By Dr. Aswin Babu
Since the first transcatheter aortic valve implantation (TAVI) in 2002, developments in valve technology, procedural techniques and operator experience have led to TAVI being utilised successfully in varying degrees of aortic stenosis severity1. In particular, the PARTNER trials have provided randomised controlled trial (RCT) data to justify the use of these valves in intermediate and low risk patients1.
The UK TAVI Trial was performed to add further evidence to this notion. It included all 34 centres in the United Kingdom (UK) that are involved in a well-established TAVI programme2. The aim of this trail was to assess whether TAVI was non-inferior to surgical aortic valve replacement (SAVR) in patients aged 70 years old or above with severe aortic stenosis (AS) and with moderate or high operative risk2.
913 patients were included with 458 being randomised to the TAVI arm and 455 randomised to the SAVR group 2. Exclusion criteria included those with a life expectancy of <1 year, previous valve intervention, primary aortic regurgitation or severe mitral regurgitation, and coronary artery disease that was more suited towards surgical revascularisation than a percutaneous option2.
Patients were followed-up for 1 year and the primary outcome was to compare all-cause mortality between both groups at 1 year. The mean age of the patients was 81 years with 46% being female. The median Society of Thoracic surgeons (STS) risk score was only 2.6%, and thus conventionally classified as a low-risk cohort. The median length of stay was 3 days for TAVI compared to 8 days for SAVR. The mean left ventricular ejection fraction was 57% and transfemoral access was the primary route of access in 92% of the patients. All types of percutaneous valves were included with the Sapien 3 valve being the most frequently implanted (45%).
After 1 year, death occurred in 4.6% (n=21) of the TAVI group compared to 6.6% (n=30) of the SAVR group (p=0.23). This met the criteria for non-inferiority.
In terms of secondary outcomes, Major bleeding was significantly less in the TAVI group (6.3% vs 17.1%, p < 0.001). Stroke occurred in 5% of the TAVI arm compared to 2.9% of the SAVR group but this did not meet statistical significance (p=0.13). However, the need for a permanent pacemaker was significantly higher in the TAVI arm (12,2% vs 6.6%, p < 0.001). Surgery also had less vascular complications (P<0.001) and mild or moderate aortic regurgitation (AR) (p < 0.001). There were no reports of Severe AR in either group.
Overall, TAVI had significantly less major bleeding with shorter hospital stays, and mortality rates that were non-inferior to surgery at 1 year. However, pacemaker implantation and aortic insufficiency was considerably higher in the TAVI arm. Therefore, long-term follow up is required to assess if the benefits are sustained in the TAVI arm and whether the valves remain durable.
Link to Article – https://jamanetwork.com/journals/jama/fullarticle/2792251
References
- Markham, R. and Sharma, R., 2020. A Review of the Partner Trials. Interventional Cardiology Clinics, 9(4), pp.461-467.
- Fairbairn, T., Kemp, I., Young, A., Ronayne, C., Barton, J., Crowe, J., McQuade, L., Clarkson, N., Sionas, M., Tobin, A. and Feeney, S., 2022. Effect of transcatheter aortic valve implantation vs surgical aortic valve replacement on all-cause mortality in patients with aortic stenosis: a randomized clinical trial. JAMA, 327(19), pp.1875-1887.
