Endocrinology & Internal Medicine & Hypertension
Primary hyperaldosteronism (Conn's syndrome)
Primary aldosteronism (PA), first described by Jerome Conn in 1955 based on an aldosterone-secreting adrenal adenoma, is now recognized as the leading identifiable cause of secondary hypertension — accounting for 5 to 10% of all cases of hypertension and up to 20 to 25% of resistant hypertension. Contrary to what Conn’s initial description suggested, the majority of PH (60–70%) is caused not by a unilateral adenoma but by bilateral adrenal hyperplasia (BAH), which responds to medical treatment with mineralocorticoid receptor antagonists. Aldosterone, a steroid hormone secreted by the glomerular zone of the adrenal cortex, acts on the distal convoluted tubule and collecting duct by activating the mineralocorticoid receptor (MCR), stimulating sodium reabsorption and the excretion of potassium and protons—explaining the hypertension, hypokalemia, and metabolic alkalosis associated with HAP. Chronic excess aldosterone also exerts direct deleterious effects on the myocardium, blood vessels, and kidneys—independent of elevated blood pressure—significantly increasing the risk of atrial fibrillation, heart failure, stroke, and nephropathy compared to hypertensive patients without PHE at equivalent blood pressure (Milliez 2005 — Journal of the American College of Cardiology). Diagnosis is based on the aldosterone-to-renin ratio (ARR), the screening test of choice, followed by a confirmatory test and adrenal vein sampling (AVS) to determine the side of origin before any surgical decision is made.
Pathophysiology, etiologies, and clinical presentation
- Physiology of Aldosterone and Mechanisms of Pulmonary Arterial Hypertension: Aldosterone synthesis: glomerular zone of the adrenal cortex → steroidogenic enzymes: CYP11B2 (aldosterone synthase) → final and rate-limiting step → physiological regulation: angiotensin II (RAAS pathway — primary stimulus) + serum potassium (hyperkalemia directly stimulates the glomerular zone) + ACTH (minor role) + ANF (inhibitor) → mechanism of action: binding of aldosterone to the mineralocorticoid receptor (MR) in the principal cells of the distal and collecting tubules → nuclear translocation → induction of transcription of the subunits of the ENaC (epithelial sodium channel) and Na/K-ATPase → Na⁺ reabsorption → K⁺ and H⁺ excretion → volume expansion → increased BP → retrofiltration: volume expansion normally suppresses the RAAS and aldosterone secretion → in PH: autonomous aldosterone secretion → resistant to suppression → low renin (suppressed by volume expansion) → high aldosterone/renin ratio; Extrarenal effects of aldosterone — target organs in untreated PH: myocardium: interstitial fibrosis + left ventricular hypertrophy (LVH) → 3.5× higher risk of AF + heart failure → Milliez 2005 JACC: PAH vs. essential hypertension at equivalent BP → AF ×3.5 + stroke ×3.0 + AMI ×2.4 + vessels: endothelial dysfunction + vascular inflammation + remodeling → ALDOSTERONE AND THE HEART (Pitt 1999 NEJM — RALES trial: spironolactone → reduced mortality in severe heart failure 30% 1-year survival) + kidneys: glomerulosclerosis + albuminuria + renal failure (Rossi 2006 — Journal of the American Society of Nephrology) + brain: increased risk of stroke independent of blood pressure; somatic and germline mutations in HAP: KCNJ5 mutations (Kir3.4 K⁺ channel): most common in adenomas → 40% of Conn’s adenomas → gain of function → depolarization of the glomerular cell → activation of Ca²⁺ channels → aldosterone secretion + CACNA1D mutations (L-type Ca²⁺ channel) + ATP1A1 + ATP2B3 + CTNNB1 → families with genetic HAP: Familial HAP type I (FH-I) — «Glucocorticoid-Remediable Aldosteronism»: CYP11B1/CYP11B2 chimeric gene (unequal meiotic crossover) → aldosterone synthesized under ACTH control → treatment: dexamethasone 0.5 mg/day + Familial HPA type II (FH-II): CLCN2 mutations (Cl⁻ channel) + Familial HPA syndrome type III (FH-III): germline KCNJ5 mutations → severe bilateral hyperplasia → bilateral adrenalectomy sometimes necessary + Familial HPA syndrome type IV (FH-IV): CACNA1H mutations
- Etiologies and prevalence — adenoma vs bilateral hyperplasia: Aldosterone-producing adrenal adenoma (APA): 30–40% of HAPs → unilateral → size 0.5–3 cm → curative treatment via laparoscopic adrenalectomy → somatic mutations in KCNJ5 (40 %) + CACNA1D + ATP1A1 + CTNNB1 → classic Conn’s syndrome: women > men + age 30–60 years + often marked hypokalemia → bilateral adrenal hyperplasia (BAH — idiopathic): 60–70% of BPH cases → bilateral → less marked hypokalemia + lower aldosterone levels + medical treatment with ARB antagonists → mechanism: hyperresponsiveness to angiotensin II + to serum potassium → unilateral hyperplasia (rare — <1 %) : équivalent fonctionnel d'un apa → traitement chirurgical + carcinome surrénalien producteur d'aldostérone très rare masse souvent>4 cm + tumor markers + primary bilateral macronodular adrenal hyperplasia (PBMAH): rare PHA + bilateral nodules visible on imaging; true prevalence — historical underdiagnosis: Douma 2008 — NEJM: multicenter study → PHA in 11.2% of unselected hypertensive patients in specialized centers → Mulatero 2004 — JCE&M: PHA prevalence 4.3–9.5% in hypertension clinics → Schwartz 2023 — Annals of Internal Medicine: PAH underdiagnosed in >90% of cases → only 1 in 20 eligible patients is tested → RAR is performed in fewer than 3% of hypertensive patients in primary care in Canada
- Clinical presentation, biological signs, and screening indications: Classic clinical presentation (Conn 1955): moderate to severe hypertension + frank hypokalemia<3.5 mmol/L) + metabolic alkalosis + polyuria/polydipsia (hypokalemic nephropathy) + muscle weakness + cramps + paresthesias → current presentation (majority of cases): often moderate hypertension + normal serum potassium (60% of HAP patients are normokalemic) + no specific symptoms → diagnosis relies on routine laboratory screening in at-risk groups → laboratory findings: spontaneous hypokalemia (<3,5 mmol/L sous aucun diurétique) → très évocatrice → hypokaliémie induite par les thiazides ou les diurétiques de l'anse → évocatrice → alcalose métabolique (HCO₃⁻ élevé) + aldostérone élevée + rénine basse + RAR élevé + pas d'hypernatrémie franche (rétention Na⁺ mais évasion à l'aldostérone par l'ANF) ; indications de dépistage par le RAR (Endocrine Society Guidelines 2016 — Funder 2016 — JCEM) : hypertension résistante (PA non contrôlée sous 3 antihypertenseurs incluant un diurétique) + hypertension + hypokaliémie spontanée + hypertension + incidentalome surrénalien + hypertension sévère (PA systolique >160 mmHg or diastolic >100 mmHg) + early-onset hypertension ((Under 40 years old) + hypertension + family history of PAH or stroke/early-onset hypertension + hypertension + sleep apnea + hypertension + AFib with no other cause
Diagnosis, lateralization, and treatment
| Diagnostic / treatment step | Methodology and Interpretation | Clinical Data and Follow-up |
|---|---|---|
| Aldosterone/renin ratio (ARR) — screening test Collection Conditions — Interfering Medications — Thresholds — False Positives/Negatives |
Aldosterone-to-renin ratio (RAR) — principle and prerequisites: principle: In HAP → elevated autonomous aldosterone + suppressed renin → high ARR → In essential or renovascular hypertension → activated RAAS → elevated renin → normal or low ARR → Standardized sampling conditions (Endocrine Society 2016 + SFE 2021): patient seated for ≥15–30 minutes → sample collection in a seated position (avoid supine position — reduces renin) → time: preferably in the morning (8–10 a.m.) → correct serum potassium if severe hypokalemia (<3.0 mmol/L) before sampling → normal-sodium diet (no strict sodium restriction — would increase renin and skew the RAR) + no fluid restriction → adjust antihypertensives based on their interference; drugs interfering with the RAR — practical management: drugs that falsely increase the RAR (false positives — inhibit renin + increase aldosterone): beta-blockers → increase RAR (inhibit renin ++) → discontinue if possible 2–4 weeks beforehand + NSAIDs → increase RAR → discontinue if possible + clonidine → discontinue → medications that falsely decrease RAR (false negatives — stimulate renin): ACE inhibitors/ARB-2 → increase renin → may normalize RAR in PAH → discontinue 2 weeks prior if formal screening → dihydropyridine calcium channel blockers (amlodipine + nifedipine): modest effect → may increase renin → discontinue if possible → diuretics (thiazides + furosemide): increase renin → discontinue 4 weeks prior → spironolactone + eplerenone: mask PAH + increase renin → discontinue 4–6 weeks prior → alternative antihypertensives during evaluation: alpha-blockers (prazosin + doxazosin) → do not significantly interfere with the RAR + non-DHP calcium channel blockers (verapamil) → neutral → hydralazine → neutral → practical considerations in clinical practice: if hypertension is severe and the patient cannot stop their medications → interpret the RAR while accounting for interferences → a very high RAR despite renin-increasing medications is highly suggestive of PH; RAR thresholds and aldosterone values: diagnostic RAR threshold (varies by units): RAR ≥30 (ng/dL) / (ng/mL/h) OR ≥750 (pmol/L) / (mU/L) → suggests PHC → according to the 2016 Endocrine Society guidelines → sensitivity 79–99% % + specificity 70–83% % depending on thresholds and methods → concomitant plasma aldosterone: must be >15 ng/dL (416 pmol/L) for the RAR to be interpretable (if aldosterone is very low → renin is undetectable → RAR is artificially elevated without HAP) → renin measured by: plasma renin activity (PRA — ng/mL/h) or direct renin (DR — mU/L or pg/mL) → different methods → different RAR thresholds → verify the laboratory’s units → in Quebec clinical practice: laboratories often use direct renin (IRMA or immunochemiluminescence method) | Interpretation of the RAR and next steps: Positive RAR (≥30 with aldosterone >15 ng/dL) → confirmation via sodium loading test or fludrocortisone test → Negative RAR + strong clinical suspicion (marked hypokalemia + resistant hypertension) → repeat under optimal conditions (discontinuation of interfering medications + correction of potassium levels) → Very high RAR (>100) + very high aldosterone + overt hypokalemia: high probability of primary aldosteronism (PA) → some experts proceed directly to imaging + CVS without formal confirmatory testing (according to the 2016 Endocrine Society guidelines); diagnostic performance of RAR in key studies: Stowasser 2003 — Journal of Hypertension: RAR ≥30 → sensitivity 90% % + specificity 91% % for PAH in a high-risk population → Montori 1998 — Annals of Internal Medicine: meta-analysis → RAR best screening test → superior to aldosterone alone or serum potassium → Schwartz 2023 — Annals of Internal Medicine: modeling → if RAR were routinely performed in all hypertensive patients → 15,000 additional strokes prevented/year in the United States |
| HAP confirmatory tests Oral salt load — Saline infusion — Fludrocortisone test — Captopril test |
Four validated confirmatory tests (Endocrine Society 2016) — general principle: to demonstrate autonomous aldosterone secretion (not suppressed by volume expansion or RAAS-blocking agents); oral sodium loading test (most commonly used in outpatient settings): high-sodium, high-chloride diet: 5–6 g of NaCl/day × 3 days → 24-hour aldosteronuria on the 3rd day → result: >12–14 µg/24h (33–39 nmol/24h) → confirms primary aldosteronism → associated measurements: 24-hour cortisoluria (to rule out hypercortisolism) + kaliuria + serum electrolyte panel → contraindications: severe renal failure + heart failure + severe uncontrolled hypertension + cardiac arrhythmia + risk of severe hypokalemia; intravenous saline infusion (test performed during hospitalization or as an outpatient): 0.9% NaCl % 2 L over 4 hours → plasma aldosterone at the end of the infusion → result: aldosterone >10 ng/dL (277 pmol/L) → confirms primary aldosteronism (PA) → aldosterone <5 ng/dL → excludes PA → gray zone: 5–10 ng/dL → same contraindications as oral sodium loading + contraindicated if atrial fibrillation (AF) + anasarca + malignant hypertension; fludrocortisone test (Florinef test — Endocrine Society 2016: reference method — «gold standard» for confirmation): fludrocortisone 0.1 mg × 4 times daily × 4 days + KCl supplement to maintain serum potassium ≥3.5 mmol/L + normal-sodium diet → plasma aldosterone on day 4 (while seated) → result: aldosterone ≥6 ng/dL confirms HAP → complex logistics + hospitalization or close monitoring → used in referral centers; Captopril test: captopril 25–50 mg orally → aldosterone measured at 1 hour and 2 hours → result: unsuppressed aldosterone (>30% of baseline value) → confirms HAP → less sensitive than other tests → useful if sodium loading tests are contraindicated; Situations where the confirmatory test may be omitted (Endocrine Society 2016): very high RAR + very high aldosterone + documented spontaneous hypokalemia + compatible imaging → very high pre-test probability → some experts proceed directly to CVS + in Quebec practice: most endocrinologists perform a confirmatory test before CVS except in cases of very high probability | Comparative performance of confirmatory tests: Rossi 2007 — Journal of Hypertension: comparison of the 4 tests in 100 patients with confirmed PAH → oral sodium load: sensitivity 96% (%) + specificity 93% (%) → saline infusion: sensitivity 88% (%) + specificity 91% (%) → fludrocortisone: sensitivity 96% (%) + specificity 95% (%) (gold standard) → captopril: sensitivity 73% (%) + specificity 85% (%) → conclusion: fludrocortisone test = most effective but most complex → saline infusion = good compromise for outpatient care → oral sodium challenge = best outpatient test; Quebec diagnostic algorithm (endocrinology centers at CHUM + CHUS + CHU Laval): RAR during consultation → if positive → confirmatory test (often oral sodium load or saline infusion) → if confirmed → adrenal imaging (CT) → CVS if surgical candidate → adrenalectomy if unilateral APA confirmed by CVS → MR antagonists if bilateral HBS |
| Adrenal Imaging and Catheterization of Adrenal Veins (CVS) TDM — adenoma — incidentaloma — CVS — lateralization — selectivity index |
Adrenal CT scan — role and limitations: indications: after laboratory confirmation of PHA → anatomical localization + screening for carcinoma (large size) → technique: thin slices (1–2 mm) + non-contrast + arterial + venous phases → measurement of densities (HU) + nodule dimensions → results and interpretation in PHA: typical adenoma: hypodense nodule (<10 HU) <4 cm → rich in intracytoplasmic lipids → APA: often 1–3 cm + homogeneous + density <10 HU → bilateral hyperplasia: normal or slightly enlarged glands + bilateral nodules or glands with increased thickness → normal CT scan (<1 cm thick) + biologically confirmed PAA → does not rule out a microadenoma → major limitations of CT in PAA: sensitivity 78% + specificity 75% for differentiating APA vs. HBS → frequent non-functional incidentalomas (overall prevalence of adrenal incidentalomas: 3–7% after age 50 → may be misleading → nodule visible on CT scan on the side opposite the APA → false lateralization) → Kempers 2009 — Journal of Clinical Endocrinology and Metabolism: meta-analysis → CT scan alone → lateralization error in 25% of cases → leading to adrenalectomy on the wrong side → conclusion: CT scan is NOT sufficient to lateralize PHA before surgery → CVS is essential in ALL patients scheduled for surgery, with rare exceptions; adrenal vein catheterization (CVS) — «gold standard» for lateralization: principle: simultaneous or sequential catheterization of the right and left adrenal veins + inferior vena cava → measurement of aldosterone and cortisol in each vein + in peripheral blood → stimulation with cosyntropin (synthetic ACTH 250 µg IV bolus or continuous infusion at 50 µg/h) → increases the gradient and improves selectivity + calculated indices: selectivity index (SI = adrenal vein cortisol / inferior vena cava cortisol) → SI ≥2 (basal) or ≥3 (post-ACTH) → confirms correct catheterization of the adrenal vein → lateralization index (LI = [Aldo/Cortisol on the dominant side] / [Aldo/Cortisol on the non-dominant side]) → LI ≥4 (post-ACTH) → unilateral APA → surgery → LI <3 → bilateral HBS → medical treatment → gray zone LI 3–4: multidisciplinary interpretation → counter-suppression: [Aldo/Cortisol on the non-dominant side] / [Aldo/Cortisol peripheral vena cava] → value <1 → confirms suppression on the non-dominant side → reinforces lateralization; CVS performed in Quebec: procedure performed by interventional radiology in tertiary centers (CHUM + CHU de Québec + Montreal General Hospital + CHU Sherbrooke) → technical success: 90–95% % in expert centers (major difficulty: catheterization of the right adrenal vein — short + opens directly into the inferior vena cava) → Rossi 2011 — European Journal of Endocrinology: CVS meta-analysis → sensitivity 95% + specificity 100% for lateralization of the HAP → complication rate: <1% (adrenal vein dissection + hematoma + thrombosis) | Situations in which CVS can be avoided (exceptions to the rule): Endocrine Society 2016: CVS optional if: age <35 years + obvious and typical APA on CT scan (>1 cm + density <10 HU + strictly normal contralateral side) + confirmed biochemical HAP → very high probability of unilateral APA → some pediatric centers and experts perform surgery without CVS in these highly selected cases → Küpers 2020 — Journal of the American Medical Association: cohort study → 30% of patients with CT scans showing a unilateral adenoma actually had bilateral HBS on CVS → confirms the need for routine CVS; Adrenal MRI: less widely available than CT for the adrenals → used if CT is inconclusive or radiation should be avoided (young women) → not superior to CT for lateralization → Adrenal NTF (NP-59 — iodocholesterol scintigraphy): very limited availability in Quebec → limited value in routine practice + failed AVS: if CVS cannot be performed or has failed → some centers use functional 3T MRI or 11C-metomidate PET (very limited availability in Canada) as localization alternatives |
| Surgical Management — Laparoscopic Adrenalectomy Unilateral APA confirmed — adrenalectomy — results — biochemical remission — normotension |
Laparoscopic adrenalectomy — indications and technique: Indications: APA or unilateral hyperplasia confirmed by CVS (IL ≥4) + acceptable surgical candidate → standard technique: laparoscopic retroperitoneal or transperitoneal adrenalectomy → posterior retroperitoneal approach: direct access to the adrenal gland + less visceral manipulation + conversion to open surgery: <3 % + operative time: 45–90 min → hospital stay: 1–2 days → essential preoperative preparation: correction of serum potassium (spironolactone 100–400 mg/day × 4–6 weeks pre-op) → correction of hypertension → serum potassium ≥3.5 mmol/L prior to surgery → comprehensive anesthesiological evaluation (cardiovascular risk associated with hypertension and chronic hypokalemia) ; adrenalectomy outcomes in primary aldosteronism (PA): biochemical remission (normalization of aldosterone and RAR): 95–100% of cases → complete hypertensive remission (cure of hypertension without antihypertensive medication): 30–60% of cases depending on the series → significant improvement in hypertension (reduction in the number of antihypertensive medications): 80–100% → predictive factors for complete hypertensive remission after surgery (Aldosteronoma Resolution Score — Zarnegar 2008 — Archives of Surgery): ≤2 antihypertensive drugs pre-op + BMI ≤25 + duration of hypertension <6 years + female gender → ARS score: 0–4 → ARS ≥3: 75% % complete remission → ARS 0: <25 % → PASO study (Hundemer 2018 — Lancet Diabetes and Endocrinology): biochemical remission is nearly constant → persistence of post-op hypertension is linked to pre-existing underlying essential hypertension (chronic irreversible vascular remodeling) → post-surgical follow-up: aldosterone + renin + serum potassium at 1 month + 3 months + 6 months + 1 year → goal: normal aldosterone + renin rebound → normalized RAR → gradual tapering of antihypertensives based on BP → note: persistent post-op hypertension ≠ surgical failure → may be underlying essential hypertension unmasked → do not operate on the contralateral side | Complications of adrenalectomy and postoperative adrenal insufficiency: transient postoperative adrenal insufficiency: common (30–60% of cases) within 1–4 weeks after adrenalectomy → mechanism: chronic suppression of the RAAS axis due to excess aldosterone → the contralateral adrenal gland has a long-standing suppression of the renin-angiotensin-aldosterone axis → recovery time: 1–6 months → presentation: hyperkalemia + orthostatic hypotension + fatigue → treatment: fludrocortisone if symptomatic hyperkalemia + sodium supplementation + close monitoring of serum potassium and blood pressure → educate the patient → corticotropic adrenal insufficiency (rare with unilateral adrenalectomy): occurs if the HPA axis is concomitantly impaired → measure post-op cortisol if symptoms are present → other rare surgical complications: hemorrhage + infection → comparison of surgical outcomes: SOPRANO study (Hundemer 2018 — NEJM Evidence): adrenalectomy vs. spironolactone for APA → adrenalectomy superior for biochemical remission and improved quality of life → SPARTACUS (Dekkers 2016 — Lancet Diabetes and Endocrinology): CVS-guided vs. CT-guided → CVS-guided → better biochemical remission + greater reduction in blood pressure → confirms the indispensability of CVS |
| Medical Treatment — Mineralocorticoid Antagonists Spironolactone — eplerenone — bilateral HBS — side effects — monitoring |
Indications for medical treatment: bilateral adrenal hyperplasia (BAH) → first-line medical treatment → no surgery (bilateral adrenalectomy → permanent adrenal insufficiency) + unilateral APA in patients who refuse surgery or have surgical contraindications → MR antagonists as lifelong medical treatment + genetic forms: FH-I → dexamethasone; spironolactone (non-selective mineralocorticoid antagonist): first-line medication → mechanism: blocks mineralocorticoid action in the collecting duct → corrects hypokalemia + hypertension → RALES trial (Pitt 1999 — NEJM): spironolactone 25–50 mg/day in severe heart failure → 30% reduction in 1-year mortality → confirms the extrarenal beneficial effects of mineralocorticoid antagonism → dosage in acute pulmonary edema: started at 25–50 mg/day → gradual titration up to 100–400 mg/day depending on serum potassium and BP response → goal: serum potassium 4.0–4.5 mmol/L without supplementation + controlled BP → antiandrogenic side effects of spironolactone (non-selective class effects): gynecomastia (men — 10–25% of patients at high doses) + erectile dysfunction + dysmenorrhea + metrorrhagia + mastodynia → dose-dependent effects → main tolerance issue in men → eplerenone: selective MR antagonist → no affinity for androgen and progestin receptors → no gynecomastia → fewer sexual side effects → dosage: 25–50 mg × 2/day (shorter half-life) → EMPHASIS-HF (Zannad 2011 — NEJM): eplerenone in mild to moderate systolic HF → reduced CV mortality + hospitalizations → higher cost than spironolactone → indicated as a second-line treatment if spironolactone is not tolerated or if anti-androgenic effects are unacceptable + finerenone (Kerendia): third-generation non-steroidal MR antagonist → FIDELIO-DKD (Bakris 2020 — NEJM) + FIGARO-DKD (Pitt 2021 — NEJM): nephroprotection + cardioprotection in diabetic nephropathy → no formal indication yet for HAP but currently under evaluation | Biological monitoring under MR antagonists: potassium + creatinine + sodium at 1 week, then at 4 weeks after initiation or dose adjustment → potassium target: 4.0–4.5 mmol/L → risk of hyperkalemia if eGFR <45 mL/min → close monitoring + contraindications to MR antagonists: eGFR <30 mL/min (risk of severe hyperkalemia) + pregnancy (teratogenic — category C/D) + pre-existing hyperkalemia ≥5.5 mmol/L → association with ACE inhibitors/ARBs + renal insufficiency → hyperkalemia + drug interactions: NSAIDs + ACE inhibitors/ARBs + heparin → increase risk of hyperkalemia + additional treatment: additional antihypertensives if necessary (ACE inhibitors or ARBs → synergy with MR antagonists + renal protection) → sodium restriction (<5 g NaCl/day) → potentiates spironolactone's effect → weight loss + exercise → standard hypertension management → blood pressure target: BP <130/80 mmHg (AHA/ACC 2017 + ESC 2020) → long-term follow-up: annual renin-aldosterone ratio + potassium + creatinine + BP + adrenal imaging if progression suspected → CT scan at 2–3 years if initial non-operated nodule; regression of target organ damage under treatment (surgical or medical): LVH: regresses under MR antagonists and after adrenalectomy → Catena 2007 — Hypertension: LVH regression at 12 months + albuminuria: decreases + AF risk: reduced + metabolic risk: spironolactone improves insulin sensitivity (effects on aldosterone in muscle and adipose tissue) |
ℹ️
Primary hyperaldosteronism is massively underdiagnosed: Only 1 in 20 eligible patients are tested in clinical practice (Schwartz 2023 — Annals of Internal Medicine). The aldosterone/renin ratio should be systematically performed in all patients with resistant hypertension, spontaneous hypokalemia, an adrenal incidentaloma, early-onset hypertension, or severe hypertension. A missed diagnosis exposes the patient not only to uncontrolled hypertension but also to the direct cardiovascular effects of excess aldosterone — a 3.5-fold increased risk of AF, a 3.0-fold increased risk of stroke, and a 2.4-fold increased risk of MI compared to hypertensive patients without primary aldosteronism at equivalent blood pressure.
Situations requiring urgent medical assessment
Severe hypokalemia (<2.5 mmol/L) + profound muscle weakness + flaccid paralysis + dysphagia + respiratory distress in a hypertensive patient → paralytic hypokalemia in the context of undiagnosed PAH → emergency → IV potassium correction + urgent VBG + adrenal CT scan → do not correct kaliemia alone without identifying the cause → risk of ventricular fibrillation if kaliemia < 2.0 mmol/L.
Malignant hypertension (BP >180/120 mmHg) + grade III-IV funduscopy (hemorrhages + exudates + papilledema) + signs of target organ damage (rising creatinine + altered consciousness + chest pain) in a patient with hypokalemia → Hypertensive emergency → Emergency stabilization + delayed PAH screening → Do not start spironolactone urgently if kalemia is unknown.
Post-adrenalectomy for PA: hyperkalemia (>6.0 mmol/L) + orthostatic hypotension + nausea + severe fatigue within 2–6 weeks postoperatively Transitory aldosterone adrenal insufficiency + possibly corticotrope → Cortisol + kaliemia + BP assessment as an emergency → Fludrocortisone + sodium supplementation → Avoid hyperkalemic medications (ACE inhibitors + ARBs + NSAIDs + potassium) during the recovery phase.
Consult at Clinique Omicron
Clinique Omicron physicians screen for primary hyperaldosteronism by measuring the aldosterone/renin ratio in at-risk patients, interpret biological results, and coordinate referrals to specialized endocrinology and interventional radiology for adrenal vein catheterization when indicated. Long-term follow-up for patients on mineralocorticoid antagonists is provided at several service points across Quebec and via telemedicine. To book an appointment, visit cliniqueomicron.ca.
The content of this page is provided for informational purposes only and does not replace the advice of a doctor or endocrinologist. The interpretation of the aldosterone/renin ratio must take into account current medications, collection conditions, and laboratory methods used.
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