Hello, Based on the severity of the blockage and arteries affected, I agree that bypass surgery can be the better choice for your father. Certain medications for atherosclerotic/ischemic heart disease in general which help decrease mortality and morbidity includes Aspirin+/- clopidogrel (which works as antiplatelets preventing cardiac events), beta blockers like Metoprolol or Carvedilol OR calcium channel blockers like Amlodipine (which decreases the work of the heart to decrease oxygen demand hence decreasing pain), statins like Atorvastatin and Rosuvastatin (which helps stabilize the clots and decreases cholesterol levels), ACE-inhibitors like Enalapril or Lisinopril to decrease and prevent cardiac remodeling, and anti anginals like nitrates (which dilates coronary vessels to permit blood flow to the cardiac muscle.) However, patients refractory to the said medications above should undergo reperfusion procedures like percutaneous coronary angiography with stenting or even coronary bypass surgery in more severe cases to permit blood flow to affected areas. Well, these procedures really carry risks, but since your father is already refractory to medications, it will put your father with a higher risk of future myocardial infarction, heart failure and even arrhythmias which is more fatal. Therefore, weighing the benefits and the risks of the procedure, I still recommend reperfusion methods like bypass surgery or even multivessel stenting for the improvement of the quality of life and preventing morbidity and mortality. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Daryl Derick B. Dizon, General & Family Physician