natriuretic factor, and brain natriuretic peptide as indicators of normal and impaired ventricular function in an unselected group of patients with coronary heart disease and a high frequency of previous myocardial infarction was relatively modest.