Transcatheter aortic valve implantation (TAVI), whether using a transfemoral or transapical approach, may be a reasonable alternative to surgery in patients with symptomatic severe stenosis who are at high or prohibitive surgical risk, according to new data from a Canadian trial published online January 20, 2010, ahead of print in the Journal of the American College of Cardiology.
The study also found that patients with porcelain aorta or frailty—2 of the most frequent comorbidities in elderly patients with severe aortic stenosis not included in surgical risk-score calculators—had similar outcomes compared with the rest of the study population.
Researchers led by Josep Rodés-Cabau, MD, of Laval University (Quebec, Canada), reviewed acute and late outcomes of 345 TAVI procedures performed in 339 patients with severe aortic stenosis. Patients were considered either inoperable or at very high risk for surgery and underwent TAVI under a compassionate use program at 1 of 6 Canadian centers between January 2005 and June 2009.
Rather than randomizing patients to either the transapical or transfemoral approach, the choice was agreed upon by a multidisciplinary team at each center. Overall, 167 patients (49.6%) were selected for transfemoral, and 172 patients (50.7%) were selected for transapical.
Comparable Mortality for Transapical and Transfemoral
Mortality was 10.4% at 30 days, with a cumulative mortality of 22.1% at a median follow-up of 8 months. The procedural success rate was 93.3%. Major access site complications were the most frequent procedural issue, occurring in about 13% of cases with either approach.
Both approaches were associated with similar survival rates at 1 (transfemoral, 75%; transapical, 78%) and 2 years (transfemoral, 65%; transapical, 64%). A total of 39 patients (11.5%) died during follow-up at a median of 162 days after the TAVI procedure. Of these, 26 patients (7.7%) died of noncardiac causes.
Among the cohort, 18% had porcelain aorta and 25% had frailty. A separate analysis found that these patients had similar acute and late outcomes compared with those lacking these comorbidities (tables 1 and 2).
Table 1. Outcomes for Patients with Porcelain Aorta
|
No
(n = 278)
|
Yes
(n = 61)
|
P Value
|
Stroke
|
2.5%
|
1.6%
|
1.00
|
30-Day Mortality
|
10.4%
|
11.5%
|
0.819
|
Cumulative Mortality
|
23.4%
|
16.4%
|
0.307
|
Table 2. Outcomes for Patients with Frailty
|
No
(n = 254)
|
Yes
(n = 85)
|
P Value
|
Stroke
|
1.9%
|
3.5%
|
0.419
|
30-Day Mortality
|
11.4%
|
8.2%
|
0.542
|
Cumulative Mortality
|
22.1%
|
22.4%
|
1.00
|
Mortality Acceptable, but Room for Improvement
In an e-mail communication with TCTMD, Dr. Rodés-Cabau said he views the cumulative mortality rate for the cohort as acceptable considering that (a) the population included in the study was very sick and high risk, and (b) the study included early experience with TAVI.
“However, there is no doubt that there is room for improvement. This includes improving patient selection, technical skills, procedural and post-procedural patient management, and patient follow-up,” he said. “That is why it remains so important to identify the factors associated with worse outcomes if we want to improve the results associated with these procedures.”
Predictive factors of acute and cumulative late outcomes identified in the study included pulmonary hypertension, severe mitral regurgitation, COPD, chronic kidney disease, periprocedural sepsis, and need for hemodynamic support.
Dr. Rodés-Cabau added that the stroke rate is encouragingly low, as is late mortality in the porcelain aorta group.
Moving in the Right Direction
“I think that we are moving in the right direction and studies like this one including several centers and a relatively large number of patients can help,” Dr. Rodés-Cabau said. “However, no randomized data comparing this technology with the standard surgical therapy are available yet.”
Ted Feldman, MD, of Evanston Hospital (Evanston, IL), commented that the low complication rates are noteworthy as TAVI research moves forward. Equally important is the fact that outcomes achieved in the transapical group are comparable to those of the transfemoral group.
“Apical results have been kind of all over the map in single-center reports prior to this, so to have a multicenter experience with apical outcomes that were basically the same as the transfemoral group is an important finding,” he told TCTMD in a telephone interview. “It reflects very well on the development of the procedure and the experience of the people involved in the study.”
Dr. Feldman congratulated the researchers for their careful risk stratification and said the findings regarding patients with porcelain aorta and frailty likely will become part of the patient-selection discussions for the randomized PARTNER (Placement of AoRTic TraNscathetER) valve trial. “Everything that helps us risk-stratify in the future is important,” he said.
During the multidisciplinary discussions in the Canadian trial, 52 patients were excluded but then enrolled in PARTNER. Dr. Feldman expressed curiosity about the reasoning behind that decision, adding that he hopes the Canadian researchers will elaborate at a later date. “If there are substantial differences between the populations, we need to understand that in order to appreciate what these results mean in relation to PARTNER,” he said.
Dr. Rodés-Cabau responded that he could not discuss the 52 patients at this time because any data related to them are now part of PARTNER, which is ongoing.
Source:
Rodés-Cabau J, Webb JG, Cheung A, et al. Transcatheter aortic valve implantation for the treatment of severe symptomatic aortic stenosis in patients at very high or prohibitive surgical risk.
J Am Coll Cardiol. 2010;Epub ahead of print.
Disclosures:
- Dr. Rodés-Cabau reports serving as a consultant for Edwards Lifesciences, Inc.
- Dr. Feldman reports serving as an investigator for the PARTNER trial, which is evaluating the Edwards Sapien valve.
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