A 70-year-old man is brought to the emergency department by his wife after an episode of syncope while working in his garden. He regained consciousness immediately and initially refused to go to the hospital saying, "I feel fine." The patient has never experienced syncope before. According to his wife, he has always been physically active but lately has had increased fatigability; he seems to work less in the garden and spends more time indoors watching television. Medical history is significant for type 2 diabetes mellitus and gout. His only current medication is metformin. He is a lifetime nonsmoker and does not drink alcohol. Blood pressure is 100/80 mm Hg and pulse is 90/min. BMI is 28 kg/m². Both carotid pulses are delayed. Lungs are clear on auscultation. A harsh crescendo-decrescendo murmur is heard at the base of the heart. The second heart sound is soft with an inaudible A2 component. There is no peripheral edema. ECG shows normal sinus rhythm, left ventricular hypertrophy, and secondary ST-segment and T-wave changes. Echocardiography shows concentric left ventricular hypertrophy with severe calcification of the aortic valve. The estimated aortic valve area is 0.78 cm² and the mean transvalvular gradient is 50 mm Hg. Laboratory studies show normal complete blood count and serum creatinine of 0.8 mg/dL. Which of the following is the best statement about this patient's condition?

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Explanation: 11ec2b69_be06_31e9_8f63_292667b65e17_MD0005_00 This patient's recent increased fatigability and syncope combined with the echocardiogram findings are consistent with severe symptomatic aortic stenosis (AS). Patients with AS usually have a prolonged asymptomatic period and begin to develop symptoms when the stenosis becomes severe. Severe AS is defined as aortic jet velocity >4.0 m/sec or mean transvalvular gradient >40 mm Hg on echocardiogram, either of which typically occurs when aortic valve area decreases to <1 cm². The onset of symptoms (eg, angina, syncope, exertional dyspnea) in severe AS is associated with a significant increase in mortality and is an indication for aortic valve replacement to improve long-term survival.(Choices B and C) Percutaneous balloon aortic valvulotomy is considered only as a bridge to surgical or transcatheter aortic valve replacement in patients with severe symptomatic AS. It is associated with high rates of procedural complications (eg, stroke, myocardial infarction, acute aortic regurgitation) and does not improve long-term prognosis in severe AS. (Choice D) Aortic valve replacement is the only effective treatment for severe symptomatic AS; conservative medical therapy provides no survival benefit in such patients. In addition, because patients with severe AS are preload dependent, the use of diuretics or vasodilators can lead to inferior outcomes due to excessive decreases in cardiac output. (Choice E) As noted above, the onset of symptoms (exertional dyspnea, angina, presyncope or syncope) in patients with severe AS is associated with a significant increase in mortality. Average survival following symptom onset is 2-3 years without valve replacement. Educational objective: Severe aortic stenosis is defined by echocardiogram findings of aortic jet velocity >4.0 m/sec or mean transvalvular gradient >40 mm Hg. Symptomatic patients with severe aortic stenosis should undergo aortic valve replacement to increase long-term survival. References: Clinical outcomes in non-surgically managed patients with very severe versus severe aortic stenosis. (http://www.ncbi.nlm.nih.gov/pubmed/21954228) The effect of aortic valve replacement on survival. (http://www.ncbi.nlm.nih.gov/pubmed/7127696) 2014 AHA/ACC guideline for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. (http://www.ncbi.nlm.nih.gov/pubmed/24603191)

A 70-Year-Old Man Is Brought to the Emergency Department by His