RecruitingPhase 4Drug trialMineralocorticoid Receptor, Coronary Microvascular Function, and Cardiac Efficiency in HypertensionThe investigators' goal is to show that in hypertensive men and women with left ventricular hypertrophy (LVH) treatment with a mineralocorticoid receptor (MR) antagonist, versus a thiazide-like diuretic, will improve coronary microvascular function and cardiac efficiency, which will associate with improvements in LV structure and function. The investigators will achieve this through a randomized, controlled, basic experimental study involving humans (BESH).