Study Evaluates Patients With Kidney Disease After Undergoing TAVR

October 16, 2017—The American College of Cardiology (ACC) announced the publication of a study demonstrating a relatively low rate of patients with chronic kidney disease undergoing transcatheter aortic valve replacement (TAVR) who eventually need to start dialysis. The study was published by James W. Hansen, DO, et al in Journal of the American College of Cardiology (JACC): Cardiovascular Interventions (2017;10:2064–2075).

According to the ACC, the new findings may allow doctors to be more aggressive with their care of patients who previously may not have been considered good candidates for TAVR because of their underlying kidney disease.

Dr. Hansen noted in the ACC press release that the findings will help physicians and patients with chronic kidney disease make more informed decisions about whether patients are good candidates for TAVR. He commented, "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." Dr. Hansen is a structural interventional cardiology fellow at the Lahey Hospital and Medical Center in Burlington, Massachusetts.

As summarized by ACC, using data from the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry, the study included 44,778 patients who underwent TAVR from November 2011 through September 2015. Patients were organized into groups according to stage of chronic kidney disease; combined stages 1 and 2 served as a control group. None of the patients were on dialysis at the start of the study.

The investigators 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 1 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 1 year. Stage 3 patients represented 43% of the patient cohort.

Dr. Hansen explained, "While patients with more severe chronic kidney disease do have a higher rate of both death and dialysis at 30 days and 1 year, we're encouraged that the absolute rate of new dialysis is relatively low in stage 3 patients." Until now, he stated, there has been no comprehensive data on the risk of dialysis for chronic kidney patients undergoing TAVR. He added, "While we have no way to predict any individual's outcome, we can tell patients that out of a cohort of patients similar to yourself, this is the likelihood of what can happen."

Patients with stage 4 or 5 kidney disease have a greater risk of dialysis at 1 month and 1 year compared with stage 3 patients. The study found one-third of stage 4 patients died within 1 year of TAVR, 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 1 year.

In an editorial on the study in JACC: Cardiovascular Interventions, Israel M. Barbash, MD, and Amit Segev, MD, agreed that the findings provide a reassuring message (2017;10:2076–2077). They point out that only patients with advanced chronic kidney disease showed high rates of dialysis (35%) at 30 days. They stated, "In this context, it should be emphasized that this high-risk group represents a small minority of the entire TAVR population, less than 6% of the patients."