Your doctor has advised MVR+CABG (Mitral Valve Replacement + Coronary Artery Bypass Grafting), meaning that your father has some valvular disease along with coronary artery disease. This valvular heart disease involving the mitral valve may or may not be related to the coronary artery disease. That can be confirmed only by perusing his Echocardiography report, which you have not provided. MVR will correct his valvular problem and CABG will tackle the blocked arteries. As open heart surgery is a major undertaking, both these diseases are being taken care of in one sitting. Whether or not MVR is required (as per your query) can be decided only after seeing your father’s echocardiography report. The medications are fairly adequate, though an ACE Inhibitor or ARB class of drugs may be added, depending on whether he has a leaking or narrowed valve. Finally it is an absolute dictum that the use of tobacco in any form and at any frequency is detrimental to all round physical and particularly cardiac health. However, this advise is based only on whatever reports you have provided. I think, you should consult your treating cardiologist for any definitive opinion.