Cardiac Effects of Mineralocorticoid Receptor Antagonism After Hypertensive Disorders of Pregnancy

Preeclampsia, a condition marked by hypertension and systemic endothelial/microvascular dysfunction in late pregnancy, affects 8% of childbearing U.S. women and is associated with two-fold risk of future material cardiovascular disease (CVD). The American College of Cardiology and American Heart Association now recognize preeclampsia as a sex-specific CVD risk factor to guide prescription of preventive statin therapy. Beyond this focused recommendation, however, specific strategies for CVD risk reduction in women with preeclampsia are not yet established. Recent preclinical evidence suggests that preeclampsia induces vascular smooth muscle cell mineralocorticoid receptor (MR) sensitivity that persists postpartum, promoting hypertension and CVD. Although MR signaling is known to underlie hypertension, MR activation also promotes cardiovascular, kidney, and metabolic disease via effects that are partially independent of blood pressure. Work by this team has implicated MR signaling in coronary microvascular dysfunction, a known predictor of heart failure with preserved ejection fraction (HFpEF) and CVD mortality. The central hypothesis is that, among women with prior preeclampsia who subsequently develop chronic hypertension, MR blockade will promote favorable cardiac remodeling and improve coronary microvascular function, independent of changes in blood pressure, and thereby reduce CVD risk in affected women. To test this hypothesis, the investigators propose a randomized, double-blind clinical study in humans. Women aged \<55 years with a history of preeclampsia, current chronic hypertension, and concentric left ventricular remodeling will be randomized 1:1 to receive eplerenone (mineralocorticoid receptor antagonist) or chlorthalidone (thiazide-like diuretic) with potassium supplementation for 48 weeks, targeting equivalent blood pressure control in both groups using daily home blood pressure measurement and 24-hour ambulatory blood pressure monitoring. The investigators will measure coronary microvascular function (myocardial flow reserve, i.e., hyperemic stress/rest myocardial blood flow) quantified by cardiac positron emission tomography (PET/CT) and cardiac structure and function by cardiac ultrasound at baseline and 48 weeks. It is expected that, compared with chlorthalidone, eplerenone will yield greater improvements in coronary microvascular function and myocardial diastolic function after 48 weeks of treatment. If the hypotheses are affirmed, these findings would support the targeted use of MR antagonists much earlier than recommended by current guidelines for the management of hypertension to more effectively prevent HFpEF and other CVD among women with a history of preeclampsia.