BASILICA, Chimney Stenting: No Clear Winner to Prevent TAVI Coronary Obstruction

PARIS, France—Two techniques to deal with potential coronary obstruction after TAVI—chimney stenting and the BASILICA procedure—are equally successful when it comes to preventing this rare but life-threatening complication, according to results of a new study.

Freedom from clinically relevant or complete coronary obstruction was nearly identical for both at 1 year, but there were signals the chimney-stenting technique was associated with a higher risk of periprocedural complications, as well as a higher risk of cardiovascular mortality.

Antonio Mangieri, MD (Humanitas Research Hospital, Milan, Italy), who presented the results today during a hotline session at EuroPCR, said that while chimney stenting is less technically demanding for operators, their results appeared to favor BASILICA. Still, the study is far from definitive. “I don’t know what’s the best solution,” Mangieri told TCTMD when asked about the optimal approach for preventing coronary obstruction.

The trend toward a higher risk of cardiovascular mortality—6.7% with chimney stenting versus 1.3% with BASILICA—is something operators will need to keep in mind, he added, and should be studied further in a randomized trial.

Pioneering interventional cardiologist Alain Cribier, MD (Hôpital Charles-Nicole, Rouen, France), one of the panelists during the EuroPCR session, pointed out that BASILICA does require more specialized training as opposed to chimney stenting, but noted that the latter approach can make it very difficult to access the coronary arteries. He questioned why all operators wouldn’t instead learn the BASILICA technique for the cases where coronary obstruction is possible.

BASILICA “doesn’t absolve all the problems,” said Mangieri in response, noting that coronary obstruction resulting from sinus sequestration can’t be managed with the approach. “I think operators should be aware of different types of coronary obstruction after TAVR and be prepared to face all these troubles related to the procedure,” he said. “My opinion, though, is that BASILICA is the future.”

Abhijeet Dhoble, MD (University of Texas Health Science Center, Houston), who wasn’t involved in the study, said chimney stenting, while easier, has “some lifelong consequences. He noted that parking a metallic stent in the coronary artery has implications for medical management. Like Cribier, he said reengaging the coronary artery is extremely difficult after chimney stenting, and that he suspects the BASILICA approach will likely win out over time.

“With newer, specialized devices for BASILICA, the operator’s learning curve will be much, much easier,” Dhoble told TCTMD. “Right now, to do BASILICA is really challenging.”

BASILICA Tougher, but Better Outcomes

Acute coronary obstruction after TAVI occurs in less than 1% of cases, but when it happens the mortality risk hovers around 50%. The incidence of obstruction is significantly higher with valve-in-valve procedures. In those with clinical and anatomic characteristics that may put them at high risk for obstruction, operators can place a stent in the coronary artery, letting it protrude into the aorta after the transcatheter valve is deployed so the coronary isn’t sealed off. Chimney stenting does have limitations, including stent distortion, risk of restenosis and thrombosis, as well as future engagement difficulties.  

BASILICA is meant to overcome the challenges of chimney stenting. With it, operators use an electrified guidewire to lacerate native aortic or bioprosthetic leaflets, which allows them to splay open at the coronary ostia so that perfusion is maintained after TAVI.

Until now, there has been no study comparing outcomes of the two procedures, said Mangieri.

The new retrospective analysis included TAVI patients treated at centers that performed either chimney stenting or BASILICA. At the dedicated chimney hospitals, this included 71 consecutive patients at high risk for obstruction undergoing TAVI between 2015 and 2021. With BASILICA, hospitals treated 97 patients between 2017 and 2022. Only centers that had performed at least three cases with the respective techniques were included in the analysis.

In the chimney group, 38% of patients underwent stenting of the left main coronary artery, 17% had the ostial right coronary artery stented, and 45% had stenting of both the left and right coronary arteries. In the BASILICA group, 85.6% had dual-leaflet splitting to prevent occlusion in the left and right coronary arteries. With BASILICA, 92% of cases involved the use of cerebral protection because of concerns of debris embolization. Mangieri pointed out that patients in the BASILICA cohort tended to have “more challenging anatomy, [and were] more prone to coronary obstruction.”

My opinion, though, is that BASILICA is the future. Antonio Mangieri

Technical success was 98.5% and 96.9% with the chimney and BASILICA approaches (P = 0.48), although eight BASILICA cases were converted to bailout coronary stenting to prevent complete or partial coronary obstruction. Overall, periprocedural complications were more frequent with the chimney technique, including a significantly higher risk of minor bleeding, and trends toward more acute kidney injury, moderate-to-severe paravalvular leak, and need for a permanent pacemaker.

“In most of the cases, [BASILICA] is very difficult to perform carefully and in a perfect way, with a center split of the leaflet,” Mangieri told TCTMD. “Sometimes, if you go too lateral, or if you’re not perfectly centered, you can’t open the leaflet nicely and avoid the problem of coronary obstruction. The other problem [with BASILICA] is the risk of embolization, and it’s the reason we observed a higher use of cerebral protection devices in patients treated in this way.”

Risk of MACE at 1 year was not significantly different between the two approaches. Additionally, there was no difference in the risk of all-cause mortality, MI, stroke, or target lesion revascularization.

Conversion to Chimney Stenting

Although the BASILICA technique is harder for operators to perform, it did appear to result in better outcomes, said Mangieri. BASILICA, he added, may make more physiologic sense than chimney stenting where a coronary stent is left protruding into the aorta after the valve is deployed.  

Darren Mylotte, MD (Galway University Hospitals, Ireland), who chaired the hotline session, questioned the investigators’ definition of a successful BASILICA procedure, noting that while 97% of operators met the definition of success, nearly one in 10 patients required bailout coronary stenting. “How is it the definition of technical success if you end up doing a BASILICA?” he asked.

Mangieri acknowledged the apparent contradiction but said BASILICA operators could end up stenting simply if they were concerned about coronary obstruction. Of the eight, three patients had clearcut coronary obstruction and required chimney stenting, “but in the other cases, the operators were not confident in leaving the [BASILICA] result as it was because of concerns about asymmetric splitting,” said Mangieri. “It wasn’t clear evidence of complete coronary obstruction—the patients were quite stable—but for safety reasons they decided to implant a bailout stent.”

Mangieri added that the introduction of future technology, such as ShortCut (PI-Cardia), can hopefully standardize the BASILICA procedure, resulting in less need for bailout stenting and making it easier for all operators to perform.

Mylotte said these data also clearly show there is a clinical impact with chimney stenting, noting the higher rates of acute kidney injury. This is likely the result of TAVI operators unsure whether or not they can get away without performing the procedure, noting they’ll use more contrast and imaging to ascertain the risks of coronary obstruction in borderline cases. “Clearly, we need to be a little more cautious when making that decision with chimney patients,” said Mylotte.