Aortic stenosis and perioperative risk with noncardiac surgery.

Aortic stenosis (AS) is characterized as a high-risk index for cardiac complications during noncardiac surgery. The American College of Cardiology/American Heart Association guidelines define severe AS as aortic valve area ≤1 cm(2), mean gradient of ≥40 mm Hg, and peak velocity of ≥4 m/s. As per current clinical practice, any of these characteristic features label a patient as at high risk for noncardiac surgery. However, these parameters appear inconsistent, particularly with respect to the aortic valve area cutoff value. The perioperative risk associated with AS during noncardiac surgery depends upon its severity (moderate vs. severe), clinical status, and the complexity of the surgical procedure (low to intermediate risk vs. high risk). A critical analysis of old and new data from published studies indicates that the significance of the presence of AS in patients undergoing noncardiac surgery is overemphasized in studies that predate the more recent advances in echocardiography and cardiac catheterization in assessment of aortic stenosis, anesthetic and surgical techniques, as well as post-operative patient care.