Idiopathic hyperaldosteronism (IHA) is the most common subtype of primary aldosteronism, typically managed with mineralocorticoid receptor antagonists (MRAs). However, long-term MRA therapy is associated with suboptimal cardiovascular outcomes and adverse effects. Superselective adrenal arterial embolization (SAAE) is a novel minimally invasive alternative, but its long-term efficacy, particularly regarding quality of life and cost-effectiveness, remains underexplored. In this study, 62 patients with bilateral IHA were prospectively enrolled and assigned to two groups: SAAE (n = 42) and MRA therapy (n = 20). Outcomes, including blood pressure, serum potassium, aldosterone-renin ratio normalization, and quality of life (measured by SF-36 and EQ-5D), were assessed at 12 months. A supervised Random Forest model was developed to predict treatment success. A 5-year cost-utility analysis compared SAAE and MRA therapy from a healthcare system perspective. Results showed that SAAE led to greater reductions in blood pressure (mean -27.4 ± 21.3 mmHg systolic, -23.1 ± 17.4 mmHg diastolic) compared to MRA therapy (-15.6 ± 11.4 mmHg systolic, -12.4 ± 10.1 mmHg diastolic, p < 0.001). Clinical success was achieved in 63.2% of the SAAE group, with biochemical remission in 39.6%. SAAE also led to greater improvements in quality of life and demonstrated lower costs and higher quality-adjusted life years (QALYs) compared to MRA therapy. SAAE is a safe, effective, and cost-effective treatment for IHA, offering superior blood pressure control, hormonal normalization, and improved quality of life compared to MRAs. Trial Registration: ClinicalTrials.gov identifier: ChiCTR2200062738.