Applying an overnight 1-mg dexamethasone suppression test reduced the equivocal aldosterone-to-renin ratio rate by 24.5 percentage points (from 39% to 18%) compared to basal testing.
Cohort (n=67)
No
Does overnight 1-mg dexamethasone suppression improve diagnostic interpretability of ARR in primary aldosteronism screening for patients on interfering drugs?
Overnight 1-mg dexamethasone suppression reduces equivocal aldosterone-to-renin ratio results by 24.5 percentage points in patients undergoing primary aldosteronism screening while on interfering medications.
Absolute Event Rate: 18% vs 39%
Absolute Risk Reduction: 24.5%
Objective: Primary aldosteronism (PA) screening rates are poor, partly due to the fact that modifying RAAS-interfering therapy is problematic. PA diagnostic cutoffs (off interfering medications) after 2-day 2 mg/d dexamethasone (DXM) intake were shown to be superior to conventional ones in several studies by Piaditis Markou, Gouli et al. An ARR of 20 ng/mIU off interfering therapy was shown to be equivalent to 10 ng/mIU on such therapy by Li et al. (Endocrine, 2024). The ODEPRASC study aims to establish screening thresholds that provide a 25% greater interpretability than conventional ARR determination in patients on interfering drugs by applying the overnight 1-mg DXM suppression test. Design and method: ODEPRASC is a single-center, ongoing, prospective study (NCT06740838) including a development and temporal validation cohort (both n=80). Participants are recruited in an endocrine clinic among adrenal incidentaloma patients with an indication for PA screening, with renin below the ULN (RIA), who are viable for medication switch. ARR is determined pre- and post-DXM on and off interfering drugs. Permissive ARR thresholds have been adopted depending on interfering medications: -positive: at least 20 ng/mIU for most patients if Ald exceeds 6 ng/dl, -negative: below 10 ng/mIU in most patients, below 8 on diuretics and off beta-blockers, below 25 ng/mIU on beta-blockers and off diuretics; otherwise equivocal. Results: So far, data of 67 patients have been obtained and analyzed. ACE-inhibitors or angiotensin II receptor blockers were used by 40 (59.7%), beta-blockers: 28 (41.8%), diuretic 22 (32.8%). While, basally, ARR was equivocal in 39%, negative in 33%, positive in 28% of patients, post-DXM ARR was equivocal in only 18% of patients. The PA diagnosis could be verified in 61 patients: it was made in 21 patients (34.4%) and ruled out in 40 patients (65.6%).Conclusions: Diagnostic accuracy measures revealed clear clinical benefit of applying overnight DXM intake on ARR interpretation: a 24.5 percentage point reduction in equivocal ARR rate. The ODEPRASC study will most likely not generate all-encompassing criteria; however, it is anticipated to provide evidence for simplified (by avoiding medication modification), yet more useful PA testing.
Kmieć et al. (Fri,) conducted a cohort in Primary aldosteronism (n=67). Overnight dexamethasone suppression test vs. Conventional basal ARR determination was evaluated on Equivocal aldosterone-to-renin ratio (ARR) rate. Applying an overnight 1-mg dexamethasone suppression test reduced the equivocal aldosterone-to-renin ratio rate by 24.5 percentage points (from 39% to 18%) compared to basal testing.