TAVR Device Orientation May Reduce Coronary Overlap

Andrew D. Bowser

March 18, 2020

For patients undergoing transcatheter aortic valve replacement, using a specific orientation at deployment may optimize valve alignment and potentially preserve coronary access, at least for some devices, results of a pilot imaging study suggest.

In particular, positioning the Evolut THV (Medtronic) at a certain way at deployment led to an improvement in commissural alignment and a significant reduction in coronary artery overlap, according to authors of the study, led by Gilbert H. L. Tang, MD, MSc, MBA, surgical director of the structural heart program at Mount Sinai Health System, and associate professor of cardiovascular surgery, Mount Sinai Medical Center, New York.

Likewise, a specific positioning of the commissural post at deployment appeared to improve alignment and reduce coronary overlap when using the ACURATE-neo (Boston Scientific), though results with this transcatheter heart valve need to be considered preliminary because of the smaller number of cases, Dr. Tang said in an interview.

By contrast, initial deployment orientation of the SAPIEN 3 (Edwards Lifesciences) did not seem to have an impact on final orientation or neocommissural overlap with arteries in this study by Dr. Tang and colleagues, which was published in JACC: Cardiovascular Interventions and had been planned for presentation at the joint scientific sessions of the American College of Cardiology and the World Heart Federation. ACC organizers chose to present parts of the meeting virtually after COVID-19 concerns caused them to cancel the meeting.

Improved positioning may have important future implications for patients undergoing transcatheter aortic valve replacement (TAVR), particularly if they are younger and therefore perhaps more likely than older patients to undergo a procedure requiring coronary access at some point in the future, according to Dr. Tang.

"Right now, device design does not permit us to have consistent commissural alignment," said Dr. Tang in the interview. "What this study shows is that, with modification of delivery catheter insertion technique, at least for the EVOLUT valve, we can improve commissural alignment and hypothetically speaking, improve the likelihood of coronary access."

While the technique modifications described by Dr. Tang and colleagues are commendable, the overall impact on commissural alignment and coronary overlap are "modest" and do not solve the problem, according to Hasan Jilaihawi, MD, associate professor of medicine and cardiothoracic surgery at NYU Langone Health, New York.

Instead, the onus should be on the device manufacturers to develop solutions that allow for better alignment between their devices and patients' commissures, said Dr. Jilaihawi.

"We need really industry to focus wholeheartedly on this," Dr. Jilaihawi said in an interview. "I think they will, and there will be some discussions about focusing on [commissural alignment], but I think it's coming really very late."

Dr. Tang agreed on the need for increased focus on achieving commissural alignment. Of note, he said, there are newer transcatheter heart valves under study that may be more likely to achieve alignment and reduce the possibility of severe coronary overlap, including the JenaValve (JenaValve Technology) and the J-Valve (JC Medical).

"We hope that manufacturers can design valves that would improve commissural alignment for these patients, so that in 10 or even 20 years' time, when these patients require reintervention, we won't have to do surgery because the valves are not aligned," said Dr. Tang. "Ideally, we might have to do one surgical intervention in their lifetime, but really what we are talking about now is the lifetime management of these patients as the coronary artery disease progresses, and also the aortic valve disease returns with the prosthetic valve."

The pilot imaging study by Dr. Tang and colleagues included a total of 828 patients undergoing TAVR, including 483 treated with SAPIEN 3, 245 with Evolut, and 100 with ACURATE-neo.

To track deployment orientation, the SAPIEN 3 cases had a commissure crimped at 3, 6, 9, or 12 o'clock orientation relative to the delivery catheter. However, crimping orientation at initial deployment did not appear to have an impact on the final orientation, with overall incidence of severe coronary overlap of 36.6% for the left main coronary artery (LMCA), 23.6% for the right coronary artery (RCA), and 51.3% for one or both, according to the report.

For 107 cases treated with Evolut, the investigators sought to have a marker on the device (known as the "hat" marker) oriented to the outer curve of the descending aorta; to do that, they inserted the delivery catheter with the flush port at the 3 o'clock position. Those cases with the hat marker at the outer curve or the center front had improved commissural alignment as compared to those with the hat at the inner curve or center back, according to investigators. The incidence of coronary overlap with the LMCA was 15.7% for those with the hat at the outer curve or center front, compared to 66.0% for those with the hat at the inner curve or center back (P < .001), and the differences in coronary overlap were likewise significantly different in favor of the outer curve/center front for the RCA or both coronaries.

Finally, the incidence of coronary overlap with the ACURATE-neo was much lower when the commissural post at initial deployment was at the center back or inner curve, and in a few cases where the operators tried to torque the delivery catheter to position the commissural post to the inner curve, commissural alignment was achieved in about three-quarters of the patients (five of seven cases).

This is believed to be the first study to systematically characterize how the initial orientation of different transcatheter heart valves impact commissural alignment and coronary overlap, according to Dr. Tang and coinvestigators.

Dr. Jilaihawi, who was not involved in the study, said the investigators studied this phenomenon in a "very detailed, methodical fashion," but emphasized the need for new device innovations to improve alignment and overlap.

"Their efforts weren't completely in vain, but they really made a small difference in something that is too important to be [addressed] in a kind of 'MacGyver' approach to this problem," he said in the interview.

Disclosures reported by Dr. Tang were related to Edwards Lifesciences (physician proctor) and Medtronic (physician proctor, consultant). Coauthors reported disclosures related to Edwards, Medtronic, and Boston Scientific, among others.

SOURCE: ACC 20. Tang GHL et al. JACC Cardiovasc Interv. 2020 Mar 16. doi: 10.1016/j.jcin.2020.02.005.

This article originally appeared on MDedge.com.


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