SAN FRANCISCO – Transcatheter aortic valve replacements seem to be holding up without feared increases in rates of stroke or regurgitation beyond what’s seen soon after the procedure, 3-year data from the PARTNER trial of 699 elderly, high-risk patients showed.
Rates of death from any cause were similar between patients randomized to transcatheter aortic valve replacement (TAVR) compared with surgical aortic valve replacement (SAVR) at each yearly follow-up so far. Those rates (the primary endpoint of the trial) were 24.3% in the TAVR group and 26.8% in SAVR group at 1 year, 33.7% and 34.6% at 2 years, and 442% and 44.8% at 3 years, respectively, according to ongoing follow-up of the PARTNER (Transcatheter vs. Surgical Aortic-Valve Replacement in High-Risk Patients) study.
Dr. Vinod H. Thourani
Previously data had shown a higher stroke rate within 30 days of TAVR (5%), compared with SAVR (2%), though the difference did not reach statistical significance. By 3 years, the stroke rate in the surgery group caught up and even surpassed that in the TAVR group. After TAVR, stroke rates were 6% at 1 year, 8% at 2 years and 8% at 3 years, compared with rates of 3%, 5% and 9%, respectively, in the SAVR group, Dr. Vinod H. Thourani and his associates reported at the annual meeting of the American College of Cardiology. None of the stroke differences reached statistical significance.
Paravalvular leaks were common and more likely with TAVR at all follow-up time points. Even mild leakage after either procedure was associated with an unexpected, significantly increased risk of death, said Dr. Thourani, codirector of the Structural Heart and Valve Center and associate professor of cardiology at Emory University, Atlanta. Death rates in patients with mild aortic regurgitation of any kind (paravalvular or central) after TAVR were 26% at year 1, 32% at year 2, and 47% at year 3. For moderate to severe aortic regurgitation after TAVR, death rates increased to 38% at 1 year, 54% at 2 years, and 61% at 3 years.
The increased death risk with mild regurgitation has not shown up in European patient registries and caught investigators by surprise. The reason for this association in the study is a mystery, he said.
Echocardiographic analysis showed that hemodynamic performance after TAVR was maintained at 3 years, with similar valve areas and gradients, compared with SAVR. Both groups had significant improvements in left ventricular ejection fractions and left ventricular mass.
The PARTNER study included elderly patients with severe aortic stenosis who had a Society of Thoracic Surgeons (STS) score of at least 10%, suggesting they would be at high risk from surgery. Patients were randomized to undergo TAVR or SAVR at 1 of 25 sites in three countries and those in the TAVR group were further randomized to either transfemoral or transapical approach to placement of the balloon-expandable bovine pericardial valve, the first-generation Edwards SAPIEN transcatheter heart valve system (N. Engl. J. Med. 2011;364:2187-98).
Combining all-cause mortality or strokes, rates for TAVR and SAVR at 1 year were 27% and 29%, respectively, at 2 years were 37% and 36%, and at 3 years were 47% and 46%, respectively, he said.
Among clinical outcomes, rates of major vascular complications were significantly higher in the TAVR group, compared with SAVR: 12% vs. 4% at year 1, rates that held steady in years 2 and 3. Major bleeding was significantly less likely in the TAVR group each year, compared with SAVR: 16% vs. 27% in year 1, 19% vs. 30% in year 2, and 21% vs. 32% in year 3. Rates of endocarditis were similar between groups each year. No patients in either group developed structural valve deterioration requiring aortic valve replacement. Roughly 80% in each group had relief of symptoms.
Future efforts should aim to reduce procedure-related complications from TAVR, including strokes, vascular events, and paravalvular regurgitation, Dr. Thourani said.
"With a 44% mortality at 3 years, what we have to learn is how to select better patients," Dr. Bernard J. Gersh commented during a panel discussion of the findings. Dr. Gersh is professor of medicine at the Mayo Clinic, Rochester, Minn.
Experts in Europe have begun a series of meetings to try to define a transcatheter-specific risk score that might be a better gauge than the STS score in selecting patients for TAVR, Dr. Thourani said.
Patients in the current analysis have a minimum of 3 years of follow-up, so the findings really give a hint of 3- to 5-year results, Dr. Thourani said. "I think we can say something about the durability of these valves."