Cardiotoxicity of Metal Implant Wear: Emerging Insights into the Roles of Cobalt and Chromium

Cobalt (Co) and chromium (Cr) are widely used in medical implants due to their strength and biocompatibility. However, implant wear and corrosion can lead to systemic release of these metals, raising concerns about cardiotoxic effects, especially with long-term exposure. This review summarizes current data on the potential cardiotoxicity of implant-derived Co and Cr, focusing on molecular mechanisms, inflammatory responses, and clinical observations. Case reports and clinical studies document considerable variability in serum Co and Cr concentrations postimplantation, influenced by implant type, material composition, and patient-specific factors. While extreme elevations are strongly associated with cardiomyopathy and fibrosis, moderate increases also correlate with subclinical changes such as ventricular dilatation and impaired strain. Nonetheless, many studies fail to find a direct relationship between ion levels and cardiac dysfunction, highlighting the complexity and interindividual variability of toxic responses and underlying pathomechanisms. Existing experimental data suggest that Co and Cr ions interfere with calcium and magnesium handling, impair mitochondrial respiration, and promote the generation of reactive oxygen species. Additionally, both metals can induce inflammatory responses, including cytokine release that results in DNA damage, apoptosis, and impaired cardiomyocyte physiology. Although Co and Cr implants offer substantial clinical benefits, emerging evidence indicates that they may contribute to cardiotoxicity in susceptible individuals. Current findings emphasize the importance of personalized monitoring, including serum ion concentration assessments and advanced imaging techniques. Given the absence of universally accepted toxicity thresholds, further mechanistic and longitudinal clinical studies are essential to define risk stratification strategies, establish safe exposure limits, and improve the cardiovascular safety of patients with metal implants.