Expanding indications of TAVR in patients with aortic stenosis
Transcatheter aortic valve replacement (TAVR) is the standard of care for high-risk patients with severe aortic stenosis (AS), and may be superior to open surgery in patients with lower risk as newer generation devices emerge, according to a presentation at the APSC Congress 2017 in Singapore.
With more data surfacing in time to come, TAVR will probably be shown to be superior to open surgery in intermediate-risk patients, according to Dr Paul Chiam, senior consultant cardiologist at The Heart & Vascular Centre, Mount Elizabeth Hospital, Singapore.
In the initial PARTNER trial, TAVR significantly reduced the rates of all-cause mortality compared with open surgery among high-risk patients with severe AS, and the survival benefit has been demonstrated up to at least 5 years. [N Engl J Med 2010;363:1597-1607]
Moving down the risk scale to patients with intermediate risk, TAVR was shown to be noninferior to surgical aortic valve replacement (SAVR) in terms of the composite endpoint of all-cause mortality or disabling stroke at 2 years in the PARTNER 2A trial using the SAPIEN XT valves and in the SURTAVI trial using a self-expanding CoreValve or Evolut R bioprosthesis. [N Engl J Med 2016;374:1609-1620; N Engl J Med 2017;376:1321-1331]
While TAVR was associated with significantly improved AV haemodynamics and lower rates of stroke at 30 days, atrial fibrillation, acute kidney injury, and transfusion needs, it was also associated with greater residual aortic regurgitation, major vascular complications, and pacemaker requirement in SURTAVI, Chiam pointed out.
Similarly, durable clinical and haemodynamic results have been observed in Asian patients, with the first Asian patient (77-year-old male) who underwent TAVR via the transfemoral route still surviving up to 8.5 years to date after the procedure, said Chiam. [Singapore Med J 2009; 50:534-537]
For AS patients with degenerated aortic surgical bioprostheses, TAVR is an attractive option to avoid the need for open surgery, according to Chiam. In a small case-series study involving Asians who underwent valve-in-valve TAVR, satisfactory haemodynamic results and clinical improvement were sustained at 1 year, with no stroke, major vascular complication, or death reported (except one noncardiac death) at 1 year after the procedure. [Singapore Med J 2016;57:401-405]
Off-label use of TAVR in bicuspid valves, noncalcific AS and selected pure severe aortic regurgitation (AR) is also feasible, said Chiam. Performing TAVR in patients with pure AR might entail a greater need for the use of two valves, while a major concern to bear in mind for both groups of patients (with pure AR or bicuspid aortic valve stenosis) is the higher risk of valve embolization, he cautioned.
“Newer and better devices [are likely to] improve the results of the procedure,” said Chiam, who is optimistic that indications for TAVR will continue to expand as newer and more improved devices become available.