SAN FRANCISCO – At 5 years, the rates of disabling stroke or death were similar among patients with severe aortic stenosis and intermediate surgical risk who underwent transcatheter aortic valve replacement or surgical aortic valve replacement.
At the same time, patients who underwent TAVR using a transthoracic approach had poorer outcomes, compared with their counterparts who underwent SAVR,, reported at the Transcatheter Cardiovascular Therapeutics annual meeting. The findings come from an analysis of the , the largest randomized study ever conducted in the field of TAVR and SAVR.
In an effort to compare the key clinical outcomes, bioprosthetic valve function, and quality-of-life measures at 5 years for TAVR versus surgery, Dr. Thourani and his colleagues used data from 2,032 intermediate-risk patients with severe AS assigned to either TAVR or SAVR at 57 centers in the PARTNER 2A trial. Their mean age was 82 years, and their average Society of Thoracic Surgery risk score was 5.8%. The 2-year primary endpoint was all-cause death or disabling stroke in the intention-to-treat (ITT) population. At 5 years, the researchers analyzed all primary and secondary clinical and echo endpoints in both ITT and prespecified as-treated populations.
At 5 years, the primary endpoint of death and disabling stroke at 5 years was 47.9% in the TAVR group and 43.4% in the surgery group, a difference that did not reach statistical significance (hazard ratio, 1.09; P = .21). In the transfemoral cohort, rates of the primary endpoint were also similar between TAVR and SAVR (44.5% vs. 42%, respectively; HR, 1.02; P = .80). In the transthoracic cohort, however, the researchers observed a divergence in the primary outcome starting at year 1, such that it was higher with TAVR at 5 years, compared with SAVR (59.3% vs. 48.3%; P = .03), reported Dr. Thourani, chair of cardiac surgery at Medstar Heart and Vascular Institute, Washington.
When he and his colleagues examined freedom from aortic valve reintervention at 5 years, the hazard ratios showed some difference between TAVR and SAVR (HR, 3.93; P = .003), yet clinically the freedom from reintervention rate was very high (96.8% vs. 99.4%, respectively). “The other issue we’ve been interested in is the difference between mean aortic valve gradients between the groups,” Dr. Thourani said at the meeting. “There was no difference in mean aortic valve gradients between TAVR and SAVR at 5 years (a mean of 11.4 mm Hg vs. 10.8 mm Hg, respectively; P = .23).”
Paravalvular regurgitation (PVR) was more common in the TAVR vs. SAVR group at all follow-up times (P less than .001 in all categories). By year 5, the proportion of patients with moderate to severe PVR was 6.5% in the TAVR group vs. 0.4% in the SAVR group, respectively, while the proportion of those with mild PVR was 26.8%, compared with 5.9%.
In other findings, no difference in mortality was seen in the TAVR cohort between those with mild PVR and no or trace PVR (48.7% vs. 41.1%; P = .07). However, those with moderate to severe PVR at the end of the procedure had an increased mortality at the end of 5 years (64.8%; P = .007). “If you had none or trace PVR at baseline, there was no major difference in mortality between the two groups at 2 years,” Dr. Thourani said. “That difference was maintained at 5 years.”
The overall findings, he continued, support the notion that TAVR should be considered as an alternative to surgery in intermediate-risk patients with severe aortic stenosis. “However, in patients without acceptable transfemoral access, surgery may be the preferred alternative,” he said.
, director of interventional cardiovascular research and clinical trials at Mount Sinai School of Medicine, New York, commented that the reassurance of the same outcomes at 5 years between the two approaches “makes TAVR superior. It’s a less invasive and durable result. One of the things we have yet to figure out is the need for anticoagulation to prevent stroke in these patients. We have very little data and understanding about that.”
The PARTNER 2A study was funded by Edwards Lifesciences. Dr. Thourani has received grant or research support from and participation in steering committees for Edwards Lifesciences, Abbott Vascular, Boston Scientific, Gore Vascular, JenaValve, and Cryolife.