I m a 57 year old man who has recently been prescribed 25mg , once daily , metoprolol er succinate by a cardiologist. I ve never had a heart attack , not diagonised high blood pressure , or experience chest pain. I m in 12 year remission of membraneous nephritis. Recent echocardiogram results came back with mildly reduced heart function and a score of 45. Could I endanger my kidneys , and will this drug improve my heart function? Thanks for your consideration , Nick.