Patients who underwent transcatheter aortic valve replacement (TAVR) did not have a higher rate of death at one year compared with those who had their heart valve replaced via open-heart surgery, according to research presented at the American College of Cardiology's Annual Scientific Session Together with World Congress of Cardiology (ACC.20/WCC).
The trial compared approaches to replacing the aortic valve in patients with severe aortic stenosis, a condition in which the valve becomes narrowed, impeding the proper flow of blood. Untreated, aortic stenosis causes breathlessness, fatigue and other symptoms and increases the risk of other heart problems. Traditionally, surgeons have replaced the valve via open-heart surgery, but the less invasive TAVR approach, in which clinicians thread the new valve through a small tube inserted into an artery in the groin, underarm or chest into the aorta and up to the heart, has rapidly become more common in recent years.
Previous clinical trials have found TAVR to be non-inferior or superior to open-heart surgery for various patient groups, but most trials have been limited to medical centers that perform a high volume of procedures or focus on the use of specific types of replacement valves. The new trial involved a broad group of patients who were treated at every medical center that performs TAVR across the United Kingdom.
"The importance of this trial is that it confirms the effectiveness of the TAVR strategy in a real-world setting," said William D. Toff, MD, professor of cardiology at the University of Leicester and the study's lead author. "It wasn't only conducted at the best centers, and it wasn't limited to a particular valve under ideal conditions. This was TAVR as it is in the real world compared with surgery as it is in the real world."
The trial enrolled 913 patients referred for treatment of severe aortic stenosis at 34 U.K. sites from 2014-2018. Half were randomly assigned to receive TAVR and half underwent open-heart surgery. Enrollment was limited to participants age 70 years or older (with additional risk factors) or age 80 years or older (with or without additional risk factors).
Overall, participants were at intermediate to low risk from surgery, with a median Society of Thoracic Surgeons risk score of 2.6% (a score below 3% is considered low risk). However, researchers did not specify a particular risk score cut-off for enrollment. This allowed the trial to evolve along with changes in guidelines and practice regarding TAVR over the course of the study and to reflect physicians' nuanced, real-world approach to considering risk in decision-making rather than taking a formulaic approach, Toff said.
