NOTION at 8 Years: TAVI Still Comparable to Surgery

Eight-year data from the NOTION trial again show no differences in clinical outcomes and bioprosthetic valve failure between TAVI and surgery among patients at low surgical risk, suggesting good long-term durability for the percutaneous approach where data have been sparse.

“The long-term results are reassuring for TAVI both regarding clinical outcomes and transcatheter heart valve durability, as TAVI is now indicated for patients with longer life expectancy,” write Troels Højsgaard Jørgensen, MD (Rigshospitalet, Copenhagen University Hospital, Denmark). “Still, further long-term data are needed including data on all types of transcatheter heart valves.”

NOTION—which randomized 280 patients with severe aortic stenosis who were at least 70 years old (mean age 79.1; mean STS score 3.0) to TAVI with CoreValve (Medtronic) or surgery at three European centers between 2009 and 2013—was not designed to assess long-term outcomes. However, 2-year, 5-year, and 6-year results consistently showed comparability between the two procedures with regard to the primary efficacy endpoint of all-cause mortality, stroke, or MI.

In the current analysis of 133 patients surviving to 8 years, published online June 28, 2021, ahead of print in the European Heart Journal, there were still no differences between TAVI and surgery in terms of the primary endpoint (54.5% vs 54.8%; P = 0.94) and each of the individual endpoints of all-cause mortality (51.8% vs 52.6%; P = 0.90), stroke (8.3% vs 9.1%; P = 0.90), and MI (6.2% vs 3.8%; P = 0.33). Moreover, the rate of structural valve deterioration was lower with TAVI (13.9% vs 28.3%; P = 0.0017) and the risk of bioprosthetic valve failure was similar (8.7% vs 10.5%; P = 0.61).

“It's important to take away that even to 8 years now we have these data that TAVI is still regarded as safe compared to surgical AVR,” Jørgensen told TCTMD, adding that even though the study was not powered to show long-term durability, “it would be a definite shame to let [the results] go to waste because this is one of the best followed-up populations with the lowest mortality rate and really quite low rate of loss to follow-up.”

Mandatory Surgical Evaluation Still Needed?

“This is encouraging information about this debate of valve durability that always comes with TAVR compared to surgery,” said Pedro Villablanca, MD (Henry Ford Hospital, Detroit, MI), who commented on the study for TCTMD, citing the progress that has been made in the TAVI field in particular since the study was conducted. “These results are very encouraging for decision-making for any patients really.”

The results led Villablanca, a structural interventional cardiologist, to question on Twitter the mandatory surgical evaluation in place for TAVI in the United States.

Villablanca clarified to TCTMD that his tweet was intended to rile up debate, and stressed that he fully supports the heart team concept and “100% agree[s] that we need the surgeons.” Still, he said, it might be “easier” for patients if they only had to make a single appointment to, optimally, see the cardiologist and surgeon in tandem or the cardiologist alone, the second-best option, instead of having to make two separate appointments for evaluation.

“I don't want to sound like we don't need surgeons,” he said. “On the contrary, I think surgeons are a great asset when we do TAVRs. They give us different input that we don't have from our training.”

But for certain patients, a heart team discussion is sufficient, according to Villablanca. “If you're 80 or 90, do you need to see a surgeon?” he asked. “Can we just discuss it with the heart team? I don't think there's a black-and-white answer. There are grey areas where you have to see the surgeon.”

In response, cardiac surgeon Michel Pompeu Sá, MD, PhD (Lankenau Institute for Medical Research, Philadelphia, PA), whose original tweet about the article prompted Villablanca’s question, said “absolutely not” to the notion about removing the surgical mandate. “There are other studies out there . . . showing that heart teams have not been so used when it comes to patients with aortic stenosis, and I'm totally against this,” he told TCTMD. “This is something that we should keep.

“If you just let people do whatever they want to, they will actually do TAVI for everybody. And TAVI is not for everybody,” Pompeu Sá continued, adding that in his experience in Brazil, surgeons participate only as “backup” players. “I don't agree with this kind of approach. This is not the kind of approach I'd like to go forward.”

Additionally, he said, procedural decisions are best made ahead of time, and this is optimally done if both the surgeon and cardiologist have the chance for a preprocedure consult. “For 99% of patients, we can make decisions before the procedure, so the evaluation before the procedure is absolutely necessary. This is not something we should just relinquish.”

Jørgensen agreed that the NOTION findings do not support any modification to how patients are assessed for TAVI. “I'm not sure if our data would add to that because of course we have an analysis of lower-surgical-risk patients but it's not enough to support changing the way it's been going,” he said. Additionally, even though the patients in NOTION were considered lower-risk, their more-advanced age precludes the findings from being applied to all patients considered low-risk, since the risk of future complications has to be weighed differently for younger patients.

Aligned With the Guidelines

In an editorial accompanying the study, Shakirat Oyetunji, MD, MPH, and Catherine Otto, MD (both University of Washington School of Medicine, Seattle, WA), write that the findings “align with” the recently released American College of Cardiology/American Heart Association guidelines for the management of valvular heart disease. “They support the Class I recommendation for TAVI in patients over age 80 with the mean age of 79 years in the NOTION trial and similar clinical outcomes between TAVI and SAVR.”

However, they point out that the incidence of structural valve deterioration (SVD) is “likely to be underestimated,” especially in younger, low-risk patients. “The significant rate of SVD might become clinically relevant with longer follow-up data,” Oyetunji and Otto write. “Increased rates of paravalvular leak (PVL) in TAVI compared with SAVR is also an area of concern. While no mortality difference was appreciated in this study between patients with moderate/severe PVL and patients with no/trace/mild PVL, other randomized clinical trials have reported higher rates of PVL in the TAVI versus SAVR patients, with associated increased mortality with increasing severity. Thus, the clinical equipoise for TAVI versus SAVR in the guidelines for aortic valve intervention in the 65- to 80-year-old cohort holds until we have longer-term data.”

The longer life expectancy of younger patients as well as the greater risk of permanent pacemaker implantation with TAVI should also “raise serious concerns” and should weigh heavily on heart team decisions, the editorialists say.

Even with the multitudes of TAVI studies published, many open questions remain, and clinicians will need to interpret the guidelines individually for each patient in the context of multidisciplinary care, they conclude. “While the results are reassuring for TAVI regarding both clinical outcomes and valve durability, longer-term data are needed before indiscriminately applying transcatheter valve therapy to younger, low-surgical-risk patients. As longer-term data on TAVI valve durability become available, the age range for recommending TAVI over SAVR may shift, but at this time patients younger than 65 should undergo SAVR and patients aged 65 to 80 should be engaged in a shared decision-making between the patient and the heart team, with special attention given to the next aortic valve intervention.”