Beta-Blockers Influence the Short-term and Long-term Prognostic Information of Natriuretic Peptides and Catecholamines in Chronic Heart Failure Independent From Specific Agents

Is Heart Rate a Norepiphenomenon in Heart Failure?

There has been an increased focus on heart rate as a target in the management of cardiovascular disease and more specifically in heart failure with preserved ejection fraction in recent years with several studies showing the benefit of a lower resting heart rate on outcomes. This review paper examines the pathophysiology behind the benefits of lowering heart rate in heart failure and also the evidence for and against the pharmacological agents available to achieve this.

The search for efficient diagnostic and prognostic biomarkers of heart failure

Several biomarkers have been tested for screening, diagnosis and prognosis purposes, as well as to guide treatment in heart failure, but only the assay of circulating B-type natriuretic peptides has widely recognized applications for clinical decision-making. Natriuretic peptides are sensitive in detecting the clinically overt or subclinical myocardial damage, but their plasma levels are increased following every generic insult to the cardiovascular system. Novel biomarkers are required to identify specific pathways of disease progression, such as diverse neurohormonal axes activation, inflammation and fibrogenesis, and to act as a tool for therapeutic tailoring. In this view, Gal-3 and ST-2 assays seem very promising, given their involvement in mechanisms of cardiac fibrosis and their prognostic value.

Clinical value of plasma B-type natriuretic peptide assay in pediatric pneumonia accompanied by heart failure

Previous studies have shown that B-type natriuretic peptide (BNP) is useful in differentiating cardiac from pulmonary causes of dyspnea in adults. To date, international guidelines have recommended measurements of circulating BNP as a biomarker for diagnostic and prognostic purposes, as well as therapeutic monitoring, in adults with cardiac diseases, particularly those suffering from acute and chronic heart failure (HF). The aim of the present study was to investigate the differential diagnostic and therapeutic analysis of BNP levels assayed in pediatric pneumonia accompanied by HF. The clinical data of 80 patients with pneumonia, aged 1-3 years, were analyzed. The patients were divided into two groups: Simple pneumonia (46 cases) and pneumonia accompanied by HF (34 cases). All patients underwent two plasma BNP assays: The first one upon admission to the hospital and the second one prior to discharge. The plasma BNP levels of 20 healthy children were used as the negative control. Plasma BNP levels were measured using the Triage® BNP automated immunoassay systems and reagents. Statistical analysis showed that the plasma BNP levels of the patients upon admission were higher in the pneumonia accompanied by HF group compared with those in the simple pneumonia group (750±120 vs. 135±50 pg/ml; P<0.05). In addition, in the pneumonia accompanied by HF group, the plasma BNP levels of the patients were higher upon admission to the hospital than they were prior to discharge (750±120 vs. 115±45 pg/ml; P<0.05); therefore, plasma BNP may comprise a sensitive diagnostic and therapeutic evaluative marker for pediatric patients with pneumonia accompanied by HF. This finding could prove invaluable in the clinical diagnosis and treatment of the disease.

BNP and NT-proBNP as prognostic markers in persons with chronic stable heart failure

Prognosis permits clinicians to separate persons with heart failure (HF) into subgroups based on likely health outcomes. Treatment is partly guided by these likely outcomes. This systematic review explores whether brain natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are independent predictors of prognosis in persons with chronic stable HF. We electronically searched Medline, Embase, AMED, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and CINAHL for English-language articles published between 1989 and mid-2012. We utilized trained reviewers and standardized forms to screen articles for inclusion and extracted data from included articles. All included studies were summarized in narrative and tabular form. We used the Hayden criteria to assess the risk of bias. Sixteen BNP publications and 88 NT-proBNP publications were included in the systematic review. BNP was positively associated with all-cause and HF mortality. NT-proBNP was positively associated with all-cause and cardiovascular mortality. BNP and NT-proBNP levels are useful for estimating prognosis in persons with chronic stable HF. Further research is required to establish optimal cutpoints and to assess whether prognostic effects differ by age, sex, or time period.

PONTIAC (NT-proBNP selected prevention of cardiac events in a population of diabetic patients without a history of cardiac disease): a prospective randomized controlled trial

OBJECTIVES

The study sought to assess the primary preventive effect of neurohumoral therapy in high-risk diabetic patients selected by N-terminal pro-B-type natriuretic peptide (NT-proBNP).

BACKGROUND

Few clinical trials have successfully demonstrated the prevention of cardiac events in patients with diabetes. One reason for this might be an inaccurate selection of patients. NT-proBNP has not been assessed in this context.

METHODS

A total of 300 patients with type 2 diabetes, elevated NT-proBNP (>125 pg/ml) but free of cardiac disease were randomized. The "control" group was cared for at 4 diabetes care units; the "intensified" group was additionally treated at a cardiac outpatient clinic for the up-titration of renin-angiotensin system (RAS) antagonists and beta-blockers. The primary endpoint was hospitalization/death due to cardiac disease after 2 years.

RESULTS

At baseline, the mean age of the patients was 67.5 ± 9 years, duration of diabetes was 15 ± 12 years, 37% were male, HbA1c was 7 ± 1.1%, blood pressure was 151 ± 22 mm Hg, heart rate was 72 ± 11 beats/min, median NT-proBNP was 265.5 pg/ml (interquartile range: 180.8 to 401.8 pg/ml). After 12 months there was a significant difference between the number of patients treated with a RAS antagonist/beta-blocker and the dosage reached between groups (p < 0.0001). Blood pressure was significantly reduced in both (p < 0.05); heart rate was only reduced in the intensified group (p = 0.004). A significant reduction of the primary endpoint (hazard ratio: 0.351; 95% confidence interval: 0.127 to 0.975, p = 0.044) was visible in the intensified group. The same was true for other endpoints: all-cause hospitalization, unplanned cardiovascular hospitalizations/death (p < 0.05 for all).

CONCLUSIONS

Accelerated up-titration of RAS antagonists and beta-blockers to maximum tolerated dosages is an effective and safe intervention for the primary prevention of cardiac events for diabetic patients pre-selected using NT-proBNP. (Nt-proBNP Guided Primary Prevention of CV Events in Diabetic Patients [PONTIAC]; NCT00562952).

Prevalence and prognostic significance of adrenergic escape during chronic beta-blocker therapy in chronic heart failure

AIMS

Like aldosterone escape to ACE-inhibitors, adrenergic escape (AE) to beta-blockers appears conceivable in chronic heart failure (CHF), as generalized systemic neurohumoral activation has been described as the pathophysiological basis of this syndrome. The aim of this study was to examine the prevalence and prognostic value of AE with respect to different beta-blocker agents and doses.

METHODS AND RESULTS

This was a prospective, observational study of 415 patients with systolic CHF receiving chronic stable beta-blocker therapy. AE was defined by norepinephrine levels above the upper limit of normal. Irrespective of the individual beta-blocker agents used and the dose equivalent taken, the prevalence of AE was 31-39%. Norepinephrine levels neither correlated with heart rate (r=0.02; 95% CI: -0.08-0.11; P=0.74) nor were they related to underlying rhythm (P=0.09) or the individual beta-blocker agent used (P=0.87). The presence of AE was a strong and independent indicator of mortality (adjusted HR: 1.915; 95% CI: 1.387-2.645; chi2: 15.60).

CONCLUSION

We verified the presence of AE in CHF patients on chronic stable beta-blocker therapy, irrespective of the individual beta-blocker agent and the dose equivalent. As AE might indicate therapeutic failure, the determination of AE could help to identify those patients with CHF that might benefit from more aggressive treatment modalities. Heart rate, however, is not a surrogate for adrenergic escape.