Abstract
Chronic kidney disease (CKD) is a very common co-morbidity in patients with cardiovascular disease, particularly in those with atrial fibrillation (AF). There is an increasing number of patients on haemodialysis who have AF and its impact is not fully understood.
To assess the prevalence of AF in patients on haemodialysis, trying to identify predictors of AF development.
Unicentric, retrospective study including all patients admitted to the Nephrology ward from October 2020 to December 2020 who had CKD. Cardiovascular risk factors, known cardiac disease, time on haemodialysis, type of vascular access and demographic data were analysed. The control group was comprised of hospitalized CKD patients who were not on renal replacement therapies.
A total of 126 patients were included, 57 on dialysis. Mean age for the renal replacement therapy group was 71.07±15.68 years and for the control group was 72.59±14.74 years old (p=0.575). There was an increased proportion of patients with type 2 diabetes mellitus in the control group (39 vs 20, p=0.021). No statistically significant differences were found regarding hypertension, heart failure, coronary disease or sleep apnoea between groups.
The prevalence of AF was similar in both the haemodialysis and the control group (26.3% vs 24.6%, p=0.829). Age, heart failure and coronary disease were significant risk factors for AF, irrespective of the studied group (p<0.05). There was also a significant correlation between time on dialysis and a greater likelihood of presenting AF (p<0.05). There was no correlation with type of vascular access.
Using the Youden index, an age of 80.5 years was determined as the cut-off for an increased prevalence of AF, irrespective of the study group (sensitivity of 66.7%; Specificity of 78.8%). Using ROC curves, an area under the curve (AUC) of 0.74 was obtained for age and the likelihood of AF (figure 1). Regarding time on dialysis, a cut-off point of 4.5 years was obtained with an AUC of 0.67 (sensitivity of 73% and specificity of 68.7%) (figure 2).
AF is very common in patients with end-stage renal disease, with a prevalence estimated to be 4 times greater than the general population. Our results suggested that, while haemodialysis may not be a risk factor for AF by itself, a longer time on haemodialysis may contribute to its onset. Age was also a contributing factor. Further prospective studies with more homogeneous groups are needed to clarify its role as an independent risk factor for AF.
Figure 1. Age as predictor of AF
Figure 2. Time on dyalisis as predictor of AF
