Unravelling a Case of Coronary Vasculitis

Abstract

Background Coronary vasculitis is a rare cause of myocardial infarction through varied mechanisms. We report the case of a 32-year-old female found to have diffuse coronary microaneurysms during treatment for an Inferior ST Elevation Myocardial Infarction (STEMI), with challenges in pinpointing the underlying aetiology. Results Our patient has been diagnosed with a seronegative arthritis and had been initiated on regular Golimumab 4 months prior. She presented with prolonged fever for 4 weeks and inflammatory oligoarthritis with left sacroiliac joint pain. During this admission, Antinuclear antibody was 1:2560 and anti ds DNA was 1:80. She had highly positive Rickettsia conorii IgG titres of 1:128, suggestive of acute infection with Orientia tsustsugamushi. Meropenem and doxycyclin for presumed typhus had no impact on her fever spikes. In the 10th week of the illness, she developed ischaemic chest pain with electrocardiographic changes of inferior STEMI and was thrombolysed. Invasive coronary angiography revealed numerous coronary microaneurysms affecting all major myocardial vessels, with minimal coronary artery disease. Following multidisciplinary discussion, she was treated with intravenous methylprednisolone, antiplatelets, a statin and warfarin for a diagnosis of coronary vasculitis. Repeat angiography showed complete resolution of the microaneurysms. She continues on anticoagulation and has since had no coronary events. Conclusion Typhus and medium vessel vasculitis such as Kawasaki and Polyarteritis Nodosa were potential diagnoses for this presentation. A diagnosis of SLE was established due to the highly specific immunological profile. As there are reports of high Rickettsial titres in autoimmune disease, which alongside the lack of response to doxycyclin makes Typhus unlikely. The possibility of golimumab induced SLE was briefly entertained due to similar reports, but the positivity of ds DNA and major organ involvement made this possibility unlikely. We highlight the cardiac involvement in this case due to its high morbidity on young patients, and the current paucity of knowledge on SLE-related endothelial dysfunction and immune-mediated vascular damage. The role of anticoagulation in this inflammatory milieu too, is controversial. This case highlights a rare presentation of SLE, with an emphasis on coronary vasculitis. It adds to the current knowledge on the complex cardiovascular risk in SLE and highlights ambiguous areas in current management strategies to prompt further research.