Eplerenone offsets cardiac and aortic adverse remodeling in spontaneously hypertensive rats

Role of the CHADS2 Score in the Evaluation of Carotid Atherosclerosis in Patients with Atrial Fibrillation Undergoing Carotid Artery Ultrasonography

Objective

This study investigated the characteristics of carotid atherosclerosis in patients with atrial fibrillation (AF) and determined the feasibility and significance of the CHADS₂ score in predicting the degree of carotid atherosclerosis.

Methods

Consecutive patients (n = 109) with nonvalvular AF were registered and classified into two groups, the paroxysmal AF group (n = 59) and persistent AF group (n = 50). Fifty healthy patients, matched by sex and age, were considered the control group. All patients were examined using carotid ultrasound and velocity vector imaging (VVI).

Results

Compared with the control group, the mean intimal-medial thickness in the paroxysmal AF group (0.56 ± 0.11 versus 0.61 ± 0.10, respectively, P < 0.05) and the persistent AF group (0.56 ± 0.11 versus 0.64 ± 0.13, respectively, P < 0.001) was significantly increased. The plaque index (PI) in the persistent AF group was significantly higher than that observed in the paroxysmal AF group (1.05 ± 1.33 versus 1.42 ± 1.47, respectively, P < 0.001). Regarding the VVI indices, those reflecting the long-axis longitudinal motion function of carotid arteries were significantly decreased in both AF groups. Compared with the control group, a significantly lower total longitudinal displacement (tLoD) index was observed in the persistent AF group (0.73 ± 0.66 versus 0.31 ± 0.23, respectively, P < 0·0001) and the paroxysmal AF group (0.73 ± 0.66 versus 0.34 ± 0.17, P < 0·0001). The CHADS₂ score was related to indicators reflecting the structure and function of the carotid artery.

Conclusions

Carotid arterial structure and function were significantly altered in patients with AF. The degree of carotid atherosclerosis depended on the duration of AF. The CHADS₂ score may be useful as a predictor of the extent of carotid atherosclerosis in patients with AF.

Myeloid mineralocorticoid receptor controls macrophage polarization and cardiovascular hypertrophy and remodeling in mice

Inappropriate excess of the steroid hormone aldosterone, which is a mineralocorticoid receptor (MR) agonist, is associated with increased inflammation and risk of cardiovascular disease. MR antagonists are cardioprotective and antiinflammatory in vivo, and evidence suggests that they mediate these effects in part by aldosterone-independent mechanisms. Here we have shown that MR on myeloid cells is necessary for efficient classical macrophage activation by proinflammatory cytokines. Macrophages from mice lacking MR in myeloid cells (referred to herein as MyMRKO mice) exhibited a transcription profile of alternative activation. In vitro, MR deficiency synergized with inducers of alternatively activated macrophages (for example, IL-4 and agonists of PPARgamma and the glucocorticoid receptor) to enhance alternative activation. In vivo, MR deficiency in macrophages mimicked the effects of MR antagonists and protected against cardiac hypertrophy, fibrosis, and vascular damage caused by L-NAME/Ang II. Increased blood pressure and heart rates and decreased circadian variation were observed during treatment of MyMRKO mice with L-NAME/Ang II. We conclude that myeloid MR is an important control point in macrophage polarization and that the function of MR on myeloid cells likely represents a conserved ancestral MR function that is integrated in a transcriptional network with PPARgamma and glucocorticoid receptor. Furthermore, myeloid MR is critical for blood pressure control and for hypertrophic and fibrotic responses in the mouse heart and aorta.

Spironolactone and hydrochlorothiazide exert antioxidant effects and reduce vascular matrix metalloproteinase-2 activity and expression in a model of renovascular hypertension

BACKGROUND AND PURPOSE

Increased oxidative stress and up-regulation of matrix metalloproteinases (MMPs) may cause structural and functional vascular changes in renovascular hypertension. We examined whether treatment with spironolactone (SPRL), hydrochlorothiazide (HCTZ) or both drugs together modified hypertension-induced changes in arterial blood pressure, aortic remodelling, vascular reactivity, oxidative stress and MMP levels and activity, in a model of renovascular hypertension.

EXPERIMENTAL APPROACH

We used the two-kidney,one-clip (2K1C) model of hypertension in Wistar rats. Sham-operated or hypertensive rats were treated with vehicle, SPRL (25 mg.kg(-1).day(-1)), HCTZ (20 mg.kg(-1).day(-1)) or a combination for 8 weeks. Systolic blood pressure was monitored weekly. Aortic rings were isolated to assess endothelium-dependent and -independent relaxations. Morphometry of the vascular wall was carried out in sections of aorta. Aortic NADPH oxidase activity and superoxide production were evaluated. Formation of reactive oxygen species was measured in plasma as thiobarbituric acid-reactive substances. Aortic MMP-2 levels and activity were determined by gelatin and in situ zymography, fluorimetry and immunohistochemistry.

KEY RESULTS

Treatment with SPRL, HCTZ or the combination attenuated 2K1C-induced hypertension, and reversed the endothelial dysfunction in 2K1C rats. Both drugs or the combination reversed vascular aortic remodelling induced by hypertension, attenuated hypertension-induced increases in oxidative stress and reduced MMP-2 levels and activity.

CONCLUSIONS AND IMPLICATIONS

SPRL or HCTZ, alone or combined, exerted antioxidant effects, and decreased renovascular hypertension-induced MMP-2 up-regulation, thus improving the vascular dysfunction and remodelling found in this model of hypertension.

Salt excess causes left ventricular diastolic dysfunction in rats with metabolic disorder

Metabolic syndrome is a highly predisposing condition for cardiovascular disease and could be a cause of excess salt-induced organ damage. Recently, several investigators have demonstrated that salt loading causes left ventricular diastolic dysfunction associated with increased oxidative stress and mineralocorticoid receptor activation. We, therefore, investigated whether excess salt induces cardiac diastolic dysfunction in metabolic syndrome via increased oxidative stress and upregulation of mineralocorticoid receptor signals. Thirteen-week-old spontaneously hypertensive rats and SHR/NDmcr-cps, the genetic model of metabolic syndrome, were fed a normal salt (0.5% NaCl) or high-salt (8% NaCl) diet for 4 weeks. In SHR/NDmcr-cps, salt loading induced severe hypertension, abnormal left ventricular relaxation, and perivascular fibrosis. Salt-loaded SHR/NDmcr-cps also exhibited overproduction of reactive oxygen species and upregulation of mineralocorticoid receptor-dependent gene expression, such as Na(+)/H(+) exchanger-1 and serum- and glucocorticoid-inducible kinase-1 in the cardiac tissue. However, in spontaneously hypertensive rats, salt loading did not cause these cardiac abnormalities despite a similar increase in blood pressure. An antioxidant, tempol, prevented salt-induced diastolic dysfunction, perivascular fibrosis, and upregulation of mineralocorticoid receptor signals in SHR/NDmcr-cps. Moreover, a selective mineralocorticoid receptor antagonist, eplerenone, prevented not only diastolic dysfunction but also overproduction of reactive oxygen species in salt-loaded SHR/NDmcr-cps. These results suggest that metabolic syndrome is a predisposed condition for salt-induced left ventricular diastolic dysfunction, possibly via increased oxidative stress and enhanced mineralocorticoid receptor signals.