TAVR in End-stage Renal Disease: Increased Risk Highlights Research Gaps

Transcatheter aortic valve replacement in patients with end-stage renal disease (ESRD) is associated with higher in-hospital mortality and bleeding than in those who are not dependent on dialysis, new registry data confirm. But some patients clearly derive benefit, and further research is needed to determine how to best select the patients with severe aortic stenosis who will do well with this procedure, investigators say.

Prior research has shown that patients with chronic kidney disease more often have a poor prognosis following TAVR compared with those with normal kidney function; however, the data are limited since this population has typically been excluded from clinical trials.

“Although there is a subset of patients who survive more than 1 year, careful selection of the ESRD patient is required to focus the therapy on patients who will survive long enough to receive benefit,” write Molly Szerlip, MD (Baylor Scott and White Health, Plano, TX), and colleagues. “Careful adjudication of the technology should be done to ensure that TAVR is offered to patients who will benefit the most from it.”

Higher Mortality, Bleeding

For the study, published in the June 11, 2019, issue of the Journal of the American College of Cardiology, Szerlip and colleagues compared demographics, risk factors, and outcomes between 3,053 ESRD patients and those not on dialysis who were enrolled in the Society of Thoracic Surgeons/American College of Cardiology TVT Registry between November 2011 and June 2016. ESRD patients were generally younger, more often male and African-American, and had more comorbidities at baseline.

Most TAVRs were elective, but there was a higher prevalence of urgent procedures in the ESRD group (17.2% vs 8.9%; P < 0.01). Additionally, the transfemoral approach was used less often in ESRD patients 76.4% vs 78.4%; P = 0.01), although device success was similar (92.4% vs 93.0%; P = 0.017). Hospital stays were longer (mean 6 vs 5 days; P < 0.001) and VARC major bleeding events were more common (1.4% vs 1.0%; P = 0.03) in patients with versus without ESRD, but there were no differences in rates of vascular-site complications, unplanned vascular procedures, and stroke.

In-hospital mortality was higher for patients with ESRD (5.1% vs 3.4%; P < 0.001), but the observed/expected mortality rate was lower (0.32 vs 0.44; P < 0.01). The presence of renal dysfunction also incrementally increased mortality risk at 30 days, 6 months, and 1 year but seemed to have no effect on stroke. Dialysis was a strong predictor of 1-year mortality (adjusted HR 1.28; 95% CI 1.17-1.41).

“Collectively, these findings demonstrate the important effect of severe renal disease in this patient population,” the researchers write.

Set ‘Realistic Expectations’

In an editorial accompanying the study, George Bayliss, MD (Brown University, Providence, RI), writes that the take-home message of this study “is that TAVR is a high-risk procedure for anyone with ESRD on dialysis or even approaching the need for dialysis.”

To optimally decide whether to perform TAVR in a patient receiving dialysis, “physicians need to know more than the outcome for ESRD patients compared to patients without ESRD,” he stresses. “What separates dialysis patients who undergo a successful TAVR from those who do not? What are the alternatives and outcomes for dialysis patients with critical aortic stenosis who do not receive a TAVR compared to those who do? These questions are outside the scope of this paper, but knowing how to answer them is crucial.”

Szerlip and colleagues also call for further work in “identifying the factors associated with survival after TAVR in patients with ESRD to improve patient selection.”

In the meantime, they note the importance of determining and setting realistic expectations for survival and rehospitalization before sending an ESRD patient for TAVR and advise thinking carefully before deciding to treat AS patients with ESRD who are at high risk and require a nontransfemoral approach.

“Although ESRD may not be an absolute contraindication to TAVR, just because we can replace the valve does not mean we should in every dialysis patient with severe AS,” Bayliss concludes.