OA18 Takayasu arteritis mimicking pulmonary embolism: a case series

Abstract

Abstract Background/Aims Takayasu arteritis (TA) is a rare autoimmune large vessel vasculitis with estimated incidence of 0.7-1.5 per million per annum in Europe. Conversely, pulmonary embolism (PE) is common with incidence estimates of 115 per 100,000 per year. Whilst TA is rare, it can have serious sequelae, including pulmonary vasculitis (PV), resulting in stenoses, aneurysm formation and pulmonary hypertension (PAH). Those with PV may have higher rates of PAH, with estimates around 42%. Early diagnosis ensures early treatment/immunosuppression to minimise arterial injury. Given the rarity of TA with PV, it can be misinterpreted on imaging as a PE. This study aimed to review initial imaging features of TA patients with confirmed PV to identify those who had been incorrectly diagnosed as having a PE. Subsequently, features to differentiate PE and PV were assessed. Methods We performed a retrospective analysis of all 158 patients in the Imperial College TA Cohort to identify those with PV. Records and imaging from these patients were reviewed including initial pulmonary vascular imaging. Results 9 patients with PV were identified, of which 3 had initially been misdiagnosed as having a PE, thereby delaying TA treatment and possibly resulting in accelerated disease course. Table 1 summarises initial presenting features. All patients received anticoagulation for PE; however, their symptoms did not improve. Details of subsequent imaging are included in the table. They each experienced a delay in diagnosis of 7 years, 3 years, and 6 months respectively. Conclusion Whilst TA is rare, it is an important diagnosis and not to be missed. Where clinical features are not fitting with a diagnosis of PE, or symptoms are persisting despite management, consider further investigation. Early diagnosis of TA can aid management to try and prevent long term sequelae. Important criteria that should raise suspicion and may suggest TA, some of which were seen in our patient cohort, could include: more insidious onset of symptoms and persistent symptoms despite treatment; normal saturations on observations; normal D-dimer results and a raised ESR/CRP. In the event of clinical doubt for PE, further investigations (ESR) and imaging (MR pulmonary angiogram) should be considered. Disclosure S. Kostich: None. S. Lee: None. S. Babar: None. T.A. Youngstein: None. J. Mason: None. A. Porter: None.