Primary Aldosteronism: Cardiovascular Risk, Diagnosis, and Management

Prevalence of High Aldosterone-Renin Ratio in Patients With Hypertension in Basrah

BACKGROUND AND AIM

Aldosterone-renin ratio (ARR) is an important screening tool for the assessment of primary aldosteronism as a cause of secondary hypertension. This study aimed to measure the prevalence of patients with elevated ARR among samples of Iraqi patients with hypertension.

METHODS

A retrospective study was conducted at Faiha Specialized Diabetes, Endocrine and Metabolism Center (FDEMC) in Basrah during the period of February 2020 to November 2021. We evaluated the records of patients with hypertension whom were screened for endocrine cause, and an ARR cut-off equal or more than 5.7 was considered elevated.

RESULTS

Of the total 150 patients enrolled, 39 (26%) of them had an elevated ARR. No statistically significant association for the elevated ARR with age, gender, BMI, duration of hypertension, systolic and diastolic blood pressure, pulse rate, and presence or absence of diabetes mellitus or lipid profile.

CONCLUSION

High frequency of elevated ARR was seen in 26% of patients with hypertension. More studies need to be conducted in the future taking larger samples.

Stroke Risks in Primary Aldosteronism with Different Treatments: A Systematic Review and Meta-Analysis

Background: Primary aldosteronism (PA) is a common cause of secondary hypertension and confers a higher risk of stroke. The treatment strategies of PA mainly include medical and adrenalectomy treatment, while there is still no solid conclusion on how these two different treatment strategies mitigate the detrimental effect of PA on stroke. Methods: PubMed, Embase, and Cochrane Library were searched for studies comparing stroke events in patients with PA receiving medical treatment versus adrenalectomy treatment published up to 19 March 2022, including patients with essential hypertension as a control group. We used either fixed or random effect models according to the heterogeneities. Sensitivity analysis was conducted by deleting each study one at a time. Results: We reviewed 201 articles, and three studies met the final criteria, including 3244 PA patients with medical treatment, 1611 PA patients with adrenalectomy treatment, and 20,568 EH patients. Patients with PA post adrenalectomy were observed with a significantly decreased risk of stroke compared to patients receiving medical treatment (OR: 0.57, 95% CI: 0.35−0.93, p = 0.03), and with no difference when compared to patients with essential hypertension. Patients with PA receiving medical treatment were still observed with higher stroke risks (OR: 1.88, 95% CI: 1.68−2.11, p < 0.00001) than patients with essential hypertension. Conclusion: PA is a critical modifiable risk factor for stroke. Adrenalectomy has a superior performance in the mitigation of stroke risks among patients with PA.

Bilateral Adrenalectomy in a Patient With Refractory Primary Aldosteronism Due to Adrenal Hyperplasia

Primary aldosteronism (PA) is a frequent cause of secondary hypertension. The main cause of PA is bilateral adrenal hyperplasia, and treatment is usually medical with mineralocorticoid receptor antagonists (MRAs) such as spironolactone or eplerenone. In this paper, we present a rare clinical case of a middle-aged female with refractory arterial hypertension and hypokalemia that complementary medical tests confirmed PA due to bilateral hyperplasia, and despite a maximum dose of spironolactone and oral potassium supplements, there was no clinical response. Because of this, finally, the patient needed surgical treatment based on bilateral adrenalectomy, which was effective. This is unusual and poorly described in the medical literature.

Concurrent Primary Aldosteronism and Renal Artery Stenosis: An Overlooked Condition Inducing Resistant Hypertension

To explore the clinical features of coexisting primary aldosteronism (PA) and renal artery stenosis (RAS), we retrospectively analyzed records from 71 patients with PA with RAS and a control group of 121 patients with PA without RAS. Aldosterone-to-renin concentration ratio tests and computerized tomography (CT) scanning of the adrenal and renal arteries were routinely conducted to screen for PA and RAS. Color Doppler flow and/or magnetic resonance imaging were used as substitute testing of patients for whom CT was contraindicated. Standard percutaneous renal arteriography (PTRA) was considered for patients with RAS exceeding 70% based on non-invasive tests and for those without PTRA contraindications. The patients with PA with RAS were further divided into severe (RAS>70%) and moderate (50% < RAS <70%) RAS groups. The prevalence of RAS among PA patients was 6.9% (71/1,033), including 3.2% (33/1,033) with severe RAS. Compared with the PA without RAS group, the severe RAS group showed higher levels of systolic blood pressure (SBP) (171.82 ± 18.24 vs. 154.11 ± 18.96 mmHg; P < 0.001) and diastolic BP(DBP) (110.76 ± 15.90 vs. 91.73 ± 12.85 mmHg; P < 0.001) and prevalence of resistant hypertension (RH) (90.9 vs. 66.9%; P = 0.008), whereas the moderate RAS group merely showed higher DBP (98.63 ± 14.90 vs. 91.73 ± 12.85 mmHg; P = 0.006). The direct renin concentrations (DRCs) (5.37 ± 3.94 vs. 3.71 ± 2.10 μU/mL; P < 0.001) and false-negative rate (33.8 vs. 3.3%; P < 0.01) of PA screening tests were significantly higher in the PA with RAS group than in the control group, but only in severe RAS group, in subgroup analysis. Among patients who underwent successful treatment for severe RAS, mean DRC decreased from 11.22 ± 9.10 to 3.24 ± 2.69 μIU/mL (P < 0.001). Overall, the prevalence of RH decreased from 81.7 to 2.8% (P < 0.001) when both PA and RAS were treated with standard methods. PA with concurrent severe RAS is a condition that induces RH. PA can be easily missed in patients with coexisting RAS. RAS patients with RH after successful revascularization for RAS should be evaluated for coexisting PA.

Incidence of Primary Aldosteronism in Patients with Hypokalemia (IPAHK+): Study Design and Baseline Characteristics

Hypokalemia plays a central role for case finding, course, treatment decision, and prognosis of patients with primary aldosteronism. However, to date there is a lack of high-level evidence about the incidence of primary aldosteronism in hypokalemic patients. The IPAHK⁺study is an epidemiological, cross-sectional, monocentric study to provide evidence on the incidence of PA in a hypokalemic population. The aim of the current analysis was to describe the baseline characteristics of the first 100 patients eligible for study inclusion. The recruitment of patients with hypokalemia (≤3 mmol/l) is carried out continuously on a referral-basis by the central laboratory of the University Hospital Zurich through an automated suitability testing and data delivery system. The careful evaluation of the first 100 reported patients was based on the available reporting system. Out of 28 140 screened patients, 222 (0.79%) were identified with a serum potassium value of≤3 mmol/l (mean 2.89±0.02 mmol/l). Mean potassium levels were slightly lower in non-hypertensive subjects compared to hypertensive subjects (mean difference 0.07 mmol/l, p=0.033), while no significant difference was found between the sexes and patients with and without the diagnosis of primary aldosteronism, atrial fibrillation, or the use of diuretics. The incidence of PA was 4% in the total population studied and 7.5% in the subgroup of hypertensive patients. In conclusion, the continuous enrollment of patients from the IPHAK⁺hypokalemia registry into the IPAHK⁺trial will provide evidence about the actual incidence of primary aldosteronism in a hypokalemic outpatient population.

DNA Methylation of the Angiotensinogen Gene, AGT, and the Aldosterone Synthase Gene, CYP11B2 in Cardiovascular Diseases

Angiotensinogen (AGT) and aldosterone play key roles in the regulation of blood pressure and are implicated in the pathogenesis of cardiovascular diseases. DNA methylation typically acts to repress gene transcription. The aldosterone synthase gene CYP11B2 is regulated by angiotensin II and potassium. DNA methylation negatively regulates AGT and CYP11B2 expression and dynamically changes in response to continuous promoter stimulation of each gene. High salt intake and excess circulating aldosterone cause DNA demethylation around the CCAAT-enhancer-binding-protein (CEBP) sites of the ATG promoter region, thereby converting the phenotype of AGT expression from an inactive to an active state in visceral adipose tissue and heart. A close association exists between low DNA methylation at CEBP-binding sites and increased AGT expression in salt-sensitive hypertensive rats. Salt-dependent hypertension may be partially affected by increased cardiac AGT expression. CpG dinucleotides in the CYP11B2 promoter are hypomethylated in aldosterone-producing adenomas. Methylation of recognition sequences of transcription factors, including CREB1, NGFIB (NR4A1), and NURR1 (NR4A2) diminish their DNA-binding activity. The methylated CpG-binding protein MECP2 interacts directly with the methylated CYP11B2 promoter. Low salt intake and angiotensin II infusion lead to upregulation of CYP11B2 expression and DNA hypomethylation in the adrenal gland. Treatment with the angiotensin II type 1 receptor antagonist decreases CYP11B2 expression and leads to DNA hypermethylation. A close association between low DNA methylation and increased CYP11B2 expression are seen in the hearts of patients with hypertrophic cardiomyopathy. These results indicate that epigenetic regulation of both AGT and CYP11B2 contribute to the pathogenesis of cardiovascular diseases.

New-Onset Atrial Fibrillation in Patients With Primary Aldosteronism Receiving Different Treatment Strategies: Systematic Review and Pooled Analysis of Three Studies

BACKGROUND

Primary aldosteronism (PA) is a common cause of secondary hypertension and associated with higher incidence of new-onset atrial fibrillation (NOAF). However, the effects of surgical or medical therapies on preventing NOAF in PA patents remain unclear. The aim of this meta-analysis study was to assess the risk of NOAF among PA patients receiving mineralocorticoid receptor antagonist (MRA) treatment, PA patients receiving adrenalectomy, and patients with essential hypertension.

METHODS

We performed the meta-analysis of the randomized or observational studies that investigated the incidence rate of NOAF in PA patients receiving MRA treatment versus PA patients receiving adrenalectomy from database inception until December 01, 2020 which were identified from PubMed, Embase, and Cochrane Library.

RESULTS

A total of 172 related studies were reviewed, of which three fulfilled the inclusion criteria, including a total of 2,705 PA patients. The results of meta-analysis demonstrated a higher incidence of NOAF among the PA patients receiving MRA treatment compared to the PA patients receiving adrenalectomy (pooled odds ratio [OR]: 2.83, 95% confidence interval [CI]: 1.76-4.57 in the random effects model, I² = 0%). The pooled OR for the PA patients receiving MRA treatment compared to the patients with essential hypertension was 1.91 (95% CI: 1.11-3.28). The pooled OR for the PA patients receiving adrenalectomy compared to the patients with essential hypertension was 0.70 (95% CI: 0.28-1.79).

CONCLUSION

Compared to the essential hypertension patients and the PA patients receiving adrenalectomy, the patients with PA receiving MRA treatment had a higher risk of NOAF.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/, identifier CRD42021222022.

Diagnostic accuracy of adrenal imaging for subtype diagnosis in primary aldosteronism: systematic review and meta-analysis

OBJECTIVES

Accurate subtype classification in primary aldosteronism (PA) is critical in assessing the optimal treatment options. This study aimed to evaluate the diagnostic accuracy of adrenal imaging for unilateral PA classification.

METHODS

Systematic searches of PubMed, EMBASE and the Cochrane databases were performed from 1 January 2000 to 1 February 2020, for all studies that used CT or MRI in determining unilateral PA and validated the results against invasive adrenal vein sampling (AVS). Summary diagnostic accuracies were assessed using a bivariate random-effects model. Subgroup analyses, meta-regression and sensitivity analysis were performed to explore the possible sources of heterogeneity.

RESULT

A total of 25 studies, involving a total of 4669 subjects, were identified. The overall analysis revealed a pooled sensitivity of 68% (95% CI: 61% to 74%) and specificity of 57% (95% CI 50% to 65%) for CT/MRI in identifying unilateral PA. Sensitivity was higher in the contrast-enhanced (CT) group versus the traditional CT group (77% (95% CI 66% to 85%) vs 58% (95% CI 50% to 66%). Subgroup analysis stratified by screening test for PA showed that the sensitivity of the aldosterone-to-renin ratio (ARR) group was higher than that of the non-ARR group (78% (95% CI 69% to 84%) vs 66% (95% CI 58% to 72%)). The diagnostic accuracy of PA patients aged ≤40 years was reported in four studies, and the overall sensitivity was 71%, with 79% specificity. Meta-regression revealed a significant impact of sample size on sensitivity and of age and study quality on specificity.

CONCLUSION

CT/MRI is not a reliable alternative to invasive AVS without excellent sensitivity or specificity for correctly identifying unilateral PA. Even in young patients (≤40 years), 21% of patients would have undergone unnecessary adrenalectomy based on imaging results alone.

Update: Selective adrenal venous sampling (AVS) - Indication, technique, and significance

BACKGROUND

 Primary aldosteronism (PA) is the most common detectable cause of secondary hypertension. The majority of patients have either an adrenal aldosterone-producing adenoma (APA) or bilateral adrenal hyperplasia (BAH) demanding different therapeutic approaches. Screening tests and imaging cannot reliably distinguish between a unilateral or bilateral PA.

METHODS

 This review article gives an overview concerning etiology, diagnostics, and therapeutic options of PA, and reviews the indication, the technique, and relevance of selective adrenal venous sampling (AVS) in the context of the current literature and the authors' experience.

RESULTS

 AVS can verify or exclude a unilaterally dominated secretion with a high success rate. Patients with PA and a unilateral APA can be treated curatively by adrenalectomy.

CONCLUSIONS

 AVS is an established diagnostic examination for differentiation of unilateral from bilateral adrenal disease in patients with PA.

KEY POINTS

· Selective adrenal venous sampling (AVS) is a safe, reliable, and minimally invasive method to detect a unilateral or bilateral adrenal adrenal gland disease.. · Verification of lateralization by AVS has direct therapeutic relevance for patients with primary aldosteronism (PA).. · AVS can be performed with low radiation exposure, without contrast medium, and with a high success rate when performed by an experienced interventional radiologist..

CITATION FORMAT

· Loberg C, Antoch G, Stegbauer J et al. Update: Selective adrenal venous sampling (AVS) - Indication, technique, and significance. Fortschr Röntgenstr 2021; 193: 658 - 666.

Hypokalemia and the Prevalence of Primary Aldosteronism

Hypokalemia is closely linked with the pathophysiology of primary aldosteronism (PA). Although hypokalemic PA is less common than the normokalemic course of the disease, hypokalemia is of particular importance for the manifestation and development of comorbidities. Specifically, a growing body of evidence demonstrates that hypokalemia in PA patients is associated with a more severe disease course regarding cardiovascular and metabolic morbidity and mortality. It is also well appreciated that low potassium levels per se can promote or exacerbate hypertension. The spectrum of hypokalemia-related symptoms ranges from asymptomatic courses to life-threatening conditions. Hypokalemia is found in 9-37% of all cases of PA with a predominance in patients with aldosterone producing adenoma. Conversely, hypokalemia resolves in almost 100% of cases after both, specific medical or surgical treatment of the disease. However, to date, high-level evidence about the prevalence of primary aldosteronism in a hypokalemic population is missing. Epidemiological data are expected from the recently launched IPAHK+study ("Incidence of Primary Aldosteronism in Patients with Hypokalemia").