Opportunities Exist to Improve Outcomes in Transapical TAVR

San Francisco, CA—The increased risk for adverse events, slower recovery time and increased risk for mortality after transcatheter aortic valve replacement (TAVR) via transapical vs. transfemoral access are due to differences in patient characteristics and the ways in which patients are selected for the two procedures, according to a presenter at TCT 2013. 

“There is a similar risk for stroke, however the risk for death is somewhat higher at 6 months in transapical TAVR patients and there is less surgical aortic [valve] replacement,” said Eugene H. Blackstone, MD, of the Cleveland Clinic. “These differences are in part related to a higher risk for surgery when compared with a percutaneous procedure, but also in part to the way that patients are selected based upon access which results in transapical patients having more CV risk factors.”

Blackstone compared the outcomes of transapical TAVR (n=1,100) vs. transfemoral TAVR (n=1,521) in patients from the PARTNER series of trials with comparable pre-procedure characteristics, including those from PARTNER cohort A and B.

“Comparing the outcomes in these very different groups is like comparing apples to oranges. To identify these otherwise noncomparable patients, we used propensity matching,” Blackstone said. “This statistical technique generates a pseudo-randomized trial. We developed a propensity score using 102 patient characteristics and then matched patients solely on a propensity score. This yielded 501 patients and 46% of possible matches.”

Blackstone examined whether the differences in outcomes are associated with the fact that one procedure is primarily surgical and the other is percutaneous, or if it is due to patient selection for transapical TAVR. “For example, are patients selected for transapical TAVR more likely to have CV risk factors?” Blackstone asked.

Researchers observed more adverse events and a slower recovery time after transapical TAVR — similar to open thoracic surgery. The risk for stroke was comparable between the two arms in comparable patients. However, there were fewer periprocedural strokes after transapical TAVR now than in PARTNER cohort A, which may be due to surgical improvements, according to Blackstone.  

The risk for mortality was due, to some extent, to differences in patient characteristics between the two procedures. Even after adjusting for these patient characteristics, the risk remained higher for transapical TAVR at 6 months. Blackstone also reported consistent total aortic regurgitation grade across time, suggesting a real difference in aortic regurgitation between transapical and transfemoral TAVR (see Figure).  

  “On the positive side, [surgical] AVR was less after transapical TAVR. Consistency of this finding across time suggests a real difference in [surgical] AVR between transapical and transfemoral TAVR,” he said. “This may be attributable to antegrade delivery of the prosthesis, which may permit more accurate valve positioning and allow for some adjustment, and more accurate and appropriate valve sizing, which led to a greater proportion of transapical TAVR patients receiving a 26-mm prosthesis (53% vs. 45%) compared with transfemoral patients. This suggests that results of transapical TAVR can be improved with a dramatic reduction in stroke. The opportunity is there to [improve outcomes] both surgically and technologically.”   

Disclosures: 

Blackstone reports financial relationships with Edwards Lifesciences and the PARTNER Publication Office.