Excluded From Trials, Patients With Severe Kidney Disease Benefit Less From TAVR

There’s more evidence that patients with chronic kidney disease (CKD) fare worse following TAVR, this time from a large US database of more than 42,000 patients treated between 2011 and 2014.

While the findings may not be much of a surprise, they serve as a reminder to physicians that despite the high numbers of patients with severe renal insufficiency now undergoing TAVR, this group was specifically excluded from randomized trials that led to device approvals in the first place. Moreover, physicians should be doing “everything in their power” to prevent at-risk patients from developing further renal deterioration post-TAVR, senior author Milind Y. Desai, MD (Cleveland Clinic, OH), told TCTMD.

Desai and colleagues, along with first author Divyanshu Mohananey, MD (Cleveland Clinic), reviewed TAVR cases between the years of 2011 and 2014 that were included in the National Inpatient Sample. They report that of the 42,189 patients who underwent TAVR in this period, more than one-third had either CKD (33.7%) or end-stage renal disease (ESRD, 4%). Compared with patients who had no kidney disease, those who did were more likely to die in the hospital, develop hemorrhage requiring transfusion, or need a pacemaker. Cardiac complications and vascular complications were also more common in patients with ESRD as compared to those in the no-CKD group.

Not surprisingly, acute kidney injury during TAVR was seen more commonly in patients with existing CKD than in patients with no CKD at baseline.

Complications in Patients With vs Without CKD/ESRD

To TCTMD, Desai stressed that the focus in this paper was not on the important problem of patients with normal renal function who develop renal dysfunction following TAVR, but rather on those patients already identified as having kidney disease preprocedure. “You take any population and you put renal dysfunction in the mix and you take a large enough sample and follow long-term, people with renal dysfunction will always do worse in the long run,” Desai said. And while that won’t be new information to physicians performing TAVR now, it does underscore the need to make sure kidney disease is identified at the outset.

“As TAVR moves into the younger realm, we should be doing everything in our power to be sure that we don't take a person in renal dysfunction and make them worse,” Desai said, or that the TAVR procedure itself doesn’t lead to new renal dysfunction in patients who didn’t have the problem in the first place.

Desai added that surgeons will often send patients with CKD or ESRD for a TAVR work-up, believing that these patients will likely do better with a less-invasive procedure. “Maybe, maybe not,” Desai said. This has not been specifically studied. In fact, he continued, while multiple trials have compared patients undergoing surgical versus transcatheter valve replacement, none have specifically looked at TAVR versus the standard of care in a population with renal insufficiency, nor has a study prospectively compared outcomes in patients with or without CKD/ESRD undergoing TAVR.

“So far, over the last 5 years or so,” Desai said, “we've been focused on the question: which patients should undergo TAVR? Now I think especially with the younger folks getting this, should we be asking the question: where would it be cost ineffective to stop the train? Is there such a thing as a cost-ineffective TAVR?”

Risks and Benefits

Commenting on the study for TCTMD, Sameer Gafoor, MD (Swedish Heart and Vascular Institute, Seattle, WA), agreed that the presence of CKD will play an important part in physician decision-making and will adversely affect outcomes, but said he didn’t “think that there are many CKD patients right now who should not be considered for TAVR. The patient who potentially would not be a good TAVR candidate is the one with very poor renal function who could end up on dialysis afterwards, and that needs to be part of the informed decision-making with the patient.”

On the other hand, patients already on dialysis may actually do better after aortic valve replacement “because the combination of ESRD and aortic stenosis is a tough one, in part because the fluid shifts that happen during dialysis can be exacerbated in the setting of severe aortic stenosis, and this may limit effective dialysis,” he explained

Gafoor seemed less convinced that trials looking specifically at TAVR versus usual care are essential at this juncture. “I think we will get some of that information from large-scale registries and that’s an important place to start. It will also be important to look at durability of TAVR and SAVR in patients with CKD,” he said. “I think registries will give us much if not all of the information we need if we structure them correctly.” 

The “take-home” message from this paper “is that CKD patients need to be carefully managed pre-, peri- and post-TAVR, which requires oversight and discussion both in TAVR meetings and from an operations standpoint,” Gafoor summarized. “When somebody comes in with CKD the heart team should thinking not only about what tests are needed for evaluation, but the timing of those tests, hydration, and contrast adjustment for procedures/imaging.”

For example, Gafoor continued, evaluations of the aortic annulus can be done with 20 cc of contrast or less, or by using 3-D transesophageal echo instead. A number of groups are also perfecting “contrast-free TAVR” using ultrasound guidance for femoral artery access, with intravascular ultrasound if needed, and either two marker pigtails or transesophageal echo guidance for positioning, Gafoor said.

As a final point, Gafoor noted that techniques and technology have advanced considerably since 2014—the last year captured in the current paper. “We use newer-generation valves with smaller access, use less contrast in evaluation and during the procedure, have less bleeding, and implant at higher depths to have lower pacemaker rates,” he said. “We can use the information from 2014 to guide but not dictate what the results will be in 2017, and soon 2018, because the technology is changing too fast.”