Test your medicine knowledge with the MKSAP challenge, in partnership with the American College of Physicians.

A 21-year-old male student is evaluated for a murmur heard during an athletic preparticipation physical examination. He is asymptomatic. His medical and family history is unremarkable and he takes no medications.

On physical examination, the patient is afebrile, blood pressure is 118/76 mm Hg, pulse rate is 68/min, and respiration rate is 14/min. BMI is 18. He wears corrective lenses for myopia. Mild thoracic scoliosis is noted. He has long, thin fingers and a mild pectus excavatum deformity. His height is 188 cm (6 ft 2 in) and arm span is 200 cm from fingertip to fingertip. On cardiac auscultation, a soft early diastolic decrescendo murmur is heard, and is best heard along the left sternal border during expiration with the patient seated and leaning forward slightly.

A transthoracic echocardiogram demonstrates dilatation of the aortic root of 6.2 cm.

Which of the following is the most appropriate treatment?

A: Admit to hospital; begin metoprolol and intravenous sodium nitroprusside
B: Begin oral losartan and metoprolol
C: Plan urgent surgery
D: Repeat echocardiogram in 6 months

MKSAP Answer and Critique

The correct answer is C: Plan urgent surgery.

This patient’s echocardiogram demonstrates a thoracic aortic aneurysm with an aortic root diameter of 6.2 cm, which requires urgent repair. The patient has multiple phenotypic manifestations of Marfan syndrome involving the skeleton, eyes, and heart. He is tall and thin, with an arm span greater than his height. Additional skeletal manifestations include long, thin fingers, scoliosis, and pectus deformity. Myopia is common in patients with Marfan syndrome, but is not as specific for the disease as ectopia lentis (not seen in this patient). Aortic root dilatation is typical of the disease, and the murmur heard on physical examination represents aortic regurgitation. This patient’s marked aortic dilatation necessitates urgent planned surgery to prevent the risk of catastrophic dissection.

The patient has no symptoms suggesting an acute aortic syndrome, and immediate hospitalization, emergency surgery, and parenteral agents to control blood pressure or heart rate are not indicated.

Oral losartan and metoprolol have both been used as part of a strategy to reduce the rate of aortic dilation in patients with Marfan syndrome. It would be appropriate to use such therapy in a patient with Marfan syndrome with a smaller aortic root, but initiating this therapy now would not supplant surgical treatment, and no data indicate it would decrease the risk of dissection while awaiting surgery.

Surveillance echocardiography is not indicated because the aortic root already surpasses 5 cm, a size at which surgery is indicated in asymptomatic patients with Marfan syndrome.

Key Point

• In patients with Marfan syndrome, repair is indicated for an asymptomatic thoracic aortic aneurysm with a root diameter greater than 5 cm.

This content is excerpted from MKSAP 16 with permission from the American College of Physicians (ACP). Use is restricted in the same manner as that defined in the MKSAP 16 Digital license agreement. This material should never be used as a substitute for clinical judgment and does not represent an official position of ACP. All content is licensed to KevinMD.com on an “AS IS” basis without any warranty of any nature. The publisher, ACP, shall not be liable for any damage or loss of any kind arising out of or resulting from use of content, regardless of whether such liability is based in tort, contract or otherwise.