XXX Congresso da Sociedade Brasileira de Hipertensão Arterial

Dados do Trabalho


Título

Sensitivity of serum aldosterone and renin measured by immunoassay for primary aldosteronism screening

Introdução

<p>Primary aldosteronism (PA) screening relies on an elevated aldosterone to&nbsp;renin ratio with a minimum aldosterone level, which varies from 10 to 15 ng/dL.&nbsp;Nowadays, most of centers&nbsp;measure direct renin concentration (DRC) using an automated chemiluminescence<br />
assay, but diagnostic cutoffs for aldosterone to DRC ratio (A/DRC) have not been&nbsp;addressed in previous guidelines, which proposed only conversion factors to change&nbsp;DRC to PRA. Recently, a single Italian study investigated the A/DRC cutoff for PA&nbsp;diagnosis in hypertensive patients.&nbsp;An A/DRC cut-off of 2.06 was associated with&nbsp;a negative predictive value of 99% for PA diagnosis. Among the patients with PA, the&nbsp;minimum aldosterone concentration was 14.7 ng/dL.</p>

Objetivo

<p>To evaluate intraindividual variability of serum aldosterone and aldosterone to&nbsp;direct renin concentration ratio (A/DRC) and its impact on PA screening sensitivity.</p>

Método

<p>We retrospectively evaluated the variability of aldosterone measurements in a large cohort of 216 patients with confirmed PA at the Hospital das Clinicas, University of São Paulo.</p>

Resultados

<p>A total of 671 aldosterone and DRC measurements were uniformly&nbsp;performed by the same chemiluminescence assays in a large cohort of 216 patients with&nbsp;confirmed PA and at least two screenings (Figure 1). Aldosterone concentrations varied&nbsp;from 3.9 to 784 ng/dL with a median value of 25 ng/dL. A/DRC ranged from 0.98 to&nbsp;196 with a median value of 6.1 (Figure 2).The median intraindividual coefficient of variability for aldosterone was&nbsp;26.8% (0 to 110%). Almost 40% of the patients had at least one aldosterone level &lt; 15&nbsp;ng/dL, 19.9% had at least two aldosterone levels &lt; 15 ng/dL and 16.2% had mean&nbsp;aldosterone levels &lt;15 ng/dL. A lower cut-off of 10 ng/dL was associated with false&nbsp;negative rates for PA screening of 14.3% for a single aldosterone measurement, 4.6%&nbsp;for two aldosterone measurements and only 2.3% for mean aldosterone levels.&nbsp;Considering the minimum aldosterone, sensitivity of aldosterone thresholds was 85.7%&nbsp;for 10 ng/dL, 78.2% for 12 ng/dL, 61.6% for 15 ng/dL and 44.4% for 20 ng/dL (Figure 3). An&nbsp;A/DRC &gt; 2 had a sensitivity for PA diagnosis of 94.4% and 98.4% when based on one&nbsp;or two assessments, respectively&nbsp;(Figure 4).</p>

<p><img alt="Figure 1. Intraindividual variability of aldosterone concentrations for each of the 216 patients with primary aldosteronism (PA) displayed in ascending order according to the mean aldosterone value. Open dots represent aldosterone concentration for each measurement and red dots represent the mean aldosterone concentration for each case. All patients had at least 2 screenings for PA." src="https://congressosbh2022.com.br/upload/cartas/images/Figure%201(1).jpg" style="width: 1008px; height: 500px;" /></p>

<p><img alt="Figure 2. Intraindividual variability of aldosterone to direct renin concentration ratio (A/DRC) for each of the 216 patients with primary aldosteronism (PA) displayed in ascending order according to the mean A/DRC value. Open dots represent A/DRC for each measurement and red dots represent the mean A/DRC for each case. All patients had at least 2 screenings for PA." src="https://congressosbh2022.com.br/upload/cartas/images/Figure%202.jpg" style="width: 800px; height: 389px;" /><img alt="Figure 3. Frequency of patients with minimum aldosterone concentration above different aldosterone thresholds used for diagnosis of primary aldosteronism (PA). An aldosterone cut-off &gt; 10ng/dL has a sensitivity of 85.7% for PA detection when using only the minimum aldosterone value for each patient. The sensitivity dropped for 61.6% with an aldosterone cut-off &gt; 15 ng/dL." src="https://congressosbh2022.com.br/upload/cartas/images/Figure%203.jpg" style="width: 1164px; height: 500px;" /><img alt="Figure 4. Frequency of patients with minimum aldosterone to direct renin concentration ratio (A/DRC) above different A/DRC thresholds used for diagnosis of primary aldosteronism (PA). An A/DRC cut-off &gt; 2 has a sensitivity of 94.4%% for PA detection when using only the minimum A/DRC value for each patient. The sensitivity dropped for 75.9% with an A/DRC cut-off &gt;3." src="https://congressosbh2022.com.br/upload/cartas/images/Figure%204.jpg" style="width: 1153px; height: 500px;" /></p>

Conclusão

<p>Aldosterone concentrations had a high intraindividual variability in PA&nbsp;patients, which results in an elevated rate of false negative testing in a single screening&nbsp;for PA. If based on two screenings, an aldosterone threshold &gt;10 ng/dL and an A/DRC&nbsp;&gt; 2 had a very high sensitivity for PA diagnosis.</p>

Palavras Chave

Área

Área Clínica

Autores

Ana Alice Wolf Maciel, Thais C Freitas, Gustavo C Fagundes, Janaina P Petenuci, Luiz A Bortolotto, Ana Claudia Latronico, Maria Candida B.V. Fragoso, Luciano F Drager, Berenice B Mendonça, Madson Queiroz Almeida