Hemoglobin and N-terminal pro-brain natriuretic peptide: Independent and synergistic predictors of mortality in patients with acute heart failure

Biomarkers for the diagnosis and management of heart failure

Heart failure (HF) is a significant cause of morbidity and mortality worldwide. Circulating biomarkers reflecting pathophysiological pathways involved in HF development and progression may assist clinicians in early diagnosis and management of HF patients. Natriuretic peptides (NPs) are cardioprotective hormones released by cardiomyocytes in response to pressure or volume overload. The roles of B-type NP (BNP) and N-terminal pro-B-type NP (NT-proBNP) for diagnosis and risk stratification in HF have been extensively demonstrated, and these biomarkers are emerging tools for population screening and as guides to the start of treatment in subclinical HF. On the contrary, conflicting evidence exists on the role of NPs as a guide to HF therapy. Among the other biomarkers, high-sensitivity troponins and soluble suppression of tumorigenesis-2 are the most promising biomarkers for risk stratification, with independent value to NPs. Other biomarkers evaluated as predictors of adverse outcome are galectin-3, growth differentiation factor 15, mid-regional pro-adrenomedullin, and makers of renal dysfunction. Multi-marker scores and genomic, transcriptomic, proteomic, and metabolomic analyses could further refine HF management.

Established and Emerging Roles of Biomarkers in Heart Failure

Heart failure (HF) is a complex syndrome with an enormous societal burden in terms of cost, morbidity, and mortality. Natriuretic peptide testing is now widely used to support diagnosis, prognostication, and management of patients with HF and are incorporated into HF clinical practice guidelines. Beyond the natriuretic peptides, novel biomarkers may supplement traditional clinical and laboratory testing to improve understanding of the complex disease process of HF and possibly to personalize care for those affected through better individual phenotyping. In this review, we will discuss natriuretic peptides and the more novel biomarkers by dividing them into categories based on the major pathophysiologic pathways they represent. Given the complex physiology in HF, it is reasonable to expect that the future of biomarker testing lies in the application of multimarker testing panels, precision medicine to improve HF care delivery, and the use of biomarkers in proteomics and metabolomics to further improve HF care.

Biomarkers of Heart Failure with Preserved and Reduced Ejection Fraction

Biomarkers are increaingly being used in the management of heart failure not only for the purpose of screening, diagnosis, and risk stratification, but also as a guide to evaluate the response to treatment in the individual patient and as an entry criterion and/or a surrogate marker of efficacy in clinical trials testing novel drugs. In this chapter, we review the role of established biomarkers for heart failure management, according to the main classification of HF phenotypes, based on the measurement of left ventricular ejection fraction, including heart failure with reduced (<40%), preserved (≥50%), and, as recently proposed, mid-range (40-49%) ejection fraction.

Diagnostic and Prognostic Utility of Procalcitonin in Patients Presenting to the Emergency Department with Dyspnea

BACKGROUND

Among patients in the emergency department, dyspnea is a common complaint and can pose a diagnostic challenge. Biomarkers are used increasingly to improve diagnostic accuracy and aid with prognostication in dyspneic patients. The purpose of this study was to examine the clinical utility of serum procalcitonin (PCT) for the diagnosis of pneumonia in patients presenting to the emergency department with dyspnea. A secondary objective was to evaluate the prognostic value of PCT for death to 1 year.

METHODS

This study pooled the patient populations of 2 prospective cohorts that previously enrolled patients presenting to 2 urban emergency departments with dyspnea. A total of 453 patients had serum samples available for biomarker analysis. Clinician certainty for the diagnosis of acutely decompensated heart failure was reviewed. Discrimination, calibration, and net reclassification improvement for the diagnosis of pneumonia as well as fatal outcomes were considered. The main outcome was accuracy of PCT for diagnostic categorization of pneumonia. The prognostic value of PCT for survival to 1 year was a secondary outcome.

RESULTS

Pneumonia alone was diagnosed in 30 patients (6.6%), heart failure without pneumonia in 212 patients (47%), and both diagnoses in 30 patients (6.6%). Procalcitonin concentrations were higher in subjects with pneumonia (0.38 vs 0.06 ng/mL; P < .001). Area under the receiver operating characteristic curve for the diagnosis of pneumonia based on PCT was 0.84 (95% confidence interval [CI], 0.77-0.91; P < .001). Across all levels of clinician-based estimates of heart failure, PCT was sensitive and specific; notably, in patients judged with diagnostic uncertainty (n = 70), a PCT value of 0.10 ng/mL had the optimal balance of sensitivity and specificity (80% and 77%, respectively) for pneumonia. Adding PCT results to variables predictive of pneumonia resulted in a net reclassification improvement of 0.54 (95% CI, 0.24-0.83; P < .001) for both up- and down-reclassifying events. In adjusted analyses, elevated PCT was a predictor of 1-year mortality (hazard ratio 1.8; 95% CI, 1.4-2.3; P < .001) and was additive when elevated in conjunction with natriuretic peptides for this application.

CONCLUSION

In emergency department patients with acute dyspnea, PCT is an accurate diagnostic marker for pneumonia and adds independent prognostic information for 1-year mortality.

Anemia in Intensive Cardiac Care Unit patients - An underestimated problem

The heterogeneous group of patients admitted to Intensive Cardiac Care Unit (ICCU) as well as nonspecific complaints associated with anemia might be the reason for underdiagnosing or minimization of this problem. Because of this heterogeneity, there are no clear guidelines to follow. It is known that anemia is impairing the outcome. Thus, it is crucial to keep alert in the diagnosis and treatment of anemia, especially in critically ill cardiac patients. The greatest groups of patients admitted to ICCU are those with acute coronary syndromes (ACS), acute decompensated heart failure (ADHF), severe arrhythmias as well as individuals after cardiac operations. However, patients suffering other critical cardiac illnesses quite often become anemic during hospitalization in ICCU. It is because anemia is typed in the clinical features of heavy diseases or may be the consequence of treatment. The current review focuses on the incidence, complex etiology and predictive role of anemia in a diverse group of ICCU patients. It discusses clinical aspects of anemia treatment in particular groups of critically ill cardiac patients because proper treatment increases chances for recovery and improves the outcome in this severe group of patients.

The use of discharge haemoglobin and NT-proBNP to improve short and long-term outcome prediction in patients with acute heart failure

AIMS

To examine the prognostic value of admission (A) and discharge (D) haemoglobin (Hb) and its relationship with N-terminal pro-hormone B-type natriuretic peptide (NT-proBNP) in patients hospitalised for acute heart failure (AHF). The outcomes of interests were rehospitalisation or death after one, six or twelve months after discharge.

METHODS

317 hospitalised AHF patients (74.7±9.4 years) were enrolled in two academic centres in Belgrade and Rome. Laboratory analyses, including NT-proBNP were assessed at admission, and Hb also at discharge. Patients were divided into two groups according to the presence of anaemia. Follow-up contact was made by telephone. Statistical analyses were performed using SPSS software version 21.0.

RESULTS

According to A and DHb levels (<120 g/l for women and <130 g/l for men), anaemia was present in 55% and 62% of patients, respectively ( P=0.497). Lower DHb was associated with the rehospitalisation risk after one (OR=0.96, P=0.004), six (OR=0.97, P<0.001) and 12 months (OR=0.97, P<0.001). For every g/l decrease of DHb, the risk of rehospitalisation after one year was increased by 3.3%. In the first six months, DHb contributed to increased risk of death (OR=0.97, P=0.005), but NT-proBNP showed greater power (OR=2.1, P<0.001).

CONCLUSIONS

In AHF patients discharge anaemia is a strong predictor for short and long-term rehospitalisation, while NT-proBNP seems to be a better predictor for mortality. Discharge Hb and NT-proBNP should be assessed together in order to detect the patients with higher risk of future death and rehospitalisation.

Circulating microRNAs in heart failure with reduced and preserved left ventricular ejection fraction

AIM

The potential diagnostic utility of circulating microRNAs in heart failure (HF) or in distinguishing HF with reduced vs. preserved left ventricular ejection fraction (HFREF and HFPEF, respectively) is unclear. We sought to identify microRNAs suitable for diagnosis of HF and for distinguishing both HFREF and HFPEF from non-HF controls and HFREF from HFPEF.

METHODS AND RESULTS

MicroRNA profiling performed on whole blood and corresponding plasma samples of 28 controls, 39 HFREF and 19 HFPEF identified 344 microRNAs to be dysregulated among the three groups. Further analysis using an independent cohort of 30 controls, 30 HFREF and 30 HFPEF, presented 12 microRNAs with diagnostic potential for one or both HF phenotypes. Of these, miR-1233, -183-3p, -190a, -193b-3p, -193b-5p, -211-5p, -494, and -671-5p distinguished HF from controls. Altered levels of miR-125a-5p, -183-3p, -193b-3p, -211-5p, -494, -638, and -671-5p were found in HFREF while levels of miR-1233, -183-3p, -190a, -193b-3p, -193b-5p, and -545-5p distinguished HFPEF from controls. Four microRNAs (miR-125a-5p, -190a, -550a-5p, and -638) distinguished HFREF from HFPEF. Selective microRNA panels showed stronger discriminative power than N-terminal pro-brain natriuretic peptide (NT-proBNP). In addition, individual or multiple microRNAs used in combination with NT-proBNP increased NT-proBNP's discriminative performance, achieving perfect intergroup distinction. Pathway analysis revealed that the altered microRNAs expression was associated with several mechanisms of potential significance in HF.

CONCLUSIONS

We report specific microRNAs as potential biomarkers in distinguishing HF from non-HF controls and in differentiating between HFREF and HFPEF.

Body mass index and mortality in acutely decompensated heart failure across the world: a global obesity paradox

OBJECTIVES

This study sought to define the relationship between body mass index (BMI) and mortality in heart failure (HF) across the world and to identify specific groups in whom BMI may differentially mediate risk.

BACKGROUND

Obesity is associated with incident HF, but it is paradoxically associated with better prognosis during chronic HF.

METHODS

We studied 6,142 patients with acute decompensated HF from 12 prospective observational cohorts followed-up across 4 continents. Primary outcome was all-cause mortality. Cox proportional hazards models and net reclassification index described associations of BMI with all-cause mortality.

RESULTS

Normal-weight patients (BMI 18.5 to 25 kg/m(2)) were older with more advanced HF and lower cardiometabolic risk. Despite worldwide heterogeneity in clinical features across obesity categories, a higher BMI remained associated with decreased 30-day and 1-year mortality (11% decrease at 30 days; 9% decrease at 1 year per 5 kg/m(2); p < 0.05), after adjustment for clinical risk. The BMI obtained at index admission provided effective 1-year risk reclassification beyond current markers of clinical risk (net reclassification index 0.119, p < 0.001). Notably, the "protective" association of BMI with mortality was confined to persons with older age (>75 years; hazard ratio [HR]: 0.82; p = 0.006), decreased cardiac function (ejection fraction <50%; HR: 0.85; p < 0.001), no diabetes (HR: 0.86; p < 0.001), and de novo HF (HR: 0.89; p = 0.004).

CONCLUSIONS

A lower BMI is associated with age, disease severity, and a higher risk of death in acute decompensated HF. The "obesity paradox" is confined to older persons, with decreased cardiac function, less cardiometabolic illness, and recent-onset HF, suggesting that aging, HF severity/chronicity, and metabolism may explain the obesity paradox.