Diagnosis of perioperative myocardial infarction in noncardiac surgery

Perioperative myocardial infarction (MI) represents an ongoing diagnostic and therapeutic concern for the disciplines of surgery, anesthesiology, and cardiology. It is an important cause of morbidity and mortality in high-risk patients undergoing noncardiac surgery [1, 2]. It is estimated that of the 3 million high-risk patients (patients with known coronary artery disease (CAD) or with two or more risk factors for CAD) undergoing noncardiac surgery annually in the United States, nearly 50,000 sustain a perioperative MI [3]. Furthermore, of nearly 40,000 perioperative deaths every year, approximately one-half are attributable to MI. The majority of episodes of perioperative myocardial ischemia and infarction are either silent or result in symptoms that go unrecognized until morbidity occurs. It is therefore important to identify patients with perioperative MI in order to implement treatment regimens in an appropriate and timely fashion. Recognition of perioperative MI is also important for planning postoperative cardiac evaluation and treatment. In the absence of well-defined and universally accepted criteria, the diagnosis of perioperative MI is often difficult. This uncertainty has resulted in a wide variation in the reported incidence of this condition [1] and has made it difficult to assess the accuracy and reliability of the various methods of predicting this complication in a given patient population. Finally, it has complicated studies of the effectiveness of the various therapeutic and management strategies in lowering the incidence of perioperative MI.