Outcomes in unilateral primary aldosteronism after surgical or medical therapy.

CONTEXT: Studies find surgery superior to medications in the treatment of primary aldosteronism (PA). It would be ideal to compare surgical and medical therapy in patients with unilateral PA only, who have the option between these treatment modalities. However, this is challenging as most patients with unilateral PA on adrenal vein sampling (AVS) undergo surgery. OBJECTIVE: To compare outcomes of surgery and medications in patients with confirmed or likely unilateral PA. DESIGN: Retrospective cohort study of 274 patients with PA managed at two referral centres from 2000 to 2019. PATIENTS: 154 patients identified with unilateral PA using AVS and a validated clinical prediction model were treated with surgical (n = 86) or medical (n = 68) therapy. MEASUREMENTS: Primary outcome was a composite incident cardiovascular event comprising acute myocardial infarction, coronary revascularization, stroke, atrial fibrillation or congestive cardiac failure. Secondary outcomes were clinical and biochemical control. RESULTS: Cardiovascular outcomes were comparable, with the surgery group having an adjusted hazard ratio of 0.93 (95% CI: 0.32-2.67), p = .89. Both treatments improved clinical and biochemical control, but surgery resulted in better systolic blood pressure, 133.0 ± 11.7 mmHg versus 137.9 ± 14.6 mmHg, p = .02, and lower defined daily dosages of antihypertensive medications, 1.0 (IQR 0.0-2.0) versus 2.6 (IQR 0.8-4.3), p < .001. In addition, 12 of 86 patients in the surgery group failed medical therapy before opting for surgery. CONCLUSION: In patients with unilateral PA who can tolerate medications, medical therapy improves clinical and biochemical control, and may offer similar cardiovascular protection. However, surgery reduces pill burden, may cure hypertension and is recommended for unilateral PA.

Tolerability and Efficacy of Long-Term Medical Therapy in Primary Aldosteronism.

INTRODUCTION: Patients with primary aldosteronism (PA) have increased cardiovascular risk, and there are concerns about the efficacy of medical therapy. OBJECTIVE: We aimed to assess long-term tolerability and efficacy of medical therapy in PA patients. METHODS: We conducted a retrospective study on 201 PA patients treated with medical therapy (spironolactone, eplerenone, or amiloride) from 2000 to 2020 at 2 tertiary centers. Clinical and biochemical control and side effects were assessed. RESULTS: Among 155 patients on long-term medications, 57.4% achieved blood pressure (BP) <140/90 mmHg, 90.1% achieved normokalemia (48.0% potassium ≥4.3 mmol/L), and 63.2% achieved renin >1 ng/mL/h. Concordance of biochemical control using potassium and renin levels was 49.1%. Side effects were experienced by 52.3% of patients, with 10.3% switching, 22.6% decreasing dose, and 11.0% stopping medications. Risk factors for side effects were spironolactone use, dose ≥ 50 mg, treatment duration ≥1 year, male gender, and unilateral PA. Patients with unilateral PA used higher spironolactone doses vs bilateral (57 vs 50 mg, P < 0.001) and had more side effects (63.2% vs 41.8%, P = 0.008). Forty-six unilateral PA patients who underwent surgery after initial medical therapy experienced improved BP (systolic from 141 to 135 mmHg, P = 0.045; diastolic from 85 to 79 mmHg, P = 0.002). CONCLUSION: Dose-dependent side effects limit efficacy of medical therapy in PA. Future prospective studies should assess the best monitoring strategy for biochemical control during long-term medical therapy. For unilateral PA, surgery remains preferable, yielding better control with less long-term side effects.

Aldosterone-potassium ratio predicts primary aldosteronism subtype.

OBJECTIVE: Prediction models have been developed to predict either unilateral or bilateral primary aldosteronism, and these have not been validated externally. We aimed to develop a simplified score to predict both subtypes and validate this externally. METHODS: Our development cohort was taken from 165 patients who underwent adrenal vein sampling (AVS) in two Asian tertiary centres. Unilateral disease was determined using both AVS and postoperative outcome. Multivariable analysis was used to construct prediction models. We validated our tool in a European cohort of 97 patients enrolled in the SPARTACUS trial who underwent AVS. Previously published prediction models were also tested in our cohorts. RESULTS: Backward stepwise logistic regression analysis yielded a final tool using baseline aldosterone-to-lowest-potassium ratio (APR, ng/dl/mmol/l), with an area under receiver-operating characteristic curve of 0.80 (95% CI 0.70-0.89). In the Asian development cohort, probability of bilateral disease was 90.0% (with APR <5) and probability of unilateral disease was 91.4% (with APR >15). Similar results were seen in the European validation cohort. Combining both cohorts, probability of bilateral disease was 76.7% (with APR <5), and probability for unilateral was 91.7% (with APR >15). Other models had similar predictive ability but required more variables, and were less sensitive for identifying bilateral PA. CONCLUSION: The novel aldosterone-to-lowest-potassium ratio is a convenient score to guide clinicians and patients of various ethnicities on the probability of primary aldosteronism subtype. Using APR to identify patients more likely to benefit from AVS may be a cost-effective strategy to manage this common condition.