Left ventricular hypertrophy precedes other target-organ damage in primary aldosteronism

Cardiovascular complications in insulin resistance and endocrine diseases

Cerebrovascular diseases, such as stroke and cardiovascular disease, are one of the leading causes of death in Japan. Type 2 diabetes is the most common form of diabetes and an important risk factor for these diseases. Among various pathological conditions associated with type 2 diabetes, insulin resistance has already been reported to be an important risk factor for diabetic complications. The major sites of insulin action in glucose metabolism in the body include the liver, skeletal muscle, and adipose tissue. However, insulin signaling molecules are also constitutively expressed in vascular endothelial cells, vascular smooth muscle, and monocytes/macrophages. Forkhead box class O family member proteins (FoxOs) of transcription factors play important roles in regulating glucose and lipid metabolism, oxidative stress response and redox signaling, and cell cycle progression and apoptosis. FoxOs in vascular endothelial cells strongly promote arteriosclerosis by suppressing nitric oxide production, enhancing inflammatory response, and promoting cellular senescence. In addition, primary aldosteronism and Cushing's syndrome are known to have adverse effects on the cardiovascular system, apart from hypertension, diabetes, and dyslipidemia. In the treatment of endocrine disorders, hormonal normalization by surgical treatment and receptor antagonists play an important role in preventing cardiovascular complications.

A non-invasive left ventricular pressure-strain loop study on myocardial work in primary aldosteronism

We investigated the myocardial work derived from left ventricular pressure-strain loop in patients with primary aldosteronism or primary hypertension. We enrolled 50 patients with primary aldosteronism, 50 age- and sex-matched patients with primary hypertension, and 25 normotensive control subjects. We performed transthoracic echocardiography and speckle-tracking echocardiography-based left ventricular pressure-strain loop analysis to evaluate cardiac structure and function. Patients with primary aldosteronism and those with primary hypertension had similar clinic and ambulatory blood pressures, except that the former had a significantly (P = 0.03) higher nighttime systolic blood pressure. All subjects had normal left ventricular ejection fraction (66.4 ± 4.7%). Patients with primary aldosteronism had a greater left ventricular mass index than those with primary hypertension and the normal controls (111.0 ± 21.6 g/m² versus 95.7 ± 17.7 and 77.9 ± 13.5 g/m², respectively, P < 0.001). The global myocardial work index (GWI, 2336 ± 333, 2366 ± 288, and 2292 ± 249 mmHg%, respectively), and global constructive work (GCW, 2494 ± 325, 2524 ± 301, and 2391 ± 193 mmHg%, respectively), were comparable in the three groups (P ≥ 0.18). However, the global work efficiency (GWE) differed significantly (P < 0.001), being lowest in primary aldosteronism (91.1 ± 2.7%), intermediate in primary hypertension (93.5 ± 2.5%) and highest in controls (95.3 ± 1.5%). The opposite was true for the global wasted work (GWW) (205.6 ± 74.6, 142.0 ± 56.4 and 99.4 ± 33.7 mmHg%, respectively, P < 0.001). GWE was significantly correlated with the logarithmically transformed plasma concentration and the urinary excretion of aldosterone in patients with primary aldosteronism or primary hypertension (r = -0.43 for both, P < 0.001). The associations remained statistically significant (P ≤ 0.04) after further adjustment for several factors, including left ventricular mass index and clinic or nighttime blood pressure. In conclusion, GWE decreased and GWW increased in primary hypertension and further in primary aldosteronism, probably because of the adrenal aldosterone hypersecretion and the left ventricular mass index increase, while GWI and GCW were similar, indicating that similar and normalized total myocardial work might be a compensation in hypertension at the expense of work efficiency.

Diurnal blood pressure pattern and cardiac damage in hypertensive patients with primary aldosteronism

PURPOSE

The aim of our study was to evaluate the relationship between the 24-h blood pressure (BP) profile, plasma NT-proBNP levels and left ventricular hypertrophy (LVH) in subjects with primary aldosteronism (PA) compared to patients with essential hypertension (EH).

METHODS

A total of 385 consecutive patients with PA [187 with aldosterone producing adenoma (APA) and 198 with idiopathic hyperaldosteronism (IHA)] and 385 patients with EH were matched based on age, sex, body mass index (BMI), BP values and duration of hypertension. Twenty-four-hour ambulatory BP monitoring (ABPM), plasma levels of NT-proBNP, left ventricular mass index (LVMI), and other clinical medical data were assessed in all patients.

RESULTS

No differences in age, sex, BMI, clinical BP, 24-h mean BP, daytime BP, or duration of hypertension were found between groups. Nighttime systolic BP (130 ± 16 vs. 127 ± 17 mmHg, p < 0.05) and diastolic BP (82 ± 10 vs. 79 ± 11 mmHg, p < 0.01) were higher in PA patients than in EH patients. In addition, nocturnal BP decline was reduced, while median NT-proBNP (53.7 vs. 33.2 pg/ml, P < 0.001) and LVMI (113 ± 25 vs. 102 ± 26 g/m², P < 0.001) were higher in PA patients than in EH patients. Moreover, the median NT-proBNP level was higher in APA patients than in IHA patients (68.0 vs. 42.4 pg/ml, P < 0.001). In stepwise multivariate regression analysis, LVMI was correlated with NT-proBNP, nighttime systolic BP and sex in PA patients.

CONCLUSIONS

Patients with PA show higher nighttime BP and NT-proBNP levels and lower nocturnal BP decline than those with EH. In addition, higher nocturnal systolic BP has been shown to be strongly associated with cardiac damage in PA patients.

A maximum likelihood approach to electronic health record phenotyping using positive and unlabeled patients

OBJECTIVE

Phenotyping patients using electronic health record (EHR) data conventionally requires labeled cases and controls. Assigning labels requires manual medical chart review and therefore is labor intensive. For some phenotypes, identifying gold-standard controls is prohibitive. We developed an accurate EHR phenotyping approach that does not require labeled controls.

MATERIALS AND METHODS

Our framework relies on a random subset of cases, which can be specified using an anchor variable that has excellent positive predictive value and sensitivity independent of predictors. We proposed a maximum likelihood approach that efficiently leverages data from the specified cases and unlabeled patients to develop logistic regression phenotyping models, and compare model performance with existing algorithms.

RESULTS

Our method outperformed the existing algorithms on predictive accuracy in Monte Carlo simulation studies, application to identify hypertension patients with hypokalemia requiring oral supplementation using a simulated anchor, and application to identify primary aldosteronism patients using real-world cases and anchor variables. Our method additionally generated consistent estimates of 2 important parameters, phenotype prevalence and the proportion of true cases that are labeled.

DISCUSSION

Upon identification of an anchor variable that is scalable and transferable to different practices, our approach should facilitate development of scalable, transferable, and practice-specific phenotyping models.

CONCLUSIONS

Our proposed approach enables accurate semiautomated EHR phenotyping with minimal manual labeling and therefore should greatly facilitate EHR clinical decision support and research.

Testing calibration of phenotyping models using positive-only electronic health record data

Validation of phenotyping models using Electronic Health Records (EHRs) data conventionally requires gold-standard case and control labels. The labeling process requires clinical experts to retrospectively review patients' medical charts, therefore is labor intensive and time consuming. For some disease conditions, it is prohibitive to identify the gold-standard controls because routine clinical assessments are performed for selective patients who are deemed to possibly have the condition. To build a model for phenotyping patients in EHRs, the most readily accessible data are often for a cohort consisting of a set of gold-standard cases and a large number of unlabeled patients. Hereby, we propose methods for assessing model calibration and discrimination using such "positive-only" EHR data that does not require gold-standard controls, provided that the labeled cases are representative of all cases. For model calibration, we propose a novel statistic that aggregates differences between model-free and model-based estimated numbers of cases across risk subgroups, which asymptotically follows a Chi-squared distribution. We additionally demonstrate that the calibration slope can also be estimated using such "positive-only" data. We propose consistent estimators for discrimination measures and derive their large sample properties. We demonstrate performances of the proposed methods through extensive simulation studies and apply them to Penn Medicine EHRs to validate two preliminary models for predicting the risk of primary aldosteronism.

Primary Aldosteronism: Cardiovascular Risk, Diagnosis, and Management

Primary aldosteronism remains a leading cause of secondary hypertension, and its diagnosis and management continue to pose a challenge for clinicians. In this article, we review the diagnosis of primary aldosteronism along with its cardiovascular manifestations. Treatment is described depending on the diagnostic outcome, focusing on medical management with mineralocorticoid receptor antagonists and unilateral adrenalectomy. Although screening and diagnosing hyperaldosteronism follows well-known algorithms, in practice, physicians may find difficulty establishing the best course of action due to complexity in testing and confirming laterality of aldosterone production by the adrenals. Recognizing and treating primary aldosteronism requires a multidisciplinary approach with primary care physicians, cardiologists, endocrinologists, and radiologists working collaboratively.

Left ventricular remodeling and dysfunction in primary aldosteronism

Primary aldosteronism (PA) is a common cause of secondary hypertension and is associated with worse cardiovascular outcomes. The elevated aldosterone in PA leads to left ventricular (LV) remodeling and dysfunction. In recent decades, clinical studies have demonstrated worse LV remodeling including increased LV mass and cardiac fibrosis in patients with PA compared to patients with essential hypertension. Several mechanisms may explain the process of aldosterone-induced LV remodeling, including directly profibrotic and hypertrophic effects of aldosterone on myocardium, increased reactive oxygen species and profibrotic molecules, dysregulation of extracellular matrix metabolism, endothelium dysfunction and circulatory macrophages activation. LV remodeling causes LV diastolic and systolic dysfunction, which may consequently lead to clinical complications such as heart failure, atrial fibrillation, ischemic heart disease, and other vascular events. Adequate treatment with adrenalectomy or medical therapy can improve LV remodeling and dysfunction in PA patients. In this review, we discuss the mechanisms of aldosterone-induced LV remodeling and provide an up-to-date review of clinical research about LV remodeling-related heart structural changes, cardiac dysfunction, and their clinical impacts on patients with PA.

[Alteration of left ventricular longitudinal systolic function in 2D-strain in primary aldosteronism: A new target organ damage marker]

OBJECTIVE

Primary hyperaldosteronism is the leading cause of secondary hypertension, and leads to frequent cardiovascular complications. Many studies have studied left ventricular geometry and function in this population, but longitudinal systolic function is still poorly described.

METHODS

We studied 35 hypertensive patients with primary aldosteronism, and 35 with essential hypertension matched for age, sex, body mass index, and 24h blood pressure. Patients benefited from an echocardiography to measure the mass and the geometry of the left ventricle, left ventricle ejection fraction, systolic longitudinal, circumferential, and radial strain, and diastolic function.

RESULTS

Compared to essential hypertensive patients, patients with primary aldosteronism presented a significantly higher left ventricular mass index and relative wall thickness (60.3±16.1g/m² vs 47.3±18.6, P=0.003, and 0.44±0.08 vs 0.36±0.06, P=0.00005, respectively), as well as a significantly reduced longitudinal systolic strain (-17.8±3,4 vs -20.3±3,6%, P=0.004). There were no significant differences in the other parameters.

CONCLUSIONS

Primary aldosteronism is associated with a deterioration of longitudinal systolic function of the left ventricle compared with essential hypertensive patients. This marker of cardiac damage, reproducible and easily available in routine could help for the screening of these patients.

Biventricular Cardiac Hypertrophy in a Patient with Primary Aldosteronism and Atrial Septal Defect

Patient: Female, 33

Final Diagnosis: Primary aldosteronism • heart failure • atrial septal defect • biventricular cardiac hypertrophy

Symptoms: Dyspneu • muscular weakness

Medication: Spironolactone • ACE inhibitor

Clinical Procedure: Captopril suppression test • adrenalectomy • right cardiac catheterization

Specialty: Endocrinology and Metabolism • Cardiology

The relationship among cardiac structure, dietary salt and aldosterone in patients with primary aldosteronism

Salt intake is highly associated with cardiac structure in patients with primary aldosteronism (PA). We investigated the association among dietary salt intake, aldosterone and left ventricular mass in patients with PA. We enrolled 158 patients with PA and 158 patients with essential hypertension. We measured 24-hour urinary sodium (UNa) and aldosterone (UAldo) level and echocardiography parameters. In patients with PA, the UAldo level was positively correlated with left ventricular mass index (LVMI; r=0.231, p=0.007). The UNa level was not linearly correlated with left ventricular structural parameters in patients with PA. To test if UNa has a non-linear relationship with LVMI among patients with PA, we categorized the participants according to the tertile of UNa (low, median, and high tertile). PA patients with medium tertile of UNa had significant lower LVMI than the other two groups (LVMI: 144.1 ± 42.9, 121.1 ± 33.4, and 136.7 ± 32.8 g/m2, from the lowest to the highest tertile of Una; analysis of variance p=0.006, post-hoc p <0.05). Multifactor analysis of variance confirmed this finding after adjustment for clinical parameters. Post-hoc analyses revealed that the high UNa tertile was associated with higher left ventricular end-diastolic volume compared with medium UNa tertile; while the low UNa tertile was associated with higher mean wall thickness compared with medium UNa tertile. The findings imply the reasons for increased LVMI may be different in patients with the highest and lowest UNa tertile. In conclusion, the medium tertile of 24-hour UNa is associated with lowest LVMI in patients with PA.

The Long-term Effect of Adrenal Arterial Embolization for Unilateral Primary Aldosteronism on Cardiorenovascular Protection, Blood Pressure, and the Endocrinological Profile

Primary aldosteronism (PA) is a major cause of secondary hypertension, divided into two subtypes: unilateral and bilateral. Unilateral PA (u-PA) is surgically-curable. Medical treatment with mineralocorticoid receptors antagonists is recommended as a second-line treatment when the patients are not candidate for surgical treatment. The present case was a 39-year-old woman with u-PA, who had refused surgery, had suffered from adverse effects of medical treatment. She was treated with transcatheter adrenal arterial embolization (TAAE). Her blood pressure had been well controlled without progression of cardiorenovascular damage for 12 years. TAAE can be the third treatment option for u-PA patients.

Aldosterone and Left Ventricular Remodeling

Experimental and clinical evidence obtained in the last 2 decades clearly indicates that protracted exposure to inappropriately elevated aldosterone levels causes significant changes in left ventricular structure and function. Animal studies have demonstrated that aldosterone induces myocardial inflammatory changes and fibrosis in the presence of a high salt diet. Moreover, the effects of aldosterone on the heart have been investigated in different clinical conditions. These conditions include systolic and diastolic heart failure, essential hypertension, and primary aldosteronism that offers a unique clinical model to study the cardiac effects of excess aldosterone because these effects are isolated from those of the renin-angiotensin axis. A relatively clear picture is emerging from these studies with regard to aldosterone-related changes in left ventricular mass and geometry. Conversely, no direct effect of aldosterone on left ventricular diastolic function can be demonstrated and improvement of diastolic function obtained in some studies that have employed mineralocorticoid receptor blockers could result from left ventricular mass reduction. Animal experiments demonstrate that effects of aldosterone on the left ventricle require high salt intake to occur, but the evidence of this contribution of salt to aldosterone-induced cardiac changes in humans remains weaker and needs further research. The article reviews the results of clinical studies addressing the role of aldosterone in regulation of LV remodeling and diastolic function, and focuses on the possible relevance of salt intake.

Pathophysiology, diagnosis, and treatment of mineralocorticoid disorders

The renin-angiotensin-aldosterone system (RAAS) is a major regulator of blood pressure control, fluid, and electrolyte balance in humans. Chronic activation of mineralocorticoid production leads to dysregulation of the cardiovascular system and to hypertension. The key mineralocorticoid is aldosterone. Hyperaldosteronism causes sodium and fluid retention in the kidney. Combined with the actions of angiotensin II, chronic elevation in aldosterone leads to detrimental effects in the vasculature, heart, and brain. The adverse effects of excess aldosterone are heavily dependent on increased dietary salt intake as has been demonstrated in animal models and in humans. Hypertension develops due to complex genetic influences combined with environmental factors. In the last two decades, primary aldosteronism has been found to occur in 5% to 13% of subjects with hypertension. In addition, patients with hyperaldosteronism have more end organ manifestations such as left ventricular hypertrophy and have significant cardiovascular complications including higher rates of heart failure and atrial fibrillation compared to similarly matched patients with essential hypertension. The pathophysiology, diagnosis, and treatment of primary aldosteronism will be extensively reviewed. There are many pitfalls in the diagnosis and confirmation of the disorder that will be discussed. Other rare forms of hyper- and hypo-aldosteronism and unusual disorders of hypertension will also be reviewed in this article.

NT-proBNP, a useful tool in hypertensive patients undergoing a diagnostic evaluation for primary aldosteronism

Primary aldosteronism (PA) is the most frequent form of secondary hypertension, but diagnostic tools for this disease still lack optimal accuracy. The heart is one important target tissue for damage due to excess aldosterone, and the role of natriuretic peptides is well recognized in diagnosing heart failure. We hypothesized that measuring the NT-proBNP could improve the diagnostic evaluation of PA. We enrolled 132 hypertensive patients, who underwent aldosterone to renin ratio (ARR) screening, and 81 underwent an intravenous saline loading test (ivSLT) because of a high ARR. The NT-proBNP level positively correlated with the ARR and inversely correlated with the renin level. The NT-proBNP level was higher in patients with a high ARR than in those with a low ARR and higher in patients with a positive ivSLT than in those with a negative ivSLT. After logistic regression analysis, an NT-proBNP value above the median and male gender were predictors of a positive ivSLT. The proportion of patients with a positive ivSLT ranged from only 23 % in females with a low NT-proBNP to 93 % in males with a high NT-proBNP. NT-proBNP and gender are predictors of a positive PA confirmatory test. These findings highlight the possibility of using NT-proBNP to identify which patients with a high ARR should receive a complete PA diagnostic evaluation.

Aldosterone and parathyroid hormone interactions as mediators of metabolic and cardiovascular disease

Inappropriate aldosterone and parathyroid hormone (PTH) secretion is strongly linked with development and progression of cardiovascular (CV) disease. Accumulating evidence suggests a bidirectional interplay between parathyroid hormone and aldosterone. This interaction may lead to a disproportionally increased risk of CV damage, metabolic and bone diseases. This review focuses on mechanisms underlying the mutual interplay between aldosterone and PTH as well as their potential impact on CV, metabolic and bone health. PTH stimulates aldosterone secretion by increasing the calcium concentration in the cells of the adrenal zona glomerulosa as a result of binding to the PTH/PTH-rP receptor and indirectly by potentiating angiotensin 2 induced effects. This may explain why after parathyroidectomy lower aldosterone levels are seen in parallel with improved cardiovascular outcomes. Aldosterone mediated effects are inappropriately pronounced in conditions such as chronic heart failure, excess dietary salt intake (relative aldosterone excess) and primary aldosteronism. PTH is increased as a result of (1) the MR (mineralocorticoid receptor) mediated calciuretic and magnesiuretic effects with a trend of hypocalcemia and hypomagnesemia; the resulting secondary hyperparathyroidism causes myocardial fibrosis and disturbed bone metabolism; and (2) direct effects of aldosterone on parathyroid cells via binding to the MR. This adverse sequence is interrupted by mineralocorticoid receptor blockade and adrenalectomy. Hyperaldosteronism due to klotho deficiency results in vascular calcification, which can be mitigated by spironolactone treatment. In view of the documented reciprocal interaction between aldosterone and PTH as well as the potentially ensuing target organ damage, studies are needed to evaluate diagnostic and therapeutic strategies to address this increasingly recognized pathophysiological phenomenon.

A case of primary aldosteronism who experienced cardiopulmonary arrest, was resuscitated and cured

A 45-year-old female went into cardiopulmonary arrest. She was in ventricular fibrillation (VF) and was defibrillated using an automated external defibrillator. After arrival at our hospital, electrocardiography monitoring showed QT prolongation. Serum potassium was low at 2.2 mEq/L, and hypokalemia-induced long QT syndrome was considered to be the cause of this patient's VF. An intravenous infusion of potassium and magnesium sulphate was started, which normalized her serum potassium and QTc interval, with no recurrence of ventricular arrhythmias. Endocrinological investigations showed a plasma renin activity of <0.1 ng/(mL h) and a plasma aldosterone concentration 258 pg/mL. Computed tomography scanning revealed a low signal area 16 mm × 20 mm in size of the right adrenal gland. From the above findings, this patient was diagnosed with a right adrenal tumor and primary aldosteronism. We concluded that the right adrenal tumor was excreting excess amounts of aldosterone from adrenal vein sampling, and performed laparascopic right adrenalectomy. Serum potassium levels rose immediately to normal levels postoperatively. We were able to withdraw her antihypertensive medication 3 months after adrenalectomy. We report a case of primary aldosteronism who experienced cardiopulmonary arrest, was resuscitated, and cured. <Learning objective: When you come across ventricular fibrillation, please consider one of the reasons is caused by hypokalemia due to primary aldosteronism. After an appropriate resuscitation, both hypokalemia and hypertension are completely curable by removing the adrenal tumor.>.

Impact of aldosterone-producing adenoma on cardiac structures in echocardiography

Background

Primary aldosteronism (PA) is a most common cause of secondary hypertension. In PA, left ventricular hypertrophy (LVH) is more progressive than in any other cause of hypertension. Aldosterone-producing adenoma (APA) and idiopathic hyperaldosteronism (IHA) are major subtypes of PA. However there is little information concerned with differences of cardiac structures between these two subtypes.

Methods

We reviewed echocardiographic findings in 46 patients with PA. All patients had a positive screen test and subtypes of PA were confirmed by adrenal vein sampling. Subjects consisted of 20 patients with APA (APA group, 52.4 ± 10.8 years) and 26 patients with IHA (IHA group, 56.2 ± 9.5 years). We investigated differences of cardiac structures and functions in the left atrium and ventricle between the APA group and IHA group.

Results

In terms of clinical characteristics, the height and duration of hypertension were greater and serum potassium concentration and BMI were lower in the APA group than in the IHA group. Plasma aldosterone concentration (PAC) and PAC to plasma renin activity ratio were higher in the APA group than in the IHA group. In echocardiographic assessment, the left atrial volume, left ventricular end-diastolic and end-systolic diameters, left ventricular mass (LVM), and prevalence of LVH were greater in the APA group than in the IHA group. Multiple linear regression analysis revealed that the diagnosis of APA independently correlated with left atrial volume, left ventricular end-diastolic diameter, and LVM.

Conclusions

We demonstrated that differences of cardiac structures between the APA group and IHA group existed. In APA, left atrial enlargement and LVH were more prominent than in IHA.

Selective improvement in renal function preserved remote myocardial microvascular integrity and architecture in experimental renovascular disease

AIM

Atherosclerotic renovascular disease (ARVD) may impair renal function and increase cardiovascular morbidity and mortality, but the mechanism by which ARVD impacts cardiovascular function is unclear. We tested the hypothesis that preservation of renal function can reverse cardiac dysfunction in ARVD.

METHODS AND RESULTS

Endothelial progenitor cells (EPC) were injected intra-renally (ARVD+EPC) after 6 weeks of swine ARVD (concurrent hypercholesterolemia and renovascular hypertension), and single-kidney function and myocardial blood-flow and microvascular permeability (MP) responses to adenosine were assessed using CT 4 weeks later. Myocardial microvascular density was evaluated by micro-CT. Inflammation and oxidative-stress were assessed in kidney venous and systemic blood samples. Normal and untreated ARVD pigs served as controls. Blood pressure was similarly increased in ARVD and ARVD+EPC. Compared to normal, ARVD showed lower glomerular filtration rate, elevated renal vein and systemic oxidized LDL (ox-LDL), aldosterone, uric acid, isoprostanes, transforming growth factor (TGF)-β, and interleukine-6. Renal vein ox-LDL and TGF-β showed a positive gradient across the stenotic kidney, indicating increased renal oxidative stress and fibrogenic activity. Furthermore, ARVD impaired myocardial blood-flow and MP response to adenosine, decreased microvascular density, and induced myocardial fibrosis. Improvement of renal function in ARVD+EPC decreased systemic aldosterone, inflammation, and oxidative stress, and improved myocardial microvascular integrity and density.

CONCLUSION

Selective improvement in renal function, which reduced renal and systemic oxidative stress and inflammation, preserved remote myocardial microvascular function and architecture, despite enduring hypertension. These findings underscore functionally important cardiorenal crosstalk possibly mediated by renal injury signals.

Deleterious combined effects of salt-loading and endothelial cell restricted endothelin-1 overexpression on blood pressure and vascular function in mice

BACKGROUND

We previously showed that young transgenic mice overexpressing preproendothelin-1 specifically in endothelial cells had hypertrophic remodeling, endothelial dysfunction, increased vascular NADPH oxidase activity, and inflammation in mesenteric small arteries without blood pressure (BP) elevation compared to nontransgenic wild-type littermates. To assess the consequences of salt-loading and the role of endothelin receptors, we investigated the effects of these on vascular structure, function, and oxidative stress in mesenteric arteries in salt-loaded transgenic mice treated with endothelin receptor antagonists.

METHODS

Ten-month-old male transgenic and wild-type littermates were salt-loaded (4% NaCl) and treated with endothelin subtype A receptor antagonist (ET(A)RA, ABT-627, 5 mg/kg per day), endothelin subtype B receptor antagonist (ET(B)RA; A-192621, 30 mg/kg per day), or ET(A)/BRA (bosentan, 100 mg/kg per day) for 4 weeks. BP was measured by radiotelemetry, vascular reactivity of mesenteric small arteries was studied on a pressurized myograph, and vascular NADPH oxidase activity was studied by lucigenin chemiluminescence.

RESULTS

Transgenic+salt mice had significantly increased BP compared with wild-type+salt mice, which was prevented by ET(A)RA and dual ET(A/B)RA but further increased by ETB antagonism. Increased small artery media/lumen ratio of transgenic+salt mice was significantly decreased only by dual ET(A/B)RA (P < 0.01), whereas no differences were found in media cross-sectional area. Impaired maximal relaxation of small arteries to acetylcholine was significantly prevented with ET(A)RA and ET(A/B)RA (P < 0.05). N(omega)-nitro-L-arginine methyl ester-induced reduction of acetylcholine maximal relaxation was partially prevented by ET(A)RA, completely prevented by dual, and partially restored by vitamin C preincubation following dual ET(A/B)RA. The blunted endothelin-1 contractile response of small arteries found in transgenic+salt mice was partially restored by ET(A)RA and completely prevented by dual ET(A/B)R antagonism. The vasoconstrictor response to endothelin-1 was not altered in the presence or absence of ET(B)RA. Increased vascular NADPH oxidase activity of transgenic+salt mice was further increased by ET(B)RA but returned to levels seen in wild-type+salt mice under either ET(A)RA and ET(A/B)RA.

CONCLUSION

Transgenic+salt mice with endothelin-1 overexpression have structural alterations of mesenteric resistance vessels, endothelial dysfunction due to reduced nitric oxide bioavailability, a reduced responsiveness to endothelin-1, and enhanced vascular NADPH oxidase activity. ET(B)RA further exacerbated these effects, whereas ET(A)RA significantly improved but did not normalize them in chronically salt-loaded transgenic mice with endothelial cell human endothelin-1 overexpression. Salt and endothelin-1 overexpression have deleterious additive effects on vascular remodeling mediated by ET(A)R and ET(B)R. ET(B)R probably located in the endothelium, however, also exerts beneficial effects on endothelial function in this experimental paradigm. The present study provides the first in-vivo demonstration that endothelin-1 overexpression when associated with high-salt intake results in enhanced endothelial dysfunction and vascular remodeling of resistance vessels, and contributes to elevated BP, via ET(A)R and ET(B)R.

Cardiovascular and cerebrovascular comorbidities of hypokalemic and normokalemic primary aldosteronism: results of the German Conn's Registry

CONTEXT

Primary aldosteronism (PA) is associated with vascular end-organ damage.

OBJECTIVE

Our objective was to evaluate differences regarding comorbidities between the hypokalemic and normokalemic form of PA.

DESIGN AND SETTING

This was a retrospective cross-sectional study collected from six German centers (German Conn's registry) between 1990 and 2007.

PATIENTS

Of 640 registered patients with PA, 553 patients were analyzed.

MAIN OUTCOME MEASURES

Comorbidities depending on hypokalemia or normokalemia were examined.

RESULTS

Of the 553 patients (61 +/- 13 yr, range 13-96), 56.1% had hypokalemic PA. The systolic (164 +/- 29 vs. 155 +/- 27 mm Hg; P < 0.01) and diastolic (96 +/- 18 vs. 93 +/- 15 mm Hg; P < 0.05) blood pressures were significantly higher in hypokalemic patients than in those with the normokalemic variant. The prevalence of cardiovascular events (angina pectoris, myocardial infarction, chronic cardiac insufficiency, coronary angioplasty) was 16.3%. Atrial fibrillation occurred in 7.1% and other atrial or ventricular arrhythmia in 5.2% of the patients. Angina pectoris and chronic cardiac insufficiency were significantly more prevalent in hypokalemic PA (9.0 vs. 2.1%, P < 0.001; 5.5 vs. 2.1%, P < 0.01). Overall, cerebrovascular comorbidities were not different between hypokalemic and normokalemic patients, however, stroke tended to be more prevalent in normokalemic patients.

CONCLUSIONS

Our data indicate a high prevalence of comorbidities in patients with PA. The hypokalemic variant is defined by a higher morbidity than the normokalemic variant regarding some cardiovascular but not cerebrovascular events. Thus, PA should be sought not only in hypokalemic but also in normokalemic hypertensives because high-excess morbidity occurs in both subgroups.

Plasma aldosterone and its relationships with left ventricular mass in essential hypertensive patients with the metabolic syndrome

BACKGROUND

The association of aldosterone with the metabolic syndrome (MetS) has not been fully elucidated. The aim of our study was to evaluate the relationships of plasma aldosterone concentration (PAC) with MetS and left ventricular mass (LVM) in nondiabetic Caucasian patients with essential hypertension.

METHODS

Measurements were taken with the patients off antihypertensive medications. The measurements included 24-h blood pressure (BP) readings, plasma renin activity (PRA) and aldosterone, and an echocardiogram.

RESULTS

Subjects with MetS (n = 201) had higher age-adjusted PAC (10.2 +/- 5.8 vs. 11.6 +/- 5.9 ng/dl; P = 0.01) and greater age-adjusted LVM indexed for height2.7 (LVMH2.7) (56 +/- 19 vs. 62 +/- 20 g/m2; P = 0.001) than those without MetS (n = 249). The difference in respect of PAC between the two groups was independent of PRA and was attributable mainly to obesity. After adjusting for potential confounders, LVMH2.7 was associated with MetS as a whole (beta = 0.11; P = 0.02) and with body mass index (BMI) (beta = 0.19; P < 0.0001) in the overall population. The latter relationship was attenuated (beta = 0.15; P = 0.001) after further adjustment for PAC. In the MetS group the association of LVMH2.7 with PAC held (beta = 0.19; P = 0.007) in multivariate analyses. In subjects without MetS, this relationship had only borderline statistical significance.

CONCLUSIONS

Our results suggest that the elevated PAC related to obesity may help to explain the increased LVM observed in association with MetS, and may contribute to enhancing the cardiovascular risk associated with MetS.

Outcomes of laparoscopic adrenalectomy for hyperaldosteronism

BACKGROUND

Primary hyperaldosteronism is a frequent cause of resistant hypertension and is amenable to surgical intervention when caused by a unilateral aldosterone-producing adenoma. The aim of this study was to investigate the long-term results of laparoscopic adrenalectomy in the control of hypertension caused by primary hyperaldosteronism.

METHODS

A prospective case series of patients undergoing laparoscopic adrenalectomy for hyperaldosteronism was studied. Blood pressure (BP), serum aldosterone levels, plasma renin activity, serum potassium and antihypertensive requirement were measured before and after adrenalectomy.

RESULTS

Sixty-two patients with hyperaldosteronism underwent laparoscopic adrenalectomy in the period from December 1995 to August 2005. The median follow up was 59 months. There was a significant decrease in both systolic blood pressure and diastolic blood pressure at final follow up compared with that before operation. Systolic blood pressure decreased from 149 mmHg to 129 mmHg at final follow up (P < 0.0001). Diastolic blood pressure decreased from 89 mmHg to 80 mmHg (P < 0.0001). Antihypertensive requirement was decreased from an average of 2.6 separate medications preoperatively to 1.4 medications at final follow up (P < 0.0001). Serum aldosterone levels were significantly lower (698 (confidence interval 534-862) pg/mL vs 181 (confidence interval 139-225) pg/mL, P < 0.0001). Overall, 34% of patients had cure of hypertension and did not require any antihypertensive agent. A further 51% had improvement in BP control, whereas 5% had no change or had worsening hypertension. Multivariate regression analysis showed that age and gland size were independent factors predicting sustained hypertension after surgery.

CONCLUSION

In appropriately selected patients with primary hyperaldosteronism, laparoscopic adrenalectomy is effective in improving long-term BP control. Larger adrenal gland size and older age at time of surgery are predictors of persisting hypertension.

Increased intima–media thickness of the common carotid artery in primary aldosteronism in comparison with essential hypertension

BACKGROUND

Aldosterone contributes to the accumulation of collagen fibers and extracellular matrix in arterial wall. The aim of this study was to compare intima-media thickness (IMT) of the common carotid artery and carotid bifurcation in patients with primary aldosteronism, essential hypertension and healthy controls.

METHODS

Carotid ultrasound studies were carried out in 33 patients aged 42-72 years with primary aldosteronism, 52 patients with essential hypertension and in 33 normotensive controls.

RESULTS

The patients with primary aldosteronism had significantly higher IMT of the common carotid artery than patients with essential hypertension and controls (0.987 +/- 0.152 mm; 0.892 +/- 0.154 mm versus 0.812 +/- 0.124 mm; P < 0.001; P < 0.05). There was also significantly higher IMT of the common carotid in patients with essential hypertension compared to control group (0.892 +/- 0.154 mm versus 0.812 +/- 0.124 mm; P < 0.01). The differences between both hypertensive groups remained statistically significant after adjustment for age and 24-h systolic blood pressure (P = 0.001). The differences of the IMT in the carotid bifurcation were statistically significant only between patients with primary aldosteronism and controls (1.157 +/- 0.243 mm versus 0.994 +/- 0.199 mm; P <0.05).

CONCLUSION

Patients with primary aldosteronism have increased common carotid IMT compared to the patients with essential hypertension. This finding could be caused by the deleterious effects of aldosterone excess on the fibrosis and thickening of the arterial wall, mainly in the straight segments of vessels.

Sex-related differences in the relations of insulin resistance and obesity to left ventricular hypertrophy in Japanese hypertensive patients

Echocardiographically determined left ventricular (LV) hypertrophy is a powerful, independent predictor of cardiovascular morbidity and mortality. Both insulin resistance and obesity have a well-known association with LV hypertrophy. However, whether or not there are sex-related differences in the relations of insulin resistance and obesity to LV hypertrophy has never been systematically explored in Japan. We enrolled 91 never-treated hypertensive patients (49 men and 42 women) to assess the possible relations of insulin resistance and obesity to LV geometry. Insulin resistance was estimated using the homeostasis model assessment (HOMA) formula. Echocardiographically determined LV mass and relative wall thickness were measured as markers of LV geometry. In addition, body mass index (BMI) was calculated as weight (kg) divided by height (m)2 as a marker of obesity. Independent determinants of LV mass in male hypertensive patients were HOMA value (p < 0.0001) and age (p = 0.034). BMI did not bear a significant relation to LV mass. In comparison, in female hypertensive patients BMI was an independent determinant of LV mass (p = 0.011). The HOMA value did not bear a significant relation to LV mass in the female hypertensive patients. In conclusion, these findings indicate the presence of sex-related differences in the relations of insulin resistance and obesity to LV hypertrophy in Japanese hypertensive patients. The effect of obesity on LV geometry was greater in female hypertensive patients than in male hypertensive patients.

The pharmacological treatment of primary aldosteronism

Aldosterone is increasingly considered to have a fundamental role in the pathophysiology of cardiovascular disease. Primary aldosteronism is a much more common cause of secondary hypertension than once suspected, accounting for approximately 10% of cases. Screening for primary aldosteronism should be considered even in the presence of normokalaemia. The non-classical effects of aldosterone, some of which are transcription-independent, may be of similar or greater importance than its traditional effects on the kidney. Treatment of primary aldosteronism should be specific and aim to ameliorate all hormone-related effects of aldosterone, not just the most obvious manifestation of hypertension. Mineralocorticoid antagonism, shown to lead to significant additional survival advantage in heart failure, offers the best prospect for achieving therapeutic goals. For the increasing proportion of patients with primary aldosteronism suitable for long-term medical treatment, mineralocorticoid receptor blockade (better tolerated with eplerenone) should be considered the most appropriate choice of treatment, pending the development of better alternatives.

Long-term follow-up of a girl with primary aldosteronism: effect of potassium supplement

We followed up a girl with primary aldosteronism for 8 y, which was diagnosed at 6 y of age when she was referred to us for evaluation of heart murmur and growth failure. The diagnosis of bilateral adrenal hyperplasia was made by selective adrenal venous sampling. Following potassium supplement, her retarded growth was corrected dramatically, and she attained a normal adult height. Puberty developed normally and menarche occurred at 12 y of age. Blood pressure was also controlled adequately. Myocardial hypertrophy associated with aortic damage was noted at 13 y of age. Chronic renal failure developed with proteinuria and enlarged renal cysts.

CONCLUSION

Serum electrolytes should be included in the evaluation of children with impaired growth. Although primary aldosteronism is a rare occurrence in children, the condition appears to deserve special attention not only from the viewpoint of growth failure and hypokalaemia but from the occurrence of late organ damage to the kidney and heart.

A case with primary aldosteronism due to unilateral multiple adrenocortical micronodules

A 46-year-old male with long-term treatment-resistant hypertension and past history of cerebral hemorrhage was found to have suppressed plasma renin activity (PRA) and normal plasma aldosterone concentration (PAC) with aldosterone/renin ratio of 25.3. Furosemide plus upright test did not stimulate PRA, but computed tomography scan of the abdomen revealed no abnormal lesions in either adrenal gland. Selective adrenal venous sampling (SAVS) showed that PAC in the left and the right adrenal vein were 1000 ng/dl and 230 ng/dl, respectively, which increased to 1500 ng/dl and 620 ng/dl, respectively, after ACTH stimulation. Diagnosis of primary aldosteronism due to hypersecretion of aldosterone from the left adrenal gland was made, and laparoscopic left adrenalectomy was performed. Pathological examination of the 'apparently normal' adrenal tissue resected revealed the presence of poorly encapsulated multiple adrenocortical micronodules which showed positive immunoreactivity for 3beta-hydroxysteroid dehydrogenase by immunohistochemical study, but negative immunoreactivity in the hyperplastic zona glomerulosa consistent with paradoxical hyperplasia associated with primary aldosteronism. Postoperatively, PRA was normalized and his high blood pressure was well controlled with lower doses of antihypertensive drugs than those used before surgery. The clinicopathological features of our case are consistent with the diagnosis of unilateral multiple adrenocortical micronodules (UMN), a new subset of primary aldosteronism, in which SAVS proved to be a useful diagnostic tool for its localization.

Sex-Related Differences in Relations of Uric Acid to Left Ventricular Hypertrophy and Remodeling in Japanese Hypertensive Patients

Both hyperuricemia and echocardiographically determined left ventricular (LV) mass have a well-determined association with cardiovascular morbidity and mortality. However, whether or not there is a sex difference in the association of serum uric acid level with LV mass has never been systematically explored. We examined the sex-specific relation of serum uric acid level and echocardiographic indexes of LV structure in never-treated patients with essential hypertension. We enrolled 160 never-treated hypertensive patients (89 men and 71 women) to assess the possible relationship between LV mass and serum uric acid levels. LV measurements were performed according to the recommendations of the American Society of Echocardiography and the Penn Convention. LV mass was indexed by height, body surface area and height raised to the 2.7th power. A positive significant correlation between LV geometry (LV mass, indexed LV mass and relative wall thickness) and serum uric acid level was found in male hypertensive patients but not in female hypertensive patients. Independent determinants of serum uric acid levels in male hypertensive patients were LV mass and serum creatinine levels. In addition, male hypertensive patients with concentric hypertrophy showed the highest serum uric acid levels. In comparison, independent determinants of serum uric acid levels in female hypertensive patients were age and serum creatinine levels. In conclusion, these findings indicate a sex difference in the association of uric acid with LV geometry in Japanese hypertensive patients. In addition, the finding that the highest levels of serum uric acid were observed in our male hypertensive patients with concentric hypertrophy confirmed the previous reports that these patients have the highest risk for cardiovascular morbidity and mortality.

Aldosterone receptor antagonists: biology and novel therapeutical applications

Recent studies suggest that a dysregulation of the aldosterone system is involved in the pathophysiology of different cardiovascular diseases, including myocardial failure and several cases of essential hypertension. In both rat models and in humans, aldosterone action has been shown to induce heart remodeling and interstitial and perivascular fibrosis of the myocardium. For these reasons, a rationale for the use of aldosterone antagonists (ARAs) of the spirolactone family, which have been available for decades in the treatment of aldosterone excess syndromes, has now emerged. Moreover, the recent validation of their use, in combination with the current therapy, for the treatment of these cardiovascular diseases by trials like the RALES Study has further strenghtened this approach. The development of compounds, like eplerenone, with a greater selectivity for mineralocorticoid receptors, seems promising also in terms of reduction of endocrine side effects. The addition of aldosterone antagonists to the conventional therapy of myocardial failure and of selected cases of hypertension thus appears beneficial, resulting in an improved survival rate and a reduced incidence of cardiac complications. This review article, after a brief recall of the physiology of the aldosterone system, addresses the emerging role of aldosterone in cardiovascular diseases, considers the pharmacology of ARAs and the novel therapeutical applications of these compounds in hypertension and heart failure.

Primary aldosteronism - treatment options

Diagnosis of primary aldosteronism results in either the surgical cure of hypertension or targeted pharmacotherapy. The two major subtypes of primary aldosteronism are unilateral aldosterone-producing adenoma (APA) and bilateral idiopathic hyperaldosteronism (IHA). Patients with APA usually are treated with unilateral adrenalectomy and patients with IHA are treated medically. The majority of patients with primary aldosteronism have the IHA subtype and require pharmacotherapy. Spironolactone has been the drug of choice to treat primary aldosteronism. However, it is not selective for the aldosterone receptor, and side effects include gynecomastia, erectile dysfunction and menstrual irregularity. Eplerenone is a new competitive and selective aldosterone receptor antagonist recently approved by the United States Food and Drug Administration for the treatment of hypertension. It lacks the side effects associated with spironolactone and will be the superior drug if it is shown to be as effective as spironolactone for the treatment of mineralocorticoid-dependent hypertension.

Minireview: primary aldosteronism--changing concepts in diagnosis and treatment

Primary aldosteronism affects 5-13% of patients with hypertension. Patients with hypertension and hypokalemia and most patients with treatment-resistant hypertension should undergo screening for primary aldosteronism with a plasma aldosterone concentration to plasma renin activity ratio. A high plasma aldosterone concentration to plasma renin activity ratio is a positive screening test result, a finding that warrants confirmatory testing. For those patients that want to pursue a surgical cure, the accurate distinction between the subtypes (unilateral vs. bilateral adrenal disease) of primary aldosteronism is a critical step. The subtype evaluation may require one or more tests, the first of which is imaging the adrenal glands with computed tomography, followed by selective use of adrenal venous sampling. Because of the deleterious cardiovascular effects of aldosterone, normalization of circulating aldosterone or aldosterone receptor blockade should be part of the management plan for all patients with primary aldosteronism. Unilateral laparoscopic adrenalectomy is an excellent treatment option for patients with unilateral aldosterone-producing adenoma. Bilateral idiopathic hyperaldosteronism should be treated medically. In addition, aldosterone-producing adenoma patients may be treated medically if the medical treatment includes mineralocorticoid receptor blockade.

Diagnosis and management of primary aldosteronism

Identifying primary aldosteronism within the hypertensive population is an important clinical challenge, as most patients with a unilateral source of excess aldosterone secretion are amenable to surgical cure. At least 20% of patients with primary aldosteronism have normal serum potassium levels. Therefore, screening tests should not be based on recognition of hypokalemia alone. Rather, the diagnosis should depend on identifying renin suppression and measuring the ratio of plasma aldosterone concentration to plasma renin activity. The diagnosis may be confirmed by performing an aldosterone suppression test after oral salt loading. Once primary aldosteronism has been established, it is necessary to exclude glucocorticoid-remediable aldosteronism and then proceed to localization studies. Detecting a unilateral source of aldosterone, usually due to an adenoma (Conn syndrome), is achieved by postural hormonal testing and confirmed by selective venous sampling (SVS) with measurement of aldosterone concentrations (expressed as the aldosterone/cortisol ratio) in each adrenal vein. SVS is enjoying a revival in many institutions as it is more sensitive and specific than either cross-sectional imaging or scintigraphy and has the potential to influence significantly both the diagnosis and clinical decision-making. Patients with unilateral disease are ideally treated by laparoscopic adrenalectomy. Patients in whom localization is not achieved usually have bilateral adrenal hyperplasia and are treated medically.

Hypertension and the eye: changing perspectives

Systemic hypertension is a common condition associated with significant morbidity and mortality. Hypertension confers cardiovascular risk by causing target-organ damage that includes retinopathy in addition to heart disease, stroke, renal insufficiency and peripheral vascular disease. The recognition of hypertensive retinopathy is important in cardiovascular risk stratification of hypertensive individuals. This review reevaluates the changing perspectives in the pathophysiology, classification and prognostic significance of fundal lesions in hypertensives.

Hyperaldosteronism: the internist's hypertensive disease

Primary aldosteronism (PA) is a disorder typically characterized by resistant hypertension, hypokalemia, alkalosis and suppressed plasma renin activity, and excessive aldosterone production. A true estimate of the prevalence of the disorder is difficult to estimate because its detection is dependent on the awareness of the healthcare provider to the disorder, but it has generally been felt to be a rare occurrence. Its frequency of detection began to change when Hiramatsu suggested calculating the ratio of plasma aldosterone/plasma renin activity as a screening tool for the disorder. He found a ratio greater than 75 as a sensitive indicator for aldosterone-producing adenomas. Using the ratio, several investigators have found prevalence ranging from 3 to 9%. Two major classifications of PA exist: aldosterone-producing adrenal adenoma (APA) and zona glomerulosa hyperplasia (IHA). Distinguishing between these 2 entities is important clinically, because removal of a unilateral aldosterone-producing adenoma may result in correction of elevated blood pressure and hypokalemia. Thus, when evaluating hypertensive patients, PA should be suspected in those with moderate to severe hypertension or with hypertension refractory to standard treatment or in hypertensive patients with disease onset at an early age. The aldosterone-to-renin ratio is an easy, inexpensive, and rapid means of screening for the disorder. The ratio is the screening test of choice, but further confirmatory testing is required to clinch the diagnosis. Frequently employed confirmatory tests include urinary aldosterone excretion on a high-salt diet, aldosterone suppression after a saline infusion, and the fludrocortisone suppression test, which is considered the most sensitive confirmatory maneuver. Both high-resolution CT and MRI scans appear to have similar ability to differentiate between APA and IHA. As with essential hypertension, the goal of treatment is to prevent the long-term sequela of hypertension. The underlying pathology resulting in PA dictates the treatment strategy. The drug of choice is spironolactone. Surgical intervention should be entertained in those patients with PA in whom imaging studies suggest an adenoma.

Primary aldosteronism: management issues

Since its initial description in 1955, primary aldosteronism was thought to be a rare cause of hypertension. However, improved screening methods show that primary aldosteronism is a common form of secondary hypertension. Diagnosis of this disorder results in improved or cured hypertension or targeted pharmacotherapy. Patients with hypertension and hypokalemia and most patients with treatment-resistant hypertension should undergo screening for primary aldosteronism. A random and ambulatory ratio of plasma aldosterone concentration (PAC) to plasma renin activity (PRA) that is elevated and a PAC higher than a set cutoff is a positive screen for primary aldosteronism. An increased PAC/PRA ratio alone is not diagnostic of primary aldosteronism; primary aldosteronism must be confirmed by demonstrating inappropriate aldosterone secretion with either the intravenous saline suppression test or measurement of 24-hr urinary aldosterone while the patient is on a high-sodium diet. The two major subtypes of primary aldosteronism are unilateral aldosterone-producing adenoma (APA) and bilateral idiopathic hyperplasia (IHA). Patients with APA are usually treated with unilateral adrenalectomy, and patients with IHA are treated medically. The subtype evaluation may require one or more tests, the first of which is imaging the adrenals with computerized tomography (CT). When a solitary unilateral macroadenoma (> 1 cm) and normal contralateral adrenal morphologic pattern are found on CT in a young patient with primary aldosteronism, unilateral laparoscopic adrenalectomy is a reasonable therapeutic option. However, in many cases, CT imaging may reveal normal-appearing adrenals or ambiguous findings. Adrenal venous sampling helps to resolve these clinical dilemmas.

Structural changes in small resistance arteries and left ventricular geometry in patients with primary and secondary hypertension

OBJECTIVE

To prospectively evaluate the interrelationships between left ventricular (LV) geometry and structural characteristics of the vessel wall in small resistance arteries in patients with consecutive primary and secondary hypertension.

METHODS

In 14 patients with phaeochromocytoma, 12 with primary aldosteronism, 25 with renovascular, 25 with essential hypertension and 12 normotensive controls, an echocardiographic study for the measurement of LV mass index and relative wall thickness (RWT) was performed. Morphological characteristics of small resistance arteries (relaxed diameter < 300 microm) were directly evaluated by a micromyographic technique.

RESULTS

A total of 25 patients had normal LV mass and geometry, 28 patients had normal RWT (< 0.45) and 23 patients had a RWT >or= 0.45; all normotensive subjects had normal LV mass and geometry. Media to lumen ratio (M/L) in subcutaneous small arteries was greater in hypertensive patients with concentric LV hypertrophy in respect to normotensives (ANOVA P = 0.01) and hypertensives with normal LV geometry (ANOVA P = 0.05). In the whole group of hypertensive patients the correlation coefficient between M/L and LV mass index was 0.33 (P < 0.05); the correlation coefficient between M/L and RWT was 0.46 (P < 0.01) and it was higher in primary aldosteronism (r = 0.67) and renovascular hypertension patients (r = 0.46).

CONCLUSIONS

A close relation between morphology of subcutaneous small resistance arteries and LV geometric patterns may be observed in hypertensive patients; this relationship is more evident when the renin-angiotensin-aldosterone system is activated.

Discriminating factors for recurrent hypertension in patients with primary aldosteronism after adrenalectomy

Patients with primary aldosteronism show relatively high rates of hypertension after adrenalectomy, but the risk factors for postoperative hypertension remain unclear. Forty-six patients with primary aldosteronism (PA) who had undergone adrenalectomy between 1976 and 1998 were enrolled in this study. Follow-up information including blood pressure (BP) and cardiovascular complications was collected by means of correspondence or telephone contact. At discharge BP was normalized in 34 patients (72%); hypertension persisted in the remaining 12 patients, but BP control was significantly improved. The patients who remained hypertensive at discharge had longer durations of hypertension than did those with normalized BP. After an average follow-up period of 12.2 years, 16 of 34 BP-normalized patients (47%) had recurrent hypertension. Age at adrenalectomy, preoperative serum creatinine level and systolic blood pressure at discharge were significantly higher in patients with recurrent hypertension than in those without it. A multivariate logistic regression analysis revealed that only the level of serum creatinine was independently associated with the incidence of recurrent hypertension. Patients with serum creatinine of 0.9 mg/dl or greater had significantly higher rates of recurrent hypertension than those with lower values of serum creatinine. Cardiovascular complications occurred in 5 patients prior to the surgery and in 2 patients during the follow-up period. Although the severity of renal involvement is subclinical, renal damage may play an important role in the development of hypertension during a long period after adrenalectomy in patients with PA.

Relative wall thickness is an independent predictor of left ventricular systolic and diastolic dysfunctions in essential hypertension

The objective of this study was to elucidate the relationship between left ventricular geometry and left ventricular (LV) function in patients with untreated essential hypertension. We evaluated LV systolic and diastolic functions by M-mode echocardiography in 24 normotensive control subjects (NC) and 129 patients with essential hypertension. Patients were divided into four groups according to the relative wall thickness and LV mass index: a normal left ventricle (n=57), a concentric remodeling (n=7), a concentric hypertrophy (n=31), and an eccentric hypertrophy (n=34) group. LV systolic function as measured by midwall fractional shortening (FS) was significantly decreased in both the concentric remodeling and concentric hypertrophy groups; no differences were observed for endocardial FS. LV diastolic function as measured by isovolumic relaxation time (IRT) was also decreased in both the concentric remodeling and concentric hypertrophy groups. In multivariate analysis, relative wall thickness (p<0.0001), end-systolic wall stress (p<0.0001), and systolic blood pressure (p=0.002) were independently associated (r2=0.72) with midwall FS in a model including age, LV mass index, body mass index, diastolic blood pressure and IRT. In addition, relative wall thickness (p=0.0008) and age (p<0.0001) were independently associated (r2=0.31) with IRT in a model including LV mass index, end-systolic wall stress, body mass index, systolic and diastolic blood pressures and midwall FS. We conclude that LV geometry as evaluated by relative wall thickness may provide a further independent stratification of LV systolic and diastolic functions in essential hypertension.

The effect of coronary vasospasm on the direction of ST-segment deviation in patients with both hypertrophic cardiomyopathy and vasospastic angina

BACKGROUND

There has been no report of ECG changes during anginal attacks in patients with coexistent hypertrophic cardiomyopathy (HCM) and vasospastic angina.

STUDY OBJECTIVES

To elucidate the change in ST-segment during anginal attacks in patients with coexistent HCM and vasospastic angina (the HCM group) in comparison with that of patients with vasospastic angina and no left ventricular hypertrophy (the non-HCM group).

DESIGN

Retrospective study.

PATIENTS

Twelve patients in the HCM group, and 28 patients in the non-HCM group.

MEASUREMENTS

The direction of ST segment shift, either ST-segment elevation or depression, on the ECGs recorded during vasospastic anginal attacks with severe vasoconstriction in the epicardial coronary artery after intracoronary injection of acetylcholine.

RESULTS

Age, male gender, and distribution of coronary arteries in which the vasospasm occurred were similar between the two groups. Collateral circulation to the affected arteries was absent in all the study patients. The prevalence of anginal attacks associated with ST-segment elevation was 2.7 times higher in the non-HCM group than in the HCM group (51. 5% [17 of 33 attacks] vs 18.8% [3 of 16 attacks], respectively; p = 0.03).

CONCLUSIONS

In the HCM group, myocardial ischemia associated with a transmural injury pattern seen on the ECG, which is represented as ST-segment elevation, seldom develops during vasospastic anginal attacks because of marked left ventricular hypertrophy.