NOTION: Outcomes similar with TAVR vs. surgical AVR in lower-risk patients
ORLANDO, Fla. — Rates of all-cause mortality, stroke and MI did not differ significantly between lower-risk patients who underwent transcatheter aortic valve replacement compared with surgical AVR at 5 years, results from the NOTION trial show.
The rate of a composite of all-cause mortality, stroke or MI — defined by Valve Academic Research Consortium (VARC)-2 criteria — was 39.2% in the group that underwent TAVR with a self-expanding valve (CoreValve, Medtronic) and 35.8% in the group that had surgical AVR at 5 years (log-rank P = .78).
Similarly, the researchers found no differences in the individual components of the composite outcome between the TAVR and surgical AVR groups, including in all-cause mortality (27.7% vs. 27.7%; log-rank P = .9), stroke (10.5% for TAVR vs. 8.2% for surgery; log-rank P = .67) and MI (8.6% for TAVR vs. 8.7% for surgery; log-rank P = .87) at 5 years.
Additionally, most patients in the TAVR and surgical AVR groups were “true” low-risk patients, with Society of Thoracic Surgeons Predicted Risk of Mortality scores lower than 4% (83.4% vs. 80%; P = .46), H. Gustav Hørsted Thyregod, MD, PhD, from the department of cardiothoracic surgery at Copenhagen University Hospital, Denmark, said during a presentation of the data at the American College of Cardiology Scientific Session. In an analysis of patients with STS scores lower than 4%, there were also no significant difference between the TAVR and surgical AVR groups for the composite outcome at 5 years (31.5% for TAVR vs. 35.2% for surgery; log-rank P = .51).
Among all patients, there were no differences in secondary outcomes between the TAVR and surgical AVR groups, except for the rate of atrial fibrillation (25.2% for TAVR vs. 62.2% for surgery; P < .001) and pacemaker implantation at 5 years (41.8% for TAVR vs. 8.4% for surgery; P < .001). Rates of aortic valve reintervention were considerably low in both groups (2.5% for TAVR vs. 0% for surgery; P = .09), Thyregod said.
In terms of valve performance as determined by echocardiography, there was a significant difference between the TAVR and surgical AVR groups in effective orifice area at all time points after the procedure, including at 5 years (TAVR, 1.66 cm2; surgery, 1.23 cm2; P < .001), which corresponded with a difference in mean gradient at all time points, including at 5 years (TAVR, 8.22 mm Hg; surgery, 13.71 mm Hg; P < .001).
At 5 years, patients who underwent TAVR vs. surgical AVR had more mild aortic regurgitation (52.9% vs. 22.6%; P < .001) and moderate aortic regurgitation (8.2% vs. 0%; P < .001). This difference was also observed at all time points, according to Thyregod.
This difference in aortic regurgitation corresponded with a difference in functional outcome between the TAVR and surgical AVR groups at 1 year (NYHA class II, 29.5% vs. 15%; P = .01), but the difference was less apparent at 5 years, with a steady decline in NYHA class in both groups, Thyregod said.
Mortality at 5 years was also higher among patients who received a new pacemaker at 30 days after TAVR compared with those who did not (38.2% vs. 21.7%; log-rank P = .07). There was no significant association between all-cause mortality and severity of aortic regurgitation, although mortality at 5 years after TAVR was numerically higher among patients who had moderate or severe vs. none, trace or mild aortic regurgitation (30.8% vs. 22.2%; log-rank P = .43).
Subgroup analyses did not demonstrate an association between 5-year all-cause mortality and age, sex and BMI at baseline. However, patients without hypertension fared better with surgical AVR vs. TAVR. The researchers also found a trend toward lower mortality rate with higher STS score in the surgical AVR group, which was counterintuitive, Thyregod said.
The multicenter, nonmasked, prospective, randomized controlled trial consecutively enrolled all comers between December 2009 and April 2013. All patients were aged at least 70 years and had severe aortic stenosis, a life expectancy of at least 1 year and were suitable for self-expanding TAVR or surgical AVR. Of the 280 patients enrolled in the study, 145 were randomly assigned to TAVR and 135 to surgical AVR. Only the CoreValve system was used for TAVR and any type of standard bioprosthesis was used for surgical AVR.
Trial compliance was also good, and the researchers had complete follow-up for all patients at 5 years, according to Thyregod.
“NOTION is the first trial to report on 5-year outcomes after TAVR vs. surgical AVR in lower-risk patients,” Thyregod said. “TAVR continued to have more mild to moderate prosthetic regurgitation and new pacemaker implantation after TAVR trended to be associated with increased mortality, so determining the longevity of TAVR prostheses will require longer-term follow-up.” – by Melissa Foster
Thyregod HGH, et al. Featured Clinical Research I. Presented at: American College of Cardiology Scientific Session; March 10-12, 2018; Orlando, Fla.
Disclosure: Statistical support was provided by Medtronic. Thyregod reports no relevant financial disclosures.