Could a common heart drug stop high blood pressure before it starts?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age 30 to 55 years old (inclusive), both genders. * Body Mass Index (BMI) 18.5 to 35.0 kg/m² (inclusive). * Office blood pressure \< 140/90 mmHg, and no use of any antihypertensive drugs. Office blood pressure is measured at 3 visits with 1-week intervals. Patients rest in a seated position for 5 minutes before measurement, measured -times per visit, and the average of the 3 visits must meet the criteria. * Serum potassium in the low-normal or normal range. * Meeting diagnostic criteria: (A) ARR ≥ 2.52 ng/dL per pg/mL (chemiluminescence immunoassay), and PAC ≥ 6 ng/dL (blood sample required in the morning, fasting, after resting in a seated position for 30 minutes); OR (B) Renin ≤ 4.0 pg/mL; OR (C) Positive confirmatory test: Saline infusion test (SIT): PAC \> 6 ng/dL after 4 hours of isotonic saline infusion; OR Captopril challenge test (CCT): PAC suppression rate \< 30% at 2 hours after oral administration of 50mg captopril. * Adrenal thin-slice CT showing unilateral adrenal nodule (\<15 mm in diameter), bilateral adrenal micronodules (\<10 mm in diameter), or negative findings. Exclusion Criteria: * History of diagnosed hypertension, including office BP ≥ 140/90 mmHg, previous use of antihypertensive drugs, or previous ABPM meeting hypertension diagnostic criteria. * Other etiologies of secondary hypertension, including renal artery stenosis, pheochromocytoma, Cushing's syndrome, thyroid dysfunction, glucocorticoid-remediable aldosteronism, etc. * Severe renal insufficiency: eGFR \< 45 mL/min/1.73m² (CKD-EPI formula), or UACR \> 300 mg/g. * Abnormal baseline serum potassium: serum potassium \> 5.0 mmol/L, or serum potassium \< 3.0 mmol/L. * Severe hepatic insufficiency: Child-Pugh Class C, or ALT/AST \> 3 times the upper limit of normal (ULN). * History of allergy to eplerenone or any excipients of the study drug. * Pregnant, lactating women, or subjects planning to become pregnant during the study period. * History of adrenal surgery. * Severe cardiovascular diseases, including New York Heart Association (NYHA) Class IV heart failure, previous myocardial infarction, cerebral infarction, transient ischemic attack (TIA), severe arrhythmia, etc. * Severe comorbidities with an expected life expectancy of \<5 years, including malignant tumors, severe autoimmune diseases, end-stage organ failure, etc. * Use of drugs that cannot be discontinued prior to enrollment: strong CYP3A4 inhibitors (ketoconazole, itraconazole, clarithromycin, nefazodone, etc.); strong CYP3A4 inducers (rifampin, carbamazepine, phenytoin, St. John's wort, etc.); other MRAs, potassium-sparing diuretics (amiloride, triamterene), potassium supplements; systemic glucocorticoids (except physiological replacement), licorice preparations; long-term high-dose NSAIDs. * History of drug abuse, alcohol dependence, or psychiatric illness that may affect study completion, as judged by the investigator. * Participation in other clinical trials or use of other investigational drugs within 3 months prior to enrollment. * Any other conditions that, in the opinion of the investigator, may affect subject safety, trial compliance, or outcome assessment.