James W Hansen (Lahey Hospital and Medical Center, Burlington, USA) and others report in JACC: Cardiovascular Interventions that the number of patients with chronic kidney disease who subsequently require dialysis after undergoing transcatheter aortic valve implantation (TAVI) is relatively low.
According to Hansen, this finding will help physicians and patients with chronic kidney disease make more informed decisions about whether patients are good candidates for TAVI.
The study, using data from the Society of Thoracic Surgeons/American College of Cardiology TVT Registry, included 44,778 patients who underwent TAVI between November 2011 and September 2015. Patients were organised into groups according to stage of chronic kidney disease; combined stages 1 and 2 (the least severe) served as a control group.
Hansen et al found that among patients with stage 3 chronic kidney disease, 2.2% had newly started dialysis 30 days after surgery and 3.5% had started dialysis one year after surgery. In contrast, among patients with stages 1 and 2 chronic kidney disease, 0.7% had started dialysis after 30 days and 1.2 % started dialysis after one year. Stage 3 patients represented 43% of the patient cohort.
Additionally, one-third of stage 4 patients died within one year of TAVI, with about one-sixth requiring dialysis. In stage 5 patients, more than one-third of patients required dialysis within 30 days and almost two-thirds required it at one year.
“While patients with more severe chronic kidney disease do have a higher rate of both death and dialysis at 30 days and one year, we are encouraged that the absolute rate of new dialysis is relatively low in stage 3 patients,” Hansen comments. He adds that although there was “no way to predict any individual’s outcome”, we can tell patients that “this is the likelihood of what can happen” to a cohort of patients similar to themselves.
Hansen further observes: “Some patients are adamant that they do not want to go on dialysis. Now doctors will be better able to answer the question of their risk of dialysis if they undergo valve replacement.”
In an editorial accompanying the study, Israel M Barbash (Sackler School of Medicine, Tel Aviv University, Israel) agreed that the findings provide a reassuring message. They indicate that only patients with advanced chronic kidney disease suffer from high rates of dialysis (35%) at 30 days.
“In this context, it should be emphasized that this high-risk group represents a small minority of the entire TAVI population, less than 6% of the patients,” he says.