A Novel Ferumoxytol-enhanced Cardiac Magnetic Resonance Imaging for the Detection of Intracardiac Thrombus

Ferumoxytol is a member of ultrasmall superparamagnetic iron oxide particles with an average diameter of 30 nm, originally developed as an intravascular contrast agent for MRI. Ferumoxytol was approved by the FDA in 2009 for the intravenous treatment of iron deficiency anaemia in adults with chronic kidney disease, and has also been used off-label as a non-gadolinium contrast agent for whole-body magnetic resonance imaging. Its iron oxide core is coated with dextran, which reduces immunogenicity and delays phagocytosis and the release of elemental iron from the core. As a result, ferumoxytol has a long intravascular half-life of approximately 15 hours and is slowly taken up by the macrophages of the reticuloendothelial system. Because of its long half-life, ferumoxytol is suitable for enhanced magnetic resonance imaging with complex scanning procedures and long repetitive scans. Ferumoxytol has been proved to be safe even in adults and children with end-stage renal failure. As feraheme is not available in the Chinese market, we experimentally synthesised a new formulation of ferumoxytol, which is identical to ferumoxytol in terms of physicochemical structure, pharmacokinetics and toxicological effects, at the request of Chia Tai Tianqing Pharmaceutical Group Co, Ltd (Nanjing, China) in 2014. This study is a single-centre, prospective, observational, non-randomised study. The study will enrol patients with ventricular aneurysm and after percutaneous ventricular reconstruction. The aim of this study is to evaluate the effectiveness of ferumoxytol-enhanced cardiac magnetic resonance imaging in detecting intracardiac thrombus in patients with ventricular aneurysm and left ventricular thrombus in the dynamic chamber and static chamber in patients 180±30 days after percutaneous ventricular reconstruction by comparing the detection rate of intracardiac thrombus with ferumoxytol-enhanced cardiac magnetic resonance imaging and transthoracic echocardiography, and to provide a clinical basis for the development and application of the new generation of magnetic resonance contrast agents in China. The echocardiography and magnetic resonance imaging experts were blinded to each other's results.

Inclusion criteria

• Age ≥ 18 years and ≤ 80 years;
• Patients with left ventricular aneurysm detected by transthoracic echocardiography or 180±30 days after percutaneous ventricular reconstruction;
• An informed consent form was signed voluntarily by the patients or an authorised family member.

Exclusion criteria

• Patients unable to lie down for any reason;
• Patients who are unable to undergo MRI for psychological (e.g. suffering from claustrophobia syndrome) or physical reasons (e.g. non-antimagnetic metal retention in the body, hearing impairment, involuntary body movements, etc.);
• Patients with a known history of iron allergy or hypersensitivity;
• Patients taking other oral or intravenous iron products;
• Patients with haemosiderin deposition or haemochromatosis;
• Pregnant or lactating women;
• Any other patient that the investigator deems inappropriate for enrolment.