TAVR beneficial in patients at low surgical risk, but data on long-term durability awaited
Click Here to Manage Email Alerts
Key takeaways:
- In patients with severe aortic stenosis at low surgical risk, TAVR appears to be just as beneficial as surgery.
- When deciding on a treatment, lifetime management of the disease must be considered.
Eligibility of patients with severe aortic stenosis for transcatheter aortic valve replacement has grown in recent years due to successful trials in patients at low surgical risk, but there is still much to learn about long-term results.
TAVR was initially reserved for patients who were unlikely to survive a surgical procedure, but over time, trials in progressively lower-risk patients have shown that TAVR has comparable outcomes to surgical AVR in those populations as well.
Key data from two trials
In March 2019, The New England Journal of Medicine published 1-year results of the PARTNER 3 trial of a balloon-expandable TAVR valve (Sapien 3, Edwards Lifesciences) and 2-year results of the Evolut Low-Risk Trial of a family of self-expanding TAVR valves (CoreValve, Evolut R or Evolut PRO; Medtronic). In PARTNER 3, the primary outcome of death, stroke or rehospitalization and the other outcomes of all-cause mortality, any stroke, disabling stroke, rehospitalization and new-onset atrial fibrillation all occurred less often in the TAVR group, though mild paravalvular regurgitation and new left bundle branch block occurred more often in the TAVR group. In the Evolut Low-Risk Trial, the primary endpoint of all-cause mortality or disabling stroke was noninferior and numerically lower in the TAVR group compared with the surgery group, and the TAVR group had lower 30-day rates of disabling stroke, major bleeding, acute kidney injury and AF, but higher rates of moderate to severe aortic regurgitation and pacemaker implantation.
Since then, 2-year results of PARTNER 3 and 3-year results of the Evolut Low-Risk Trial have been published. In PARTNER 3, the primary outcome of death, stroke or rehospitalization remained lower in the TAVR group at 2 years, though the rates of death and stroke individually no longer favored TAVR and the rate of valve thrombosis was higher in the TAVR group. In the Evolut Low-Risk Trial, the primary endpoint of all-cause mortality or disabling stroke remained numerically lower in the TAVR group at 3 years. The rates of moderate to severe aortic regurgitation and pacemaker implantation remained higher in the TAVR group, but valve hemodynamics were better in those who had TAVR.
However, the definitive data on durability of TAVR valves are yet to come, Vinod H. Thourani, MD, chair of the department of cardiovascular surgery for Piedmont Healthcare in Atlanta, told Healio, noting the 5-year data from the PARTNER 3 study and the 4-year data from the Evolut Low-Risk Trial will be presented at the Transcatheter Cardiovascular Therapeutics (TCT) conference in October.
“That will be the best randomized data for low-risk TAVR vs. surgical AVR,” he said. “The data that we have so far show that in patients in their early 70s, which is what most of the patients from those trials were, there is no major difference when it comes to mortality. In the 2-to-3-year period, the durability looks the same between TAVR and surgical AVR in low-risk patients in their early 70s.”
Particularly important will be data on structural valve deterioration, Thourani said.
“We don’t know if the TAVR valves will have the longevity of the surgical valves,” he told Healio. “In the balloon-expandable valves, we need to know whether gradients or thrombosis are important. In the self-expanding valves, we need to know whether higher pacemaker implantation rates are important.”
Lifetime management of aortic stenosis
When deciding on the best option for patients with severe aortic stenosis at low surgical risk, clinicians need to consider how the disease is going to be managed over the lifetime, and in younger patients, that may mean more than one procedure will be needed, Thourani said.
“The [American College of Cardiology/American Heart Association] guidelines talk about to consider surgery for people younger than 65 years if they are going to live longer than 10 years, but for those who are older than 65 years and are expected to have longevity less than 10 years, a transcatheter valve pathway may be best for them,” he told Healio. “When I see a low-risk patient, what is important is mapping out their next 20 to 30 years, and allowing the best plan for that 20-to-30-year period. It may mean surgery with a large surgical valve ... which could be a setup for a TAVR down the road. Or it could mean they get a TAVR this time, understanding that they may need TAVR-in-TAVR or surgical therapy to remove the TAVR valve.
“There needs to be a realistic conversation with patients that if they have a TAVR at a younger age, they have other options available to them, because as they get older, they get coronary artery disease and their coronary arteries may need to be accessed,” Thourani said. “Also what’s important is that if you have a TAVR at a younger age, will you be able to have a second TAVR or will you need a surgery? Surgery for TAVR removal does have a predicted mortality rate of 10% to 15%, which is higher than it would have been if they had surgery the first time around. It is important for surgeons, cardiologists and other professionals to see these patients in consult together to give them that balanced approach of lifetime management.”
Once a TAVR procedure has been performed in a low surgical risk patient, regular echocardiograms should be given, first at 30 days after the procedure and then once per year thereafter, Thourani said.
When determining the best approach for a low-risk patient, “anatomical considerations are exceedingly important,” he told Healio. “For instance, whether the patient has an aortic aneurysm; if it is significant, they should likely head toward surgery. If the patient has a bicuspid valve, a realistic expectation of whether TAVR is feasible without leaving the patient with a significant leakage around the valve or the risk of root rupture would probably lead the patient toward surgery. If a patient with a bicuspid valve has anatomy that is amenable to TAVR, then TAVR is potentially a viable option, but it becomes unbelievably important for the heart team to assess all variables of the anatomy including the risk for paravalvular regurgitation and root rupture to give that patient the best option.”
Once the 4-year and 5-year data are revealed, “anecdotal experience should give way to randomized trials that have clinical events committees and echocardiography core labs,” he said.
References:
- Forrest JK, et al. J Am Coll Cardiol. 2023;doi:10.1016/j.jacc.2023.02.017.
- Leon MB, et al. J Am Coll Cardiol. 2021;doi:10.1016/j.jacc.2020.12.052.
- Mack M, et al. N Engl J Med. 2019;doi:10.1056/NEJMoa1814052.
- Popma JJ, et al. N Engl J Med. 2019;doi:10.1056/NEJMoa1816885.
For more information:
Vinod H. Thourani, MD, can be reached at vinod.thourani@piedmont.org; X (Twitter): @vinodthourani.
Collapse
Click Here to Manage Email Alerts