Perioperative surveillance for adverse myocardial events

Perioperative myocardial infarctions occur in 1 to 4% of unselected noncardiac surgical patients, and are associated with high mortality. Detection of these events can be challenging, because 'typical' symptoms of myocardial ischemia may not be present or may be masked in the perioperative period. Therefore, surveillance by means of intraoperative cardiac monitoring and postoperative serial electrocardiograms (ECGs) and troponins may be needed. Cardiac monitoring not infrequently detects ST-segment changes suggestive of ischemia during or shortly after surgery. To respond to these changes, the risk for coronary artery disease should be assessed before recommending additional interventions. For all vascular surgery patients, and for patients who have or are felt to be at risk for coronary artery disease, serial postoperative 12-lead ECGs and troponins should be considered. Among surgical patients not meeting these criteria, obtaining routine ECGs in the absence of signs or symptoms that suggest a cardiac event may be falsely reassuring and is not felt to be useful. The presence of elevated postoperative troponins predicts worsened prognosis, and argues for intensified risk factor modification. The need for noninvasive cardiac testing or cardiac catheterization should be made on an individual basis.