Abstract
We present three cases of thoracic aortic aneurysms caused by giant cell aortitis. Thoracic aortic aneurysms are common and usually related to hypertension, a bicuspid aortic valve or connective tissue diseases such as Marfan syndrome. Our report serves as a reminder that giant cell aortitis is an unusual yet very important cause of thoracic aortic aneurysm.
Introduction
We present three cases of thoracic aortic aneurysms caused by giant cell aortitis. Thoracic aortic aneurysms are common and usually related to hypertension, a bicuspid aortic valve or connective tissue diseases such as Marfan syndrome. Our report serves as a reminder that giant cell aortitis is an unusual yet very important cause of thoracic aortic aneurysm.
Case 1
A 39-year-old man was admitted in February 2001 with palpitations that was preceded by a three-week history of an influenza-like illness. On examination, he was apyrexial and had no systemic features of infective endocarditis. BP in left arm was 132/66 with right arm BP of 158/75. A loud systolic bruit was heard in left supraclavicular fossa. Full blood count was normal but CRP was 16 and ESR 46. Syphilis and autoantibody screen were negative. ECG and echocardiograph were normal. Ultrasound of left subclavian region showed increased flow velocity consistent with subclavian artery stenosis. MRI showed no definite anomaly of the aorta or head and neck vessels. Possibility of large vessel vasculitis was considered; however, follow-up CRP and plasma viscosity in March and May 2001 were normal (<2 and 1.65, respectively).
The patient re-presented in August 2006 with further palpitations that had settled by the time of assessment. BP difference in upper limbs was still present. A new loud early diastolic murmur was heard at left sternal edge. Echocardiogram showed dilated aortic root at 5 cm with severe aortic regurgitation. Left ventricular end-diastolic dimension was 5.9 cm. A normal left ventricular ejection fraction was reported. FBC and CRP were normal. An MRI scan confirmed an enlarged root and ascending aorta with normal head and neck vessels.
He underwent composite aortic root replacement (mechanical size 27 mm carbomedic composite valve conduit) in November 2006. Histopathology showed giant cell aortitis without active inflammation. His aortic dimensions have remained stable on two yearly follow-up MRI and CT scans. He did not receive immunosuppressive therapy. There was evidence of mild atheromatous left subclavian disease.
Case 2
A 73-year-old woman presented with increasing breathlessness in July 2011. She had a history of temporal arteritis and polymyalgia rheumatica diagnosed in 2005 that had been treated with steroids. Examination revealed an early diastolic murmur. Echocardiogram showed severe aortic regurgitation with dilated aortic root at 5.4 cm. CT confirmed a dilated ascending aorta of 6.8 cm and normal coronary arteries. She underwent tissue aortic valve and ascending aorta replacement in September 2011. Histology of the ascending aorta revealed giant cell aortitis. A follow-up CT in December 2014 showed a proximal ascending aorta measuring 3.5 cm. The aortic arch was dilated at 5.6 cm compared to measurement of 5.1 cm one year previously. Inflammatory markers remain under control and she continues on steroids. Her latest CT in August 2015 showed no change in size of aortic arch and descending aorta. Continued surveillance was advised.
Case 3
A normally fit and well 51-year-old man was referred with a murmur in December 2013. Echocardiography showed severe aortic regurgitation, mildly dilated left ventricle with an end-diastolic dimension of 5.9 cm, aortic root of 5.2 cm and a tri-leaflet aortic valve. CT showed dilated ascending aorta at 5.0 cm with normal coronaries. He had mechanical aortic valve and aortic root replacement in March 2014. Beta-blocker and Warfarin were started. Histology showed giant cell aortitis. He was seen by a rheumatologist who elicited a history of right-sided ear, temporal pain and tenderness but without visual symptoms or jaw claudication. His inflammatory markers were normal. Three weeks following surgery, his CRP was 55, ESR 26, Hb 119 and WCC 8.88. He was started on low-dose steroids. Echocardiogram in April 2014 showed a stable aortic valve replacement and normal aortic root with a mild para-valvular leak. Methotrexate with folic acid were added in June 2014. A CT was repeated in May 2015 that showed a stable aortic root and ascending aorta but a dilated descending aorta of 50–55 cm. An ACE inhibitor was added and 6-month follow-up CT has been arranged.
Discussion
Giant cell arteritis is a vasculitis that affects large and medium-sized arteries in patients usually aged greater than 50 years of age and was first described by Hutchinson. 1 In one of the largest series published by the Mayo Clinic 2 the age range was 56–92 years with a median age of 75 years. The male to female ratio was 1:4 with an incidence of 17/100,000. Giant cell aortitis was reported in only 7% of cases of giant cell arteritis. Similar figures were reported in an Olmsted County, Minnesota population study. 3 Giant cell aortitis is usually asymptomatic in contrast to classical giant cell arteritis.
Our first patient presented at a relatively young age compared to the reported literature. He was asymptomatic and developed giant cell aortitis despite normal inflammatory markers. This mode presentation has been reported previously.4,5 Our second patient had a history of possible temporal arteritis. The third patient developed a thoracic aortic aneurysm in the absence of previously established giant cell arteritis, a finding that is also well described in the literature. 6
Our cases highlight the association of thoracic aortic aneurysm and giant cell aortitis and underline the involvement of the whole of the thoracic aorta. Following surgery, frequent and long-term surveillance of the remaining aorta is very important. 7 Furthermore, giant cell aortitis should be considered even in the absence of a history of temporal arteritis, raised inflammatory markers and in the age group less than 55 years.
Giant cell aortitis is an unusual but clinically important cause of thoracic aortic aneurysm, presents at a younger age than giant cell arteritis, often occurs without typical features of arteritis. Giant cell aortitis may involve the arch and descending aorta with significant implications for long-term management.