CLCNKA (Ka Renal Chloride Channel[ClC-Ka]) Polymorphism Effects on Hypertrophy Regression

Inclusion Criteria:

1. Caucasians with hypertension who are homozygous for the ClC-Ka Gly/Gly83 and the ClC-Ka Arg/Arg 83 allele.
2. Male or non-pregnant female aged 40 to 80 years.
3. Hypertension, defined as currently taking high blood pressure medications or not on medications but having SDP >140 or DBP >90.
4. Ejection fraction > 50% by any method within 6 months of the screening visit.
5. The Investigator must obtain written informed consent before the subject is screened for the study.
6. Subject should be on stable dose of ACE or ARB at moderate dosing for at least 4 weeks before randomization.

Exclusion Criteria:

1. History of heart failure with preserved or depressed ejection fraction.
2. Creatinine clearance of < 45 mL/min based on the Cockcroft-Gault formula (Appendix C).
3. Pregnancy
4. Life expectancy less than 12 months.
5. Planned cardiac surgery or percutaneous cardiac intervention within 3 months.
6. Serum potassium >5.5 mEq/L.
7. History of hyperkalemia (K>6.0 mEq/L) with eplerenone or spironolactone.
8. Myocardial infarction or stroke within 3 months of screening.
9. Evidence of clinical instability (hypotension, arrhythmias, unstable angina etc.).
10. Subjects on or requiring K-sparing diuretics or spironolactone.
11. Concomitant use of potent inhibitors of CYP3A4 including ketoconazole, itraconazole, nefazodone, troleandomycin, clarithromycin, ritonavir, and nelfinavir or any drug noted in the Contraindications, Warnings or Precautions sections of their labeling to be potent CYP3A4 inhibitors
12. Known hypersensitivity to eplerenone or spironolactone.
13. Evidence of current alcohol or drug abuse Severe organic disorders or surgery or disease of the gastrointestinal tract that in the opinion of the Investigator may interfere in the absorption and elimination of the study drug.
14. Psychoses or behavioral conditions that in the opinion of the Investigator would limit study compliance.
15. Subjects who have received any investigational medication or used any investigational device within 30 days prior to first dose of study drug or subjects actively participating in any investigational drug or device study.