Relationship between iron deficiency and corrected QT-interval prolongation in Japanese patients undergoing maintenance hemodialysis.

BACKGROUND

The cause of QT-interval prolongation in patients undergoing hemodialysis (HD) remains unknown. Lower transferrin saturation (TSAT) is associated with cardiovascular complications in patients with chronic kidney disease. This study aimed to evaluate the association of iron deficiency with QT-interval prolongation in patients undergoing HD.

METHODS

This cross-sectional study included adult patients undergoing maintenance HD who were enrolled in the 2020 Japanese Society for Dialysis Therapy Renal Data Registry. Multivariable logistic regression analysis was performed with serum ferritin level and TSAT as explanatory variables and QT-interval prolongation (corrected QT interval > 500 ms) as the outcome. A restricted cubic spline (RCS) with three knots was used to explore potential non-linear relationships.

RESULTS

Of 175,448 patients, 13,343 (7.6%) experienced QT-interval prolongation. In the multivariable analysis, the RCS between logged serum ferritin level and QT-interval prolongation was non-linear, indicating that QT-interval prolongation does not increase at a constant rate with higher ferritin levels. Contrastingly, the RCS between TSAT and QT-interval prolongation showed an inverse relationship, indicating that lower TSAT is associated with a higher risk of QT-interval prolongation.

CONCLUSIONS

Low TSAT is associated with QT-interval prolongation in patients undergoing HD. Circulatory iron deficiency may play a role in prolonging ventricular repolarization time, independent of other risks in patients undergoing HD. These findings could help prevent and manage QT-interval prolongation.