42. Large vessel vasculitis with rapidly expanding aortic aneurysm

Introduction This case report describes the delay in diagnosis and potentially life-threatening complications of a patient with large vessel vasculitis. The initial diagnosis was of vascular Ehlers-Danlos Syndrome, based on family history and imaging. However, recurrent episodes of chest pain and a rapidly expanding aortic aneurysm prompted further diagnostics which led to the diagnosis of giant cell arteritis with large vessel vasculitis. The patient required thoracic surgery due to expansion of the aortic aneurysm. This case demonstrates the risk of delaying the diagnosis of large vessel vasculitis and the complexities of immunosuppression in the context of major surgery. Case description A previously fit and well 69-year-old man presented with constitutional symptoms and intermittent chest pain for six months. Two months after symptom onset, he was admitted with chest tightness and shortness of breath. He had raised inflammatory markers with thrombocytosis and was given antibiotics for a probable chest infection. A CT pulmonary angiogram revealed ascending aorta dilatation, 47mm with wall thickening. The radiologist reported this as being most likely due to systemic hypertension. There was no evidence of malignancy on abdominal and pelvic imaging. The aortic changes were attributed to possible underlying Ehlers-Danlos syndrome, as his daughter had a diagnosis of Ehlers-Danlos Type III. He was discharged despite persistently raised inflammatory markers and no positive microbiology. He was readmitted after six weeks with pyrexia and severe chest pain. A CT of his thoracic aorta showed further expansion of the aortic aneurysm, 59mm with a slightly thickened abdominal aorta wall. With a rapidly expanding aortic aneurysm and persistent raised inflammatory markers, the suspicion of large vessel vasculitis was raised. No symptoms of cranial temporal arteritis or polymyalgia rheumatica. A FDG-PET scan showed high uptake in the ascending, thoracic and upper abdominal aorta in keeping with extra-cranial large vessel vasculitis. He was treated with IV methylprednisolone for three days with subsequent oral prednisolone. Whilst on high dose glucocorticoids, he developed steroid induced diabetes and hypomania hence oral methotrexate 15 mg once weekly was added. The cardiothoracic team elected to delay cardiothoracic surgery until he was on less than 15 mg of oral prednisolone daily. However, reduction of oral prednisolone led to a flare of giant cell arteritis. The patient had to undergo elective aortic valve and ascending aorta replacement whilst on 40 mg of prednisolone. Tocilizumab was added two months after surgery and prednisolone was successfully reduced to 3mg. Discussion Critically, appropriate treatment was delayed due to misdiagnosis of Ehlers-Danlos Syndrome; this was largely based on the family history. This red herring likely distracted clinicians from seeking a better explanation for the patient’s presentation and aortic changes. The initial oral steroid course was complicated by steroid induced complications and pending cardiothoracic surgery. The surgical team planned to delay surgery until the patient is on a lower prednisolone dose, due to the increased risk of infection and poor wound healing. The patient therefore had a rapid steroid tapering regime, reducing by 5mg two-weekly, from a starting oral dose of 65mg. Such rapid steroid tapering carries a risk of disease flare, and in fact two weeks prior to surgery, his inflammatory markers rose, and his prednisolone dose had to be increased from 25mg to 40mg. A collaborative decision between the rheumatologists and surgeons was then made to proceed with surgery despite the high-dose steroids, as simultaneous inflammation control and prompt surgical repair took precedence over the potentially increased post-operative risks. The patient also experienced steroid-related side-effects, but the switch to steroid-sparing agents was challenging. Starting tocilizumab as a further immunosuppressant had to be delayed until after surgery, as IL-6 inhibition would distort C-reactive protein as a measure of both disease activity and potential post-operative infection. In summary, this case highlights the difficulty in diagnosing large vessel vasculitis and the potential delay in treatment can cause significant morbidity and mortality. Appropriate imaging is crucial to ascertain a diagnosis of large vessel vasculitis. Immunosuppression must be tailored individually, accounting for side-effects and competing risks. Points for discussion include the use of newer imaging modalities in diagnosing large vessel vasculitis and monitoring disease activity. The efficacy and safety of tocilizumab as a steroid-sparing agent for this condition should also be investigated. Key learning points The importance of early diagnosis and treatment in patients with large vessel vasculitis, as vascular complications can arise if treatment is delayed. The use of appropriate imaging modalities such as MR angiogram and FDG-PET is crucial for diagnosis of large vessel vasculitis. Glucocorticoid therapy is the mainstay treatment for large vessel vasculitis, but side-effects can be limiting. Steroid sparing agents, such as IL-6 inhibitors should be considered early as an alternative immunosuppressant for patients with large vessel vasculitis. Careful planning of immunosuppression is required prior to major surgery. Conflicts of interest The authors have declared no conflicts of interest.