WASHINGTON (FRONTLINE MEDICAL NEWS) – Transcatheter aortic valve replacement is a noninferior alternative to surgery in patients with severe aortic stenosis and intermediate risk of dying from surgical complications, according to a multicenter trial of 1,660 patients.

Of the 864 patients randomized to transcatheter aortic valve replacement (TAVR), 12.6% met the study’s primary endpoint – death from any cause or disabling stroke at 24 months – versus 14% of the 796 randomized to surgery, a statistically nonsignificant difference.

Surgery was associated with higher rates of acute kidney injury, atrial fibrillation, and transfusions, while TAVR had higher rates of residual aortic regurgitation (5.3% vs. 0.6% in the surgery group at 1 year) and need for pacemaker implantation.

All of the patients met criteria for intermediate risk, defined in the study as a 3%-15% chance of 30-day surgical death according to Society of Thoracic Surgeons Predicted Risk of Mortality criteria , as well as coexisting illnesses, frailty, and disability. The mean risk in both groups was about 4.5%.

Although TAVR “is an accepted alternative to surgery in patients with severe aortic stenosis who are at high surgical risk, less is known about comparative outcomes among patients with aortic stenosis who are at intermediate surgical risk,” said investigators led by Michael J. Reardon, MD , of the Methodist DeBakey Heart and Vascular Center, Houston. “Our results provide reassurance that TAVR is an alternative to surgery in patients at the lower boundaries of intermediate risk.”

The study was presented at the annual meeting of the American College of Cardiology and published simultaneously in the New England Journal of Medicine (2017 Mar 17. doi: 10.1056/NEJMoa1700456 ).

Medtronic funded the trial. The company’s CoreValve bioprosthesis was used in 84% of TAVR patients, and the Evolut R bioprosthesis in the rest.

“Although we might have expected a lower rate of permanent pacemaker implantation with the introduction of the Evolut R valve on the basis of rates of 11.7% and 16.4% in previous studies, the rates among patients who received the CoreValve (25.5%) and the Evolut R valve (26.7%) were similar,” the investigators said.

The TAVR group had lower aortic valve gradients and larger aortic valve areas than the surgery group on follow-up. There was no valve deterioration at 24 months in either group.

Patients were an average of 80 years old. Most had coexisting illnesses, including diabetes in a third and chronic lung disease in a third. More than half (52.3%) had 5-meter gait speeds of more than 6 seconds, and 12.2% reported recent falls. Both TAVR and surgery significantly reduced cardiac symptoms and improved quality of life at 24 months.

Surgery patients had coronary revascularization at the time of aortic valve replacement if needed. In the TAVR group, percutaneous coronary intervention was performed as indicated either as a staged procedure before TAVR or at the time of TAVR. Transfemoral access was preferred for TAVR; the use of embolic protection during TAVR was not permitted.

In addition to funding the work, Medtronic was responsible for site selection, data monitoring, and trial management. Dr. Reardon reported personal fees from Medtronic outside of the submitted work.