In the patients with heart failure and preserved EF we will measure the effects of Spironolactone therapy on them based on clinical and laboratory findings and echocardiography to find out how it can help them to improve the quality of their life and to reduce in rehospitalization ,any complications and overall costs. This study is a prospective randomized double-blind clinical trial with placebo, phase 2, and single control center and will be done on 60 patients with symptomatic heart failure that have any EF equal to or greater than 45%, and required hospitalization in ICU. Exclusion criteria are serum creatinine > 2.5 mg/DLit in males and > 2 mg/DLit in females or GFR < 30ml/min/1.73 m2 and serum potassium> 5.5 mEq/L. Patients are divided randomly to two groups (based on the right first digit of national code): Intervention group (20 patients) and control group (40 patients). In the intervention group, we will start with 12.5 mg spironolactone tablets daily and if there is no increase in creatinine and potassium after two weeks it will be increased to 25 mg daily. The control group will receive placebo. In both groups we will check clinical characteristics and laboratory parameters (NT-proBNP, sodium, potassium, troponin, hemoglobin, creatinine, uric acid) five times (at the time of admission, 72 hours of hospitalization, at discharge, one month and three months after discharge).we will also check heart functional class and echocardiographic criteria (LA size, grade (DD), E / E ', E / A, PAP, RV size, MR (%), deceleration time, Tapse, EF) three times (at the time of admission, one month and three months after discharge) as well as length of stay in ICU, Acute Physiology and Chronic Health Evaluation 2 (APACHE II) score in the first 24 hours of hospitalization. Complications of spironolactone are checked too. All findings will be recorded properly.