Coronary artery involvement in Takayasu arteritis has been documented in up to 10% of cases . This may occur as coronary stenosis, occlusion, diffuse or focal coronary arteritis or aneurysm formation . Coronary artery aneurysm formation is distinctly uncommon in aortoarteritis, with fewer than 1.5% of Takayasu arteritis cases associated with it .Multiple mechanisms have been postulated for aneurysm formation in this scenario, one being accelerated atherosclerosis (following Systemic hypertension and systemic inflammatory response occurring in Takayasu Arteritis) and the other due to Arteritis proper [5, 6]. The chronic inflammation involving large to medium sized arteries and related edema have also been documented to result in active vasculitis leading to coronary and vascular lesions . It is believed that the majority of coronary lesions in aortoarteritis are related to the extension of chronic aortic inflammation into the coronary media and adventitia, as substantiated by predominant ostial coronary involvement. It is known that coronary artery aneurysms are associated with increased mortality . While in general, coronary artery aneurysms have been most commonly noted in the RCA, both the left and right have been equally implicated in coronary aneurysms in Takayasu arteritis (Fig. 2) [7, 8].
Other diseases which may present with peripheral arterial aneurysm and in the setting of coronary artery aneurysm are Kawasaki disease, atherosclerosis and polyarteritis nodosa. However, characteristic involvement of the aorta and its branches in our case clinched the diagnosis of Takayasu arteritis.
While aneurysmal involvement of the aorta is common in aortoarteritis, subclavian artery aneurysm is extremely rare . The subclavian arteries generally show stenotic involvement of the proximal or middle third in aortoarteritis. In the index case, there was aneurysmal involvement of the ostioproximal left subclavian artery with short segment occlusion distal to it. Distally the subclavian artery assumed normal caliber with contribution from cervical collaterals Fig. 1c.
Identification of disease activity is also important in these situations for which MR contrast administration and T2 weighted imaging are useful. . Interventions are deferred in the active phase of the disease.