From the Guidelines
The diagnostic approach to primary hyperaldosteronism should begin with screening using the aldosterone-to-renin ratio (ARR) in patients with hypertension at increased risk, such as those with adrenal incidentaloma, early-onset hypertension, or cerebrovascular accident at a young age, as recommended by the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline 1. The ARR is currently the most accurate and reliable means of screening for primary aldosteronism, with a cutoff value of 30 when plasma aldosterone concentration is reported in nanograms per deciliter (ng/dL) and plasma renin activity in nanograms per milliliter per hour (ng/mL/h) 1. Before testing, patients should have unrestricted salt intake, serum potassium in the normal range, and mineralocorticoid receptor antagonists (e.g., spironolactone or eplerenone) withdrawn for at least 4 weeks 1. Key points to consider in the diagnostic approach include:
- Screening with ARR in high-risk patients
- Confirmation testing with intravenous saline suppression test or oral salt-loading test if the ARR is positive
- Adrenal imaging with CT or MRI to identify potential adenomas
- Adrenal vein sampling to determine if hyperaldosteronism is unilateral or bilateral, especially if surgical treatment is being considered
- Treatment guided by diagnosis, with unilateral disease typically managed surgically and bilateral disease treated medically with mineralocorticoid receptor antagonists like spironolactone or eplerenone 1. It is essential to follow the most recent and highest-quality guidelines, such as the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline, to ensure the best possible outcomes in terms of morbidity, mortality, and quality of life for patients with primary hyperaldosteronism 1.
From the FDA Drug Label
- 4 Primary Hyperaldosteronism Spironolactone tablets are indicated in the following settings: Short-term preoperative treatment of patients with primary hyperaldosteronism. Long-term maintenance therapy for patients with discrete aldosterone-producing adrenal adenomas who are not candidates for surgery Long-term maintenance therapy for patients with bilateral micro or macronodular adrenal hyperplasia (idiopathic hyperaldosteronism).
The diagnostic approach to primary hyperaldosteronism is not directly addressed in the provided drug labels. Key points:
- The labels discuss the treatment of primary hyperaldosteronism with spironolactone.
- They do not provide information on the diagnostic approach to primary hyperaldosteronism. 2
From the Research
Diagnostic Approach to Primary Hyperaldosteronism
The diagnostic approach to primary hyperaldosteronism involves a step-wise process, including:
- Screening: The aldosterone-to-renin ratio (ARR) is used as a screening test due to its high sensitivity and low variability 3
- Confirmatory testing: If the ARR is elevated, confirmatory testing and adrenal imaging are performed to confirm the diagnosis 4, 5, 6, 7
- Subtype differentiation: Adrenal venous sampling is considered the gold standard for differentiating between unilateral and bilateral disease 4, 5, 7
Screening Parameters
The screening parameters for primary hyperaldosteronism include:
- Aldosterone-to-renin ratio (ARR): Calculated from plasma aldosterone and plasma renin activity or direct plasma renin values 3
- Plasma aldosterone level: Must be >240 pmol/l (90 pg/ml) to rule out ARR elevation due to very low renin values 3
- Plasma renin activity or direct plasma renin: Must be measured under standard conditions, including normal dietary salt intake and no antihypertensive drugs that interfere with the renin-angiotensin-aldosterone system 3
Diagnostic Thresholds
The diagnostic thresholds for primary hyperaldosteronism include:
- ARR threshold values: Depend on the units used and a conversion factor (pg to mIU) for direct plasma renin 3
- Plasma aldosterone level: <240 pmol/l (90 pg/ml) on two measurements excludes the diagnosis of primary hyperaldosteronism 3
Further Evaluation and Management
Further evaluation and management of primary hyperaldosteronism include:
- Adrenal imaging: To confirm the diagnosis and differentiate between unilateral and bilateral disease 4, 5, 7
- Adrenal venous sampling: To differentiate between unilateral and bilateral disease and guide surgical or medical management 4, 5, 7
- Surgical or medical management: Depending on the subtype of primary hyperaldosteronism, treatment options include laparoscopic adrenalectomy or mineralocorticoid receptor antagonists 4, 5, 6, 7