Myocardial and microvascular remodeling in dust-related lung pathology as a morphological substrate of occupational cardiomyopathy in miners

Introduction. Heart diseases are the leading cause of death among miners (>60%). Between 2000 and 2016, 1,797 acute cardiovascular events occurred at the workplace, including 467 fatal cases. These are usually classified as ischemic heart disease, but this is not confirmed by microscopy and does not account for direct damage to the heart by coal-rock dust.

Objective. To provide microscopic evidence for defining “dust cardiomyopathy” as a distinct occupational heart disease.

Materials and methods. Heart tissue from 80 miners (work experience from 1 to 30 years) and 30 age‑matched healthy controls was examined using histology, histochemistry, and immunohistochemistry (markers CD34, CD31, α-SMA, TGF-β1, Bcl-2) with morphometric measurements.

Results. With increasing work experience, microvessel walls thickened by 1.5–2.5 times, and endothelial cell area increased by 2–4 times. As early as 1–5 years of exposure, lipofuscin pigment appeared in cardiomyocytes (area 143.7±33.6 µm²), peaking at 12–20 years (159.6±33.4 µm²) — significantly higher than in controls (p<0.001). Cardiomyocyte diameter increased up to 20.02±4.66 µm, heart weight to 530–580 g. For the first time, there was demonstrated a sign of endothelial‑to‑mesenchymal transition as the appearance of CD31 and CD34 proteins in vessel walls.

Limitations. Autopsy remains the gold standard for determining the cause of death. Experimental animal studies also end with autopsy, which does not question their validity. The study was conducted only on material from Kuzbass, using samples from those who died in industrial catastrophes, which requires careful interpretation.

Conclusion. The obtained morphological data provide a scientific basis for distinguishing dust cardiomyopathy as an independent occupational heart disease. Its hallmarks are damage to the inner lining of vessels, perivascular fibrosis, and lipofuscin accumulation. Further clinical studies are needed for final confirmation.

Compliance with ethical standards. The protocol was approved by the local ethics committee (Protocol No. 4, 21.11.2024).

Contribution:
Bondarev O.I. — concept, design, writing, editing;
Filimonov E.S. — material collection, data processing, literature review.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Conflict of interest. The authors declare no conflict of interest.

Funding. The study had no sponsorship.

Received: April 24, 2026 / Revised: May 17, 2026 / Accepted: July 1, 2026 / Published: August 14, 2026

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