Toxic heavy metal exposure and heart health: a systematic review and meta-analysis of 324,331 patients.

INTRODUCTION: Heavy metal pollution is a concerning cardiovascular risk factor and a major public health concern. While traditional cardiovascular disease (CVD) risk factors are well-established, environmental exposures are less recognized, despite their growing significance. METHODS: Adhering to PROSPERO and PRISMA guidelines, a search was conducted across PubMed, Cochrane, and Embase until April 2025 for studies involving patients with heart disease or stroke who were exposed to heavy metals. Primary outcomes were the events of CVD, CHD, and stroke. Proportions of events within populations with 95% confidence intervals were pooled. R software was used for the analysis, with statistical significance set at p < 0.05. RESULTS: We included 16 studies involving 324,331 participants. The cadmium subgroup showed a pooled proportion of 0.09 (95% CI: 0.01-0.17), with individual values ranging from 0.01 to 0.22; the arsenic subgroup showed a pooled proportion of 0.04 (95% CI: 0.04-0.04). The overall pooled proportion was 0.08 (95% CI: 0.01-0.15). Six studies found cases of CHD in groups exposed to cadmium and arsenic, with combined rates of 0.10 (95% CI: 0.00-0.22) for cadmium and 0.00 (95% CI: 0.00-0.00) for arsenic. The overall pooled proportion was 0.08 (95% CI: 0.00-0.18). Ten studies assessed CVD proportions by metal exposure. Arsenic showed a pooled proportion of 0.06 (95% CI: 0.00-0.18), cadmium 0.14 (95% CI: 0.00-0.31), lead 0.08 (95% CI: 0.01-0.14), and mercury 0.05 (95% CI: 0.04-0.06). The overall pooled proportion was 0.10 (95% CI: 0.03-0.17). CONCLUSION: This study emphasizes the significance of the toxic environmental metals contributing to cardiovascular risk beyond behavioural risk factors.