TAVR Comparable to SAVR in Lower-Risk Patients at 2 Years in NOTION

May 19, 2015—The results of the Nordic Aortic Valve Intervention (NOTION) trial were presented by Lars Søndergaard, MD, in the opening Hot Line session of the EuroPCR 2015 meeting being held May 19–22 in Paris, France. The 2-year outcomes showed that transcatheter aortic valve replacement (TAVR) is safe and effective and is comparable to surgical aortic valve replacement (SAVR) in patients whose surgical risk was lower than that of patients studied in the pivotal randomized trials for these new devices.  

NOTION, which was funded by the Danish Heart Foundation, compared TAVR using a retrograde transfemoral or transsubclavian approach with the third-generation, CE Mark-approved, 18-F CoreValve system (Medtronic plc) versus conventional SAVR with a bioprosthesis using normothermic cardiopulmonary bypass and cold blood cardioplegia cardiac arrest.

In the EuroPCR press release, Dr. Søndergaard, who is from the Heart Center Rigshospitalet at Copenhagen University Hospital in Copenhagen, Denmark, commented, “The NOTION study is the first randomized clinical trial to include all-comer patients. Despite the fact that the trial was launched in the early days of TAVR, the 2-year data show that the therapy is as efficient and safe as the well-established SAVR. Although we are still waiting for data on long-term durability of the TAVR prosthesis before routinely offering this new technology to younger patients, the NOTION trial indicates that TAVR can be offered to selected lower-risk patients.”

The EuroPCR announcement noted that the first, large, randomized trials supporting a role for TAVR in patients with severe aortic stenosis enrolled very high-risk patients, typically with a logistical EuroSCORE of approximately 20 or higher. Recent clinical trials and registry studies, however, indicate that TAVR is being used increasingly in patients at lower surgical risk. In one analysis, approximately half of patients enrolled in the major European registries had EuroSCOREs < 20. 

As summarized by EuroPCR, NOTION enrolled patients at three hospitals in Denmark and Sweden. Investigators randomized 139 patients to a self-expanding TAVR device and 135 to a surgical bioprosthesis. Mean EuroSCORE was similar (8.4% for TAVR and 8.9% for SAVR) in the two groups, and 82% of the patients were at low surgical risk (STS score < 4%). 

At 1 year, the primary endpoint—a composite of death from any cause, stroke, or myocardial infarction—was not statistically different between groups (SAVR, 15.7% vs TAVR, 11.3%; log-rank P value = .26). At 2 years, those numbers were 18.8% and 15.8%, again, a nonstatistically significant difference (P = .43). 

At both the 1-year and 2-year follow-up periods, pacemaker implantation was higher in the TAVR group than in the SAVR group, while atrial fibrillation was more common in patients treated with surgery than with the minimally invasive procedure. 

At 2 years, the NOTION investigators found that rates of moderate to severe aortic regurgitation remained significantly more common with TAVR procedures than SAVR (15% vs 1%; P < .001). However, Dr. Søndergaard observed that since the trial was launched, CT imaging has been adopted as the gold standard to improve aortic annular sizing in TAVR, which has been shown to reduce rates of aortic regurgitation in patients receiving the devices today. Furthermore, new-generation TAVR devices have been designed to reduce aortic regurgitation. 

“Aortic regurgitation after TAVR has been shown to be associated with increased mortality, but awareness of proper annulus sizing, newer valve prostheses, and procedural aspects have led to much lower rates of regurgitation today,” stated Dr. Søndergaard, who also noted that the rate of moderate regurgitation seen in NOTION was just 15% and did not appear to be linked to mortality.