Effect of Sequential Nephron Blockade versus Dual Renin-Angiotensin System Blockade Plus Bisoprolol in the Treatment of Resistant Hypertension, a Randomized Controlled Trial (Resistant Hypertension on Treatment - ResHypOT)

Introduction

Hypertension is the most important modifiable risk factor for cardiovascular disease and a leading public health concern.

Objectives

The primary aim was to compare sequential nephron blockade (SNB) versus dual renin-angiotensin system blockade (DRASB) plus bisoprolol in patients with resistant hypertension to observe reductions in systolic and diastolic blood pressure (SBP and DBP) levels after 20 weeks of treatment.

Material and Methods

This trial was an open-label, prospective, randomized, parallel-group, clinical study with optional drug up-titration. Participants were evaluated during five visits at 28-day intervals.

Results

The mean age was 55.5 years in the SNB and 58.4 years in the DRASB + bisoprolol group (p=NS). Significant office BP reductions were observed in both groups. SNB group, SBP decreased from 174.5±21.0 to 127.0±14.74 mmHg (p<0.0001), and DBP decreased from 105.3±15.5 to 78.11±9.28 mmHg (p<0.0001). DRASB group, SBP decreased from 178.4±21.08 to 134.4 ± 23.25 mmHg (p<0.0001) and DBP decreased from 102.7±11.07 to 77.33±13.75 mmHg (p<0.0001). Ambulatory blood pressure monitoring (ABPM) showed also significant SBP and DBP reductions in both groups (p<0.0001).

Conclusion

In patients with RHTN adherent to treatment, SNB and DRASB plus bisoprolol showed excellent therapeutic efficacy, although SNB was associated with earlier SBP reduction.

Central blood pressure and aortic pulse wave reflection in water-exercised postmenopausal hypertensive women: A cross-sectional study

Exercise training has been associated with the attenuation of cardiovascular impairment after menopause. This study aimed to compare central and peripheral blood pressure and aortic pulse wave reflection in sedentary and trained (aerobic exercise in the water) hypertensive postmenopausal women. Hypertensive postmenopausal women were divided into sedentary (SED, n = 53) and trained groups (TR, n = 31). Self-reporting from the trained group presented a mean of 1.7 ± 0.3 years of exercise practice in the water. Central blood pressure and amplification indexes (AIx) were obtained by the applanation tonometry of radial and aortic arteries. No changes were observed in systolic blood pressure (SBP) in the TR group than the SED group; however, office diastolic blood pressure (DBP) was reduced compared to the SED group. Central blood pressure and augmentation index (AIx@75%) values were similar in the SED and TR groups. These data suggest that self-reported long-term exercise training in the water could not improve central hemodynamic variables in postmenopausal hypertensive women compared to sedentary ones. However, it should be emphasized that DBP levels were reduced in trained subjects, which might reduce cardiovascular outcomes.

A Proposed Inflammatory Score of Circulating Cytokines/Adipokines Associated with Resistant Hypertension, but Dependent on Obesity Parameters

Background

There is evidence that subclinical systemic inflammation is present in resistant hypertension (RHTN).

Objective

The aim of the study was to develop an integrated measure of circulating cytokines/adipokines involved in the pathophysiology of RHTN.

Methods

RHTN (n = 112) and mild to moderate hypertensive (HTN) subjects (n=112) were studied in a cross-sectional design. Plasma cytokines/adipokines (TNF-alpha, interleukins [IL]-6, -8, -10, leptin and adiponectin) values were divided into tertiles, to which a score ranging from 1 (lowest tertile) to 3 (highest tertile) was assigned. The inflammatory score (IS) of each subject was the sum of each pro-inflammatory cytokine scores from which anti-inflammatory cytokines (adiponectin and IL-10) scores were subtracted. The level of significance accepted was alpha = 0.05.

Results

IS was higher in RHTN subjects compared with HTN subjects [4 (2-6) vs. 3 (2-5); p = 0.02, respectively]. IS positively correlated with body fat parameters, such as body mass index (r = 0.40; p < 0.001), waist circumference (r = 0.30; p < 0.001) and fat mass assessed by bioelectrical impedance analysis (r = 0.31; p < 0.001) in all hypertensive subjects. Logistic regression analyses revealed that IS was an independent predictor of RHTN (OR = 1.20; p = 0.02), independent of age, gender and race, although it did not remain significant after adjustment for body fat parameters.

Conclusion

A state of subclinical inflammation defined by an IS including TNF-alpha, IL-6, IL-8, IL-10, leptin and adiponectin is associated with obese RHTN. In addition, this score correlates with obesity parameters, independently of hypertensive status. The IS may be used for the evaluation of conditions involving low-grade inflammation, such as obesity-related RHTN. Indeed, it also highlights the strong relationship between obesity and inflammatory process.

Metabolic Syndrome-Related Features in Controlled and Resistant Hypertensive Subjects

Background

Metabolic syndrome (MetS) is widespread among hypertensive patients. Clinical features and potential biomarkers of MetS in the presence of hypertension and resistant hypertension (RHTN) represent a great area of interest for investigation.

Objective

The purpose of this study was to evaluate the prevalence of MetS and the clinical features associated with it in resistant and mild to moderate hypertensives.

Methods

This cross-sectional study included 236 patients, (i) 129 mild to moderate hypertensive patients and (ii) 107 patients with RHTN. We measured blood pressure (BP) and adipokines levels, and performed bioelectrical impedance analysis. Microalbuminuria (MA), cardiac hypertrophy and arterial stiffness were also assessed. The significance level of alpha = 0.05 was adopted.

Results

We found a MetS prevalence of 73% in resistant and 60% in mild-to-moderate hypertensive patients. In a multiple regression analysis, MA (odds ratio = 8.51; p = 0.01), leptin/adiponectin ratio (LAR) (odds ratio = 4.13; p = 0.01) and RHTN (odds ratio = 3.75; p = 0.03) were independently associated with the presence of MetS apart from potential confounders.

Conclusions

Our findings suggest that both resistant and controlled hypertensive subjects have a high prevalence of MetS. In addition, MetS-related metabolic derangements may cause early renal and hormonal changes. Finally, LAR may be useful as a reliable biomarker for identifying those hypertensive subjects who are at risk for developing MetS.

Inducible nitric oxide synthase haplotype associated with hypertension and responsiveness to antihypertensive drug therapy

Hypertension is a multifactorial disorder associated with increased inducible nitric oxide synthase (iNOS) expression and activity. While genetic polymorphisms affect iNOS expression, it is not known whether iNOS gene polymorphisms affect the susceptibility to hypertension and the responses to antihypertensive therapy. This study aimed at assessing whether iNOS polymorphisms ((CCTTT)(n), g.-1026C>A, and g.2087G>A) and haplotypes are associated with hypertension and with responsiveness to drug therapy. We studied 115 well controlled hypertensive patients (HTN), 82 hypertensive patients resistant to optimized antihypertensive therapy (RHTN), and 113 normotensive healthy subjects (NT). Genotypings were carried out using real-time polymerase chain reaction (PCR) and PCR amplification followed by capillary electrophoresis. The software PHASE 2.1 was used to estimate the haplotype frequencies in each group. Variant genotypes (GA+AA) for the g.2087G>A polymorphism were more commonly found in hypertensive patients (HTN+RHTN) than in normotensives (P=0.016; OR=2.05). We found no associations between genotypes and responsiveness to therapy (P>0.05). The S-C-A haplotype was more commonly found in hypertensive patients (HTN+RHTN) than in normotensives (P=0.014; OR=6.07). Interestingly, this haplotype was more commonly found in the HTN group than in the RHTN group (P=0.012; OR=0.14). Our findings indicate that the g.2087G>A polymorphism in the iNOS gene affects the susceptibility to hypertension. Moreover, while the S-C-A haplotype is associated with hypertension, it is also associated with responsiveness to antihypertensive therapy.

Near-fatal pulmonary embolism in an experimental model: hemodynamic, gasometric and capnographic variables

INTRODUCTION

Experimental studies on pulmonary embolism (PE) are usually performed under mechanical ventilation. Most patients with suspicion of PE enter the Emergency Services in spontaneous breathing and environmental air. Thus, under these conditions, measurements of hemodynamic, gasometric and capnographic variables contribute largely to a more specific comprehension of cardiopulmonary and gasometric alterations in the acute phase of the disease. Studies which evaluated animals under conditions are lacking.

OBJECTIVE

This study aimed to submit animals under spontaneous ventilation and without supplemental oxygen to PE.

METHODS

PE was induced in six pigs using autologous blood clots, and cardiorespiratory and gasometric records were performed before and after PE. The values of "near fatal" mean pulmonary arterial pressure (MPAP) were previously determined.

RESULTS

The presence of obstructive shock could be evidenced by increased MPAP (from 17.8 ± 3.5 to 41.7 ± 3.3 mmHg) (P<0.0001) and decreased cardiac output (from 4.9 ± 1.0 to 2.7 ± 1.0 L/min) (P<0.003). Consequently, metabolic acidosis occurred (Lac art) (from 2.4 ± 0.6 to 5.7 ± 1.8 mmol/L)(P<0.0001). It was observed hypoxemia (from 73.5 ± 12.7 to 40.3 ± 4.6 mmHg) (P<0.0001); however, PaCO2 did not vary (from 44.9 ± 4.4 to 48.2 ± 6.0 mmHg) (NS). There were significant increases in both P(a-et)CO2 (from 4.8 ± 2.8 to 37.2 ± 5.8 mmHg) and P(A-a)O2 (from 8.2 ± 8.9 to 37.2 ± 10.3 mmHg) (both P<0.0001). There was also a significant increase in the total alveolar minute volume (from 4.0 ± 0.9 to 10.6 ± 2.9 L/min) (P<0.0001).

CONCLUSIONS

In this model, the near fatal MPAP was from 2 to 2.5 times the basal MPAP; and the capnographic variables, associated with arterial and venous gasometry, showed effective in discriminating an acute obstructive profile.

[Vasopressin intravenous infusion causes dose dependent adverse cardiovascular effects in anesthetized dogs.]

BACKGROUND: Arginine vasopressin (AVP) has been broadly used in the management of vasodilatory shock. However, there are many concerns regarding its clinical use, especially in high doses, as it can be associated with adverse cardiovascular events. OBJECTIVE: To investigate the cardiovascular effects of AVP in continuous IV infusion on hemodynamic parameters in dogs. METHODS: Sixteen healthy mongrel dogs, anesthetized with pentobarbital were intravascularly catheterized, and randomly assigned to: control (saline-placebo; n=8) and AVP (n=8) groups. The study group was infused with AVP for three consecutive 10-minute periods at logarithmically increasing doses (0.01; 0.1 and 1.0U/kg/min), at them 20-min intervals. Heart rate (HR) and intravascular pressures were continuously recorded. Cardiac output was measured by the thermodilution method. RESULTS: No significant hemodynamic effects were observed during 0.01U/kg/min of AVP infusion, but at higher doses (0.1 and 1.0U/kg/min) a progressive increase in mean arterial pressure (MAP) and systemic vascular resistance index (SVRI) were observed, with a significant decrease in HR and the cardiac index (CI). A significant increase in the pulmonary vascular resistance index (PVRI) was also observed with the 1.0U/kg/min dose, mainly due to the decrease in the CI. CONCLUSION: AVP, when administered at doses between 0.1 and 1.0U/kg/min, induced significant increases in MAP and SVRI, with negative inotropic and chronotropic effects in healthy animals. Although these doses are ten to thousand times greater than those routinely used for the management of vasodilatory shock, our data confirm that AVP might be used carefully and under strict hemodynamic monitoring in clinical practice, especially if doses higher than 0.01 U/kg/min are needed. Martins, LC et al.

Bradykinin or acetylcholine as vasodilators to test endothelial venous function in healthy subjects

INTRODUCTION

The evaluation of endothelial function has been performed in the arterial bed, but recently evaluation within the venous system has also been explored. Endothelial function studies employ different drugs that act as endothelium-dependent vasodilatory response inductors.

OBJECTIVES

The aim of this study is to compare the endothelium-dependent venous vasodilator response mediated by either acetylcholine or bradykinin in healthy volunteers.

METHODS AND RESULTS

Changes in vein diameter after phenylephrine-induced venoconstriction were measured to compare venodilation induced by acetylcholine or bradykinin (linear variable differential transformer dorsal hand vein technique). We studied 23 healthy volunteers; 31% were male, and the subject had a mean age of 33 +/- 8 years and a mean body mass index of 23 +/- 2 kg/m(2). The maximum endothelium-dependent venodilation was similar for both drugs (p = 0.13), as well as the mean responses for each dose of both drugs (r = 0.96). The maximum responses to acetylcholine and bradykinin also had good agreement.

CONCLUSION

There were no differences between acetylcholine and bradykinin as venodilators in this endothelial venous function investigation.

[Venous endothelial dysfunction in Chagas' disease patients without heart failure]

OBJECTIVE

To analyze the venous endothelial function in Chagas' disease patients without heart failure.

METHODS

The Chagas' disease Group (G1) was composed by 14 women and 2 men aged 46 +/- 2.7 and the Control Group (G0) by 7 women and 1 man matched by age, weight and height. Dorsal Hand Vein Compliance Technique was used to evaluate the venous endothelial function. Crescent doses of phenylephrine were infused to get a 70% pre-constriction of the vein; after that, acetylcholine and sodium nitroprusside were respectively administrated to analyze the endothelium-dependent and -independent venodilation.

RESULTS

No significant systemic hemodynamic changes were observed in both groups during the experiment. The necessary phenylephrine dose to reach 70% pre-constriction of the vein was significantly higher in the G1 (1116 +/- 668.2 ng/ml) compared to G0 (103 +/- 28 ng/ml) p = 0.05. The endothelium-dependent venous dilation was significantly lower in G1 (65.5 +/- 8%) compared to G0 (137 +/- 20%) p = 0.009. No difference was observed in the endothelium-independent venous dilatation between groups.

CONCLUSION

Patients with Chagas' disease without heart failure presented venous endothelial dysfunction.

Microbial risk indicators of early childhood caries

The aim of this study was to use molecular identification methods, such as 16S RNA gene sequence and reverse-capture checkerboard hybridization, for identification of the bacteria associated with dental caries and with dental health in a subset of 204 twins aged 1.5 to 7 years old. A total of 448 plaque samples (118 collected from caries-free subjects and 330 from caries-active subjects) were used for analysis. We compared the bacteria found in biofilms of children exhibiting severe dental caries, with different degrees of lesion severity, with those found in biofilms of caries-free children. A panel of 82 bacterial species was selected, and a PCR-based reverse-capture checkerboard method was used for detection. A simple univariate test was used to determine the overabundance and underabundance of bacterial species in the diseased and in the healthy groups. Features identified with this univariate test were used to construct a probabilistic disease prediction model. Furthermore, a method for the analysis of global patterns of gene expression was performed to permit simultaneous analysis of the abundance of significant species by allowing cross-bacterial comparisons of abundance profiles between caries-active and caries-free subjects. Our results suggested that global patterns of microbial abundance in this population are very distinctive. The top bacterial species found to be overabundant in the caries-active group were Actinomyces sp. strain B19SC, Streptococcus mutans, and Lactobacillus spp., which exhibited an inverse relationship to beneficial bacterial species, such as Streptococcus parasanguinis, Abiotrophia defectiva, Streptococcus mitis, Streptococcus oralis, and Streptococcus sanguinis.