To the Editor:—
I applaud Dr. Park's 1conclusion that preoperative cardiology consultations are often unnecessary if the patient is amenable to perioperative β-blockade; however, if β-blockade is contraindicated, I disagree with obtaining a consultation when the American College of Cardiology–American Heart Association algorithm 2recommends stress testing. Anesthesiologists should be sufficiently knowledgeable to determine the indicated type of stress test. Frequently, the test may be ordered after discussion with the patient's primary care physician, as the test has long-term patient-care issues. If the test is negative for ischemia at a significant workload (e.g. , achievement of 85% of maximum predicted heart rate for exercise or dobutamine echocardiography), then no consultation is indicated. If a stress test is positive for significant ischemia, the cardiologist should be asked whether more invasive testing (coronary angiography) with possible treatment (percutaneous coronary intervention or coronary artery bypass graft) is indicated.
The author also concludes that cardiac consultation is not indicated for patients with severe aortic stenosis (AS) because studies demonstrate no increased risk of surgery if the AS is recognized. However, the studies were small and did not have the power to determine increased risk (Okeefe et al. 3studied only 23 patients with general anesthesia or spinal anesthesia, and Raymer and Yang's 4sample size was adequate to detect only a fourfold increase in risk). Patients with severe AS and any of the triad (angina, syncope, or dyspnea) should be referred for prompt valve replacement. 5In addition, even if patients with severe AS are asymptomatic, some authors believe that certain patients with stress testing–induced symptoms will benefit from aortic valve replacement. 5Every patient with a murmur consistent with AS should be sent for echocardiography; if the aortic valve area is less than 1.0 cm2, a cardiology consultation should be strongly considered prior to elective surgery to determine if preoperative valve replacement is indicated.