Risk of mortality associated to chronic kidney disease in patients with complete left bundle branch block.

Chronic kidney disease (CKD) is associated with cardiac conduction defects and is a strong risk factor for heart failure. Complete left bundle branch block (cLBBB), a cardiac conduction abnormality, may have an unfavorable effect on ventricular mechanical synchrony and lead to the progression of heart failure. Once heart failure develops, it seems to act together with underlying CKD in a vicious circle. Therefore, this study aimed to explore the influence of CKD in patients with cLBBB by assessing the estimated glomerular filtration rate (eGFR). We examined a hospital-based sample of 416 adult patients with cLBBB from 2010 to 2013. The eGFR was calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Cox proportional hazard models were used to estimate the hazard ratio for all-cause mortality and cardiovascular mortality. A total of 416 adult patients with a mean age of 71 ± 13 years were enrolled. The median follow-up period was 3.6 years. After adjusting for clinical, electrocardiographic parameters, and medication use, cox regression analysis showed that total mortality was significantly associated with older age (Hazard Ratio (HR) = 1.03, 95% CI = 1.01-1.05, p = 0.002), presence of congestive heart failure (HR = 2.39, 95% CI = 1.63-3.49, p < 0.001), advanced CKD (HR = 2.48, 95% CI = 1.71-3.59, p < 0.001), higher HR (HR = 1.02, 95% CI = 1.01-1.03, p < 0.001) and without use of ACEI/ARB (HR = 0.59, 95% CI = 0.41-0.85, p = 0.005) were independent predictors of the total mortality. Multivariate Cox hazard regression analysis demonstrated that, in comparison to patients lacking cLBBB, the coexistence of CKD (eGFR < 60 mL/min/1.73 m) among those with LBBB significantly heightened the risks of both total mortality (HR ratio of 5.01 vs. 2.40) and CV death (HR ratio of 61.78 vs. 14.41) even following adjustment for clinical covariates and ECG parameters. In summary, within patients exhibiting cLBBB, the presence of CKD serves as a significant risk factor for all-cause mortality.