Journal: Curr Opin Anaesthesiol 20(3):254-260, 2007. 67 References
Reprint: Dept of Anesthesiology, Erasmus Medical Center, Dr Molewaterplein 40, 3015 GD Rotterdam, The Netherlands (D Poldermans, MD, PhD)
Faculty Disclosure: Abstracted by S. Ouellette, who has nothing to disclose.
Cardiovascular disease is the leading cause of death after anesthesia and surgery. Preoperative identification of patients with underlying coronary disease is important to initiate appropriate strategies in order to reduce the risk of perioperative complications. This article highlights new insights in the field of perioperative medicine that can be applied to clinical practice.
The old Goldman risk index was revised by Lee to identify patients at risk. The revised index identifies six predictors of major cardiac complications: high-risk surgery, ischemic heart disease, congestive heart failure, cerebrovascular disease, diabetes and renal failure. Based on the presence of none, one, two, or three or more of these predictors, the rate of major cardiac complications was estimated to be 0.4%, 0.9%, 7% and 11%, respectively. It has also been demonstrated that the risk index could be improved by adding the type of surgical procedure. Preoperative cardiac exercise or pharmacological stress testing is recommended for patients who have increased risk based on clinical risk profile, functional capacity and type of surgery.
New laboratory markers are being used for risk stratification. Natriuretic peptides are endogenous, cardiac hormones that include atrial natriuretic peptide (A-type), brain natriuretic peptide (B-type), and its N-terminal portion N-terminal pro-B-type natriuretic peptide (NT-proBNP). NT-proBNP is synthesized in the ventricular myocardium and released in response to ventricular wall stress. NT-proBNP is an important diagnostic marker in patients with heart failure. Recent studies demonstrate that elevated natriuretic peptide levels predict short-term adverse cardiovascular events in patients undergoing elective noncardiac surgery.
Numerous clinical trials have shown that perioperative use of β-blockers can reduce the incidence of postoperative myocardial ischemia, myocardial infarction, and cardiac mortality. Perioperative ischemia is significantly reduced by β-blocker therapy. The mechanism by which β-blockers exert their cardioprotective is still not completely understood. Proposed mechanisms include reduction in heart rate, restoration of myocardial oxygen supply-demand balance and prolongation of coronary diastolic filling time. Adequate β-blocker dosage and heart rate control, continuation of β-blocker therapy in the postoperative period may also be recommended. Withdrawal of β-blocker therapy in the perioperative period has been associated with a 2.6-fold increased risk of 1-year mortality.
Statins have emerged as a promising cardioprotective drug in the perioperative period. The beneficial properties of statins beyond the lipid-lowering effect include oxidative stress reduction and decrease in vascular inflammation, suggesting a plaque stabilizing effect. Statins can lower cardiac events, reduce hospital length of stay, preserve renal function after suprarenal aortic clamping, and lower the incidence of stroke after carotid angioplasty and stent placement in patients with symptomatic carotid disease. Other agents that may have cardioprotective effects include alpha2-adrenergic agonists (clonidine, dexmedetomidine), calcium channel blockers, and nitroglycerin. |
