• 3 Studies Highlight Potential for Coronary Obstruction After TAVR

    Now that transcatheter aortic valve replacement (TAVR) is approved as treatment in all patients with severe, symptomatic aortic stenosis, feasibility of future access to the coronary arteries for selective angiography and PCI is receiving more attention.

    Three articles published in the March 23 issue of JACC: Cardiovascular Interventions focus on this possible challenge, which can result from misalignment between the transcatheter heart valve (THV) and the coronary ostia.

    “Heart Team members need to be thinking long-term in younger TAVR patients in whom access to the coronary arteries and future TAVR-in-TAVR may be required. The commercially available transcatheter heart valves (THVs) of today do not guarantee unimpeded access to the coronaries and may preclude TAVR-in-TAVR because they may occlude the coronary arteries altogether,” said Toby Rogers, MD, PhD, of MedStar Washington Hospital Center, Washington, DC. “While there may be some simple modifications to implantation technique we can implement today, the real solution to these challenges is engineering: future THVs need to ensure true commissural alignment 100% of the time; THV stent frame designs need to allow unimpeded access to the coronaries for percutaneous coronary intervention; and THV leaflet designs need to allow TAVR-in-TAVR without occluding the coronaries."

     

    Balloon-expandable valves

    Rogers and colleagues analyzed 137 patients from the Low-Risk TAVR trial who received the balloon-expandable Sapien 3 valve (Edwards Lifesciences) and had 30-day cardiac computed tomography (CT) scans of adequate image quality for analysis. These patients, at 11 U.S. centers, were at low risk for surgical mortality and were generally younger than the higher-risk patients, who previously had been the only ones for whom TAVR was approved in the U.S.

    These younger, lower-risk TAVR patients are more likely than older, higher-risk patients to require coronary angiography, percutaneous coronary intervention, or aortic valve reintervention, but their THVs may impede coronary access and cause coronary obstruction during TAVR-in-TAVR, Rogers and colleagues wrote.

    The investigators found in their analysis that the THV frame extended above the sinotubular junction in 21% of subjects and that in 13%, the distance between the THV and the sinotubular junction was less than 2 mm, signifying that TAVR-in-TAVR may not be feasible in the future in these patients without causing coronary obstruction.

    The most challenging anatomy for coronary access, which Rogers and colleagues said was the THV frame above and commissural suture post in front of a coronary ostium, was estimated to be present in approximately 9% to 13% of low-surgical-risk TAVR patients.

    The investigators also hypothesized that intentionally crimping the THV might help determine commissural alignment. They crimped the Sapien 3 THV with one commissural suture post on the outer curvature of the delivery catheter so that two commissure suture posts would land on either side of the left main ostium after the valve was deployed. They performed this prospectively on selected patients and compared the results to other study patients in whom the valve was not intentionally crimped. However, the investigators found that the crimping did not meaningfully influence commissural alignment after the valve was deployed.

    An accompanying editorial comment by Gilbert H.L. Tang, MD, MSC, MBA, of Mount Sinai Health System, New York, noted that surgeons have worked “for decades” when surgically replacing aortic valves to ensure commissural alignment to prevent coronary obstruction in the event of future procedures. With less-invasive TAVR now available to all severe, symptomatic aortic stenosis patients, it is time for TAVR operators to do the same as their surgeon colleagues, Tang wrote.

    “Commissural alignment to facilitate coronary access and redo TAVR, all of which were once thought difficult or impossible, may become a bigger issue, which will require increasing refinements in both techniques and technologies to facilitate both procedures,” he wrote. “We owe a strategy of lifetime management of both coronary and aortic valve diseases to our patients. The time to act is now!”

     

    Self-expanding valves

    Mohammad Abdelghani, MD, PhD, of Segeberger Kliniken, Germany, and colleagues analyzed 101 lower-risk TAVR patients at their center who underwent multislice CT after receiving the self-expanding Evolut R or Pro (Medtronic) THV. They found that potential interference with coronary access from the Evolut R or Pro THV frame “is mainly due to an antianatomic commissural post overlapping the coronary ostium, whereas possible overlap of coronary ostia by the (THV’s) sealing skirt seems uncommon.”

    Bioprosthetic valve commissures were antianatomic, which the authors explained means that the they were not aligned with native commissures, in 45 patients (47%), and that the commissural post overlapped a coronary ostium in 15 patients (16%). Two patients (2.0%) had a possible interference of the paravalvular sealing skirt with coronary access.

    An accompanying editorial by Stefan Stortecky, MD, and Daniel Malebranche, MD, both of Bern University Hospital, Switzerland, praises the work by Abdelghani and colleagues.

    “This investigation and the results may represent an important step toward addressing the pivotal issue of coronary access in the TAVR patient with suspected CAD (coronary artery disease),” Stortecky and Malebranche wrote. “Indeed, valuable information derived from such studies may translate into incremental improvements in THV platforms, such as larger open cells within the vicinity of the coronary ostia or modifications to the paravalvular sealing skirt.”

     

    Both valve types

    Tomoki Ochiai, MD, of Cedars-Sinai Medical Center, Los Angeles, and colleagues, evaluated 411 patients in their institution’s RESOLVE registry with analyzable CT images. Of these, 66 received the Evolut R or Pro valve, and 345 received the Sapien 3.

    The investigators found CT-identified features of unfavorable coronary access in 34.8% of patients for the left coronary artery and 25.8% in the right coronary in the Evolut group, and 15.7% in the left and 8.1% in the right coronary artery in the Sapien 3 group. Among patients in the Evolut group, 16 coronary engagements were performed after TAVR, and 64 were performed in the Sapien 3 patients. Success rates of these procedures were significantly lower in patients with unfavorable coronary access in both the Evolut (0.0% vs. 77.8%, p=0.003) and Sapien 3 (33.3% vs. 91.4%, p=0.003) groups, the study shows.

    “Ochiai et al.  should be congratulated for their meaningful contribution to the important issue of coronary reaccess in TAVR recipients, providing unique data on the interaction between the THV and coronary ostia on the basis of an accurate analysis of post-TAVR CT,” Laurent Faroux, MD, MSC, and Josep Rodés-Cabau, MD, of Laval University, Quebec, Canada, wrote in an accompanying editorial comment. “This highlights the need to consider coronary reaccess when choosing THV type and position.”

    Faroux and Rodés-Cabau added that larger studies are needed to determine the clinical implications of these findings.

    Source:

    Rogers T, Greenspun BC, Weissman G, et al. Feasibility of Coronary Access and Aortic Valve Reintervention in Low-Risk TAVR Patients. JACC Cardiovasc Interv 2020;13:726-735. DOI: 10.1016/j.jcin.2020.01.202

    Abdelghani M, Landt M, Traboulsi H, et al. Coronary Access After TAVR With a Self-Expanding Bioprosthesis: Insights From Computed Tomography. JACC Cardiovasc Interv 2020 Mar 23;13:709-722. DOI: 10.1016/j.jcin.2020.01.229

    Ochiai T, Chakravarty T, Yoon S-H, et al. Coronary Access After TAVR. JACC Cardiovasc Interv 2020;13: 693-705. DOI: 10.1016/j.jcin.2020.01.216

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