March 29, 2020
TAVR Compared to Surgery in Low-Risk Patients at 2 Years in PARTNER 3 Trial
March 29, 2020—Michael J. Mack, MD, presented 2-year clinical and echocardiographic outcomes from the PARTNER 3 study at the virtual conference of the American College of Cardiology’s (ACC) Annual Scientific Session Together with World Congress of Cardiology (ACC.20/WCC). The PARTNER 3 trial focused on a low-risk patient population.
According to the ACC announcement, the trial found that these low-risk patients undergoing transcatheter aortic valve replacement (TAVR) fared equally well compared with patients undergoing surgical aortic valve replacement in terms of the combined risk of death, stroke, or rehospitalization at 2 years, which is the primary endpoint of the PARTNER 3 trial.
In 2019, investigators reported that TAVR showed superior outcomes compared with surgery at 1 year in PARTNER 3 patients. The new findings indicate both approaches are equivalent in this low-risk population in terms of outcomes occurring up to 2 years later.
Dr. Mack commented in the ACC press release, “The 1-year outcomes were only the first look at how these patients do, and this is the second look. On the basis of 1-year data, many physicians were counseling patients that TAVR outcomes were better than surgery. Now, we see that the outcomes are roughly the same at 2 years.”
As summarized in the ACC announcement, PARTNER 3 enrolled 1,000 patients with severe aortic stenosis and a Society of Thoracic Surgeons risk score of < 4%. All patients had a tricuspid aortic valve. Half of the participants were randomly assigned to undergo TAVR with the Sapien 3 valve (Edwards Lifesciences, which sponsored the trial) and half underwent surgery.
At 2 years, 11.5% of TAVR patients and 17.4% of surgical patients died, had a stroke, or were rehospitalized for cardiovascular problems. This difference in the composite primary endpoint showed noninferiority.
In a secondary analysis, rates of death (2.4% vs 3.2%) and stroke (2.4% vs 3.6%) were found to be not significantly different between the two groups. Rehospitalization rates showed a significant difference in favor of TAVR (8.5% vs 12.5%).
The 2-year outcomes also indicate patients undergoing TAVR had a significantly higher rate of valve thrombosis (2.7% vs 0.7%). However, there was no significant deterioration in the functioning of the valve itself between years 1 and 2 in either study group.
Noting that investigators will continue to track patient outcomes for up to 10 years, Dr. Mack stated, “Longer-term outcomes are particularly important for this patient population because younger, low-risk patients have longer to live with this valve than patients that have been previously studied. Therefore, the durability of the valve is of utmost importance.”
In the ACC announcement, Dr. Mack advised that the trial’s findings are limited to patients with severe, symptomatic aortic stenosis with a tricuspid valve and the same inclusion criteria as patients who were enrolled in the study; additionally, the trial is limited by a reduced follow-up rate among patients who received surgery compared with those who underwent TAVR.