Discussion
HD, arrhythmia, fibrosis, arrhythmias
ARRHYTHMIA, RECRUITMENT, FIBROSIS, ATRIAL FIBRILLATION, EVENTS, ARRHYTHMIAS
In this Although one of the major effects of mineralocorticoid receptor stimulation by aldosterone is to promote renal sodium reabsorption and potassium secretion in the distal nephron, the mineralocorticoid receptor is known to be present in many other cell types, with overactivation being associated with development of fibrosis of the heart,Atrial fibrillation is the most common clinically evident arrhythmia in HD patients and has been found to occur in up to 40% of patients in studies using implantable loop recorders.Recent studies using implantable loop recorders in patients receiving maintenance HD have consistently reported a relatively high frequency of bradycardic and conduction block events.There are notable strengths to our present analyses, including the use of continuous electrocardiographic monitoring, the evaluation of multiple doses of spironolactone with placebo comparisons, and the recruitment and detailed follow-up of patients from multiple centers in the setting of a randomized controlled trial. However, there are several limitations to be acknowledged. Only a subset of SPin-D participants were included in the continuous monitoring component of the trial, follow-up was relatively short, and patients were younger and had better preservation of ejection fraction than the overall HD population in the United States, thus limiting generalizability. Not all patients in the monitoring substudy contributed arrhythmia data at all time points, raising the possibility of some element of selection bias and precluding analyses according to the interdialytic interval. Furthermore, the small sample size and lack of blood collection that was standardized with respect to the timing of the rhythm monitoring periods limited the ability to conduct explanatory and mechanistic analyses. Finally, owing to the modest sample size, the categories of prespecified arrhythmias were necessarily broad with small numbers of events precluding meaningful subgroup analyses—thus, the relative clinical importance of subtypes within a category may also not be comparable.In summary, in this 