Survival Better, No ‘Risk Creep’ for TAVR vs Surgery in Lower-Risk Patients

Concern about “risk creep" as TAVR expands to lower-risk populations appears to be unsubstantiated, according to subanalysis of the randomized CoreValve US Pivotal High Risk Trial.

Published online August 17, 2016, ahead of print in JAMA Cardiology, the analysis looked at death and quality of life (QoL) outcomes through 2 years in the 383 subjects who had low STS PROM scores for mortality (median 5.3% for TAVR and SAVR, respectively). The scores have been on the decline, on average, as TAVR has transitioned from clinical trials to real-world practice, with a 2015 report from the Society of Thoracic Surgeons/American College of Cardiology TVT Registry showing a median score of 7.1%.

“What we found is that at a mean STS of 7% and lower, patients did well and [TAVR] outperformed surgery,” said lead investigator Michael J. Reardon, MD (Houston Methodist DeBakey Heart and Vascular Center, Houston, TX), in an interview with TCTMD. “The bottom line is that using STS alone as a metric and seeing decreasing STS should not be cause for concern, because we can do a really good job in these patients.”

The study comes on the heels of the decision last week by the US Food and Drug Administration (FDA) to expand indications for the Sapien XT and Sapien 3 valves (Edwards Lifesciences; Irvine, CA) to patients classified as being at intermediate surgical risk for death or complications. The devices can now be used in patients who have been determined by a heart team to have a predicted risk of surgical mortality of at least 3% at 30 days, based on the STS risk score and other clinical comorbidities. The decision follows the news from Europe earlier this month that CoreValve Evolut R (Medtronic) was approved for use there in intermediate-risk patients.

Recognizing that STS alone is not sufficient for making decisions about intervention, Reardon stressed that the CoreValve analysis was post hoc and not prespecified, and in a sense is more clinically than statistically relevant.

“The bottom line is that dropping STS score does not mean that we are now treating people who should not be treated or who will not have a good outcome,” Reardon said. “This study was done as a harbinger of what we thought we might see in an intermediate-risk trial, because those trials had no data available yet.”

In fact, results from at least one of those intermediate-risk trials, PARTNER 2A, were published in April to coincide with a presentation at the American College of Cardiology 2016 Scientific Sessions. It found that TAVR with the Sapien XT was at least as good as surgery in intermediate-risk patients with severe symptomatic aortic stenosis. Looking ahead, Reardon said he hopes to present data from another randomized intermediate-risk trial, SURTAVI, at next years’ ACC meeting, adding that “if the data look good, and I’m certainly optimistic that they will, I would expect Evolut R to be approved for intermediate risk in the US, also.”

Better Survival with TAVR

In the new analysis, all-cause mortality at 2 years was lower with TAVR than with SAVR (15.0% vs 26.3%; log-rank P = .01), as was cardiovascular mortality (11.7% vs 19.5%; log-rank P = 0.06). QoL, as assessed by the Kansas City Cardiomyopathy Questionnaire summary score, improved in both groups but did not differ between them at 2 years.

Compared with surgery patients, those who had TAVR had better forward flow hemodynamics at each follow-up and lower likelihood of patient-prosthesis mismatch. In terms of complications, TAVR patients had more major vascular events and need for new pacemaker, while surgery patients had more life-threatening or disabling bleeding, new A-fib, and acute kidney injury.

To TCTMD, Reardon said it “is interesting” to see data showing superior survival for TAVR over surgery.

“The overall [CoreValve] High Risk Trial showed that. This subanalysis showed that. If you look at just the transfemoral cases in PARTNER 2A, they showed superior survival,” he observed. “We are seeing this trend that this technology, which has only been around for a little over a decade, has improved at a rate beyond what anyone could have imagined, and it certainly leads one to think that in a decade from now, we will be doing even better.”