SAVR 5-Year Survival Tops 92% in Low-Risk Patients: STS Registry

Among real-world patients undergoing surgical aortic valve replacement, 5-year survival averages almost 93%. The findings from the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery database should set a “benchmark” for soon-to-be-released clinical trial data on transcatheter procedures, according to the authors.

As TAVI has moved to lower-risk patients, clinicians have been awaiting longer-term data comparing outcomes with surgery in order to make more-informed decisions on patient care. Next week, randomized data from both the PARTNER 3 and Evolut Low Risk trials—out to 5 and 4 years, respectively—will be presented at TCT 2023.

“Regardless of what the [clinical trial] data shows, the purpose of this information is it now provides this real-world benchmark and backdrop to help us all interpret the data that is going to be coming out,” senior author Vinay Badhwar, MD (West Virginia University, Morgantown), told TCTMD. As both a SAVR and a TAVI enthusiast, he added that he supports wherever “the evidence takes us,” so long as the patient is at the forefront.

“As the data comes out, I think we all have to take a breath and make sure that when it comes down to the valvular therapist that's sitting down with the patient, that that decision is informed and it's informed based on all evidence and not just one particular trial,” Badhwar said.

I think we all have to take a breath and make sure that when it comes down to the valvular therapist that's sitting down with the patient, that that decision is informed. Vinay Badhwar

The timing of this paper, published this week in the Annals of Thoracic Surgery, is contextually relevant, said Gilbert Tang, MD, MBA (Mount Sinai Health System, New York, NY), who was not involved in the study. But it’s a bit of an “apples to oranges” comparison to pit the real-world STS registry patients against those in PARTNER 3 or Evolut Low Risk, he told TCTMD. For example, he noted, the current study enrolled patients who were treated over a longer time period—some included when the STS risk calculator used a different definition of “low risk”—and excluded those who received concomitant CABG surgery.

“This is at best a good reference point for isolated AVR outcomes in the United States, which have come a long way,” Tang said. “Beyond that, everything else is purely conjectural and I don't think can be a fair comparison.”

Real-world Data

For the study, Badhwar and colleagues included 42,586 patients (mean age 74.3 years; 44.2% women) undergoing primary isolated SAVR at one of 981 hospitals in the STS database between July 2011 and March 2019. Patients were included if they met inclusion and exclusion criteria for PARTNER 3 and Evolut Low Risk, and the mean overall STS PROM score was 1.9%.

All-cause mortality was 2.6%, 4.5%, 7.1%, and 12.4% at 1, 3, 5, and 8 years, respectively. Subgroup analyses showed that survival was significantly better when STS PROM was lower, patients were younger, and LVEF was higher (P < 0.001 for all).

Notably, 8-year survival following SAVR was 95% when STS PROM was below 1% or patient age was below 75 years.

Badhwar said he was somewhat surprised by the “very good outcomes” shown here, and because of their inclusion and exclusion criteria, he called this data a “true apples to apples comparison of TAVR and SAVR.”

But Tang disagreed, offering several caveats. First, because of the length of this study’s enrollment period, “when we lump such a long period together, [outcomes] might have changed over time” with improvements in surgical techniques, he said, adding that he wished this study would have started from 2016 to better match the low-risk trials.

He also highlighted two major differences between the real-world population studied here and those in the clinical trials. Up to one fifth of PARTNER 3 and Evolut Low-risk patients received concomitant cardiac surgery, which would substantially increase their predicted risk. Also, because patients in the trials were randomized to either TAVI or SAVR, there were some anatomic exclusions not represented in the registry data.

“To try to compare this directly with the two randomized trials with some of the confounding factors that I mentioned, I think do the comparison a bit injustice,” Tang said. “It was almost like apples versus oranges.”

Lifetime Management Conversations

Badhwar hopes these data can continue to inform patient and physician choices, with any eye, too, to the future.

“Overall, we are all very much in full embrace of TAVR, particularly for selected patient populations,” Badhwar said. “The challenge we are seeing across the specialty now is one of the most frequently rising operations are TAVR explants in the STS database. . . . When you look at the balance between the embrace of new technology and longitudinal outcomes, that's the overarching impetus for doing this study.”

Ultimately, “as we look to next week and future iterations of these low-risk trials and we start to push down the risk threshold to do transcatheter therapies, we really want to make sure that we are doing the right thing for our patients as age drops as well as risk drops,” he added.

Tang also said he’s excited to see next week’s data. They will be important to help put the decision of SAVR versus TAVI into context for patients and their families, especially for those conversations regarding lifetime management and secondary interventions, he said. Key questions now become: “What valve should the patient choose as the first valvular intervention? Is it a TAVR? Is it a SAVR? Which valve would the heart team recommend?”