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. Patients with cardiac implantable electronic devices (CIEDs), including pacemakers (PPMs), ICDs and LVADs, are at elevated risk of iron deficiency anaemia (IDA) and gastrointestinal bleeding, especially when prescribed antiplatelet or anticoagulant therapy.CE is recommended for evaluating obscure gastrointestinal bleeding or persistent anaemia when upper and lower endoscopy are inconclusive, yet its use in patients with CIEDs remains limited.Concerns about electromagnetic interference (EMI) between capsule transmitters and cardiac devices despite being largely theoretical. This has led to conservative manufacturer warnings and inconsistent professional guidance.Prior observational studies and case series suggest a low risk of adverse cardiac events or signal disruption. Still, no definitive pooled analysis has quantified these outcomes or their impact on diagnostic performance. Patients with cardiac implantable electronic devices (CIEDs), including pacemakers (PPMs), ICDs and LVADs, are at elevated risk of iron deficiency anaemia (IDA) and gastrointestinal bleeding, especially when prescribed antiplatelet or anticoagulant therapy. CE is recommended for evaluating obscure gastrointestinal bleeding or persistent anaemia when upper and lower endoscopy are inconclusive, yet its use in patients with CIEDs remains limited. Concerns about electromagnetic interference (EMI) between capsule transmitters and cardiac devices despite being largely theoretical. This has led to conservative manufacturer warnings and inconsistent professional guidance. Prior observational studies and case series suggest a low risk of adverse cardiac events or signal disruption. Still, no definitive pooled analysis has quantified these outcomes or their impact on diagnostic performance. Video CE (VCE) can be safely performed in patients with cardiac implantable electronic devices (CIEDs), with a 0.9% rate of transient, clinically insignificant cardiac events and no evidence of device malfunction. The pooled signal interference rate was 0%, with no transmission loss in PPM or ICD users, and only minor, non-impactful artefacts in LVAD recipients. Diagnostic yield remained high across all device types (overall 69%), with capsule completion rates exceeding ESGE key performance benchmarks (92%). These findings are reassuring for long-standing concerns around EMI and support the inclusion of CIED patients in capsule-based diagnostic pathways for gastrointestinal bleeding and anaemia.