Cardiac assessment of patients with Hip Implants
Research type
Research Study
Full title
Cardiac assessment of patients with Hip Implants
IRAS ID
157144
Contact name
Alister Hart
Contact email
Sponsor organisation
Royal National Orthopaedic Hospital R&D Department
Research summary
The Food and Drug Administration (FDA, USA) recently highlighted systemic toxicity from metal on metal hip implants as a cause for concern and recommended that patients with systemic symptoms are assessed, including cardiovascular systems.
A number of cases of suspected toxicity to circulating cobalt and chromium from metal on metal (MOM) hip implants have been reported recently. The most profound case involves a patient who died from cardiac failure secondary to cardiomyopathy and cobalt deposition within the cardiac tissues. A recent cross sectional health screen and isolated case reports, suggest that raised metal ion levels have the potential to cause cardiomyopathy and cardiac failure. Such cases have raised public anxiety in the process.
Cardiac or hepatic iron overload is a significant cause of morbidity in primary and secondary haemochromatosis. Excessive iron deposition within cardiac tissues can lead to premature death secondary to fatal arrhythmias and heart failure. Cardiovascular magnetic resonance (CMR) imaging has revolutionised the management of this particular group of patients by allowing a robust non-invasive method of detecting iron loading.
CMR is the gold-standard for quantification of cardiac volumes and function with standardised protocols. Cardiac tissue iron is detected as a result of its effects on relaxation times through the interaction of iron with hydrogen nuclei in normal cardiac tissue. Cobalt is a ferromagnetic material, containing unpaired electrons allowing it to align in parallel to applied magnetic fields, and therefore should be detected by MRI in a similar way to iron. No study has attempted to use CMR for detection of metal ions deposited in cardiac tissues in patients with metal hip implants.
We therefore aim to detect cobalt deposition in the cardiac tissue of patients with metal hip implants with markedly raised cobalt blood ion levels. We also aim to assess whether this has any clinical effect on cardiac function.
REC name
London - Westminster Research Ethics Committee
REC reference
14/LO/1722
Date of REC Opinion
9 Oct 2014
REC opinion
Further Information Favourable Opinion