The prevalence of cardiovascular disease and the death rate associated with it rise sharply after age 45, an age when the incidence of noncardiac surgeries is also increasing, and approximately one-third of the 50 million surgical procedures done annually in the United States 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 provide prophylactic treatment to reduce risk.
Preoperative Risk Assessment
An individual patient’s preoperative risk profile depends on three main factors: the patient’s age, current medical and functional status, and the type of surgery. Preoperative electrocardiography can detect arrhythmias and prior silent MI, but it rarely changes management. Preoperative echocardiography would probably provide more useful information, but the cost effectiveness of such testing has not been determined.
Table 10–1 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 various algorithms that can help identify perioperative risk and the need for further cardiac testing.
Table 10–1.Cardiac Risk Stratification for Noncardiac Surgical Procedures ||Download (.pdf) Table 10–1. Cardiac Risk Stratification for Noncardiac Surgical Procedures
High (reported cardiac risk often > 5%)
Emergent major operations, particularly in the elderly
Aortic and other major vascular surgery
Anticipated prolonged surgical procedures associated with large fluid shifts and/or blood loss (eg, liver transplantation)
Intermediate (reported cardiac risk generally 1–5%)
Carotid endarterectomy surgery
Head and neck surgery
Intraperitoneal and intrathoracic surgery
Peripheral vascular surgery
Low (reported cardiac risk generally < 1%)
Cataract or other eye surgery