ORLANDO, Florida — In older patients with severe aortic stenosis but low surgical risk, 5-year survival and cardiovascular outcomes among those who underwent transcatheter aortic valve replacement (TAVR) with the CoreValve (Medtronic) prosthesis were similar to outcomes among those who had surgical aortic valve replacement (SAVR).
In 280 patients in the Nordic Aortic Valve Intervention (NOTION) trial, the primary outcome of combined all-cause mortality, stroke, or myocardial infarction (MI) at 5 years was similar after TAVR or SAVR, although between-group differences included a higher rate of pacemaker placement with TAVR and a trend toward increased mortality in this group.
Hans Gustav Thyregod, MD, PhD, from Copenhagen University Hospital, Denmark, presented these results, which build on 1-year results presented in 2015, at the American College of Cardiology (ACC) 2018 Annual Scientific Sessions.
This is the first trial to report 5-year outcomes in this lower-risk patient population, Thyregod said. Importantly, “at 5 years, both groups had a mortality of 27.7%, which is the lowest recorded 5-year mortality rate for any TAVR study.”
“The results do not suggest that you should use one type of therapy over the other,” he told theheart.org | Medscape Cardiology in an interview. “The new treatment, transcatheter treatment, seems effective and safe over time.”
However, “our trial was small and somewhat underpowered,” he conceded, “so we need more data, but it’s very comforting that in our trial, both patient groups fared well.”
In the panel discussion, session chair Martin B Leon, MD, from the Center for Interventional Vascular Therapy, at Columbia University Medical Center in New York City, pointed to the concerning higher rates of pacemaker implantation and paravalvular regurgitation in the TAVR group, although he acknowledged that the same relatively low 5-year mortality in both groups was “encouraging.”
First 5-Year Results
In the previously reported PARTNER trial, all-cause death was similar at 5 years in high-risk patients with severe aortic stenosis who underwent TAVR and those who had SAVR, Thyregod noted. In that trial, the composite endpoint of death from any cause or repeat hospitalization and cardiac symptoms was also reduced, “despite the higher incidence of major strokes and major vascular events,” the PARTNER investigators noted.
NOTION was an “all-comers” trial of 280 patients aged 70 years or older with severe aortic stenosis who were enrolled in two centers in Denmark and one in Sweden from 2009 to 2013 and were randomly assigned to TAVR (145 patients) or SAVR (135 patients).
The patients had a mean age of 79 years and a moderate burden of comorbidities: Nineteen percent had diabetes; 5% had prior MI, and 9% had prior percutaneous coronary intervention.
Most patients (82%) had a Society of Thoracic Surgeons (STS) score that predicted a 30-day postsurgery mortality rate of less than 4%, so they were “true low-risk patients,” said Thyregod.
There were no significant differences in the primary endpoint or its components at any follow-up time point out to 5 years.
Table. NOTION: Five-Year Outcomes
| Endpoint | TAVR (%) | SAVR (%) | P Value |
|---|---|---|---|
| Primary outcome: all-cause mortality, stroke, or MI | 39 | 36 | .78 |
| All-cause mortality | 28 | 28 | .90 |
| Stroke | 11 | 8 | .67 |
| MI | 9 | 9 | .87 |
| Atrial fibrillation | 25 | 62 | <.001 |
| Pacemaker | 42 | 8 | <.001 |
There were differences in other secondary outcomes, though.
Patients who underwent SAVR were more likely to develop new-onset atrial fibrillation. However, the small subset of patients who did not have hypertension fared better after SAVR and, counterintuitively, so did patients with an STS score of 4% or greater.
On the other hand, patients who had TAVR were more likely than those having SAVR to receive a pacemaker soon after their valve replacement, at 42% vs only 8%. And of the patients who had TAVR, those who received a new pacemaker implant showed a trend toward higher mortality within 5 years (38% vs 22%; P = .07).
TAVR was also associated with greater likelihood of valve regurgitation. At 5 years, 53% of TAVR patients vs only 23% of SAVR patients had mild valve regurgitation, and 8% of TAVR patients but no SAVR patients had moderate valve regurgitation.
However, having early moderate to severe vs no or mild regurgitation was not associated with a significantly increased rate of all-cause mortality (31% vs 22%; P = .43).
The rate of prosthetic valve reintervention was low (2.5% in TAVR vs 0% in SAVR; P = .09).
A “Wash,” Prelude to Ongoing Trials
Leon commended the researchers for having 100% follow-up at 5 years and starting a randomized trial with a first-generation transcatheter prosthetic device.
However, in the TAVR group, “the idea of dealing with a 40% pacemaker rate is certainly distracting,” and the higher paravalvular regurgitation, although not associated with increased mortality, is “not a good thing,” he noted.
“I would say the jury is still out in terms of what we would offer our low-risk patients.”
To theheart.org | Medscape Cardiology, Leon elaborated that this was an early-generation transcatheter aortic valve implantation device “showing essentially equivalent outcomes, and there were benefits on both sides.”
For surgery, there were higher atrial fibrillation rates, he said, “which is certainly a little bit of a concern; they generally had higher bleeding and their hemodynamics were not as good, and TAVR had higher pacemaker rates and they had a slightly higher rate of endocarditis” (11% vs 6%, P = .10).
Therefore, “I think that it’s pretty much of a wash,” said Leon. “I think it’s really a prelude to large, randomized [studies in low-risk patients] that are ongoing and will be available for analysis over the next several years.”
Similarly, session co-chair Christopher B Granger, MD, from Duke University School of Medicine, Durham, North Carolina, speaking to theheart.org | Medscape Cardiology, said that this was an extremely high-quality, small trial with excellent follow-up in all comers with severe aortic stenosis.
“Overall, it suggested that TAVR looks very comparable in terms of major outcomes compared to surgical aortic valve replacement over a long period of time.”
However, the “very high rate of pacemaker implantation [was] somewhat concerning and some aortic insufficiency was a little bit concerning.”
“We need to await the results of the ongoing trials that included patients who are low risk, which we’ll get over the next couple of years, but this study in the meantime added to the body of evidence that suggests that TAVR seems to be very promising for the low risk population.”
Thyregod agreed that the study was underpowered and was more of a pilot study because they “rather optimistically” expected a composite outcome of 5% for transcatheter and 15% for surgery.
The ongoing NOTION 2 trial will provide more information about low-risk patients.
The study was funded by the Danish Heart Foundation, and Medtronic provided statistical support. Thyregod has disclosed no relevant financial relationships. Leon has received consultant fees/honoraria from Abbott, Boston Scientific, and Medtronic; has ownership interest in Claret Medical; and has received research grants from Edwards Life Science. Granger has received consultant fees/honoraria from AbbVie, Armetheon, AstraZeneca, Bayer, Boehringer Ingelheim, Boston Scientific, Bristol-Myers Squibb, Daiichi Sankyo, Gilead Sciences, GlaxoSmithKline, Janssen, Medscape, Medtronic, Merck, National Institutes of Health, Novartis, Pfizer, SIRtex, and Verseon and has received research grants from Armetheon, Astra Zeneca, Bayer, Boehringer Ingelheim, Bristol-Myers Squibb, Daiichi, the US Food and Drug Administration, GlaxoSmithKline, Janssen, Medtronic, Novartis, and Pfizer.
American College of Cardiology (ACC) 2018 Annual Scientific Sessions. Abstract 402-14. Presented March 10, 2018.
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