The prevalence of cardiovascular disease and the death rate associated with it rises sharply after age 45, an age when the incidence of
noncardiac surgeries is also increasing, and approximately one-third
of the 25 million surgical procedures done annually are performed
in patients with cardiovascular diseases. Cardiac deaths and nonfatal
myocardial infarction (MI) occur in about 0.2% of all cases
of general anesthesia and surgery (about 500,000 events annually).
Cardiac deaths account for approximately 40% of all perioperative
mortality, the same proportion as sepsis, although in many cases
the cause of death is multisystem organ failure. These figures underestimate
the total effect of cardiovascular diseases because another 500,000
persons a year suffer nonfatal MI, unstable angina, or congestive
heart failure (CHF) perioperatively, prolonging both their time
in the intensive care unit and the total hospital stay.
Although there is great potential to reduce perioperative cardiovascular risk, it is also impractical, unnecessary, and potentially harmful
to perform cardiovascular testing in all patients prior to noncardiac
surgery. Therefore, it is important to determine perioperative risk,
decide whether cardiac testing is appropriate, and to provide prophylactic
treatment to reduce risk.
An individual patient’s preoperative risk profile depends on three main factors: the patient’s history, current medical and functional status, and the type of surgery. Preoperative electrocardiography
can detect arrhythmia and prior silent MI, but it rarely changes management.
Table 36–1 lists cardiac risk based on type of noncardiac surgery. In the evaluation of perioperative patients, understanding the nature of the surgery is of prime importance.
Is this an emergency surgery? If yes, the clinician should advise
to proceed with the surgery and evaluate the patient’s
cardiac risk postoperatively. On the other hand, if the patient
is young, without systemic disease, and undergoing a minor surgery
or procedure, the clinician should advise to proceed with surgery
without further cardiac workup. However, most patients who require
perioperative cardiac consultation are not so straightforward. In
these patients, there are three algorithms that can help identify
perioperative risk and the need for further cardiac testing.
Table 36–1. Cardiac Risk Stratification for Noncardiac Surgical Procedures According to ACC Guidelines. |Favorite Table|Download (.pdf)
Table 36–1. Cardiac Risk Stratification for Noncardiac Surgical Procedures According to ACC Guidelines.
High (Reported cardiac risk often greater than 5%)
Intermediate (Reported cardiac risk generally less than 5%)
Low (Reported cardiac risk generally less than 1%)
Revised Cardiac Risk Index (RCRI)