Old MI: Preoperative risk assessment

For preoperative risk assessment, the age of a myocardial infarction (MI) is important. Acute MI is defined as occurring within the past 7 days. Recent MI is defined as happening between 7 and 30 days ago. Both acute and recent MIs, along with unstable angina, are considered unstable coronary syndromes and place the patient at considerably higher risk for a perioperative cardiac event. According to the 2014ACC/AHA Guidelines for Perioperative Cardiovascular Evaluation and Care for Non-Cardiac Surgery, the following conditions should prompt delay of elective non-cardiac surgery for further assessment and treatment:

Evaluate and Treat Before Elective Non-cardiac Surgery

1. Unstable coronary syndromes
2. Decompensated heart failure
3. Significant arrythmias
4. Severe valvular disease

Having an older MI (i.e. > 30 days ago) is a clinical risk factor for perioperative cardiac morbidity, falling under one of the variables of the (Lee) Revised Cardiac Risk Index.

Revised Cardiac Risk Index Variables:

1. History of ischemic heart disease
2. History of congestive heart failure
3. History of cerebrovascular disease
4. Insulin therapy for diabetes
5. Preoperative serum creatinine > 2.0 mg/dL
6. High-risk type of surgery

Unless the patient with an old MI has at least 2 more of the above risk factors, and either poor (<4 METs) or unknown functional capacity, surgery should proceed without further workup.