Evolution of the Primary Aldosteronism Syndrome: Updating the Approach.

CONTEXT: New approaches are needed to address the evolution of the primary aldosteronism syndrome and to increase its recognition. Herein, we review evidence indicating that primary aldosteronism is a prevalent syndrome that is mostly unrecognized, and present a pragmatic and pathophysiology-based approach to improve diagnosis and treatment. METHODS: Evidence was gathered from published guidelines and studies identified from PubMed by searching for primary aldosteronism, aldosterone, renin, and hypertension. This evidence was supplemented by the authors' personal knowledge, research experience, and clinical encounters in primary aldosteronism. INTERPRETATION OF EVIDENCE: Renin-independent aldosterone production is a prevalent phenotype that is diagnosed as primary aldosteronism when severe in magnitude, but is largely unrecognized when milder in severity. Renin-independent aldosterone production can be detected in normotensive and hypertensive individuals, and the magnitude of this biochemical phenotype parallels the magnitude of blood pressure elevation, the risk for incident hypertension and cardiovascular disease, and the likelihood and magnitude of blood pressure reduction with mineralocorticoid receptor antagonist therapy. Expansion of the indications to screen for primary aldosteronism, combined with the use of a pathophysiology-based approach that emphasizes inappropriate aldosterone production in the context of renin suppression, will substantially increase the diagnostic and therapeutic yields for primary aldosteronism. CONCLUSIONS: The landscape of primary aldosteronism has evolved to recognize that it is a prevalent syndrome of renin-independent aldosterone production that contributes to the pathogenesis of hypertension and cardiovascular disease. Expanding screening indications and simplifying the diagnostic approach will enable implementation of targeted treatment for primary aldosteronism.

Prevalence of primary aldosteronism in hypertensive kidney transplant recipients: A cross-sectional study.

Due to high prevalence of primary aldosteronism (PA) in the general hypertensive population, and its association with worse cardiovascular and renal outcomes, the 2016 Endocrine Society Guidelines explicitly recognize PA as a major public health issue requiring urgent attention. Its prevalence in hypertensive kidney transplant recipients (KTRs) is unknown. In this cross-sectional study, we screened KTRs with hypertension who were on ≥4 antihypertensive medications, on 3 antihypertensive medications with BP ≥ 140/90, and on potassium supplements, or were hypokalemic. 172 of 280 eligible patients successfully completed the testing. A positive screen for PA defined by an aldosterone-to-renin ratio of ≥20 and a plasma aldosterone concentration of >15 ng/dL yielded a prevalence of 15.7%. Potassium supplement requirement (52% vs 27%, P = .01) and hypokalemia (25.9% vs 4.8%, P < .01) were more common in patients who screened positive compared with those who screened negative. 67% of patients who screened positive were on potassium supplements and/or were hypokalemic. Our study is the first to systematically explore the prevalence of PA among the hypertensive KTR population, which has inherently high cardiovascular risk. Further studies are needed to determine the cardiovascular and renal risk attributable to PA, and define optimal therapy for KTRs with PA.

Issues in the Diagnosis and Treatment of Primary Aldosteronism.

Primary aldosteronism (PA) is associated with a high rate of cardio- and cerebrovascular complications and metabolic alterations. PA is also recognized as the most frequent, although often unrecognized, secondary form of hypertension. Guidelines have been released to assist clinicians in the diagnostic work-up and subtype differentiation of PA. In this review we discuss and compare the available guidelines in the context of our professional experience and evaluate diagnostic and therapeutic aspects that are still a matter of debate.

Age below 40 or a recently proposed clinical prediction score cannot bypass adrenal venous sampling in primary aldosteronism.

CONTEXT: Adrenal venous sampling (AVS) is used to distinguish bilateral from unilateral primary aldosteronism (PA). Due to its limited availability, clinical prediction scores have been proposed to diagnose unilateral disease without AVS. OBJECTIVE: Our goal was to test 2 recently proposed predictors of unilateral PA: 1) a clinical prediction score using imaging, serum potassium, and glomerular filtration rate and 2) the combination of visible unilateral adenoma on imaging and age <40 years. DESIGN AND SETTING: We used the data of all patients with PA of the prospective German Conn's Registry treated in Munich and Berlin since 2008. PATIENTS AND INTERVENTION: Of 205 patients with PA, 194 had a successful AVS and were included. MAIN OUTCOME MEASURES: Parameters were compared between patients with lateralized and nonlateralized AVS. Specificity and sensitivity of the proposed predictors were calculated. RESULTS: A total of 130 patients (67%) had unilateral PA according to AVS. Patients with unilateral PA showed a significantly lower estimated glomerular filtration rate compared with patients with bilateral disease (P < .05). The cohorts differed significantly in potassium supplementation, serum potassium, baseline and post-saline plasma aldosterone, baseline aldosterone to renin ratio, and adenoma in imaging. The proposed prediction score had a sensitivity of 46% (58 of 127) and a specificity of 80% (53 of 66). In patients below 40 years (n = 28), the prediction score achieved a specificity of 100%; however, relying only on imaging in this young cohort, the specificity dropped to 83%. CONCLUSIONS: The suggested prediction score has high accuracy only in young patients but cannot substitute for AVS in the elderly.

[Aldosterone-to-renin ratio threshold for screening primary aldosteronism in Chinese hypertensive patients].

OBJECTIVE: In recent years, the assessment of the plasma aldosterone-to-renin ratio (ARR) has become a most effectively and commonly used method for screening primary aldosteronism from hypertensive patients. It is known that there is a large variance in ARR value between races and ARR is affected by many factors, such as drugs, posture and serum potassium etc. The objective of this study is to establish the threshold of ARR for screening primary aldosteronism in Chinese hypertensive patients. METHODS: A total of 110 hypertensive patients were recruited and divided into essential hypertension group (n=65) and adenoma/hyperplasia group (n=45) according to the adrenal contrast CT scan. Antihypertensive drugs which can affect ARR such as beta-blockers, dihydropyridine calcium channel blockers (CCBs), ACE inhibitors (ACEIs), angiotensin II receptor blockers (ARBs) and clonidine, were withdrawn for at least 2 weeks. Washout period for diuretics including spironolactone were 4 weeks. Non-dihydropyridine calcium channel blockers (slow released verapamil) and/or alpha-blocker (terazosin) are allowed for controlling blood pressure when needed. If the serum potassium value<3.6 mmol/L, an oral potassium supplement was prescribed. After keeping upright position for 2 hours, blood samples were drawn for PRA and PAC measurement between 9:00AM-10:00AM. RESULTS: ARR was 100.00+/-48.65 (14.19-285.16) pg/ml vs ngxml-1xh-1 in patients with essential hypertension and 699.33+/-213.33 (185.8-2150) pg/ml vs ngxml-1xh-1 in patients with adenoma/hyperplasia. ARR value was greater than 240 in 42 out of 45 patients (93.3%) with adenoma/hyperplasia and was less than 240 in 59 out of 65 (90.7%) patients with essential hypertension. We used ARR 240 as the cut-off threshold for screening primary aldosteronism in another 178 hypertensive patients and ARR was greater than 240 in all 15 patients with confirmed primary aldosteronism. CONCLUSION: It is suitable to use upright ARR 240 as a cut-off threshold for screening primary aldosteronism in Chinese hypertensive patients.

Clinical experience with the adrenal scanning agents iodine 131-19-iodocholesterol and selenium 75-6-selenomethylcholesterol.

Adrenocortical scintigraphy with iodine 131-19-iodocholesterol or selenium 75-6-selenomethylcholesterol was performed in 94 patients with proven or suspected adrenal disease. According to the final diagnosis, 36 patients suffered from primary aldosteronism, 33 from Cushing's syndrome, 8 from low renin hypertension, 6 from nonfunctioning adrenal tumour, 4 from simple obesity, 3 from adrenal metastases, 1 from congenital adrenal hyperplasia, 1 from virilizing adrenal adenoma, 1 from extraadrenal phaeochromocytoma, 1 from ganglioneuroma. Surgical confirmation of the diagnosis was obtained in most cases. With a few exceptions, the scintigraphy results were consistent with the final diagnosis. The two tracers were equally effective adrenal scanning agents. Tracer concentration was measured in a number of surgical specimens, mostly from patients given selenocholesterol. This measurement in surgical samples has not been reported in previous studies with this agent. The results provided a direct validation of uptake measurements in vivo. The data, collected over a 17-year period, demonstrate that despite the advent of new imaging techniques, adrenal scintigraphy that gives both functional and morphologic information still has an important role in the diagnosis of adrenal disease.