Diagnostic and prognostic evaluation of left ventricular systolic heart failure by plasma N-terminal pro-brain natriuretic peptide concentrations in a large sample of the general population

Abstract

Objective: To evaluate N-terminal pro-brain natriuretic peptide (NT-proBNP) as a diagnostic and prognostic marker for systolic heart failure in the general population.

Design: Study participants, randomly selected to be representative of the background population, filled in a heart failure questionnaire and underwent pulse and blood pressure measurements, electrocardiography, echocardiography, and blood sampling and were followed up for a median (range) period of 805 (60-1171) days.

Setting: Participants were recruited from four randomly selected general practitioners and were examined in a Copenhagen university hospital.

Patients: 382 women and 290 men in four age groups (50-59 (n = 174); 60-69 (n = 204); 70-79 (n = 174); > or = 80 years (n = 120)).

Main outcome measures: Value of NT-proBNP in evaluating patients with symptoms of heart failure and impaired left ventricular (LV) systolic function; prognostic value of NT-proBNP for mortality and hospital admissions.

Results: In 38 (5.6%) participants LV ejection fraction (LVEF) was < or = 40%. NT-proBNP identified patients with symptoms of heart failure and LVEF < or = 40% with a sensitivity of 0.92, a specificity of 0.86, positive and negative predictive values of 0.11 and 1.00, and area under the curve of 0.94. NT-proBNP was the strongest independent predictor of mortality (hazard ratio (HR) = 5.70, p < 0.0001), hospital admissions for heart failure (HR = 13.83, p < 0.0001), and other cardiac admissions (HR = 3.69, p < 0.0001). Mortality (26 v 6, p = 0.0003), heart failure admissions (18 v 2, p = 0.0002), and admissions for other cardiac causes (44 v 13, p < 0.0001) were significantly higher in patients with NT-proBNP above the study median (32.5 pmol/l).

Conclusions: Measurement of NT-proBNP may be useful as a screening tool for systolic heart failure in the general population.

Figure 1

Plasma concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) in normal participants and in patients with symptoms of heart failure (HF) ⩽ 50/⩽ 45/⩽ 40/⩽ 35 and left ventricular ejection fraction (LVEF) ⩽ 50%, ⩽ 45%, ⩽ 40%, and ⩽ 35%, respectively. ANOVA, analysis of variance. *Log scale; †geometric mean concentrations.

Figure 2

Receiver operating characteristic (ROC) curves for the ability of NT-proBNP to diagnose systolic HF ⩽ 50/⩽ 45/⩽ 40/⩽ 35, respectively, and LVEF ⩽ 50%/⩽ 45%/⩽ 40%/⩽ 35%, respectively.

Figure 3

Kaplan-Meier survival curves for patients with NT-proBNP plasma concentrations > 32.5 pmol/l and with NT-proBNP concentrations < 32.5 pmol/l (study median NT-proBNP concentration).

Figure 4

Kaplan-Meier curves for the first admission to hospital for congestive heart failure (CHF) for patients with NT-proBNP plasma concentrations > 32.5 pmol/l and with NT-proBNP concentrations < 32.5 pmol/l (study median NT-proBNP concentration).

Figure 5

Kaplan-Meier curves for the first admission to hospital for cardiac causes other than CHF for patients with NT-proBNP plasma concentrations > 32.5 pmol/l and with NT-proBNP concentrations < 32.5 pmol/l (study median NT-proBNP concentration).