Critical Care Medicine-Infections and Immunologic Disease>>>>>Immunological Diseases
Question 1#

A 72-year-old woman with hypertension, hypothyroidism, and a history of giant cell arteritis (GCA) presents with acute onset of chest pain. Computed tomography (CT) angiography in the emergency department reveals a type B aortic dissection, and she is brought to the surgical intensive care unit (ICU) for close hemodynamic monitoring and medical management of the dissection.

Which of the following factors most increased her risk for thoracic aortic dissection?

A. Hypertension
B. Gender
C. Age
D. GCA
E. Hypothyroidism

Correct Answer is D

Comment:

Correct Answer: D

GCA is an inflammatory vasculopathy affecting predominantly elderly patients, with a mean age of 70 to 80 years. 65% to 75% diagnoses are made in females. GCA affects medium and large arteries, specifically, those that have well-defined layers and in which vaso vasorum are present. It preferentially affects the external carotid arteries and its branches and thus typically presents with headache. The American College of Rheumatology (ACR) requires three of the following criteria for diagnosis of GCA:

• Age at disease onset ≥50 years
• New headache, either new onset or new type of localized pain in the head
• Abnormal temporal artery, with tenderness to palpation or decreased pulsation
• Elevated ESR >50 mm/h during first hour of testing (Westergren method)
• Biopsy evidence of vasculitis with predominance of mononuclear-cell infiltration or granulomatous inflammation, usually with multinucleated giant cells 

Aortitis was previously thought to occur in 3% to 18% of patients with GCA, but these diagnoses were only made when aortic aneurysm formation or dissection became clinically apparent. Now, the true rate of aortic involvement is thought to be much higher, and thus regular screening of the aorta is recommended for patients with GCA to exclude aortitis and presence of an asymptomatic aneurysm. The screening modalities recommended are either the combination of chest radiograph, echocardiogram, and abdominal Doppler ultrasound or a CT scan of the chest and abdomen with intravenous contrast. 

Although increasing age and hypertension are both risk factors for aortic dissection, the diagnosis of GCA is a much stronger risk factor for thoracic aneurysm formation and aortic dissection. In one population-based cohort study, patients with giant GCA were 17 times more likely to develop thoracic aortic aneurysm and 2.4 times more likely to develop isolated abdominal aortic aneurysm. Male gender, not female, increases risk for aortic dissection.

References

1. Weyand CM, Goronzy JJ. Giant-cell arteritis and polymyalgia rheumatica. N Engl J Med. 2014;371:50-57.
2. Bossert M, Prati C, Balblanc JC, Lohse A, Wendling D. Aortic involvement in giant cell arteritis: current data. Joint Bone Spine. 2011;78(3):246-251.
3. Martínez-Valle F, Solans-Laqué R, Bosch-Gil J, Vilardell-Tarrés M. Aortic involvement in giant cell arteritis. Autoimmun Rev. 2010;9(7):521-524.
4. Kermani TA, Warrington KJ, Crowson CS, et al. Predictors of dissection in aortic aneurysms from giant cell arteritis. J Clin Rheumatol. 2016;22(4):184-187.