Both databases had good news for high-risk or inoperable patients. TAVR outcomes in the first couple of years immediately following PARTNER in both the United States and Germany showed clinically meaningful improvements over the way TAVR performed during the first PARTNER trial. Less optimistic news for the low- and intermediate-risk patients who underwent TAVR in Germany, where wider device use is possible, was that in broad terms open surgery outperformed TAVR in these lower-risk patients, although TAVR’s defenders are quick to point out how tricky it is to make cross-treatment comparisons with registry data.
Mitchel L. Zoler/IMNG Medical Media
Dr. William F. Fearon
The nonrandomized, continued-access cohort that followed the first PARTNER trial at 22 U.S. centers, 3 sites in Canada, and 1 site in Germany included 1,017 inoperable or high-risk patients who had successful transfemoral TAVR between August 2009 and December 2011. When compared with the 415 inoperable or high-risk patients who underwent transfemoral TAVR in both cohorts of PARTNER, the more recently treated patients had a statistically significant decrease in all-cause 1-year mortality, from a 25% death rate in PARTNER to a 20% rate during the continued-access period, Dr. William F. Fearon reported at the meeting.
The continued-access patients also showed significant cuts in their rates of major vascular complications, which dropped from 15% of patients in PARTNER to 6% during continued access; and in rates of major bleeding complications, which fell from 15% in PARTNER to 7% during continued access. Strokes were also down during continued access, 5% compared with 7% during PARTNER, but this was not a statistically significant drop, reported Dr. Fearon, a cardiologist at Stanford (Calif.) University.
"Maybe these improvements are due to better patient selection, and maybe we have also gotten better at what we do," commented Dr. Popma.
The latest German experience
The 1-year German Aortic Valve Registry (GARY) results from 2011 show similar improvements compared with PARTNER. Among the 2,689 patients who underwent transvascular TAVR, the 1-year total mortality rate was 21%, and in the subset of patients with stroke data the combined rate of major and minor stroke was 5%.
But it was the way that transvascular TAVR (which includes both transfemoral and other vascular approaches but excludes the 1,181 patients who underwent transapical TAVR) stacked up against open surgical replacement that raised concern.
Of the 13,860 total patients entered into GARY during 2011, 9,985 underwent SAVR, with 6,523 of these patients undergoing an isolated procedure (the rest had valve replacement combined with coronary artery bypass). One-year mortality was 7% in patients who had isolated SAVR, dramatically below the 21% rate among the transvascular TAVR patients, Dr. Friedrich-Wilhelm Mohr reported at the meeting. The transapical TAVR patients had a 28% 1-year mortality rate.
To address the issue of between-treatment differences in patients’ underlying risk, Dr. Mohr presented two sets of analyses that stratified patients with two different risk-scoring systems, the EuroSCORE and the AKL (aortic valve surgery) score, also known as the German aortic valve score. The results showed how disparate the outcomes were when patients were subgrouped by their underlying risk. Among the patients who had lone SAVR, 80% fell into the lowest-risk level, with an AKL score of less than 3. Among the transvascular TAVR patients, only 17% had AKL scores below 3.
Among patients with AKL scores less than 3, those who underwent SAVR without bypass had a roughly 5% mortality rate after 1 year, compared with about a 15% mortality rate among the transvascular TAVR patients. Analyses in higher-risk patient subgroups showed that the survival gap between SAVR and TAVR patients progressively shrank, until in high-risk patients – as in those studied in PARTNER – the mortality rates were about the same in the SAVR and TAVR groups, said Dr. Mohr, professor and director of heart surgery at Leipzig University, Germany. He also reported similar findings when patients were stratified by their baseline EuroSCORE.
A big factor behind the worse survival among lower-risk TAVR patients is the problem of aortic regurgitation, Dr. Mohr said. Following valve replacement, 56% of the transvascular TAVR patients had grade 1 regurgitation, 7% had grade 2, and less than 1% had grade 3 leakage. These rates are way too high, he said. "Our major concern is the incidence of aortic regurgitation; more than half of the [TAVR] patients had some kind of regurgitation. Regurgitation matters whether it is mild or severe."
Despite his concern, TAVR use in Germany is accelerating. The total number of aortic valve replacements done in Germany jumped from just less than 14,000 in 2011 to more than 22,000 last year; TAVR cases more than doubled, from fewer than 4,000 in 2011 to nearly 10,000 in 2012, with a "move to intermediate-risk groups," said Dr. Mohr, who made it clear that he does not endorse this trend. "TAVR must be proven better than or equal to surgery before it’s used on a large scale," he said. The GARY results show "a clear difference [between TAVR and SAVR] in lower-risk patients. The GARY results do not support going into intermediate-risk patients."