N-terminal pro-brain natriuretic peptide – a promising biomarker for the diagnosis of left ventricular hypertrophy in hypertensive women

NT-proBNP Levels in Relation to Various Grades of Hypertension – An Observational Study

Objectives:

The objectives of this study were to compare levels of NT-proBNP in various grades of hypertension, correlate with electrocardiographic criteria of LVH and with diastolic function on echocardiography.

Materials and Methods:

This study was conducted on 100 patients attending the cardiology outpatient department of Nizam’s Institute of Medical Sciences, patients satisfying the inclusion criteria were enrolled in this study after taking informed consent.

Results:

This study includes the patient population with a mean of 54.32 ± 6 years of age. ECG criteria of LVH are more common in patients with Grade 1 (60%) and Grade 2 (89%) hypertension.

Conclusion:

Patients with higher grades of hypertension have more LV mass which is corresponding to ECG criteria satisfying LVH and more diastolic dysfunction as well as higher NT pro-BNP values.

NT-proBNP, Cardiometabolic Risk Factors, and Nutritional Status in Hemodialysis Patients

Background

We aimed to evaluate the association between NT-proBNP and malnutrition in HD patients while taking into account the four established categories of parameters for diagnosis of protein energy wasting (PEW).

Methods

A cross-sectional study was performed in Afro-Caribbean dialysis patients. One component in each of the 4 categories for the wasting syndrome was retained: serum albumin ≤ 38 g/L, BMI ≤ 23 Kg/m², serum creatinine ≤ 818 µmol/L, and normalized protein catabolic rate (nPCR) ≤ 0.8 g/kg/day. NT-proBNP was assessed using a chemiluminescence immunoassay. Two multivariate logistic regression models were performed to determine the parameters associated with high NT-proBNP concentrations.

Results

In 207 HD patients, 16.9% had PEW (at least three components). LVEF lower than 60% was found in 13.8% of patients. NT-proBNP levels ranged from 125 to 33144 pg/mL. In model 1, high levels of NT-proBNP (≥6243 pg/mL) were independently associated with PEW OR 14.2 (3.25–62.4), male gender 2.80 (1.22–6.57), hsCRP > 5 mg/L 3.90 (1.77–8.57), and dialysis vintage > 3 years 3.84 (1.35–10.8). In model 2, LVEF OR was 0.93 (0.88–0.98). NT-proBNP concentrations were significantly higher when the PEW component number was higher.

Conclusion

In dialysis patients, high NT-proBNP levels must draw attention to cardiac function but also to nutritional status.

[Renal denervation for treating hypertension: experience at the University Hospital in Lyon]

AIM

We report the first experience of Lyon's university hospital regarding renal denervation to treat patients with resistant essential hypertension.

PATIENTS AND METHODS

Over a one-year period, 17 patients were treated (12 men, 5 women) with renal denervation. Baseline characteristics were as follows: age 56.5±11.5 years, BMI 33±5kg/m(2) and ambulatory blood pressure 157±16/87±13mmHg with 4.2±1.5 anti-hypertensive treatment.

RESULTS

We did not observe intra-operative or early complications. After a median follow-up of 3 months and with the same anti-hypertensive treatment, office systolic blood pressure (SBP) and diastolic blood pressure (DBP) decrease respectively of 20±15 (P<0.001) and 10±13mmHg (P=0.014) (n=17). After six months of follow-up, ambulatory blood pressure (ABPM) decrease of 17.5±14.9mmHg (P=0.027) for SBP and of 10.5±9.6mmHg (P=0.029) for DBP (n=6). Among these patients, five of them were controlled (ABPM inferior to 130/80mmHg) and electrical left ventricular hypertrophy indexes decreased: R wave in aVL lead of 4±3mm (P=0.031), Sokolow index of 3±3mm (P=0.205), Cornell voltage criterion of 9±7mm (P=0.027) and Cornell product of 1310±1104 (P=0.027).

CONCLUSION

Our results are in accordance with data from other centers. On average blood pressure decreases significantly but important inter individual variations are observed. The procedure seems safe.

Biological, electrical and echocardiographic indices versus cardiac magnetic resonance imaging in diagnosing left ventricular hypertrophy

The aim of this study was to compare the diagnostic performance of N-terminal pro-brain natriuretic peptide (NT-proBNP), electrocardiographic (ECG) criteria and transthoracic echocardiography (TTE) versus cardiac magnetic resonance imaging in detecting left ventricular hypertrophy (LVH). The study included 42 hypertensive subjects with mean±s.d. age 48.1±12.3 years, 57.1% men, 24-h ambulatory blood pressure 144/89 mm Hg, left ventricular ejection fraction >50%, without symptoms of heart failure, and not taking any drugs that interfere with hormonal regulation. The accuracies of the methods in detecting LVH were compared at two diagnostic LVH cutoffs: low, 83 g m(-2) in men and 67 g m(-2) in women; and high, 96 g m(-2) in men and 81 g m(-2) in women. With the low and high LVH cutoffs, the areas under the receiver-operating characteristic curves and the optimal values for NT-proBNP were 0.761, 0.849, 200 and 421 pg ml(-1), respectively. An NT-proBNP level under 30 pg ml(-1) ruled out LVH with 100% sensitivity. The optimal values and literature-based values of NT-proBNP allowed a correct classification of 73-81% of the subjects. In 80-90% of the cases, the diagnostic accuracy of NT-proBNP was close to that of ECG criteria but lower than that of TTE criteria. Interestingly, combining ECG criteria and NT-proBNP level improved the diagnostic performance to be at least comparable to that of TTE: the percentages of correctly classified subjects were 73-95% vs. 67-86%, respectively. Of note, the range considers both diagnostic LVH cutoffs. The simultaneous use of ECG criteria and NT-proBNP plasma levels seemed to be powerful enough to detect LVH in most hypertensive subjects.

Natriuretic peptides: ready for prime-time in hypertension?

Over the past years, natriuretic peptides have been recognised not only as important contributors to cardiovascular regulation but also as valuable markers in overt cardiac disease, including heart failure or coronary disease. More recently, these markers have shown their ability to detect preclinical cardiac alterations in different settings. In this respect, natriuretic peptides offer a new perspective for risk stratification in hypertension. They are correlated to various features of cardiac remodelling provoked by hypertension. They also depend on vascular properties, including blood pressure level and aortic stiffness. In addition to being integrative markers of cardiovascular alterations, several studies have shown their value in predicting all-cause mortality or cardiovascular mortality and morbidity in the general population. At least three consistent studies are now available in hypertension also showing this prognostic value. This performance, together with the ease of measurement, low cost and widespread availability, should prompt the wide use of natriuretic peptides for risk stratification in hypertension, at least in patients with normal electrocardiography, but also in most hypertensive patients.

[Diagnostic accuracy of NT-proBNP compared with electrocardiography in detecting left ventricular hypertrophy of hypertensive origin]

Electrocardiography (ECG) is the most widely used method for diagnosing left ventricular hypertrophy (LVH) in hypertensive patients. We assessed the value of N-terminal pro-brain natriuretic peptide (NT-proBNP) determination compared with ECG for detecting LVH in 336 consecutive hypertensive patients with preserved systolic function. We found a significant correlation between NT-proBNP levels and left ventricular mass adjusted for body surface area (r=.41; P<.001). The area under the receiver operating characteristic curve was 0.75 (95% CI, 0.7-0.8). A cut-off of 74.2 pg/mL had a greater sensitivity than ECG (76.6% vs 25.5%; P<.001) and a higher negative predictive value (87.8% vs 76.6%; P<.001) in the identification of LVH. NT-proBNP determination may be a useful tool for LVH screening in hypertensive patients.

N-Terminal Pro-Brain Natriuretic Peptide

See Editorial Commentary, pp 670–671

Natriuretic peptides are controregulatory hormones associated with cardiac remodeling, namely, left ventricular hypertrophy and systolic/diastolic dysfunction. We intended to address the prognostic value of N-terminal pro-brain natriuretic peptide (NT-proBNP) in hypertension. We prospectively studied the relationship between plasma NT-proBNP and all-cause mortality in 684 hypertensive patients with no history or symptoms of heart failure referred for hypertension workup in our institution from 1998 to 2008. After a mean duration of 5.7 years, we observed 40 deaths (1.04 deaths per 100 patients per year). After adjustment for traditional cardiovascular risk factors, including ambulatory blood pressure and serum creatinine, the risk for all-cause mortality more than doubled with each increment of 1 log NT-proBNP (hazard ratio: 2.33 [95% CI: 1.36 to 3.96]). The risk of death of patients with plasma NT-proBNP ≥133 pg/mL (third tertile of the distribution) was 3.3 times that of patients with values <50.8 pg/mL (first tertile; hazard ratio: 3.30 [95% CI: 0.90 to 12.29]). This predictive value was independent of, and superior to, that of 2 ECG indexes of left ventricular hypertrophy, the Sokolov-Lyon index and the amplitude of the R wave in lead aVL. In addition, it persisted in patients without ECG left ventricular hypertrophy, which allowed refining risk stratification in this relatively low-risk patient category. In this large sample of hypertensive patients, plasma NT-proBNP appeared as a strong prognostic marker. This performance, together with the ease of measurement, low cost, and widespread availability of NT-proBNP test kits, should prompt a wide use of this marker for risk stratification in hypertension.

The detection of left ventricular diastolic dysfunction in hypertensive patients: Performance of N-terminal probrain natriuretic peptide

AIM

Diastolic dysfunction (DD) results in increased cardiovascular risk in hypertensives. We studied the performance of N-terminal probrain natriuretic peptide (NT-proBNP) in detecting DD.

MATERIALS AND METHODS

241 hypertensive patients admitted to cardiology polyclinics were included in this study. They were grouped according to the presence of DD. Group 1: Essential hypertensive patients without DD (n= 119); group 2: essential hypertensive patients with DD (n= 122). All underwent trans-thoracic echocardiography for the evaluation of transvalvular flow, morphology, left ventricular wall motion abnormalities and ejection fraction. NT-proBNP levels were measured by an electrochemiluminescence immunoassay.

RESULTS

The systolic blood pressure (BP) (mean+/-SD) was 140+/-12 mmHg in group 1 and 144+/-16 mmHg in group 2 (p=0.049), the diastolic BP (mean+/-SD) was 88+/-10 mmHg in group 1 and 90+/-14 mmHg in group 2 (p=0.043). The median (1st-3rd quartile) NT-proBNP level in group 2 was significantly higher than group 1 [121.05 (61.03-207.66) and 31.17 (17.07-54.09) pg/ml, respectively (p<0.001)]. In the receiver operating characteristics analysis, the area under the curve was 0.862 (95% CI 0.816-0.908). At the cut-off of 45 pg/ml, sensitivity was 86.9%, specificity was 62.4%, and at the cut-off 65 pg/ml, sensitivity was 74.6%, specificity was 83.8%.

CONCLUSION

Plasma NT-proBNP levels may be useful for identifying patients with DD and it is conceivable to use a cut-off level 65 pg/ml as a "rule in" test.

The midregional portion of proadrenomedullin is an independent predictor of left ventricular mass index in hypertension

Left ventricular hypertrophy (LVH) is a risk factor for cardiovascular disease. Elevated natriuretic peptides in LVH have spurred interest that biomarkers may play a role in screening programs. Adrenomedullin (ADM) is a 52-amino acid peptide mediating vasorelaxation, natriuresis, and diuresis. The midregional portion of proADM (MRproADM) is secreted stoichiometrically with ADM; hence, it can be used as a surrogate marker of ADM. We compared the diagnostic performance of MRproADM for the detection of LVH with N-terminal pro-B-type natriuretic peptide (NTproBNP). Two hundred fifty-three hypertensive patients were derived from a local screening study. The MRproADM and NTproBNP levels were assayed using immunoluminometric assays. The MRproADM levels were significantly elevated in patients with LVH than those without (mean [SD]: 0.73 [0.25] vs 0.59 [0.18] nmol/L, P < .001). In multivariate analyses, male sex (P < .001) and log MRproADM (P = .003) retained significance for detecting LVH. Receiver operating characteristic curve for MRproADM yielded an area under the curve of 0.71; confidence interval, 0.62-0.81; P < .001, superior to NTproBNP. An optimal cutoff value for MRproADM as an indicator of LVH was 0.50 nmol/L, with a sensitivity, specificity, and negative predictive value of 90.5%, 36.5%, and 95.1%, respectively. The high negative predictive value of the MRproADM assay allows it to be used as a rule-out test for LVH when stratifying patients into high or low risk. Patients who test positive would necessitate echocardiography, enabling better resource allocation.