To the Editor:—
We read with interest Dr. Mangano’s paradigm for preoperative assessment of patients with cardiac disease. 1We have several concerns. First, the paradigm does not differentiate major surgery from minor surgery. Obviously, preoperative evaluation and perioperative treatment are different for patients undergoing cataract surgery, cholcystectomy, or abdominal aortic aneurysm resection. Second, the only management technique that has been proven to reduce perioperative morbidity is β blockade, 2,3and this should be included in the paradigm for patients with coronary artery disease or suspected coronary artery disease who are scheduled for intermediate or major surgery (unless contraindicated). Third, there is no substantial evidence that 24–48 h postoperative hemodynamic and ischemic monitoring will benefit patients with mild to moderately positive stress test results. Intensive care unit monitoring is costly and should be reserved for patients undergoing major surgery. Fourth, most patients with coronary artery disease and impaired functional status should not bypass stress testing and automatically undergo coronary angiography. A patient may have impaired functional status as a result of previous myocardial infarction, yet have a minimal amount of residual myocardium at risk. Also, impaired functional status may result from many nonischemic causes, including obesity and emphysema. A specialized stress test, such as an adenosine thallium scan or dobutamine echocardiography, assesses functional myocardium at risk in this subset, compared with angiography, which delineates only anatomic information.
Unfortunately, a randomized study that proves whether preoperative testing improves patient outcome has yet to be performed. It is unknown whether the risk-stratification costs (delays in surgery; money for testing; complications from angiography, angioplasty, and coronary artery bypass surgery) are offset by improved patient care. Because patient history, physical examination, and electrocardiography adequately assess which patients will benefit from β blockade, 2there is unproven benefit to specialized testing until we demonstrate that other management techniques improve perioperative outcome.