Prevalence and risk factors of acquired long QT syndrome in hospitalized patients with chronic kidney disease

Patients with chronic kidney disease (CKD) have a high risk of fatal arrhythmias. The extended severe corrected QT (QTc) interval is a hallmark of ventricular arrhythmias and sudden cardiac death. The objective of this study was to evaluate the prevalence of acquired long QT syndrome (aLQTS) in hospitalized patients with CKD and search for potential risk factors to improve clinical risk stratification in patients with CKD. Information about patients with CKD was retrospectively collected in our hospital between January 2013 and June 2017. The prevalence of aLQTS in different stages of CKD was evaluated. The common risk factors for QTc prolongation in patients with CKD were compiled, and multivariable logistic regression analysis was used to evaluate how each factor was related to aLQTS in CKD. A total of 804 patients with CKD (299 females, 37.2%) participated in our study. The prevalence of aLQTS among all 804 patients was 56.97%, and the prevalence of QTc prolongation (>500 ms) was 10.07%. Among the elderly, impaired kidney function, hemodialysis, low serum potassium and low left ventricular ejection fraction (LVEF) were associated with QTc prolongation in patients with CKD. The prevalence of aLQTS is much higher and increases with the decline of kidney function in hospitalized patients with CKD, which is related to older age, impaired kidney function, hemodialysis, serum potassium and low LVEF.