The International Journal of Cardiovascular Imaging | 2021
A critical stenosis isn’t always atherosclerosis
Abstract
A 67 year old female, with no cardiac history or risk factors, was referred to the outpatient chest pain clinic with exertional chest pain and dyspnoea. Her resting electrocardiogram showed first degree heart block with T wave inversion in leads V1 and V2. Left ventricular systolic function on echocardiogram was normal with no evidence of pulmonary hypertension. Elective computed tomography (CT) cardiac angiography revealed a significant stenosis in her left anterior descending (LAD) artery. Invasive angiography demonstrated the presence of severe proximal LAD stenosis (Fig. 1a). Optical coherence tomography (OCT) (Fig. 1b) confirmed this and was suspicious for a fibrotic aetiology, although the appearances could have also represented impressive positive remodelling. Given her symptoms and the critical luminal stenosis, the decision was made to perform percutaneous coronary intervention. As the lesion involved the ostium of the LAD the stent was placed within the distal left main stem artery. Intravascular ultrasound was used to confirm good stent opposition but also illustrated the presence of a large inflammatory reaction outside the external lamina of the LAD (Fig. 1c). This was not seen on OCT, highlighting the difference in image depth capabilities between the two imaging techniques. To investigate further the patient underwent a CT-PET scan, which demonstrated a large vessel vasculitis affecting the aortic root, aortic arch and ascending aorta, with patchy changes to her descending aorta. There was also a suggestion of inflammation in LAD (Fig. 1d), although the scan was not cardiac gated. The patient had a past medical history of asthma, rhinosinusitis and nasal polyps, indicating a predisposition to autoimmune conditions. Following a rheumatology review and bloods work up she was diagnosed with eosinophilic granulomatosis with polyangiitis (EGPA), for which she was commenced on Methotrexate. From a cardiology perspective, close follow up of this patient will be needed to ensure stent patency in this non-atherosclerotic process. This case reminds us of the importance of considering a wide range of aetiologies when presented with a critical coronary artery stenosis, and illustrates the utility of multi-modality imaging to aid diagnosis.