When do diagnostic indicators show a high risk of myocardial infarction, and what options are best for a 90 year old female having suffered a prior myocardial infarction, angina, diabetes, high cholesterol, and high blood pressure?

Controlling the risk factors that can be controlled is crucial to try to avoid a recurrent myocardial infarction. So, controlling her blood sugars without having low blood sugar numbers, controlling cholesterol and high blood pressure. These can be controlled with diet and/or medications. In someone this age, there needs to be caution with meds so she should be monitored closely by her doctor.

Since it's already established that this patient has very significant coronary artery disease, we then have to use as diagnostic indicators for high risk of recurrent myocardial infarction, clinical factors, namely unstable symptoms like recurrent& more frequent angina episodes, angina occurring at rest or during sleep,prolonged bouts of angina,increasing otherwise unexplained fatigue or weakness.