Evaluating the Effect of Spironolactone on Hypertrophic Cardiomyopathy

Hypertrophic Cardiomyopathy (HCM) is the most common hereditary heart disease with high mortality. Heart failure is the most common complication (about 50% incidence) in these patients. However, it is lack of efficiency medicine to treat heart failure for HCM patients. Recent studies found fibrosis was common in HCM patients and it was progressive with aging. Late gadolinium enhancement cardiac magnetic resonance (LGE-CMR) is a gold standard to measure the left ventricular(LV) fibrosis extent and been proven to be useful in HCM patients. Aldosterone plays an important role in the development of fibrosis. Meanwhile, a few studies suggested that aldosterone might participate the development of fibrosis in HCM patients. Spironolactone, a mineralocorticoid receptor antagonist, has been proven its effect on inceasing the survival of the heart-failure patients with the eject fraction lower than 35%. Thus, the investigators hypothesize that fibrosis is one important reason of heart failure for HCM patients. The purpose of this study is to investigate whether small dosage and early prescription of spironolactone to HCM patients can relieve and/or reverse the fibrosis progress and improve patients' symptoms. This study is a multicenter, randomized, controlled and open-label study being conducted in 4 centers in Shanghai, China. The primary objective of the study is to evaluate the efficacy of spironolactone on relieving the LV fibrosis in HCM patients. This study plans to recruit 260 participants with definite HCM diagnosis. Then these participants will be randomized to two groups-- "control group "(not taking spironolactone) and "spironolactone group" (taking 20mg spironolactone orally and daily). LGE-CMR, echocardiography, 24-hour Holter, electrocardiography (ECG), and blood test (including hemoglobin, creatitine, potassium, liver enzymes, proBNP, TnT, angiotensin and aldosterone) will be performed before random allocation and after 2 years. LGE-CMR will be used to mea