Prognostic Utility of Anemia and Pro-B-Type Natriuretic Peptide in Patients With Nonischemic Dilated Cardiomyopathy and Normal Renal Function

The role of natriuretic peptides for the diagnosis of left ventricular dysfunction

Natriuretic peptides (NPs) are entered in current guidelines for heart failure (HF) diagnosis and management because of their high specificity and sensibility in screening patients with acute dyspnea. Due to their availability and relatively low cost, they became the first step examinations in HF patients evaluation at hospital admission together with clinical and chest radiography examination. NPs are released following any cardiac haemodynamic stress due to volume or pressure overload and should be considered as a mirror of cardiac condition helping in recognizing patients with poor outcome. Moreover, the exact role of NPs in early HF stages, in isolated diastolic dysfunction, and in general population is questioned. Several promising reports described their potential role; however, the wide cut-off definition, inclusion criteria, and intrinsic measurement biases do not actually consent to their clinical application in these settings. A multimodality strategy including both NPs and imaging studies appears to be the best strategy to define the cardiac dysfunction etiology and its severity as well as to identify patients with higher risk. In this review, we describe the current and potential role of NPs in patients with asymptomatic cardiac insufficiency, evaluating the requirement to obtain a better standardization for imaging as for laboratory criteria.

Prospective evaluation of NT-proBNP assay to detect occult dilated cardiomyopathy and predict survival in Doberman Pinschers

BACKGROUND

Occult (asymptomatic) dilated cardiomyopathy (ODCM) is highly prevalent in Doberman Pinschers.

HYPOTHESIS/OBJECTIVES

Assess ability of NT-proBNP assay to detect ODCM and predict death.

ANIMALS

155 asymptomatic Dobermans presenting for ODCM screening.

METHODS

Echocardiography, 24-hour Holter, and NT-proBNP assay were performed prospectively. Diagnosis was based on increased left ventricular end-systolic dimension, >50 ventricular premature complexes (VPCs), or both on Holter. Utility was evaluated using receiver-operating characteristic curves. Effect of age, weight, sex, disease status, VPCs, and NT-proBNP on survival was analyzed using Kaplan-Meier and Cox-proportional hazard analysis.

RESULTS

Seventy-three (47.1%) Dobermans were diagnosed with ODCM, including 31, 17, and 25 that met Holter, echocardiographic, or both criteria, respectively. Sensitivity of NT-proBNP > 457 pmol/L to detect these groups was 45.2, 76.5, and 96.0%, respectively. Combination of NT-proBNP and Holter to detect ODCM yielded sensitivity of 94.5%, specificity of 87.8%, and accuracy of 91.0%. Follow-up data were available for 78 Dobermans. The median survival time of Dobermans with > 50 VPCs (469 days), NT-proBNP > 900 pmol/L (284 days), or ODCM (474 days) was significantly (P < .0001) shorter than those with < 50 VPCs (1743 days), NT-proBNP < 900 pmol/L (1743 days), or without disease (1743 days). NT-proBNP concentration and disease status were independently predictive of all-cause mortality.

CONCLUSIONS AND CLINICAL IMPORTANCE

The combination of NT-proBNP assay and Holter detected ODCM with high accuracy. NT-proBNP and disease status were independently associated with survival. NT-proBNP assay identified Dobermans with high probability of increased LVIDs consistent with ODCM, and can facilitate pursuit of confirmatory diagnostic testing, such as echocardiography, in suspected Dobermans.

Natriuretic peptides and NGAL in heart failure: does a link exist?

In recent years there has been growing interest in the development of new diagnostic tools and particularly in laboratory tests for the identification of heart failure (HF) patients. Because of the rise in HF occurrence, it is necessary to use simple and reliable method to recognize those patients at risk before the onset of the clinical symptoms. To date HF diagnosis remains difficult: its symptoms and signs are often non specific as well as being poor sensitive indicators for HF severity. Throughout the last 10 years published literature has highlighted a boom in the use of biomarkers for HF. Both B-type and N-terminal pro-B-type natriuretic peptides have demonstrated specific role in heart failure diagnosis, as well as risk assessment. A single determination of BNP at any time during the development of chronic heart failure (CHF) provides a clinically useful tool to establish the outcome. Renal dysfunction is often associated with heart failure and predicts adverse clinical outcomes. Many studies have recently suggested the clinical use of serum neutrophil gelatinase-associated lipocalin (NGAL) levels in patients admitted to the hospital for acute HF can be used to estimate the risk of early worsening renal function. This could be potentially applied in clinical practice for early identification of renal dysfunction development in patients with HF. NGAL levels appear also to predict renal dysfunction in patients with chronic HF and preserved renal function. For all these reasons, BNP and NGAL are two emerging tools useful for diagnosis and prognosis in HF. The combination of two laboratory biomarkers could potentially identify patients with more elevated risks of both cardiac hemodynamic impairment and kidney dysfunction.