Kidney disease, injury predict poor outcomes after TAVR

Patients with chronic kidney disease or end-stage renal disease who underwent transcatheter aortic valve replacement had an elevated risk for death, renal replacement therapy and worse outcomes, according to two studies published in JACC: Cardiovascular Interventions.

Renal replacement therapy after TAVR

“Some patients are adamant that they do not want to go on dialysis,” James W. Hansen, DO, structural interventional cardiology fellow at Lahey Hospital and Medical Center in Burlington, Massachusetts, 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.”

Hansen and colleagues analyzed data from 44,778 patients (mean age, 82 years; 49% women) from the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry who underwent TAVR from November 2011 to September 2015. Patients who were dialysis-dependent were excluded. Data from CMS on 30-day and 1-year outcomes were also reviewed.

Patients were categorized by stages of chronic kidney disease (CKD): stages 1 and 2 (51.13%), stage 3 (43.03%), stage 4 (5.39%) and stage 5 (0.46%). Stages 1 and 2 served as the control group.

The primary outcome was new requirement for renal replacement therapy, all-cause death or a composite of both at 30 days and 1 year after the procedure.

Preprocedural glomerular filtration rate was associated with risk for death (HR = 0.982; P < .001) after TAVR in patients with a glomerular filtration rate less than 60 mL/min/m². This also increased the risk for renal replacement therapy at 30 days. The risk for death significantly increased when the glomerular filtration rate was less than 30 mL/min/m².

At 30 days, incremental increases of 5 mL/min/m² in glomerular filtration rate was statistically significant (unadjusted HR = 0.71; P < .001), which continued at 1 year in patients whose glomerular filtration rate was less than 60 mL/min/m².

Thirty-three percent of patients with stage 4 CKD will die within 1 year and 14.6% will require renal replacement therapy, according to the study. Renal replacement therapy was required in 35% of patients with stage 5 CKD at 30 days and 60.1% of those patients needed it at 1 year.

“We have shown that [glomerular filtration rate] is a discrete and continuous variable that is associated with [renal replacement therapy] and death following TAVR,” Hansen and colleagues wrote. “This information can be used to facilitate informed decision-making in patients with advanced CKD. It can also be used to aid in the model development of outcomes following TAVR. Recognition of this risk can focus on future efforts on therapies to ultimately reduce the hazard of renal failure and need for postprocedure [renal replacement therapy].”

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“Physicians should be advised that patients with severely reduced [glomerular filtration rate] who experience additional comorbidities beyond chronic kidney disease may not benefit from TAVR because of high short- and long-term hazard,” Israel M. Barbash, MD, of the Sackler School of Medicine at Tel Aviv University in Ramat Gan, Israel, and Amit Segev, MD, senior lecturer at Tel Aviv University Medical School and senior interventional cardiologist at Chaim Sheba Medical Center, wrote in a related editorial. “If a procedure is planned, these patients should be meticulously informed of the high risk for postprocedural [renal replacement therapy] and mortality.”

Poor in-hospital outcomes

Patients with end-stage renal disease or CKD who underwent TAVR had worse in-hospital outcomes, and acute kidney injury is linked to higher in-hospital mortality, according to a separate study.

Tanush Gupta, MD, cardiology fellow at Montefiore Medical Center at Albert Einstein College of Medicine, Bronx, New York, and colleagues analyzed data from 41,025 patients (mean age, 81 years; 48% women) who underwent TAVR from the 2012 to 2014 National Inpatient Sample database. Patients had CKD (33.5%), no CKD (62.4%) or end-stage renal disease (4.1%) and were on long-term dialysis or no chronic dialysis.

The primary outcome of interest was all-cause in-hospital mortality. Secondary outcomes included discharge disposition in patients who survived hospitalization and length of stay. Additional outcomes that were examined were acute kidney injury and whether it required dialysis.

The incidence of in-hospital mortality was significantly higher in patients with end-stage renal disease (8.3%; adjusted OR = 2.58; 95% CI, 2.09-3.13) or CKD (4.5%; adjusted OR = 1.39; 95% CI, 1.24-1.55) vs. those without CKD (3.8%).

MACE, which was a composite of MI, death or stroke, occurred more in patients with CKD (9%) or end-stage renal disease (11.8%) vs. patients without CKD (8.3%; P < .001). The incidence of net adverse CV events, a composite of major bleeding, MACE or vascular complications, was also higher in patients with end-stage renal disease (34%) or CKD (25.9%) compared with those without CKD (22.9%; P < .001).

The rate of requirement for pacemaker implantation was also higher in patients with CKD or end-stage renal disease vs. those without CKD.

Risk-adjusted in-hospital mortality in patients without CKD was sevenfold higher in those with acute kidney injury vs. those without it (17.3% vs. 2.2%; P < .001). It was also 15-fold higher in patients with acute kidney injury that required dialysis compared with those who did not require dialysis (56.3% vs. 3.5%; P < .001).

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In patients with CKD, risk-adjusted in-hospital mortality was fourfold higher in patients with acute kidney injury vs. those without injury (9% vs. 2.3%; P < .001). It was also sevenfold higher in patients with acute kidney injury that required dialysis compared with patients who did not need dialysis (28.8% vs. 3.9%; P < .001).

Throughout the study period, the rate of acute kidney injury and injury that required dialysis did not decline.

“Future studies should focus on identifying methods for optimally risk stratifying patients with [end-stage renal disease] undergoing evaluation for TAVR,” Gupta and colleagues wrote. “Also, concerted efforts are required to define strategies to reduce the risk of [acute kidney injury] in patients undergoing TAVR.”

“Although none of these findings is necessarily surprising, the high rates of [acute kidney injury] and the markedly higher mortality rates linked to the occurrence of [acute kidney injury] are sobering and merit further attention,” Brian R. Lindman, MD, MSc, medical director of the Structural Heart and Valve Center and associate professor of medicine at Vanderbilt University Medical Center, wrote in a related editorial. “Pre-existing renal impairment will be an ongoing reality in this patient population when they are sent for treatment of their aortic stenosis. The pressing question is what can be done to decrease the risk of [acute kidney injury] and its adverse consequences.” – by Darlene Dobkowski

References:

Barbash IM, et al. JACC Cardiovasc Interv. 2017;doi:10.1016/j.jcin.2017.09.006.
Gupta T, et al. JACC Cardiovasc Interv. 2017;doi:10.1016/j.jcin.2017.07.044.
Hansen JW, et al. JACC Cardiovasc Interv. 2017;doi:10.1016/j.jcin.2017.09.001.
Lindman BR. JACC Cardiovasc Interv. 2017;doi:10.1016/j.jcin.2017.08.022.

Disclosures: Barbash, Gupta and Hansen report no relevant financial disclosures. Lindman reports he receives research grants from Edwards Lifesciences and Roche Diagnostics, serves on a scientific advisory board for Roche Diagnostics and consults for Medtronic and Roche Diagnostics. Segev reports he serves on the advisory board for Medtronic. Please see the studies for all other authors’ relevant financial disclosures.