MANAGEMENT OF ASYMPTOMATIC AORTIC STENOSIS: WHAT IS NEW IN 2015?
Hari P. Chaliki, M.D., Mayo Clinic, Scottsdale, AZ, USA
Calcific aortic stenosis is now the primary etiology of aortic stenosis in the majority of patients. Risk factors such as hyperlipidemia play an important role in the progression of aortic stenosis. According to the most recent American College of Cardiology/American Heart Association guidelines, peak velocity greater than 4 m/sec, or a mean gradient of more than 40 mmHg and a valve area of less than 1.0 cm2 is considered hemodynamically severe aortic stenosis. Aortic valve surgery promptly should be done in symptomatic patients due to dismal prognosis without operation. Features such as reduced left ventricular ejection fraction (<50%), very high velocity (>5 m/sec) or a high mean gradient (>60 mm Hg) or a positive exercise test identify high risk asymptomatic patients who would benefit from early aortic valve surgery. Recently, it was recognized that up to 25% of severe aortic stenosis patients may have low trans-valvular gradient despite preserved left ventricular ejection fraction due to concentric remodeling and high vascular resistance. Although challenging, identification of this subgroup is important due to reduced long term survival without surgery. Currently percutaneous aortic valves are used only in very high-risk patients with severe symptomatic aortic stenosis. Their role may expand in the future, depending on the technological advances and operator experience.