Shafiq U. Rehman

Use of amino-terminal pro-B-type natriuretic peptide to guide outpatient therapy of patients with chronic left ventricular systolic dysfunction.

OBJECTIVES The aim of this study was to evaluate whether chronic heart failure (HF) therapy guided by concentrations of amino-terminal pro-B-type natriuretic peptide (NT-proBNP) is superior to standard of care (SOC) management. BACKGROUND It is unclear whether standard HF treatment plus a goal of reducing NT-proBNP concentrations improves outcomes compared with standard management alone. METHODS In a prospective single-center trial, 151 subjects with HF due to left ventricular (LV) systolic dysfunction were randomized to receive either standard HF care plus a goal to reduce NT-proBNP concentrations ≤1,000 pg/ml or SOC management. The primary endpoint was total cardiovascular events between groups compared using generalized estimating equations. Secondary endpoints included effects of NT-proBNP-guided care on patient quality of life as well as cardiac structure and function, assessed with echocardiography. RESULTS Through a mean follow-up period of 10 ± 3 months, a significant reduction in the primary endpoint of total cardiovascular events was seen in the NT-proBNP arm compared with SOC (58 events vs. 100 events, p = 0.009; logistic odds for events 0.44, p = 0.02); Kaplan-Meier curves demonstrated significant differences in time to first event, favoring NT-proBNP-guided care (p = 0.03). No age interaction was found, with elderly patients benefitting similarly from NT-proBNP-guided care as younger subjects. Compared with SOC, NT-proBNP-guided patients had greater improvements in quality of life, demonstrated greater relative improvements in LV ejection fraction, and had more significant improvements in both LV end-systolic and -diastolic volume indexes. CONCLUSIONS In patients with HF due to LV systolic dysfunction, NT-proBNP-guided therapy was superior to SOC, with reduced event rates, improved quality of life, and favorable effects on cardiac remodeling. (Use of NT-proBNP Testing to Guide Heart Failure Therapy in the Outpatient Setting; NCT00351390).

Characteristics of the Novel Interleukin Family Biomarker ST2 in Patients With Acute Heart Failure

OBJECTIVES The purpose of this study was to examine the patient-specific characteristics of the interleukin-1 receptor family member ST2 in patients with acute heart failure (HF). BACKGROUND ST2 signaling is involved in the process of cardiac fibrosis and hypertrophy. METHODS In all, 346 patients with acute HF had ST2 measured. Associations between ST2 and demographics, severity/type of HF, and other biomarkers were examined. Receiver-operator characteristic curves and multivariable Cox proportional hazards analyses evaluated the prognostic ability of ST2. RESULTS The ST2 values correlated with the severity of HF (p < 0.001), left ventricular ejection fraction (r = -0.134; p = 0.014), creatinine clearance (r = -0.224; p < 0.001), B-type natriuretic peptide (r = 0.293; p < 0.001), amino terminal B-type natriuretic peptide (r = 0.413; p < 0.001), and C-reactive protein (r = 0.429; p < 0.001). ST2 was not associated with age, prior HF, or body mass index. The ST2 levels at presentation were higher among patients who died by 1 year. The area under the receiver-operator characteristic for death at 1 year was 0.71 (p < 0.001). In a multivariable Cox model containing established clinical and biochemical predictors (including natriuretic peptides), ST2 remained a predictor of mortality (hazard ratio: 2.04, 95% confidence interval: 1.30 to 3.24, p = 0.003), and was equally predictive in patients with HF and preserved or impaired systolic function. When both ST2 and natriuretic peptides were elevated, the highest rates of death were observed in cumulative hazard analysis (p < 0.001). In the presence of a low ST2 level, natriuretic peptides did not predict mortality. CONCLUSIONS Consistent with its proposed role in a myocardial-specific response to stretch, ST2 has strong clinical and biochemical correlates in patients with acute HF. Prognostically, ST2 is powerful in acute HF and is synergistic with natriuretic peptides for this use.

Heart failure outcomes and benefits of NT-proBNP-guided management in the elderly: results from the prospective, randomized ProBNP outpatient tailored chronic heart failure therapy (PROTECT) study.

BACKGROUND Elderly patients with heart failure (HF) have a worse prognosis than younger patients. We wished to study whether elders benefit from natriuretic peptide-guided HF care in this single-center study. METHODS AND RESULTS A total of 151 patients with HF resulting from left ventricular systolic dysfunction (LVSD) were treated with HF treatment by standard-of-care (SOC) management or guided by N-terminal pro-B type natriuretic peptide (NT-proBNP) values (with a goal to lower NT-proBNP ≤1000 pg/mL) over 10 months. The primary end point for this post-hoc analysis was total cardiovascular events in 2 age categories (<75 and ≥75 years). In those ≥75 years of age (n = 38), NT-proBNP values increased in the SOC arm (2570 to 3523 pg/mL, P = .01), but decreased in the NT-proBNP-guided arm (2664 to 1418 pg/mL, P = .001). Elderly patients treated with SOC management had the highest rate of cardiovascular events, whereas the elderly with NT-proBNP management had the lowest rate of cardiovascular events (1.76 events per patient versus 0.71 events per patient, P = .03); the adjusted logistic odds for cardiovascular events related to NT-proBNP-guided care for elders was 0.24 (P = .008), whereas in those <75 years (n = 113), the adjusted logistic odds for events following NT-proBNP-guided care was 0.61 (P = .10). CONCLUSIONS Natriuretic peptide-guided HF care was well tolerated and resulted in substantial improvement in cardiovascular event rates in elders (ClinicalTrials.Gov #00351390).

Independent and incremental prognostic value of multimarker testing in acute dyspnea: Results from the ProBNP Investigation of Dyspnea in the Emergency Department (PRIDE) study

BACKGROUND Acute dyspnea is common in the emergency department (ED) and is associated with mortality. Biomarkers may help stratify risk in this setting. METHODS Among 577 dyspneic subjects we identified 5 candidate biomarkers with prognostic value: amino terminal B-type natriuretic peptide (NT-proBNP), C-reactive protein (CRP), the interleukin family member ST2, hemoglobin and blood urea nitrogen (BUN); these were assessed using both receiver operating characteristic curve and Cox proportional hazards analyses. Results were validated in a population of dyspneic patients from a distinct cohort. RESULTS At 1 y follow up, 93 (16.1%) patients had died. Independent predictive ability was established in an age-adjusted Cox model containing all markers: NT-proBNP (HR=1.89); CRP (HR=1.95); ST2 (HR=7.17); hemoglobin (HR=1.68); BUN (HR=2.06) (all P<.05). Following categorical assessment based on number of abnormal markers, the 1-y risk of death increased in a monotonic fashion with mortality rates of 0%, 2.0%, 7.8%, 22.3%, 29.3%, and 57.6% respectively; similar results were seen in the validation set. CONCLUSION Simultaneous assessment of pathophysiologically diverse markers in acute dyspnea provides powerful, independent and incremental prognostic information.

Improvement in structural and functional echocardiographic parameters during chronic heart failure therapy guided by natriuretic peptides: mechanistic insights from the ProBNP Outpatient Tailored Chronic Heart Failure (PROTECT) study

We sought to determine if heart failure (HF) care with a goal to lower N‐terminal pro B‐type natriuretic peptide (NT‐proBNP) concentrations, compared with standard of care (SOC) management, is associated with improvement in echocardiographic parameters of cardiac structure and function.

Importance of Biomarkers for Long-Term Mortality Prediction in Acutely Dyspneic Patients

BACKGROUND Although numerous biomarkers may be prognostically meaningful in patients with acute dyspnea, few comparative analyses have addressed possible associations between a wide range of candidate biomarkers and clinical variables. METHODS Vital status was obtained for 517 acutely dyspneic patients at 4 years after emergency department presentation. A wide array of biomarkers was measured in this cohort, including natriuretic peptides, necrosis markers, inflammatory markers, hematologic markers, and renal markers. We performed statistical evaluation by using minimization of the Bayesian information criterion to evaluate predictors of 4-year mortality. Cox proportional hazards analysis was used to confirm results from the Bayesian information criterion. A final risk model was derived, and this model was then validated by applying it to patients from a separate cohort of acutely dyspneic patients. RESULTS By 4 years, there were 186 deaths (36%). In addition to several clinical variables, several biomarkers were significant predictors of death, including log-transformed concentrations of hemoglobin (hazard ratio=0.77; P < 0.001), soluble ST2 (hazard ratio=1.38; P < 0.001), and amino-terminal pro-B-type natriuretic peptide (hazard ratio=1.19; P < 0.001). Risk models that used these significant variables were accurate in predicting 4-year mortality in both the training and validation sets. CONCLUSIONS When added to traditional clinical variables, selected biomarkers added significant value for long-term prognostication in acute dyspnea.

Quality of life and chronic heart failure therapy guided by natriuretic peptides: Results from the ProBNP Outpatient Tailored Chronic Heart Failure Therapy (PROTECT) study

BACKGROUND Heart failure (HF) treatment guided by amino-terminal pro-B type natriuretic peptide (NT-proBNP) may reduce cardiovascular event rates compared to standard-of-care (SOC) management. Comprehensive understanding regarding effect of NT-proBNP guided care on patient-reported quality of life (QOL) remains unknown. METHODS One hundred fifty-one subjects with HF due to left ventricular systolic dysfunction were randomized to either SOC HF management or care with a goal to reduce NT-proBNP values ≤1000 pg/mL. Effects of HF on QOL were assessed using the Minnesota Living with HF Questionnaire (MLHFQ) quarterly, with change (Δ) in score assessed across study procedures and as a function of outcome. RESULTS Overall, baseline MLHFQ score was 30. Across study visits, QOL improved in both arms, but was more improved and sustained in the NT-proBNP arm (repeated measures P = .01); NT-proBNP patients showing greater reduction in MLHFQ score (-10.0 vs -5.0; P = .05), particularly in the physical scale of the questionnaire. Baseline MLHFQ scores did not correlate with NT-proBNP; in contrast, ∆MLHFQ scores modestly correlated with ∆NT-proBNP values (ρ = .234; P = .006) as did relative ∆ in MLHFQ score and NT-proBNP (ρ = .253; P = .003). Considered in tertiles, less improvement in MLHFQ scores was associated with a higher rate of HF hospitalization, worsening HF, and cardiovascular death (P = .001). CONCLUSIONS We describe novel associations between NT-proBNP concentrations and QOL scores among patients treated with biomarker guided care. Compared to SOC HF management, NT-proBNP guided care was associated with greater and more sustained improvement in QOL (Clinical Trial Registration: www.clinicaltrials.govNCT00351390).

Natriuretic peptide testing in clinical medicine.

Since the discovery of atrial natriuretic factor in 1981 by de Bold et al, there has been tremendous progress in our understanding of natriuretic peptides (NPs). Recently, testing for brain-type NP (BNP) and its amino terminal cleavage equivalent (NT-proBNP) has been rapidly adopted in clinical medicine for numerous indications, including the diagnosis and exclusion of heart failure (HF). In this regard, logical application of BNP or NT-proBNP testing may not only reduce healthcare costs but also potentially reduce adverse clinical outcomes. With respect to this fact, the potential importance of the concentration of the NPs for prognosis and the response of BNP or NT-proBNP to therapeutic intervention in terms of clinical events has been demonstrated. On the basis of these observations it is reasonable to expect that concentrations of these peptides might be useful for the management of patients with HF, acting as a gauge of therapeutic accuracy and/or stability of disease. Besides HF, the prognostic utility of NPs has been explored in other settings, particularly in ischemic heart disease and those conditions that lead to right ventricular dysfunction.

Relative value of amino-terminal pro-B-type natriuretic peptide testing and radiographic standards for the diagnostic evaluation of heart failure in acutely dyspneic subjects

To define more clearly the relationship between the information provided by the chest radiograph (CXR) and the natriuretic peptide (NT-proBNP) test as part of the evaluation of dyspneic patients presenting to the emergency department with suspected acute heart failure (HF), we evaluated the PRIDE cohort of 599 patients with and without HF, focusing on blinded NT-proBNP and unblinded CXR information. Clinical characteristics and diagnostic performance for each test were compared. We found that NT-proBNP measurement is superior to routine CXR interpretation for diagnosis or exclusion of acute HF and that normal CXR results should not be used to exclude HF in this population.

Natriuretic Peptide Testing in Primary Care

The incidence, as well as the morbidity and mortality associated with heart failure (HF) continue to rise despite advances in diagnostics and therapeutics. A recent advance in the diagnostic and therapeutic approach to HF is the use of natriuretic peptide (NP) testing, including both B-type natriuretic peptide (BNP) and its amino terminal cleavage equivalent (NT-proBNP). NPs may be elevated at an early stage among those with symptoms as well among those without. The optimal approach for applying NP testing in general populations is to select the target population and optimal cut off values carefully. Superior diagnostic performance is observed among those with higher baseline risk (such as hypertensives or diabetics). As well, unlike for acute HF, the cut off value for outpatient testing for BNP is 20-40 pg/mL and for NTproBNP it is 100-150 ng/L. In symptomatic primary care patients, both BNP and NT-proBNP serve as excellent tools for excluding HF based on their excellent negative predictive values and their use may be cost effective. Among those with established HF, it is logical to assume that titration of treatment to achieve lower NPs levels may be advantageous. There are several ongoing trials looking at that prospect.