Non-ischemic myocardial fibrosis after long-term asbestos exposure

To determine whether or not myocardial fibrosis in the left ventricle increases after exposure to asbestos fiber, we studied myocardial fibrosis in 42 autopsied hearts; 17 of asbestosis (AS) and 18 of chronic pulmonary disease (CP) without pneumoconiosis. Seven patients with extracardiopulmonary disease were used as a control group (CONT). The extent of myocardial fibrosis in the left ventricle was significantly greater in the AS group compared to the other groups (AS 3.6 +/- 1.3% vs. CP 2.4 +/- 1.0% vs. CONT 1.6 +/- 0.8%). There was a significant difference in the appearance ratio of focal fibrosis between the asbestosis group and the other groups. Focal fibrosis was observed in none of 7 control patients, in 3 of 18 patients with chronic pulmonary disease and in 9 of 17 patients with asbestosis. We concluded that characteristic myocardial fibrosis was observed in humans after long-term asbestos exposure.