Screening for Primary Aldosteronism: Implications of an Increased Plasma Aldosterone/Renin Ratio

Abstract

Background: The value of the ratio of plasma aldosterone concentration (aldosterone) to plasma renin activity (renin) to identify patients at risk for primary aldosteronism is controversial. We determined the sensitivity, specificity, and predictive value of the ratio to identify combinations of renin and aldosterone compatible with primary aldosteronism. Methods: The ratio was calculated in 505 adults with essential hypertension (143 black women, 82 black men, 122 white women, and 158 white men). We used a conventional cutpoint for an increased ratio (i.e., 20 mL/dL · h). The primary combination of renin and aldosterone considered compatible with primary aldosteronism was increased aldosterone for the concomitant renin, defined as aldosterone in the highest quartile predicted by linear regression on renin. Renin was considered low if it was in the lowest quartile of the sample distribution. Results: The sensitivity of the ratio to identify individuals with increased aldosterone for the concomitant renin was 66% (80% in blacks and 56% in whites; P = 0.009), and the specificity of the ratio was 67% (46% in blacks and 84% in whites; P <0.0001). In 36% of instances of an increased ratio, it was a measure of low renin alone without increased aldosterone for renin (32% in blacks and 45% in whites; P = 0.072). The positive predictive value of the ratio to identify individuals with increased aldosterone for the concomitant renin was 34% (49% in whites and 27% in blacks; P <0.002). Conclusion: The aldosterone/renin ratio lacks sensitivity and specificity and has only a modest predictive value for combinations of renin and aldosterone that are compatible with primary aldosteronism.

Obesity and the diagnostic accuracy for primary aldosteronism

“…The comparison of ARR accuracy and predictability between different studies is limited as a result of differences in inclusion criteria, sampling conditions (supine or upright), and ARR cutoff values. This is reflected by the wide range of PPV (34%–75%), NPV (84.8%–88.0%), and area under the receiver operating characteristic curve (0.80–0.97) reported to date. Only a few studies have performed confirmatory testing for negatively screened patients .…”

Prevalence of primary aldosteronism in primary care: a cross-sectional study

“…In this research a relatively low cut-off value for the ARR of >40 pmol/ mU was deliberately used with the aim to miss as few PA patients as possible. 47,48 To prevent too many false-positive test results due to low renin hypertension, the criterion of a minimum plasma aldosterone level of 400 pmol/l was added. 49 However, the cutoff for the SIT in this study was quite strict.…”

Phenotypic consequences of variation across the aldosterone synthase and 11‐beta hydroxylase locus in a hypertensive cohort: data from the MRC BRIGHT Study

“…The importance of aldosterone excess in hypertension and cardiovascular disease is increasingly recognized. Numerous studies, worldwide, report a high prevalence of primary aldosteronism (PA) in cohorts of hypertensive patients 1–7 mainly due to increasing use of the aldosterone to renin ratio (ARR) as a screening tool. Large‐scale clinical trials confirm that aldosterone contributes significantly to the pathophysiology of cardiac failure 8 and that use of aldosterone‐receptor antagonists as additional treatment in moderate to severe heart failure results in significant improvements in cardiovascular mortality 9,10 .…”