Use Of Natriuretic Peptide Research Articles

Diagnostic and prognostic usefulness of natriuretic peptides in emergency department patients with dyspnea

More than 4.5 million Americans have congestive heart failure (CHF), close to 550,000 new cases are diagnosed each year, and one third of known patients with CHF are annually admitted to the hospital. Emergency department diagnosis of CHF is often based on history and physical examination findings along with results of ancillary tests, such as chest radiography and ECG. Although signs and symptoms of fluid overload, such as lower extremity edema and dyspnea, raise the suspicion of CHF, their lack of sensitivity makes them poor screening tools. The natriuretic peptides are promising markers of myocardial dysfunction and heart failure. Because of their relationship to myocardial pressure and stretching, natriuretic peptides have been investigated over the past 5 decades as both diagnostic and prognostic markers in acute coronary syndromes and CHF. This article discusses each of the natriuretic peptides and attempts to delineate their potential diagnostic and prognostic roles in the ED. [Ann Emerg Med. 2003;41:532-545.]

Plasma natriuretic peptides for community screening for left ventricular hypertrophy and systolic dysfunction: the Framingham heart study.

Several reports have suggested the usefulness of plasma brain natriuretic peptide (BNP) as a screening test for left ventricular hypertrophy (LVH) and systolic dysfunction (LVSD). Prior studies were limited by small sample sizes and selection bias and none compared the diagnostic performance of these peptides in men and women. To examine the usefulness of natriuretic peptides for screening for elevated LV mass and LVSD in the community. Community-based prospective cohort study of 3177 participants (1707 women) from the Framingham Study who attended a routine examination in 1995-1998. Receiver operating characteristic (ROC) curves, test sensitivity, specificity, positive and negative predictive values, and likelihood ratios for identifying elevated LV mass (sex-specific 90th percentile or higher of LV mass/[height](2)), LVSD (ejection fraction < or = 50% and/or fractional shortening <29%), and moderate to severe LVSD (ejection fraction < or = 40% and/or fractional shortening <22%) at different discrimination limits of plasma BNP and N-terminal proatrial natriuretic peptide (NT-ANP), with echocardiography as the criterion standard. The areas under the ROC curves for elevated LV mass or LVSD were at or below 0.75 for both peptides, were higher for men compared with women, and were similar for BNP and NT-ANP. The diagnostic performance of natriuretic peptides for LVSD improved in women but not in men when select high-risk subgroups were targeted. Discrimination limits based on high specificity (0.95) yielded better positive predictive values and likelihood ratios compared with age- and sex-specific reference limits yet only identified less than one third of participants who had elevated LV mass or LVSD. In our large community-based sample, the performance of BNP and NT-ANP for detection of elevated LV mass and LVSD was suboptimal, suggesting limited usefulness of natriuretic peptides as mass screening tools.

Biochemical detection of left-ventricular systolic dysfunction

In previous studies on the use of natriuretic peptides to detect left-ventricular systolic dysfunction, a higher rate of cardiac disorders in the control groups than in the study groups could have led to bias. We investigated the effectiveness of plasma N-terminal atrial natriuretic peptide (NT-ANP) and brain natriuretic peptide (BNP) concentrations to show left-ventricular systolic dysfunction in a random sample of the general population. We randomly selected 2000 participants aged 25-74 years from family physicians' lists in Glasgow, UK. We sent all participants questionnaires. 1653 respondents underwent echocardiography and electrocardiography. We took a left-ventricular ejection fraction of 30% or less to show left-ventricular systolic dysfunction. NT-ANP and BNP were measured in plasma by RIAs. 1252 participants had analysable electrocardiograms and echocardiograms, completed questionnaires, and available blood samples. Median concentrations of NT-ANP and BNP were significantly higher in participants with left-ventricular systolic dysfunction (2.8 ng/mL [IQR 1.8-4.6] and 24.0 pg/mL [18.0-33.0]) than in those without (1.3 ng/mL [0.9-1.8] and 7.7 pg/mL [3.4-13.0]; each p < 0.001). Among participants with left-ventricular systolic dysfunction, both symptomatic and asymptomatic subgroups had raised NT-ANP and BNP concentrations. A BNP concentration of 17.9 pg/mL or more gave a sensitivity of 77% and specificity of 87% in all participants, and 92% and 72% in participants aged 55 years or older. Measurement of BNP could be a cost-effective method of screening for left-ventricular systolic dysfunction in the general population, especially if its use were targeted to individuals at high risk.