Renal Function Gains Seen in CKD Patients After TAVR

Kidney function is more likely to get better than worse in aortic stenosis patients with renal disease who undergo TAVR, according to new data from the PARTNER trials.

Speaking with TCTMD, Robert J. Cubeddu, MD (Cleveland Clinic Florida, Weston), lead author of the analysis, said the high prevalence of renal failure in patients with severe aortic stenosis is illustrated by the fact that 91% of patients had chronic kidney disease (CKD) stage 2 or greater.

“It also highlights that there is a strong relationship between the two entities—aortic stenosis and renal failure—and that this is not entirely coincidental or related just to age. There's a plausible intrinsic mechanism of pathophysiologic relationship, if you will, between aortic stenosis and renal insufficiency,” he added. “After you complete a TAVR procedure and you relieve the aortic stenosis, the kidney function is more likely to improve than worsen.”

In an editorial accompanying the study in the Journal of the American College of Cardiology, Benjamin Z. Galper, MD, MPH (Mid-Atlantic Permanente Medical Group, McLean, VA), and colleagues observe that TAVR may arrest the downward spiral of cardiorenal syndrome and say that “it seems reasonable to recommend TAVR with judicious contrast use as part of a strategy to stabilize and improve kidney function in patients with progressive CKD and severe aortic stenosis who are otherwise good candidates for the procedure.”

Until now, we really have not had any clinical guidelines, any clinical tool, or data to look at a patient straight in the eye who's got stage 4 kidney disease and who needs a valve replacement, and tell them, ‘Your odds of ending up on dialysis are very high, are rare, are very unlikely.’ . . . We just didn't know. Robert Cubeddu

According to Galper and colleagues, the new data could change the way physicians manage those with severe symptomatic aortic stenosis and CKD.

“Previously, both CKD patients and their physicians may have been reluctant to pursue TAVR, fearing worsening postprocedure renal function,” they write. “The findings of this study will influence shared decision-making between CKD patients and the heart team.”

Only one Patient Progressed to Stage 5

For the analysis, Cubeddu and colleagues looked at change in CKD stage for 5,190 patients who underwent TAVR in the PARTNER 1, PARTNER 2, and PARTNER 2 Sapien 3 (S3) trials between April 2007 and October 2014.

Within 7 days of TAVR, the researchers documented either improvement or unchanged CKD status in most patients across all stages of renal disease: stage 1 (77%), stage 2 (90%), stage 3A (89%), stage 3B (94%), and stage 4 (99%). Only one patient progressed to CKD stage 5 after the procedure. Additionally, only 2% of patients required dialysis following TAVR.

Approximately two-thirds of patients had estimated glomerular filtration rate (eGFR) measurements taken within 7 days of TAVR. Higher baseline eGFR and the transfemoral approach were associated with higher post-TAVR eGFR, while greater body mass index, diabetes, greater left ventricular hypertrophy, mitral valve regurgitation, and major bleeding were associated with lower post-TAVR eGFR. Higher levels of two echocardiographic variables at baseline, visual left ventricular ejection fraction and mean aortic valve gradient, also were associated with higher eGFR.

In the 2,156 patients who died over the follow-up periods of the individual trials, having lower risk-adjusted baseline and post-TAVR eGFR were both associated with early mortality.

Contrast volume was a median of 100 mL, with lower volumes used in patients with higher baseline eGFR. In post-TAVR analyses, use of higher contrast volume was not statistically significantly associated with higher post-TAVR eGFR at 7 days.

Support for Cardio-Renal Syndrome

To TCTMD, Cubeddu said the findings provide “a good deal of reassurance” for both physicians and patients alike.

“Until now, we really have not had any clinical guidelines, any clinical tool, or data to look at a patient straight in the eye who's got stage 4 kidney disease and who needs a valve replacement, and tell them, ‘Your odds of ending up on dialysis are very high, are rare, are very unlikely.’ . . . We just didn't know,” he commented. “The fact that the kidney function gets better in so many of these patients supports our belief that there is a cardiorenal syndrome, a relationship between aortic stenosis and kidney disease, that perpetuates in time.”

What all of this is telling us is that it's better to perform the TAVR, and that you can do so without too much risk of renal compromise. Sameer Gafoor

Galper and colleagues add that, based on the data from Cubeddu and colleagues, “patients with stage 3B and stage 4 CKD being considered for TAVR can be reassured that there are only 6% and 1% chances, respectively, of CKD progression with TAVR.”

Commenting on the study for TCTMD, Sameer Gafoor, MD (Swedish Heart and Vascular Institute, Seattle, WA), said the results are impressive.

“I think this really helps us understand that there is a sizable component to valve disease in this really complex condition called the cardiorenal syndrome,” he noted. “Using these data, you can help educate your patients with some real-life numbers and it helps us push for even less contrast.”

While contemporary practice is evolving toward a “do more with less” attitude with regard to contrast use in TAVR, Gafoor said the data from the PARTNER series demonstrate that even during the 2007 to 2014 time frame of those trials, patients were being treated safely and avoiding further kidney injury. That’s important, he added, because in addition to using less contrast, it appears that multiple procedural and periprocedural factors that can put patients at risk for kidney injury have become less of an issue as TAVR has improved and matured.

“What all of this is telling us is that it's better to perform the TAVR, and that you can do so without too much risk of renal compromise,” Gafoor said.