Preanesth eval: Cardiac

Pre-operative cardiac risk stratification is a common and important topic for anesthesiologists. There are several risk calculators in use; both patient factors and surgery factors play into overall risk of a major adverse cardiac event (MACE).

The two most commonly used and data-driven approaches to estimating risk of a major cardiovascular event in the perioperative period are the RCRI (Revised Cardiac Risk Index) and the NSQIP database calculator. RCRI will determine risk of a major cardiovascular event (ventricular fibrillation, primary cardiac arrest, pulmonary edema, myocardial infarction, complete heart block) based upon:

• Procedure (high risk or vascular procedures)
• Patient history of ischemic heart disease, congestive heart failure, or CVA, respectively;
• Insulin-dependent diabetes mellitus
• Pre-operative creatinine greater than or equal to 2.0.

It will then assign a risk percentage based on the number of positive risk factors:

• 0: 0.4%
• 1: 0.9%
• 2: 6.6%
• 3 or more: 11%

Taking this risk stratification into consideration, we can then use the AHA/ACC algorithm for determining overall risk and consideration of further testing.

For a patient scheduled for surgery with known or suspected risk factors for CAD:

1. Determine if the case represents an emergency. If yes, proceed to surgery; if no, continue to step 2.
2. Determine if the patient is having an MI/having ACS. If yes, treat as appropriate. If no, proceed to step 3.
3. Determine risk of MACE using clinical/surgical risk calculation (RCRI, NSQIP).
   1. If less than 1% (low risk), proceed to surgery
   2. If greater than 1%, proceed to 4.
4. Determine the patient’s functional capacity using metabolic equivalents.
   1. If greater than or equal to 4, patient can proceed to surgery
   2. If less than 4, proceed to step 5
   3. If unknown, proceed to step 5
5. For patients with poor or unknown functional capacity, determine whether further testing will actually change perioperative management or change decision making.
   1. If no, then proceed to surgery
   2. If yes, then obtain pharmacologic stress testing; proceed to 6.
6. If stress test is:
   1. Positive: Consider coronary revascularization
   2. Negative: Proceed to surgery.