- Major vessel disease: arterial aneurysms or arterial stenosis, myocarditis and/or major deep vein thrombosis (i.e. inferior vena cava, superior vena cava, cardiac cavity thrombosis, pulmonary embolism, supra-hepatic vessels, renal and mesenteric vessels). Diagnosis of major vessel involvement will be done using vascular doppler sonography, echocardiography, angio-CT scan and/or cardiac magnetic resonance imaging (MRI).