[Prevention of perioperative myocardial ischemia--an update]

Perioperative cardiac morbidity and mortality are a major health care challenge with important individual as well as economic aspects. Up to 30% of all perioperative complications and up to 50% of all postoperative deaths are related to cardiac causes. Perioperative myocardial ischemia, which occurs in more than 40% of patients with or at risk for coronary artery disease and undergoing noncardiac surgery, represents a dynamic predictor of postoperative cardiac complications. Long-duration myocardial ischemia and ischemic episodes associated with myocardial cell damage are particularly of prognostic relevance. In patients suffering from this type of ischemia, the incidence of adverse cardiac outcome is increased up to 20-fold. Reducing the incidence of perioperative myocardial ischemia is associated with a decrease in adverse cardiac outcome. Important issues related to perioperative myocardial ischemia are hematocrit level, body temperature, and hemodynamic variables. In contrast, the choice of anesthetic agents and techniques appears to be less important. Perioperative administration of anti-ischemic drugs in patients at risk, however, leads to a further decrease in the incidence of myocardial ischemia and to an improvement in patient outcome. Recent studies suggest that alpha 2-agonists and particularly beta-adrenoreceptor blocking agents are effective anti-ischemic drugs in the perioperative setting. Perioperative administration of beta-adrenoreceptor blocking agents in coronary risk patients undergoing noncardiac surgery is associated with a reduced rate of postoperative cardiac complications and an improvement in long-term outcome. This is particularly relevant in high risk patients with preoperative stress-induced ischemic episodes. In clinical practice, therefore, chronically administered anti-ischemic drugs should also be administered on the day of surgery and during the postoperative period. In untreated patients with or at risk for coronary artery disease and who have to undergo urgent surgical procedures without the opportunity of preoperative anti-ischemic intervention, perioperative administration of beta-adrenoreceptor blocking agents is mandatory.