Transcatheter aortic valve implantation (TAVI) is increasingly being performed in patients with symptomatic, severe aortic stenosis. Both TAVI and surgical aortic valve replacement (SAVR) can be performed in patients with low surgical risk. Randomised TAVI trials in low-risk patient groups are industry-sponsored and have tested certain transcatheter heart valves in selected patient populations. There is insufficient evidence to compare TAVI and SAVR in a real-life patient population.

The aim of the study was to compare TAVI and SAVR in patients with low or intermediate surgical risk and suitable for both treatment strategies.

Patients from 38 centres in Germany were randomised to TAVI and SAVR. Patients with symptomatic severe aortic stenosis, aged 65-85 years, and at low or intermediate surgical risk were included. Patients were classified according to the STS-PROM risk score and defined as <2% low risk and 2-4% moderate risk. Patients with bicuspid aortic valve, non-calcified aortic valve, percutaneous coronary intervention and stroke in the last 1 month, endocarditis, cardiac reoperation, severe mitral and tricuspid valve disease and left ventricular ejection fraction <20% were excluded. The primary outcome was the composite of all-cause death or fatal or non-fatal stroke within 1 year after randomisation. Secondary outcomes include acute kidney injury, arrhythmia and pacemaker implantation, bleeding, myocardial infarction, prosthetic valve dysfunction, rehospitalisation and vascular complications, with components of the primary outcome.

A total of 1414 patients were randomised 1:1 to TAVI (701 patients) and SAVR (713 patients). The mean age was 74±4 years, 790 (57%) patients were male, and the median STS-PROM score was 1.8%. At 1 year, the composite of death from any cause or fatal or non-fatal stroke was 5.4% in the TAVI group and 10.0% in the SAVR group (P<0.001 for noninferiority). In secondary outcomes, the incidence of death from any cause at 1 year was 2.6% in the TAVI group and 6.2% in the SAVR group. (hazard ratio, 0.43; 95% CI, 0.24 to 0.73). The incidence of stroke was 2.9% and 4.7%, respectively (hazard ratio, 0.61; 95% CI, 0.35 to 1.06), and the incidence of stroke or transient ischaemic attack was 4.1% and 5.1%, respectively (hazard ratio, 0.78; 95% CI, 0.47 to 1.27). Cardiovascular death occurred in 2.0% of patients in the TAVI group and 4.4% in the SAVR group (hazard ratio, 0.47; 95% CI, 0.24 to 0.86). New-onset atrial fibrillation occurred in 12.4% of patients in the TAVI group and 30.8% in the SAVR group (hazard ratio, 0.36; 95% CI, 0.28 to 0.46); permanent pacemaker implantation was performed in 11.8% and 6.7% of patients, respectively (hazard ratio, 1.81; 95% CI, 1.27 to 2.61). Prosthetic valve dysfunction was 1.6% in the TAVI group and 0.6% in the SAVR group (hazard ratio, 2.44; 95% CI, 0.87 to 8.15). The number of patients with at least moderate valve regurgitation at 1 year was 16 (2.8%) and 5 (1.0%) in the TAVI and SAVR groups. The incidence of major or life-threatening bleeding was 4.3% in the TAVI group and 17.2% in the SAVR group. Procedural complications occurred in 1.5% of patients undergoing TAVI and 1.0% of patients undergoing SAVR.

In patients at low or intermediate surgical risk with symptomatic severe aortic stenosis, TAVI was non-inferior to SAVR for death from any cause or stroke at 1 year.

TAVI was associated with lower all-cause mortality or stroke incidence at 1 year compared with SAVR. Despite the infrequent use of cerebral embolic protection, the incidence of stroke was low in the TAVI group (1.3%). Atrial fibrillation and major or life-threatening bleeding were more frequent in the SAVR group. This is an important non-industry-sponsored study that contributes to the growing body of evidence supporting the expanding role of TAVI in the treatment of aortic valve disease; however, it excluded patients with bicuspid aortic valve disease. The frequency of bicuspid valve will increase as the indications for TAVI expand to younger patients with low surgical risk. The follow-up period of the study is limited to 1 year and long-term results will be re-evaluated at year 5.