TAVI, safe and effective as surgical valves at two years in lower risk patients
Two year outcomes in a study comparing implantation of transcatheter and surgical bioprosthestic aortic valves shows that the less invasive procedure is safe and effective, and comparable to the gold standard, surgical valve replacement, in patients whose operational risk was lower than that of patients studied in the pivotal randomized trials for these new devices.
Dr. Lars Søndergaard from the Heart Center, Rigshospitalet, Copenhagen University Hospital, Denmark presented the results of the Nordic Aortic Valve Intervention (NOTION) trial here today in the opening Hot Line session of EuroPCR 2015.
"The NOTION study is the first randomised clinical trial to include all-comer patients," Søndergaard said. "Despite the fact that the trial was launched in the early days of transcatheter aortic valve implantation (TAVI), the two-year data show that the therapy is as efficient and safe as the well-established surgical aortic valve replacement (SAVR). Although we are still waiting for data on long-term durability of the TAVI prosthesis before routinely offering this new technology to younger patients, the NOTION trial indicates that TAVI can be offered to selected lower risk patients."
The first, large, randomised trials supporting a role for TAVI in patients with severe aortic stenosis enrolled very high-risk patients, typically with logistical EuroSCOREs of approximately 20 or higher. Recent clinical trials and registry studies, however, indicate that TAVI 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 less than 20.
NOTION enrolled patients at three hospitals in Denmark and Sweden, ultimately randomising 139 patients to a self-expanding TAVI device and 135 to a surgical bioprosthesis. Mean EuroSCORE was similar (8.4% for TAVI and 8.9% for SAVR) in the two groups) and 82% of the patients were at low surgical risk (STS score <4%).
At one year, the primary end point - a composite of death from any cause, stroke, or myocardial infarction - was not statistically different between groups (SAVR = 15.7%, TAVI 11.3%, log-rank p-value = 0.26). By two years, those numbers were 18.8% and 15.8%, again, a non-statistically significant difference (p=0.43).
At both the one-year and two-year follow-up period, pacemaker implantation was higher in the TAVI group than in the SAVR group, while atrial fibrillation was more common in patients treated with surgery than with the minimally invasive procedure.
In NOTION at two-years, rates of moderate to severe aortic regurgitation remained significantly more common with TAVI procedures than SAVR (15% vs 1%, p<0.001). 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 TAVI, which has been shown to reduce rates of aortic regurgitation in patients receiving the devices today. Furthermore, new generation TAVI devices have been designed to reduce aortic regurgitation.
"Aortic regurgitation after TAVI 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." Søndergaard added. Of note, the rate of moderate regurgitation seen in NOTION was just 15% and did not appear to be linked to mortality.