Survival and Stroke Similar for TAVR and SAVR at 5 Years

Debra L Beck

November 26, 2018

In patients with severe aortic stenosis at high surgical risk, 5-year survival and stroke rates after transcatheter aortic valve replacement (TAVR) with the CoreValve System (Medtronic) were similar to outcomes after surgical valve replacement (SAVR).

A meaningful survival advantage had been seen for TAVR at the 1-year mark, with a numerical, but not statistical, advantage remaining at 3 years.

This was no longer the case at 5 years, when all-cause mortality rates were 55.3% for TAVR and 55.4% for SAVR (P = .50). Stroke rates also did not differ, at 12.3% and 13.2%, respectively (= .49)

The 5-year data were presented at Transcatheter Cardiovascular Therapeutics 2018 in October and published in manuscript form then, with the final publication appearing November 26 in the Journal of the American College of Cardiology.

This is the second TAVR vs SAVR comparison in high-risk patients to report 5-year outcomes, said Thomas G. Gleason, MD, University of Pittsburgh Medical Center.

The PARTNER 1 trial reported 5-year outcomes in 2015 in 699 high-risk patients. In that trial, 5-year risk for death was 67.8% for TAVR and 62.4% for SAVR (P = .76).

"The relevance here is that with 5-year data from CoreValve and PARTNER 1, what we can now say is that the TAVR valves appear to be performing as well as the SAVR valves," Gleason said in an interview with theheart.org | Medscape Cardiology.

The study enrolled 797 patients, 750 of whom underwent an attempted TAVR or SAVR. The mean age was 83 years and the mean Society of Thoracic Surgery Predicted Risk of Mortality (STS-PROM) score was 7.4%.

Predictors of 5-year mortality with either TAVR or SAVR included the usual culprits: be older than 85 years, an STS PROM score above 7%, and advanced heart failure.

Serial echocardiograms through 5 years showed TAVR to be superior to SAVR for effective orifice area and mean gradient at all time points, but inferior for total aortic regurgitation, which was mostly because of paravalvular leak.

No patients developed severe aortic regurgitation, and six TAVR and no SAVR patients had moderate aortic regurgitation.

All Eyes on Safety and Durability

Valve durability is an ongoing concern as clinicians consider implanting TAVR prostheses in progressively younger and lower-risk patients.

Using the recent standardized definitions for structural valve deterioration (SVD) by Capodanno et al, the incidence of severe SVD in this trial was low and did not differ between groups (0.8% for TAVR and 1.7% for SAVR; P = .32). Moderate SVD was noted in 9.2% and 26.6%, respectively (P < .001).

In an accompanying editorial, Hasan Jilaihawi, MD, and Mathew Williams, MD, both from NYU Langone Health in New York City, suggested that the superior durability data throw the advantage to TAVR for the majority of patients.

"Although much concern has been raised on the durability of TAVR, if anything, the presented data suggest that TAVR could be more durable than SAVR, with significantly less structural valve deterioration with TAVR versus SAVR," Jilaihawi and Williams write.

Armed with the 5-year clinical outcomes and durability data, along with a significantly higher number of days alive and out of the hospital in the TAVR group, the editorialists conclude: "Undoubtedly, there are anatomic subsets where the 'TAVR risk' may outweigh the 'SAVR risk,' but this has become the exception rather than the rule."

Gleason vehemently disagrees with this. His group used the Capodanno et al definition for SVD, "but in my opinion, it is not an appropriate definition because it is based on an elevated gradient and many of the surgical valve implants for those trials were relatively small valves and generated a fairly high gradient immediately out of the gate, at which time we all know they are not structurally deteriorating."

"If an adequately sized valve had been implanted surgically, they would not be meeting criteria for moderate structural valve deterioration."

He thinks the definition will ultimately be refined, "but to categorize those patients — many of whom had an elevated gradient likely due to relative patient–prosthesis mismatch — as structural valve deterioration and then draw conclusions based on that is not appropriate."

Although Gleason insists "the jury is still out about whether or not there's going to be a durability issue out beyond 5 years after TAVR," what can be agreed on is that, for the average 83-year-old — the mean age in this trial — TAVR is most likely the way to go.

"When this trial was designed 8 years ago, we didn't know about the safety in the high-risk cohort, and that was the point of the trial. At this point, I think there is uniform agreement that for the average 83-year-old who is not truly low risk, most patients are going to want a TAVR over a SAVR. This remains true given that PARTNER showed no survival advantage at 5 years and this trial showed an early survival advantage that was gone by 5 years," said Gleason.

This study was funded by Medtronic. Gleason reports receiving institutional grant support from Medtronic and Boston Scientific and has served on medical advisory boards for Abbott and Cytosorbents Corporation.

J Am Coll Cardiol. Published online November 26, 2018. Abstract, Editorial

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