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Background Satisfactory tools to preclude low-risk patients from intensive diagnostic testing for primary aldosteronism (PA) are lacking. Therefore, we aimed to develop a decision tool to determine which patients with difficult-to-control hypertension have a low probability of PA, thereby limiting the exposure to invasive testing while at the same time increasing the efficiency of testing in the remaining patients. Methods Data from consecutive patients with difficult-to-control hypertension, analysed through a standardized diagnostic protocol between January 2010 and October 2017 (n = 824), were included in this cross-sectional study. PA was diagnosed by a combined approach: 1) elevated aldosterone-to-renin ratio (> 5.0 pmol/fmol/s), confirmed with 2) non-suppressible aldosterone after standardized saline infusion (≥280 pmol/L). Multivariable logistic regression analyses including seven pre-specified clinical variables (age, systolic blood pressure, serum potassium, potassium supplementation, serum sodium, eGFR and HbA1c) was performed. After correction for optimism, test reliability, discriminative performance and test characteristics were determined. Results PA was diagnosed in 40 (4.9%) of 824 patients. Predicted probabilities of PA agreed well with observed frequencies and the c-statistic was 0.77 (95% confidence interval (95%CI) 0.70–0.83). Predicted probability cut-off values of 1.0–2.5% prevented unnecessary testing in 8–32% of the patients with difficult-to-control hypertension, carrying sensitivities of 0.98 (95%CI 0.96–0.99) and 0.92 (0.83–0.97), and negative predictive values of 0.99 (0.98–1.00) and 0.99 (0.97–0.99). Conclusions With a decision tool, based on seven easy-to-measure clinical variables, patients with a low probability of PA can be reliably selected and a considerable proportion of patients with difficult-to-control hypertension can be spared intensive diagnostic testing. more...

Introduction: Adrenal venous sampling is useful for discriminating unilateral and bilateral hypersecretion in patients with primary aldosteronism, but it is relatively invasive. To determine the site of hypersecretion more non-invasively, we evaluated predictors of unilateral hypersecretion. Materials and methods: We evaluated the baseline characteristics and the results of confirmatory tests of 123 patients with primary aldosteronism who underwent adrenal venous sampling. Results: Unilateral hypersecretion was identified in 22.0%. The plasma aldosterone concentration and aldosterone–renin ratio were significantly higher and serum potassium concentration and plasma renin activity were significantly lower in patients with unilateral hypersecretion. Plasma aldosterone concentrations after captopril challenge test, saline infusion test and rapid adrenocorticotropic hormone stimulation test were significantly higher among patients with unilateral hypersecretion. The plasma aldosterone concentration reduction ratio in saline infusion test and plasma aldosterone concentration elevation ratio during rapid adrenocorticotropic hormone stimulation test were significantly higher in patients with unilateral hypersecretion. However, areas under the curve for these parameters were not superior to the values after confirmatory tests. Conclusions: The plasma aldosterone concentration values after captopril challenge test, saline infusion test and rapid adrenocorticotropic hormone stimulation test were useful for identifying patients with unilateral hypersecretion. However, value changes or ratios during confirmatory tests are less useful for this aim. more...

Einleitung und Fragestellung: Der Kochsalzinfusionstest (KIT) ist der am häufigsten eingesetzte Bestätigungstest für den primären Hyperaldosteronismus (PA) an den Zentren, die an das Deutsche Conn-Register angeschlossen sind. Die KIT-Ergebnisse werden in diesen Zentren wie folgt beurteilt: post-KIT Aldosteronwerte >50 ng/l bestätigen die Diagnose „primärer Hyperaldosteronismus“ und Werte 100 ng/l post-KIT (n=88). Bei 46 von 80 adrenalektomierten Patienten lagen Ergebnisse der genetischen Testung auf Mutationen vor. Ergebnisse: Die Patientengruppe mit post-KIT Aldosteronspiegeln >100 ng/l hatte eine signifikant kürzere Hypertoniedauer (7,5 vs. 11,7 Jahre (Median), p=0,014), höhere systolische Blutdruckwerte (151±16 vs. 143±17 mmHg, p=0,036), niedrigere Kaliumspiegel im Serum (3,3±0,6 vs. 3,5±0,4 mmol/l, p=0,006), höhere Proteinausscheidung im 24 h Urin (7,4 vs. 5,4 mg/dl (Median), p=0,012) und wies einen höheren Frauenanteil auf (p=0,038). Diese Patientengruppe war öfter von einer unilateralen Erkrankung (p100 ng/l hatten einen signifikant höheren Aldosteron-Renin-Quotienten (ARQ) prä- und post-KIT. Die Analyse der unilateralen Fälle zeigte einen signifikant höheren ARQ prä- und post-KIT im Vergleich zu bilateralen Fällen. Die ARQ prä- und post-KIT nahmen kontinuierlich vom Outcome-Status „geheilt" in Richtung „keine Besserung" ab (p=0,048 und 0,041). Gegensätzlich verhielten sich die Reninspiegel prä-KIT: diese stiegen in Richtung „keine Besserung" an (p=0,007). Diskussion: Wir zeigten, dass Patienten mit post-KIT Aldosteron Werten >100 ng/l eine schnellere und progressivere Form von PA zu haben scheinen, häufiger verursacht durch unilaterale Erkrankung mit größeren Tumoren. Trotzdessen scheinen diese Patienten verglichen mit der Subgruppe 1 mit post-KIT Aldosteronwerten 50-100 ng/l ein besseres Outcome zu haben: Verbesserung nach Adx in 77% vs. 50% der Patienten (p=0,038) und tendenzielle Verbesserung nach medikamentöser Therapie in 82% vs. 71% der Patienten (p-Wert nicht signifikant)., Objective: The most widely used confirmatory test for primary aldosteronism (PA) in Germany is the saline infusion test (SIT). SIT results are judged as follows: post-test aldosterone levels 50ng/l confirm PA. We hypothesized that post SIT aldosterone concentrations indicate the severity of PA and might predict outcome. Methods: 256 PA patients of the German Conn Registry prospectively underwent SIT and were re-evaluated every 6 to 12 months following treatment. The data of 126 patients with complete follow up of 1.2±0.3 years after diagnosis were analyzed. Patients were divided into two groups with post-SIT aldosterone levels of 50-100ng/l (n=38) and of >100ng/l (n=88). In 46 of 80 patients who underwent adrenalectomy adrenal tissue was available for genetic testing. Results: Patients with post- SIT aldosterone levels of >100ng/l had a significantly shorter duration of hypertension (7.5 vs. 11.7 years (median), p=0.014), higher systolic blood pressure (151±16 vs. 143±17 mmHg, p=0.036), lower serum potassium (3.3±0.6 vs. 3.5±0.4 mmol/l, p=0.006), higher 24h urine protein excretion (7.4 vs. 5.4 mg/dl (median), p=0.012), and were more often female (p=0.038). They showed more often unilateral disease (p100ng/l had significantly higher aldosterone-renin-ratio (ARR) pre and post SIT. Analysis of unilateral PA showed also a significantly higher ARR pre and post SIT compaired with bilateral PA. ARR pre and post SIT decreased continuously from the outcome status "cured" towards the outcome status "no improvement" (p=0.048 and 0.041). In contrast renin concentrations pre SIT increased continuously towards the outcome status "no improvement" (p=0.007). Conclusions: PA patients with post-SIT aldosterone levels of >100ng/l have a more rapid development of PA caused more frequently by unilateral disease with larger APAs. However, this group of patients may have a significantly better outcome following specific treatment: outcome improvement after adrenalectomy in 77% vs. 50% (p=0.038) and a trend to improvement after medical therapy in 82% vs. 71% ( p-value not significant). more...