What are the indications for coronary artery bypass surgery and mitral valve replacement?

       Indications for coronary artery surgery: 1. Left coronary artery trunk lesion stenosis >50%.  2.Stenosis of the proximal segment of the left anterior descending branch and gyrus branch greater than or equal to 70%.  3.3-branch coronary artery lesion with left ventricular ejection fraction less than or equal to 50%.  4.Stable angina is not responding well to medical treatment, affecting work and life.  5.Severe ventricular arrhythmias with left main or 3-branch lesions.  6, Failure of interventional therapy still has angina or abnormal hemodynamics.  Indications for mitral valve replacement: 1, severe leaflet and subvalvular structural calcification, malformation, and inappropriate separation.  2, mitral valve stenosis combined with obvious mitral valve closure insufficiency.