Insights into natriuretic peptides in heart failure: an update

Measuring lung water adds prognostic value in heart failure patients undergoing cardiac magnetic resonance

To assess whether a simplified cardiac magnetic resonance (CMR)–derived lung water density (LWD) quantification predicted major events in Heart Failure (HF). Single-centre retrospective study of consecutive HF patients with left ventricular ejection fraction (LVEF) < 50% who underwent CMR. All measurements were performed on HASTE sequences in a parasagittal plane at the right midclavicular line. LWD was determined by the lung-to-liver signal ratio multiplied by 0.7. A cohort of 102 controls was used to derive the LWD upper limit of normal (21.2%). The primary endpoint was a composite of time to all-cause death or HF hospitalization. Overall, 290 patients (mean age 64 ± 12 years) were included. LWD measurements took on average 35 ± 4 s, with good inter-observer reproducibility. LWD was increased in 65 (22.4%) patients, who were more symptomatic (NYHA ≥ III 29.2 vs. 1.8%; p = 0.017) and had higher NT-proBNP levels [1973 (IQR: 809–3766) vs. 802 (IQR: 355–2157 pg/mL); p < 0.001]. During a median follow-up of 21 months, 20 patients died and 40 had ≥ 1 HF hospitalization. In multivariate analysis, NYHA (III–IV vs. I–II; HR: 2.40; 95%-CI: 1.30–4.43; p = 0.005), LVEF (HR per 1%: 0.97; 95%-CI: 0.94–0.99; p = 0.031), serum creatinine (HR per 1 mg/dL: 2.51; 95%-CI: 1.36–4.61; p = 0.003) and LWD (HR per 1%: 1.07; 95%-CI: 1.02–1.12; p = 0.007) were independent predictors of the primary endpoint. These findings were mainly driven by an association between LWD and HF hospitalization (p = 0.026). A CMR-derived LWD quantification was independently associated with an increased HF hospitalization risk in HF patients with LVEF < 50%. LWD is a simple, reproducible and straightforward measurement, with prognostic value in HF.

A combined-biomarker approach to clinical phenotyping renal dysfunction in heart failure

BACKGROUND

Differentiating heart failure (HF) induced renal dysfunction (RD) from intrinsic kidney disease is challenging. It has been demonstrated that biomarkers such as B-type natriuretic peptide (BNP) or the blood urea nitrogen to creatinine ratio (BUN/creat) can identify high- vs low-risk RD. Our objective was to determine if combining these biomarkers could further improve risk stratification and clinical phenotyping of patients with RD and HF.

METHODS AND RESULTS

A total of 908 patients with a discharge diagnosis of HF were included. Median values were used to define elevated BNP (>1296 pg/mL) and BUN/creat (>17). In the group without RD, survival was similar regardless of BNP and BUN/creat (n = 430, adjusted P = .52). Similarly, in patients with both a low BNP and BUN/creat, RD was not associated with mortality (n = 250, adjusted hazard ratio [HR] = 1.0, 95% confidence interval [CI] 0.6-1.6, P = .99). However, in patients with both an elevated BNP and BUN/creat those with RD had a cardiorenal profile characterized by venous congestion, diuretic resistance, hypotension, hyponatremia, longer length of stay, greater inotrope use, and substantially worse survival compared with patients without RD (n = 249, adjusted HR = 1.8, 95% CI 1.2-2.7, P = .008, P interaction = .005).

CONCLUSIONS

In the setting of decompensated HF, the combined use of BNP and BUN/creat stratifies patients with RD into groups with significantly different clinical phenotypes and prognosis.

Characterization of a long-acting recombinant human serum albumin-atrial natriuretic factor (ANF) expressed in Pichia pastoris

The cardiac hormone atrial natriuretic factor (ANF) combines pharmacological properties of drugs used to treat essential hypertension (EH), congestive heart failure (CHF) and acute myocardial infarction (AMI). Treatment of CHF or AMI patients with an intravenous (iv) infusion of the circulating form of ANF (ANF(99-126)) produces significant clinical improvement. The short half-life (5 min) and peptide nature of ANF impose logistic restrictions for chronic administration. To increase its half-life, we fused ANF and human serum albumin (HSA) mini-genes by recombination in Pichia pastoris. The activity of three configurations of the fusion protein was tested in vitro and in vivo. The fusion protein that comprised of C-terminus HSA connected to N-terminus ANF via a hexaglycine linker showed the best outcome; it increased cGMP production in vitro. In vivo an iv bolus of HSA-ANF into mice increased significantly plasma cGMP levels and lowered blood pressure (BP) for up to 6 h hence successfully extended ANF half-life in plasma while retaining its biological activity. HSA-ANF represents the basis for development in the chronic therapeutic use of ANF.

Systems biology and heart failure: concepts, methods, and potential research applications

Dramatic advances in molecular biology dominated twentieth century biomedical science and delineated the function of individual genes and molecules in exquisite detail. However, biological processes cannot be fully understood based on the properties of individual genes and molecules alone, since these elements act in concert to enable the specific functions that make for living cells and organisms. The discipline of systems biology provides a novel conceptual framework for understanding biological phenomenon. Systems biology synthesizes information concerning the interactions of genes and molecules and allows characterization of the supramolecular networks and functional modules that represent the most essential aspects of cell organization and physiology.

CD-NP: an innovative designer natriuretic peptide activator of particulate guanylyl cyclase receptors for cardiorenal disease

The natriuretic peptide (NP) family consists of structurally similar, although physiologically distinct, peptides that play an important role in cardiorenal homeostasis. CD-NP is a novel chimeric natriuretic peptide developed by the Mayo Clinic, in which the 15-amino acid COOH-terminus of dendroaspis NP is fused to C-type NP. CD-NP is a dual activator of NP receptors A and B, and therefore, possesses the strong antiproliferative and antifibrotic properties of C-type NP with the potent natriuretic, diuretic, and aldosterone-inhibiting properties of dendroaspis NP. CD-NP has favorable cardiorenal properties when compared to recombinant B-type NP (nesiritide), including preservation of glomerular filtration rate with minimal blood pressure-lowering effects. Thus, CD-NP has emerged as an appealing novel therapeutic strategy for heart failure. The endogenous NP system, the development rationale for CD-NP, as well as in vitro, animal, and human studies and future directions will be reviewed.