Atrial fibrillation and amino-terminal pro-brain natriuretic peptide as independent predictors of prognosis in systolic heart failure

N-terminal pro brain natriuretic peptide eliminates the prognostic effect of atrial fibrillation in patients with chronic heart failure

AIMS

Co-morbid atrial fibrillation (AF) increases both mortality and N-terminal pro brain natriuretic peptide (NT-proBNP) concentrations in patients with chronic heart failure (CHF). It is unclear whether AF worsens prognosis independently from NT-proBNP concentrations. If AF was an independent risk factor, NT-proBNP levels for outcome prediction would need to be adjusted in patients with AF. We aimed to analyse the influence of AF on the prognostic value of NT-proBNP in patients with CHF.

METHODS AND RESULTS

A total of 2541 consecutive CHF patients with sinus rhythm (SR) or AF were identified in the outpatients' CHF registry of the University of Heidelberg, Germany. Of these, 250 patients with SR were individually matched to 250 patients with AF with respect to NT-proBNP, New York Heart Association functional class, sex, age, and aetiology of CHF. In the general sample, both AF and NT-proBNP were associated with all-cause mortality [hazard ratio (HR) = 1.96, 95% confidence interval (CI) 1.61-2.39, P < 0.001; and HR = 1.03 per 1000 ng/L increase, 95% CI 1.02 to 1.04, P < 0.001, respectively]. After matching, NT-proBNP retained its prognostic power (HR = 1.13 per 1000 ng/L increase, 95% CI 1.10 to 1.16, P < 0.001), but AF did not (HR = 0.91, 95% CI 0.66 to 1.25, P = 0.56). Despite similar prognosis, matched patients with SR were in more advanced CHF than were AF patients as indicated by a lower left ventricular ejection fraction (30 ± 13% vs. 34 ± 14%, P < 0.001).

CONCLUSIONS

The prognostic value of NT-proBNP in CHF is not influenced by concomitant AF. AF, in return, might be a surrogate of a worse cardiac condition rather than an independent risk factor.

BNP and NT-proBNP as Diagnostic Biomarkers for Cardiac Dysfunction in Both Clinical and Forensic Medicine

Currently, brain natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are widely used as diagnostic biomarkers for heart failure (HF) and cardiac dysfunction in clinical medicine. They are also used as postmortem biomarkers reflecting cardiac function of the deceased before death in forensic medicine. Several previous studies have reviewed BNP and NT-proBNP in clinical medicine, however, few articles have reviewed their application in forensic medicine. The present article reviews the biological features, the research and application status, and the future research prospects of BNP and NT-proBNP in both clinical medicine and forensic medicine, thereby providing valuable assistance for clinicians and forensic pathologists.

NT-proBNP prognostic value is maintained in elderly and very elderly patients with chronic systolic heart failure

BACKGROUND

Circulating concentrations of N-terminal fragment of the prohormone of brain natriuretic peptide (NT-proBNP) are influenced by age and common age-related comorbidities, such as renal dysfunction. Therefore, utility of NT-proBNP for prediction of prognosis in the aged has been questioned. We aimed to investigate the prognostic value of NT-proBNP across age classes in a cohort of patients with chronic systolic HF.

METHODS AND RESULTS

We enrolled 2364 consecutive outpatients with HF and left ventricular ejection fraction ≤50%. Patients were classified according to age quartiles, and a very elderly subgroup was identified, aged ≥85 years. After baseline assessment (including NT-proBNP testing), patients were followed-up for the composite of cardiovascular death, heart transplantation or ventricular assistance device implantation (primary outcome) and for all-cause death (secondary outcome). Patients in the fourth quartile (Q4, age ≥ 77 years, n = 638) and in the very elderly subgroup (age ≥ 85 years, n = 153), had higher NT-proBNP (p < .001 vs Q1). NT-proBNP was independently associated with primary and secondary outcome at 1- and 5-years follow-up in the whole population, as well as in Q4 and in the very elderly subgroup (all p < .05). Compared to the whole population, Q4 and very elderly had higher NT-proBNP cut-off for prediction of 1-year primary (4188 and 9729 ng/l, respectively vs 3710 ng/l) and secondary outcome (4296 and 7634 ng/l, respectively vs 3056 ng/l).

CONCLUSIONS

NT-proBNP predicts mortality in elderly and very elderly patients with chronic systolic HF, both at mid- and long-term follow-up. Higher NT-proBNP prognostic cut-off should be considered in the aged HF population.

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.

AXL receptor tyrosine kinase is increased in patients with heart failure

BACKGROUND

AXL is a membrane receptor tyrosine kinase highly expressed in the heart and has a conspicuous role in cardiovascular physiology. The role of AXL in heart failure (HF) has not been previously addressed.

METHODS AND RESULTS

AXL protein was enhanced 6-fold in myocardial biopsies of end-stage HF patients undergoing heart transplantation compared to controls from heart donors (P<0.0001). Next, we performed a transversal study of patients with chronic HF (n=192) and a group of controls with no HF (n=67). sAXL and BNP circulating levels were quantified and clinical and demographic data were collected. sAXL levels in serum were higher in HF (86.3 ± 2.0 ng/mL) than in controls (67.8 ± 2.0 ng/mL; P<0.0001). Also, sAXL correlated with several parameters associated with worse prognosis in HF. Linear regression analysis indicated that serum creatinine, systolic blood pressure and atrial fibrillation, but not BNP levels, were predictive of sAXL levels. Cox regression analysis indicated that high sAXL values at enrollment time were related to the major HF events (all-cause mortality, heart transplantation and HF hospitalizations) at one year follow-up (P<0.001), adding predictive value to high BNP levels.

CONCLUSIONS

Myocardial expression and serum concentration of AXL is elevated in HF patients compared to controls. Furthermore, peripheral sAXL correlates with parameters associated with the progression of HF and with HF events at short term follow-up. All together these results suggest that sAXL could belong to a new molecular pathway involved in myocardial damage in HF, independent from BNP.

Relation of hs-CRP and BNP levels with the atrial spontaneous echo contrast and thrombi in permanent atrial fibrillation patients with different etiologies

Background

Thromboembolic risk in permanent atrial fibrillation (AF) is strongly associated with the underlying etiology, and inflammatory parameters may contribute. The present study aimed to investigate the relationship of hs-CRP and BNP levels with left and right atrial appendage (LAA and RAA) function, presence of spontaneous echo contrast (SEC) and thrombus.

Material/Methods

Eighty-four permanent AF patients with different etiologies (20 mitral stenosis, 44 hypertension and 20 hyperthyroidism) and 23 patients with sinus rhythm were included. LAA and RAA flow velocities were measured by pulsed-wave Doppler and wall motion velocities with tissue Doppler imaging (TDI) in transesophageal echocardiography.

Results

Hs-CRP and BNP levels significantly differed among the 3 AF groups: levels were highest in mitral stenosis patients (8.6±5.3 mg/L and 98.0±125.7 pg/mL, respectively), the lowest hs-CRP was in hyperthyroidism patients (4.3±3.8 mg/L), and the lowest BNP was in hypertensive patients (64.8±44.3 pg/mL). There were also significant differences between the AF group and controls regarding hs-CRP and BNP levels. In the correlation analysis, BNP level was not significantly correlated with LAA and RAA functions, whereas hs-CRP level was significantly correlated with some LAA and RAA functions. On the other hand, hs-CRP level was significantly related to the presence of mild-moderate SEC and thrombi, mainly in mitral stenosis patients. Moreover, hs-CRP was the most important determinant of RAA thrombus formation, followed by RAA ejection fraction. In contrast, no positive or negative correlation was found between BNP levels and RAA and LAA thrombi.

Conclusions

Higher hs-CRP levels in AF patients may be a predictor for the presence of SEC and thrombi in the atria.

Prevalence and Predisposing Factors of Atrial Fibrillation in a Multi-Ethnic Society: The Impact of Racial Differences in Bahrain

Background

The prevalence and epidemiological data of atrial fibrillation (AF) among multi-ethnic populations is less well studied worldwide.

Aim

Evaluation of the prevalence and predisposing factors of AF in patients who were admitted to acute medical emergencies (ER) in Bahrain over the period of one year.

Methods

Two hundred and fifty three patients with onset of AF were studied. The mean difference of biochemical data and clinical characteristics between Middle Eastern (ME) and sub continental (SC) patients was evaluated. The odds ratio of different predisposing factors for the development of clinical events in AF patients was assessed using multiple logistic regression analysis.

Results

Out of 7,450 patients that were admitted to ER over one year, 253 had AF based on twelve leads Electrocardiogram (ECG), with prevalence of 3.4%. In the whole study, the mean age was 59.45 ± 18.27 years, with 164 (65%) male. There were 150 ME patients (59%), and 107 (41%) SC, 55 (22%) were Indian (IND) and 48 (19%) were South Asian (SA). In the whole study clinical presentation was of 48% for palpitation, pulmonary edema was of 14%, angina pectoris on rest of 12%, 10% had embolic phenomena, 6% had dizziness, and 7% were asymptomatic. The odds ratio of different variables for occurrence of clinical events in the study was positive of 2.2 for history of hypertension, 1.8 for sickle cell disease, 1.2 for high body mass index (BMI) >30, 1.1 for mitral valve disease. The ME patients, compared with SC, were older, had significantly higher body mass index, higher history of rheumatic valve disease, sickle cell disease with high level of uric acid and lower hemoglobin. The history of hypertension, DM and smoking was higher among the SC patients. The rate of thyroid disease was equal in both groups.

Conclusion

The prevalence of atrial fibrillation was 3.4% with male predominance of 65%. Patients of sub continental origin were younger with a significantly high history of hypertension and ischemic heart disease. The patients of Middle Eastern origin had significantly high rate of rheumatic heart disease, and sickle cell disease. The history of hypertension was the most important independent clinical predictor of adverse events in patients presented with AF.