Heart attacks & Microplastics

The results of a study conducted at the Department of Advanced Medical and Surgical Sciences, University of Campania, show that microplastics and nanoplastics (MNPs) are emerging as a potential risk factor for cardiovascular disease in preclinical studies.

Methods

In this research, a prospective, multicenter, observational study conducted on patients who were undergoing carotid endarterectomy for asymptomatic carotid artery disease. The excised carotid plaque specimens were analyzed for the presence of MNPs with the use of pyrolysis–gas chromatography–mass spectrometry, stable isotope analysis, and electron microscopy. Inflammatory biomarkers were assessed with enzyme-linked immunosorbent assay and immunohistochemical assay. The primary end point was a composite of nonfatal myocardial infarction, nonfatal stroke, or death from any cause among patients with plaque containing MNPs and patients with plaque that did not contain those substances. Secondary end points included levels of tissue biomarkers interleukin-18, interleukin-1β, tumor necrosis factor α (TNF-α), interleukin-6, CD68, CD3, and collagen in patients with evidence of MNPs as compared with those without.

Patients

Patients were eligible if they were 18 to 75 years of age, had asymptomatic extracranial high-grade (>70%) internal carotid artery stenosis, and were scheduled to undergo carotid endarterectomy. Exclusion criteria were evidence of heart failure, valvular defects, malignant neoplasms, or secondary causes of hypertension. Patients with complications in the postoperative period before discharge, who had incomplete data, or who were lost during follow-up were excluded from the analysis.

Results

A total of 304 patients were enrolled in the study, and 257 completed a follow-up of 34 months. Polyethylene was detected in carotid artery plaque of 150 patients, with a mean level of 21.7±24.5 μg per milligram of plaque; 31 patients also had measurable amounts of polyvinyl chloride, with a mean level of 5.2±2.4 μg per milligram of plaque. Electron microscopy revealed visible, jagged-edged foreign particles among plaque macrophages and scattered in the external debris. Radiographic examination showed that some of these particles included chlorine. Patients in whom MNPs were detected within the atheroma were at higher risk for a primary end-point event (a composite of myocardial infarction, stroke, or death from any cause) than those in whom these substances were not detected.

Ref: Published March 6, 2024

DOI: 10.1056/NEJMoa2309822

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