Investigating anaemia in those with cardiac devices using capsule endoscopy: a systematic review and meta-analysis

The number of patients with cardiac implantable electronic devices (CIEDs) is steadily rising. This population, typically older, comorbid, and often on antiplatelet or anticoagulant therapy, is at increased risk of iron deficiency anaemia (IDA) and gastrointestinal bleeding. Despite the value of video capsule endoscopy (VCE) for panenteric investigation, its use remains limited due to persistent concerns about electromagnetic interference (EMI), which restricts access to this important diagnostic modality.

To systematically evaluate the safety and diagnostic performance of VCE in patients presenting with anaemia/gastrointestinal bleeding and CIEDs.

We searched EMBASE, MEDLINE and PubMed. A random-effects meta-analysis of proportions using Freeman-Tukey transformation estimated rates of cardiac events, signal interference and diagnostic yield.

From 275 publications, 18 studies (443 patients) were included. Cardiac device malfunction occurred in 0.9% (4/443) of patients, with no clinically significant events. Pooled malfunction rates were 0% for ICDs and LVADs (95% CI: 0-1%), and 0% for pacemakers (PPMs) (95% CI: 0-6%; I² = 63%). Signal interference occurred in 1.8% (8/443); the pooled rate was 0% (95% CI: 0-2%; I² = 0%), with slightly higher rates in LVADs (1%; 95% CI: 0-6%; I² = 25%). The overall diagnostic yield was 69% (95% CI: 58-80%; I² = 55.5%).

This meta-analysis shows that VCE is safe in patients with CIEDs, with low rates of adverse events and signal interference. Diagnostic performance was not compromised. These findings support revision of current guidance to improve access to CE for patients with anaemia and CIEDs.