Increased plasma concentrations of N-terminal pro-brain natriuretic peptide reflect the presence of mildly reduced left ventricular diastolic function in hypertension

Circulating biomarkers in the early detection of hypertensive heart disease: usefulness in the developing world

Although the varying phenotypic spectra of hypertensive heart disease (HHD) can be assessed by electrocardiography (ECG), echocardiography and cardiovascular magnetic resonance (CMR), ECG criteria for left ventricular hypertrophy (LVH) are insensitive, while echocardiography and CMR are expensive, less readily available and often lack requisite expertise. Consequently, the use of circulating biomarkers in the diagnosis and prognostication of HHD beyond the traditional N-terminal pro- b-type natriuretic peptide (NT-proBNP) and B-type natriuretic peptide (BNP) have become an attractive alternative. We carried out a PubMed and Google Scholar databases' search of original articles on circulating biomarkers used in the diagnosis of the different spectrum of HHD over the last 10 years [2005-2015] in humans. Fourteen studies met the inclusion criteria with NT-pro BNP being the most studied circulating biomarker in HHD followed by soluble ST2 (sST2). There is a lack of data on the use of circulating biomarkers in HHD. There is a need to explore further this area of investigative cardiology.

Associations of candidate biomarkers of vascular disease with the ankle-brachial index and peripheral arterial disease

BACKGROUND

The use of multiple biomarkers representing various etiologic pathways of atherosclerosis may improve the prediction of interindividual variation in the ankle-brachial index (ABI). To this end, we investigated associations of 47 candidate biomarkers with the ABI and presence of peripheral arterial disease (PAD) in African-Americans (AAs) and non-Hispanic whites (NHWs).

METHODS

Study participants included 1,291 AAs (71.1% women, mean age, 63.4±9.3 years) and 1,152 NHWs (57.5% women, mean age 58.5±10.1 years) belonging to hypertensive sibships. Peripheral arterial disease was defined as an ABI ≤ 0.90. Circulating levels of 47 candidate biomarkers were log-transformed before analysis because of skewed distribution. Multivariate regression analyses were used to identify biomarkers associated with ABI or PAD independently of age, sex, conventional risk factors, and medication use.

RESULTS

After adjustment for covariates, higher levels of nine biomarkers were associated with a lower ABI in AAs (all P ≤ 0.005); these biomarkers were C-reactive protein (CRP), interleukin-6, tumor necrosis factor receptor-II (TNF-R II), lipoprotein(a), N-terminal pro-brain natriuretic peptide (NT-proBNP), pro-atrial natriuretic peptide, C-terminal pro-arginine vasopressin, osteoprotegerin, and fibrinogen. Three biomarkers - myeloperoxidase, NT-proBNP, and D-dimer - were associated with ABI in NHWs (all P ≤ 0.01). C-reactive protein, interleukin-6, TNF-R II, lipoprotein(a), NT-proBNP, pro-atrial natriuretic peptide, D-dimer, and fibrinogen were associated with PAD (all P ≤ 0.005) in AAs after adjustment for covariates. None of the biomarkers were independently associated with PAD in NHWs.

CONCLUSION

A multimarker approach improved the prediction of interindividual variation in the ABI in AAs and NHWs, and improved prediction of the presence of PAD in AAs.

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.

Relation between N-terminal pro-B-type natriuretic peptide and coronary plaque components in patients with acute coronary syndrome: virtual histology-intravascular ultrasound analysis

BACKGROUND

The N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) is a sensitive indicator of hemodynamic stress and its increased level is associated with higher mortality in acute coronary syndrome (ACS) patients. Virtual histology-intravascular ultrasound (VH-IVUS) can provide quantitative information on plaque components.

METHODS

We measured preprocedural serum NT-pro-BNP levels in 156 ACS patients with preserved left ventricular systolic function and normal serum creatinine. VH-IVUS classified the color-coded tissue into four major components: fibrotic, fibro-fatty, dense calcium, and necrotic core (NC). Thin-cap fibroatheroma (TCFA) was defined as focal, NC-rich (>or=10% of the cross-sectional area) plaques being in contact with the lumen in a plaque burden of at least 40%. We divided the patients into two groups according to the NT-pro-BNP levels [group I: >or=200 pg/ml (n = 58) vs. group II: <200 pg/ml (n = 98)].

RESULTS

The percent areas of NC at the minimum lumen site (19.8+/-13.1% vs. 15.2+/-11.1%, P = 0.027) and at the largest NC site (24.7+/-10.3% vs. 19.2+/-11.4%, P = 0.015) were significantly greater in group I than in group II. Percent NC volume was significantly greater in group I than in group II (15.8+/-8.1% vs. 10.1+/-9.1%, P = 0.008). The total number of TCFAs was 38 in group I and 56 in group II. The presence of at least one TCFA (58 vs. 38%, P = 0.009) and multiple TCFAs (25 vs. 10%, P = 0.005) within culprit lesions were observed more frequently in group I than in group II. The TCFAs were located more in proximal in group I than in group II [the length from coronary ostium to TCFA: 10.8+/-7.6 mm in group I vs. 25.7+/-16.3 mm in group II (P<0.001)]: 85% of TCFAs was located within 20 mm from coronary ostium in group I; conversely only 36% of TCFAs was located within 20 mm from coronary ostium in group II (P<0.001).

CONCLUSION

VH-IVUS analysis shows that ACS patients with high NT-pro-BNP levels had more vulnerable plaque component (more NC-containing lesions and higher frequency of culprit lesion TCFAs) and had more proximally located TCFAs.

Obese and nonobese patients with essential hypertension show similar N-terminal proBNP plasma levels

BACKGROUND

Multiple studies have focused on the influence of obesity on natriuretic peptide levels. However, the effect of obesity on amino-terminal propeptide of B-type natriuretic peptide (NT-proBNP) levels in hypertensive (HT) patients remains uncertain.

METHODS

We studied 252 asymptomatic patients (60 +/- 13 years, 136 men) with essential HT. A routine physical examination, anthropometry, laboratory analyses, echo-Doppler study, and NT-proBNP level determination were performed.

RESULTS

NT-proBNP levels were similar in both obese and nonobese HT (median 56 (25-130) pg/ml vs. median 51 (26-129) pg/ml, P = 0.488). No significant differences were found in obese or nonobese patients with left ventricular hypertrophy (LVH) (median 135 (73-425) pg/ml vs. median 151 (64-274) pg/ml, P = 0.597). The area under the curve was 0.89 +/- 0.03 for NT-proBNP to diagnose LVH in the obese HT patients and 0.88 +/- 0.03 in the nonobese. A logistic regression analysis showed that age, gender, and left ventricular mass index (LVMI) were independent predictors of NT-proBNP levels. Body mass index (BMI) was not significantly associated with NT-proBNP in LVH HT patients.

CONCLUSIONS

Obesity is not statistically associated with NT-proBNP levels in HT asymptomatic patients. The same results were observed in our group of patients with LVH. These data are in contrast with those previously found in heart failure, and raise questions about the role of obesity per se as primary cause of decreased NT-proBNP levels in other pathophysiological conditions.

The role of N terminal pro-brain natriuretic peptide in the evaluation of left ventricular diastolic dysfunction: correlation with echocardiographic indexes in hypertensive patients

The utility of N-Terminal pro Brain Natriuretic Peptide (NT-proBNP) and Brain Natriuretic Peptide (BNP) for detecting left ventricular (LV) diastolic dysfunction in hypertensive patients without heart failure symptoms is unclear. In this study, we investigated the relation between NT-proBNP plasma levels and LV diastolic dysfunction in hypertensive patients without systolic dysfunction.

METHOD

We studied 40 ambulatory patients (26 women, mean age 52 +/- 5) with controlled hypertension. LV diastolic function was assessed with conventional Doppler, by means of mitral inflow and with tissue Doppler echocardiography by means of mitral annulus. The ratio of early diastolic transmitral E wave velocities to tissue Doppler mitral annulus early diastolic E' wave velocities (E/E'), was used to detect LV filling pressures. Patients were divided in three groups according to E/E' ratios < 10 (group I), E/E' ratios ''between'' 10 and 15 (group II) and E/E' ratios > 15 (group III). Plasma concentrations of NT-proBNP were measured by electro chemiluminescence's immunoassay.

RESULTS

The NT-proBNP blood levels were positively correlated significantly with E/E' ratio (r = 0.80, P < 0.0001). Patients with elevated LV end diastolic pressure (LVEDP), defined as E/E' > 15 (n = 8) had highest NT-proBNP (203 +/- 75 pg/ml) levels. E/E' 10 to 15 group (n = 16) had a mean NT-proBNP level of 71 +/- 26 pg/ml, and those with E/E' < 10 (n = 16) had 39 +/- 20 pg/ml. A NT-proBNP value of 119 pg/ml had a sensitivity of 87%, a specificity of 100% for predicting E/E' > 15.

CONCLUSION

The assessment of the blood concentration of NT-proBNP is of potential value for identification of those patients with hypertension to detect early cardiovascular changes, especially LV diastolic dysfunction.

Mechanisms of pathogenesis in Chagas disease

Chagas disease, caused by the obligate unicellular parasite Trypanosoma cruzi, presents itself in a diverse collection of clinical manifestations, ranging from severe, fatal heart and digestive tract pathologies to unapparent or minor alterations that do not compromise survival. Over the years, a number of mechanisms have been proposed to explain the pathogenesis of chagasic tissue lesions, all of which have faced some criticism or been received with skepticism. This article excludes the autoimmunity hypothesis for Chagas disease because it has been extensively reviewed elsewhere, and summarizes the various alternative hypotheses that have been advanced over the years. For each of these hypotheses, an outline of its main tenets and key findings that support them is presented. This is followed by the results and comments that have challenged them and the caveats that stand on their way to wider acceptance. It is hoped that this writing will draw attention to our shortcomings in understanding the pathogenesis of Chagas disease, which, unfortunately, continues to figure among the most serious health problems of the American continent.

Comparison of classifications for heart failure in children undergoing valvular surgery

OBJECTIVES

To characterize correlations between clinical classifications of heart failure and diagnostic workup.

STUDY DESIGN

Pre- and postoperative characteristics of 20 children with heart failure secondary to valvular rheumatic disease were studied.

RESULTS

Both scoring systems correlated with N-terminal pro-brain natriuretic peptide (N-proBNP) but not with troponin I (TnI). The PHFI correlated with N-proBNP, end-systolic wall stress, left ventricular mass index and left atrium to aorta diameter ratio. No correlation could be established between modified Ross score, or the New York Heart Association (NYHA) grade and echocardiographic measurements. Cardiothoracic and Sokolow indexes were correlated with the PHFI as well as to the NYHA classification.

CONCLUSION

In this study, PHFI seems better correlated with radiologic, electrocardiographic, echocardiographic, and biologic assessment of heart failure in children. Clinical severity was correlated with N-proBNP but not with TnI.