Splitting Leaflets Mitigates TAVR Coronary Obstruction Risk

A new technique of intentional leaflet laceration may enable safe transcatheter aortic valve replacement (TAVR) in patients at risk for coronary obstruction, according to first-in-human results.

No hemodynamic compromise was seen with the technique, and all seven patients had successful TAVR with no coronary obstruction, stroke, or other major complications in the small series.

Moreover, all patients survived to 30 days, Robert Lederman, MD, of the National Heart, Lung, and Blood Institute in Bethesda, Maryland, and colleagues reported in the April 9 issue of JACC: Cardiovascular Interventions.

Under the strategy dubbed BASILICA (bioprosthetic or native aortic scallop intentional laceration to prevent coronary artery obstruction), operators make lacerations in pericardial leaflets using catheter electrosurgery such that TAVR can be performed as usual in hearts with unusually large leaflets.

BASILICA was first tested in pigs, then offered to seven high-risk individuals on the basis of compassionate use. They had undergone BASILICA TAVR at three centers: University of Washington in Seattle, Henry Ford Health System in Detroit, and Emory University Hospital in Atlanta.

"BASILICA may durably prevent coronary obstruction from TAVR. The procedure was successful across a range of presentations, and requires further evaluation in a prospective trial," Lederman's group concluded. In the face of coronary obstruction, the current strategy is ad hoc percutaneous intervention or up-front coronary protection using a pre-positioned wire -- both variably successful, according to the authors.

The operators did not use the novel technique to treat failed TAVR devices but suggested it is worth considering in the future.

"Such a pioneering study must be commended, as it represents an effort toward TAVR refinement and evolution, aiming to solve a procedure-related complication that still does not have a definitive solution," commented Azeem Latib, MD, and Matteo Pagnesi, MD, both of the San Raffaele Scientific Institute in Milan, Italy, in an accompanying editorial.

"A definitive demonstration of safety and efficacy would provide us a valuable instrument in current TAVR practice: indications for TAVR would be expanded to patients otherwise ineligible for any therapy, and the risk for acute and delayed coronary obstruction would be mitigated among at-risk patients currently treated with TAVR," Latib and Pagnesi said.

Nonetheless, they called out the technical challenges and potential risks of this approach, including: acute severe aortic regurgitation as a consequence of leaflet laceration, collateral mechanical damage to surrounding structures like the aortic annulus, mechanical injury in the case of double BASILICA, and periprocedural cerebral embolization upon laceration of heavily calcified aortic leaflets.

"Although the investigators give a detailed explanation of the procedural steps, there is a significant amount of 'art' to this new and technically demanding procedure, and thus we would advise readers to refrain from reproducing it without significant training or proctoring," the editorialists cautioned.

"Certainly it's shown to be safe and feasible," Ankur Kalra, MD, of University Hospitals Cleveland Medical Center, told MedPage Today, even if "it obviously will require proctoring and training." He added that pre-procedural imaging -- perhaps via CT, transesophageal echocardiography, or both -- may be required for the technique to be standardized.

Kalra called BASILICA a "neat" technique that is particularly advantageous in patients who have coronary ostia that are low in height, as BASILICA creates an opening for the ostia while the TAVR valve is being deployed. "I think it's an important contribution to the armamentarium of the TAVR operator," he said.

Yet this will not be standard of care for every patient, Kalra noted, given that coronary ostial obstruction is a complication affecting fewer than 2% of TAVR patients. Given the rapid growth of TAVR, however, "I'm sure there is a subset of patients that will merit at least pre-procedural consideration of this technique for safer valve deployment," he said.