EPs Push for More Involvement in TAVI Heart Team Discussions

BARCELONA, Spain—With the explosion of transcatheter aortic valve interventions to treat patients with severe aortic stenosis, electrophysiologists (EPs) are telling their interventional colleagues that they’d like to be more involved in heart team discussions, particularly given the high incidence of electrical disorders after the procedure.

Andreu Porta-Sanchez, MD (Hospital Clinic of Barcelona, Spain), who chaired a session at the European Heart Rhythm Association (EHRA) 2023 congress on the electrical management of TAVI-treated patients, said EPs currently play almost no role on the heart team prior to the procedure and thinks that should change.

“The number of TAVI procedures is increasing more and more, and the absolute number of pacemaker implantations will also be increasing more and more,” he told TCTMD. “We’ll need to be part of the discussion and decision-making at that time, and even before TAVI implantation.”

While left bundle branch block (LBBB) is the most commonly encountered electrophysiologic complication after TAVI, different presentations this week at EHRA highlighted the unknowns around others, including mild PR prolongation as well as conduction disorders involving the His-Purkinje system that may facilitate ventricular tachycardia (VT).   

Jean-Claude Deharo, MD (Hôpital La Timone of Marseille, France), who focused on conduction block after TAVI, noted that the number of procedures performed across Europe has roughly doubled since 2016, with approximately 230 TAVIs done for every 1 million people in France. “This will impact our practice if conduction disturbances are a large part of patients who have TAVI,” he said. 

The reasons for the problem are “obvious,” said Deharo, noting the transcatheter valve lands close to important conduction-system structures.

However, aortic stenosis itself also can contribute to conduction disturbances, he said, highlighting data showing that a small percentage of patients would have an indication for a permanent pacemaker even before they undergo TAVI, which makes the involvement of EPs important. Overall, ambulatory ECG monitoring before TAVI suggests that about 2% of patients meet criteria for a permanent pacemaker preprocedure, although some data have suggested that number might be as high as 9%, Deharo pointed out.

Other studies, meanwhile, have shown that ambulatory ECG monitoring before TAVI detected bradyarrhythmias or tachyarrhythmias in roughly 15% of patients, with new-onset atrial fibrillation found in 6%.

Patients, said Deharo, “should have a pre-TAVI assessment by an EP doctor.” Doing so can not only help identify those with existing AV block, who “should receive a pacemaker right away,” but also can help find those at high risk of developing conduction disturbances after TAVI. While not all patients require ambulatory screening, EP involvement helps put the problem on everyone’s radar, said Deharo.

Needing a Permanent Pacemaker

As TAVI operators well know, the risk of conduction disturbances varies between the different valve types, and there also is wide heterogeneity in reported rates among centers. Transcatheter valve technology has improved significantly in recent years, with the incorporation of design changes intended to lower the risk of conduction abnormalities. As Deharo pointed out, however, the rate of atrioventricular (AV) block or need for permanent pacemaker is still around 17.5% with newer valves. 

That translates into more than 3,300 people each year in France receiving a new pacemaker after TAVI, Deharo calculated, although he said he’s optimistic that the use of standardized TAVI techniques can reduce this number, highlighting data from US and Canada that showed the pacemaker rate was as low as 5.8% when operators adhered to a care pathway and a cusp overlap technique.

Presenting data on the clinical impact of new-onset LBBB in TAVI patients, Carlos Minguito Carazo, MD (Clinic Hospital Santiago de Compostela, Coruna, Spain), estimated that this occurs in roughly 25% of patients and is not a benign development. While roughly 40% of patients with new-onset LBBB will recover at 1 month, it is associated with high-degree AV block and need for a permanent pacemaker in 15% of patients. In PARTNER II, post-TAVI LBBB was also associated with a more than twofold higher risk of all-cause and cardiovascular mortality, while a meta-analysis showed it was associated with higher all-cause mortality and HF hospitalizations.

The potential mechanisms include a progression to high-degree AV block, development of ventricular arrhythmias, and possibly ventricular dyssynchrony and worsening heart failure, said Carazo. 

One of the key roles of EPs is to identify high-risk patients with LBBB who will go on to develop high-degree AV block, but this isn’t easy, he said. “Despite more than 20 years of TAVI, there are no current clear predictors,” said Carazo. In new-onset LBBB, ambulatory ECG monitoring or an EP study are both recommended by European guidelines, he said.

Importance of PR Prolongation

Sebastian Reif, MD (München Klinik, Bogenhausen, Germany), also made a case for EP involvement in TAVI procedures, stressing the importance of late-stage ECGs. During his presentation, Reif focused on the problem of PR prolongation—which is defined as a PR interval > 200 ms and is known as first-degree AV block—after TAVI.

In the general population, patients with this type of PR prolongation are asymptomatic, have a good prognosis, and are unlikely to progress to high-degree AV block. In TAVI patients, though, the prognosis is uncertain, and it’s not always known if the patient will require subsequent pacing, said Reif.

We’ll need to be part of the discussion and decision-making at that time, even before TAVI implantation. Andreu Porta-Sanchez

The 2021 European Society of Cardiology guidelines on cardiac pacing recommend ambulatory ECG monitoring in patients with preexisting conduction abnormalities who have a prolongation of the QRS or PR interval after TAVI (class IIb), the caveat being that there is no further prolongation of QRS or PR interval in next 48 hours.

Reif said the dynamics of PR prolongation varies in patients, but PR prolongation before and after a TAVI procedure is a risk factor for permanent pacing. Together, a PR interval > 240 ms after TAVI and further prolongation within the first 48 hours increase the risk of the need for permanent pacing. These data, said Reif, highlight the importance of the ECG before the procedure, immediately after TAVI, and at 48 hours. 

Speaking with TCTMD, Porta-Sanchez pushed back on the feasibility and necessity of keeping patients in hospital for 48 hours in order to undergo ECG testing, noting there is wide variability across Europe in terms of TAVI length of stay. “Right now, many centers are doing TAVI as same-day discharge,” he said. At their center, only patients with new conduction disturbances are monitored, said Porta-Sanchez, adding that all others are sent home before 48 hours.

In Germany, said Reif, patients are monitored after TAVI for several days, but he worries that without the 48-hour ECG, some people who would have been given a pacemaker could be lost once discharged.

The final presentation, by Martina Nesti, MD (Fondazione Toscana Gabriele Monasterio, Pisa, Italy), focused on bundle branch reentrant VT, which she noted has been documented in a few patients with valvular heart disease, particularly after TAVI. While the number of cases is still very small, she said the morphology of bundle branch reentrant VT mimics LBBB in sinus rhythm. This conduction disturbance has also been reported after SAVR, she said.