Micro-nanoplastics significantly increase adverse events and economic burden associated with carotid endarterectomy: a health economic modelling evaluation

Backgrounds:
Micro-nanoplastics (MNPs) are increasingly detected in human cardiovascular tissues and have been linked to higher rates of adverse cardiovascular events. However, the clinical and economic implications of MNP contamination for vascular surgery populations remain unclear. We aimed to model the potential impact of MNPs on outcomes and healthcare costs among Australian patients undergoing carotid endarterectomy.

Methods:
We performed a modelling study using secondary data. Rates of carotid plaque MNP contamination and associated risks of stroke, myocardial infarction, and death were derived from international cohort data, while procedure numbers and costs were obtained from Australian national sources. A cohort of 1900 patients undergoing carotid endarterectomy in 2020–2021 was modelled across MNP contamination scenarios from 0% to 100%, estimating additional adverse events, healthcare costs, and years of life lost (YLL).

Results:
At the current reported contamination rate of 58.4%, MNPs were estimated to contribute to 139 additional adverse events, including 52 strokes, 53 myocardial infarctions, and 34 deaths, among 1900 Australian carotid endarterectomy patients. This corresponded to an additional AUD$25.5 million in healthcare costs and 441 YLL. A hypothetical 100% contamination rate increased the incremental burden to AUD$43.6 million and 881 YLL.

Conclusion:
MNP contamination may substantially increase the clinical and economic burden associated with carotid endarterectomy in Australia. Although model-based and subject to uncertainty arising from potential false positives of MNPs due to challenges with analysis in tissue matrices, these findings highlight MNPs as a plausible, previously unrecognised contributor to adverse vascular outcomes and healthcare expenditure.