Does NT-proBNP remain a sensitive biomarker for chronic heart failure after administration of a beta-blocker?

B-type natriuretic peptide-guided treatment for heart failure

BACKGROUND

Heart failure is a condition in which the heart does not pump enough blood to meet all the needs of the body. Symptoms of heart failure include breathlessness, fatigue and fluid retention. Outcomes for patients with heart failure are highly variable; however on average, these patients have a poor prognosis. Prognosis can be improved with early diagnosis and appropriate use of medical treatment, use of devices and transplantation. Patients with heart failure are high users of healthcare resources, not only due to drug and device treatments, but due to high costs of hospitalisation care. B-type natriuretic peptide levels are already used as biomarkers for diagnosis and prognosis of heart failure, but could offer to clinicians a possible tool to guide drug treatment. This could optimise drug management in heart failure patients whilst allaying concerns over potential side effects due to drug intolerance.

OBJECTIVES

To assess whether treatment guided by serial BNP or NT-proBNP (collectively referred to as NP) monitoring improves outcomes compared with treatment guided by clinical assessment alone.

SEARCH METHODS

Searches were conducted up to 15 March 2016 in the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library; MEDLINE (OVID), Embase (OVID), the Database of Abstracts of Reviews of Effects (DARE) and the NHS Economic Evaluation Database in the Cochrane Library. Searches were also conducted in the Science Citation Index Expanded, the Conference Proceedings Citation Index on Web of Science (Thomson Reuters), World Health Organization International Clinical Trials Registry and ClinicalTrials.gov. We applied no date or language restrictions.

SELECTION CRITERIA

We included randomised controlled trials of NP-guided treatment of heart failure versus treatment guided by clinical assessment alone with no restriction on follow-up. Adults treated for heart failure, in both in-hospital and out-of-hospital settings, and trials reporting a clinical outcome were included.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, extracted data and evaluated risk of bias. Risk ratios (RR) were calculated for dichotomous data, and pooled mean differences (MD) (with 95% confidence intervals (CI)) were calculated for continuous data. We contacted trial authors to obtain missing data. Using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, we assessed the quality of the evidence and GRADE profiler (GRADEPRO) was used to import data from Review Manager to create a 'Summary of findings' table.

MAIN RESULTS

We included 18 randomised controlled trials with 3660 participants (range of mean age: 57 to 80 years) comparing NP-guided treatment with clinical assessment alone. The evidence for all-cause mortality using NP-guided treatment showed uncertainty (RR 0.87, 95% CI 0.76 to 1.01; patients = 3169; studies = 15; low quality of the evidence), and for heart failure mortality (RR 0.84, 95% CI 0.54 to 1.30; patients = 853; studies = 6; low quality of evidence).The evidence suggested heart failure admission was reduced by NP-guided treatment (38% versus 26%, RR 0.70, 95% CI 0.61 to 0.80; patients = 1928; studies = 10; low quality of evidence), but the evidence showed uncertainty for all-cause admission (57% versus 53%, RR 0.93, 95% CI 0.84 to 1.03; patients = 1142; studies = 6; low quality of evidence).Six studies reported on adverse events, however the results could not be pooled (patients = 1144; low quality of evidence). Only four studies provided cost of treatment results, three of these studies reported a lower cost for NP-guided treatment, whilst one reported a higher cost (results were not pooled; patients = 931, low quality of evidence). The evidence showed uncertainty for quality of life data (MD -0.03, 95% CI -1.18 to 1.13; patients = 1812; studies = 8; very low quality of evidence).We completed a 'Risk of bias' assessment for all studies. The impact of risk of bias from lack of blinding of outcome assessment and high attrition levels was examined by restricting analyses to only low 'Risk of bias' studies.

AUTHORS' CONCLUSIONS

In patients with heart failure low-quality evidence showed a reduction in heart failure admission with NP-guided treatment while low-quality evidence showed uncertainty in the effect of NP-guided treatment for all-cause mortality, heart failure mortality, and all-cause admission. Uncertainty in the effect was further shown by very low-quality evidence for patient's quality of life. The evidence for adverse events and cost of treatment was low quality and we were unable to pool results.

Carvedilol and nebivolol improve left ventricular systolic functions in patients with non-ischemic heart failure

Objective:

It is unclear whether carvedilol and nebivolol produce different effects on short-term left ventricle (LV) systolic function in heart failure (HF). These drugs could improve systolic and diastolic functions of the LV. Thus, we aimed to compare their effects on LV systolic functions in patients with non-ischemic HF.

Methods:

This study included 61 symptomatic non-ischemic HF patients with low ejection fraction (EF) (EF≤40%) between September 2008 and November 2010. The patients were randomized to carvedilol (n=31, 16 males) or nebivolol (n=30, 19 male). They were evaluated clinically and echocardiographically at baseline and 3 and 6 months after target dose; 42% of patients in the carvedilol group and 47% in the nebivolol group achieved the target dose before randomization. LV systolic functions were evaluated with ventricle diameters, EF, ejection time (ET), isovolumic contraction time (IVCT), isovolumic relaxation time (IVRT), and myocardial performance index (MPI).

Results:

At 6 months, carvedilol and nebivolol similarly improved EF (from 33±4% to 36±5%, p<0.01 and from 34±5% to 37±5%, p<0.01, inter-group p=0.30, respectively) and MPI (from 0.71±0.10 to 0.53±0.07, p<0.01 and from 0.69±0.13 to 0.52±0.08, p<0.01, intergroup p=0.45, respectively). LV diameter was reduced by a similar extent in both groups. In each group, IVCT and IVRT were significantly shortened and ET was prolonged, but there was no inter-group difference. Functional capacity improved similarly (from NYHA Class II-III to Class I-0) in both groups, as did heart rate and blood pressure. Reduction of pro-B-type natriuretic peptide levels was also comparable in both groups (p=0.41).

Conclusion:

Carvedilol and nebivolol can similarly improve LV systolic functions in non-ischemic HF patients.