WASHINGTON –Anticipating two pivotal trials scheduled for presentation at the 2019 annual meeting of the American College of Cardiology (ACC), an investigator-led study of transaortic valve replacement (TAVR) for aortic stenosis presented as a latebreaker at 2019 CRT meeting produced excellent results.
Not least impressive, “our mortality rates are the lowest ever reported in any TAVR study at one year,” said Ronald Waksman, MD, Associate Director, Division of Cardiology, Medstar Heart Institute, Washington, DC.
In a population of patients with a median age of 71.1 years, all-cause mortality was just 3% at one year while the rate of deaths due to cardiovascular causes was only 1%, according to results of the 200-patient Low Risk TAVR study (LRT 1.0, NCT02628899) that Dr. Waksman presented.
In addition, there were low rates at one year for stroke (2.1%, none of which was deemed disability), myocardial infarction (1%), new onset atrial fibrillation (6.2%), and pacemaker placement (7.3%). The rate of rehospitalization for any cause was 20.4% but only 3.1% were considered related to TAVR. Rehospitalization for any cardiovascular cause at one year occurred in 6.8%.
Although leaflet thickening was observed at one year with imaging in 14%, this has not had any identifiable clinical consequences so far, and hemodynamics have remained stable, according to Dr. Waksman, who presented the interim 30-day outcomes at the 2018 CRT meeting.
These findings are raising expectations for two phase 3 TAVR trials in low-risk patients that are being presented as latebreakers at the 2019 ACC annual meeting. Both are large randomized trials comparing TAVR to surgical aortic valve replacement (SAVR) in low risk patients. Each trial is testing a single type of value and is funded by the valve manufacturers.
In the PARTNER-3 trial, patients randomized to TAVR received the Sapien 3 valve (Edwards Lifesciences). In the other latebreaking trial, patients randomized to TAVR received an Evolut valve (Medtronic Cardiovascular). Both are comparing TAVR to SAVR with a composite primary outcome that includes mortality and stroke measured at 30 days and one year.
In contrast to these trials, LRT 1.0 was conducted with no funding from a third party, according to Dr. Waksman. The eleven centers participated in the study at their own cost. Also, the choice of TAVR device was left to the discretion of the interventional cardiologist. Finally, most of the participating centers, although experienced in TAVR, did not have a high-volume case load. In general, with the exception of Dr. Waksman’s center, most performed 100 to 150 TAVRs per year.
“We were struck by the excellence of the performance of these sites,” said Dr. Waksman, noting that a comparison of outcomes at his center relative to the lower volume centers showed no significant differences in outcome.
This real-world experience raises the bar for the pivotal phase 3 trials, which, if positive, are expected to lead the FDA to grant an indication for TAVR in low-risk patients, according to Dr. Waksman. He announced that an LRT 2.0 trial, which will again include centers performing TAVRs at moderate volumes, is now enrolling.
SOURCE: 2019 Cardiovascular Research Technologies (CRT) Meeting.