Insertable cardiac monitors in high-risk post-infarction patients: a cost-effectiveness analysis

Abstract Funding Acknowledgements Type of funding sources: None. Background The randomised SMART-MI trial demonstrated that telemonitoring with insertable cardiac monitors (ICMs) for post-acute myocardial infarction patients with cardiac autonomic dysfunction and a left ventricular ejection fraction between 35-50% is highly effective in detecting serious arrhythmic events (SAE) compared to standard of care (SoC). In SMART-MI, SAE were also predictive of subsequent major adverse cardiac and cerebrovascular events (MACCE) which might be prevented by preemptive interventions. It is unknown whether such a monitoring strategy would be cost-effective. Purpose To evaluate the cost-effectiveness of ICM-based telemonitoring compared to SoC among a UK post-acute myocardial infarction population. Methods We created a Markov model to conduct a cost-effectiveness analysis comparing ICMs to SoC for the SMART-MI population. For the analyses, we hypothesized that the SAE-triggered interventions could prevent clinical complications with certain probabilities. A UK National Health System (NHS) perspective was employed with costs and health-related benefits discounted at 3.5%. We employed 6-months Markov cycles and calculated the model over a lifetime horizon. Patient characteristics and detection probabilities were based on the SMART-MI diagnostic study. UK-specific costs and risk-adjusted parameters were used to model the cardiovascular and cerebrovascular pathways. Scenario, deterministic and probabilistic sensitivity analyses were conducted to control for uncertainty. Results The base-case scenario found an incremental cost-effectiveness ratio (ICER) of the ICM to be £7,812.92 per QALY gained compared to SoC. There were 0.0646 less ischaemic strokes events per patient and 0.0168 less syncope events per patient in the ICM arm compared to SoC. Results were robust to sensitivity analysis. Conclusion Under the assumptions of the study, ICMs were a cost-effective diagnostic tool for detecting arrhythmias compared to SoC, preventing stroke and syncope events in post-acute myocardial infarction patients in the UK.