Association of blood essential and non-essential element levels with echocardiographic parameters among Saudi heart failure patients: a case-control study

Background Essential elements such as manganese (Mn), iron (Fe), and zinc (Zn) are critical in for cardiovascular function, whereas exposure to non-essential toxic metals, including cadmium (Cd) and chromium (Cr) may contribute to cardiac dysfunction and the development or progression of heart failure (HF). Aim This study evaluated the blood levels of Mn, Fe, Zn, Cd, and Cr in adult Saudi patients with HF and in controls with normal ventricular function, and explored their associations with HF status, functional class, and echocardiographic parameters. Methods Consecutive adult patients referred for clinically indicated transthoracic echocardiography at the outpatient department of King Fahad Medical City hospital between November 2019 and March 2020 were invited to participate. Clinical data were collected, echocardiograms were reviewed, and blood concentrations of of Mn, Fe, Zn, Cd, and Cr were measured using atomic absorption spectrophotometry. Result A total of 180 participants were included (mean age 60.3 years), of whom 65.6% had HF. Most measured element levels were within reference ranges, except for Mn, which was below the reference range (4 ug/L) in 98% of participants, with median (IQR) of 0.40 (0.30, 0.60). Higher Cr levels were observed among younger participants ( P = 0.046). Higher Cd levels were associated with increased left ventricular dilatation ( P = 0.013; P 0.001 after adjusting for confounders). Conversly, higher Mn levels were associated with lower lateral mitral annular velocity in univariate analysis ( P = 0.04), but this association was not retained after multivariable adjustment ( P = 0.099). Conclusion This study provides insight into Mn, Fe, Zn, Cd, and Cr concentrations across a spectrum of HF severity. Alteration in Cd and Mn blood levels were associated with selected echocardiographic markers of HF severity. Further longitudinal studies are needed to establish the prognostic significance of element imbalances in HF.