TAVR carries low dialysis risk for most kidney patients

Relatively few patients with chronic kidney disease (CKD) require dialysis after undergoing transcatheter aortic valve replacement (TAVR), according to a new study.

The findings, published online Oct. 16 in JACC: Cardiovascular Interventions, represent the first comprehensive data on the risk of dialysis for CKD patients undergoing TAVR, said lead researcher James W. Hansen, DO, structural interventional cardiology fellow at the Lahey Hospital and Medical Center in Burlington, Massachusetts.

“Some patients are adamant that they do not want to go on dialysis,” Hansen said in a press release. “Now doctors will be better able to answer the question of their risk of dialysis if they undergo valve replacement.”

The researchers studied nearly 45,000 patients—51.3 percent male with an average age of 82—who underwent TAVR over a four-year period. Patients were organized by stage of CKD, which is determined by how much blood can be filtered through the kidney in a given period of time. Stages 1 and 2, combined, served as the control group.

In that control group, 0.7 percent of patients had started dialysis 30 days after TAVR and 1.2 percent had started it after one year. Among patients with stage 3 CKD—representing 43 percent of the study cohort—the 30-day dialysis rate was 2.2 percent and the one-year rate was 3.5 percent.

“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’re encouraged that the absolute rate of new dialysis is relatively low in stage 3 patients,” Hansen said. “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.”

Outcomes among stage 4 and 5 patients were significantly worse. About one-third of stage 4 patients died within a year of TAVR and one-sixth required dialysis. More than one-third of stage 5 patients required renal replacement therapy (RRT) within 30 days and 60 percent required it at one year.

About 30 percent of patients in both stage 4 and 5 died within a year. The researchers said a low number of patients and selection bias could have suppressed the mortality rate among stage 5 patients.

In an accompanying editorial, Israel Barbash, MD, and Amit Segev, MD, pointed out less than 6 percent of TAVR patients have advanced chronic kidney disease (stage 4 or 5).

“In this respect, the manuscript by Hansen et al. provides the physician invaluable information by identifying a small subgroup with an extremely high risk of RRT or death,” they wrote. “Physicians should be advised that patients with severely reduced GFR (glomerular filtration rate) who experience additional comorbidities beyond chronic kidney disease may not benefit from TAVR because of high short- and long-term hazard. If a procedure is planned, these patients should be meticulously informed of the high risk for post-procedural RRT and mortality.”