Coronary Access After TAVR May Be Challenging

Debra L Beck

April 02, 2020

Three recent reports shed light on a topic that has so far received little attention: impeded access to the coronary arteries after transcatheter aortic valve replacement (TAVR).

Nonoptimal alignment of the transcatheter heart valve and the coronary ostia, which lie just above the aortic valve, was seen in up to 35% of patients.

However, evidence that post-TAVR interventions were not feasible or higher risk is limited.

"This is not something that should deter you from doing TAVR, as the surgeons are maybe advising, but it may impact on valve selection and being more careful on positioning. That said, I believe that it's going to be, in most cases, a temporary problem because the industry will come with solutions," said one of the authors, Ron Waksman, MD, MedStar Washington Hospital Center, Washington, DC.

The reports were published in the March 23 issue of JACC: Cardiovascular Interventions.

In the early TAVR days, the procedure was only done on elderly patients with relatively short longevity, explained Waksman in an interview. Because post-TAVR coronary access wasn't an issue people worried much about, the first-generation TAVR devices did not address the problem.

Now, with progressively younger and less-ill patients undergoing TAVR, the issue of whether it's more difficult to perform cardiac catheterization or intervention on patients who have had TAVR is a "potential" issue, although one that Waksman took pains to point out is not what one might consider a "big" problem.

"Theoretically, it's something that might disturb you should you need to do a reintervention, particularly an emergent one, because the procedure might be more technically challenging, but I think it's a little bit of an exaggeration to consider it a big problem," he said.

Study Series Published

In the first study, Waksman's group, including senior author Toby Rogers, MD, PhD, also from MedStar, looked at a cohort of TAVR patients from the Low Risk TAVR (LRT) trial. Of the 200 patients at low surgical risk enrolled, 177 received the balloon-expandable SAPIEN 3 valve (Edwards Lifesciences).

In 137 of those patients for whom full data were available, 48.2% were found on contrast-enhanced CT imaging at 30 days to have the transcatheter heart valve (THV) frame extended above the level of the left, right, or both coronary ostia.

The highest-risk configuration, wherein the THV frame extends above an ostium and there is a THV commissural suture post in front of the coronary, was seen in 8.7% of subjects.

"The post can be in the way or the height of the valves can cover the ostia, which usually means we have to change our technique, use smaller catheters or a more refined technique. There definitely isn't the same ease in cannulating the patient that we have in a patient who has never had TAVR," explained Waksman.

Waksman and colleagues tested whether intentional crimping of the THV on the delivery catheter might help with commissural alignment. "It's basically impossible to line things up perfectly. We tried several cases and our success was zero in our lab."

In a second study, Tomoki Ochiai, MD, and colleagues used registry data from Cedars-Sinai Medical Center in Los Angeles to look at coronary access after TAVR with Evolut R or Evolut PRO valves (n = 66) or SAPIEN 3 valves (n = 345).

Coronary access was defined as unfavorable if on CT the ostium was below the skirt or in front of the THV commissural posts above the skirt in each coronary artery.

For the Evolut R/Evolut PRO group, unfavorable coronary access of the left and right coronary arteries were observed in 34.8% of recipients and 25.8% of recipients, respectively. The corresponding figures for the SAPIEN 3 valve were 15.7% and 8.1%.

THV positioning, as seen on CT, restricted access to the left coronary artery in about one-third of patients and the right coronary artery in about one-quarter.

In a subgroup of patients requiring post-TAVR angiography or PCI, THV "blocking" of the coronary arteries was shown to be significantly associated with a higher rate of difficult coronary access.

Ochiai said that their findings are consistent with other studies that have shown self-expanding THVs with taller skirts, commissures, and frames are associated with greater difficulties in angiography and PCI after TAVR.

In an editorial that accompanied this study, Laurent Faroux, MD, and Josep Rodes-Cabau, MD, Quebec Heart and Lung Institute, Quebec City, Canada, write that the clinical impact of these findings "remain to be determined, particularly considering that the previously reported incidence of significant coronary access issues seems to be lower than that reported in the Ochiai et al study."

In the third study, Mohammad Abdelghani, MD, PhD, Heart Centers, Bad Segeberg, Germany, and colleagues found that in 101 patients who received an Evolut R/PRO THV, the closest aligned cell of the THV frame was opposite the left and right coronary ostia in 58% and 63% of cases.

However, in the five patients who underwent coronary angiography shortly after TAVR for indications that included angina and heart failure, no issues with reaccess of the arteries was reported.

Industry to Send the Fix

The problem isn't just what happens if the patient needs PCI, but also what happens if the THV fails, which is obviously a bigger issue in younger, lower-risk patients, given the known lifespan of THVs.

"If the first THV is in close proximity or in direct contact with the STJ [sinotubular junction], there is a significant risk for coronary obstruction caused by sequestration of the coronary sinus and the coronary artery that arises therein," Waksman and colleagues write.

For this reason, TAVR-in-TAVR procedures in patients with failed THVs may not be feasible in up to 13% of low-risk patients based on their data. This is a lower estimate than in previous studies, but is nonetheless a "significant" number, considering their younger age and greater likelihood for requiring a repeat intervention.

"Heart teams and operators need to think beyond the index TAVR in low-risk patients and consider how structural valve deterioration, if it develops, will be managed in the future," said Waksman.

Already, the newer SAPIEN 3 device has some advantages over the CoreValve devices, said Waksman, because of its shorter stature. "With CoreValve, you always cover the coronaries," he said.

Waksman and Ochiai both suggested that the solution to this potentially escalating issue will come from industry in the form of second-generation devices that improve post-TAVR coronary artery access.

"Already there are newer devices in development that may alleviate the issue, such as the JenaValve (JenaValve Technology, Munich, Germany) and J-Valve (JC Medical, Burlingame, California), which are designed to align the THV commissures closer to the native valve commissures and may allow easier access to the coronary arteries after TAVR," he added.

Ochiai reported no conflicts of interest. Waksman is an advisory board member or consultant for a number of companies, including Amgen, Boston Scientific, Cardioset, Cardiovascular Systems Inc, Medtronic, Philips, and Pi-Cardia.

J Am Coll Cardiol Intv. 2020;13:693-705, 706-708, 726-735, 736-738. Ochiai abstract, Editorial, Waksman abstract, Editorial

J Am Coll Cardiol. 2020;13:709-722. Abdelghani abstract, Editorial

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