Why is the study important? 

The ACURATE investigational device exemption (IDE) Trial demonstrated that at 1 year the Acurate neo2 did not meet criteria for non-inferiority with regards to a composite of all-cause mortality, stroke, or rehospitalization when compared to commercially available transcatheter heart valves (THV).

Should I change my practice because of these findings? 

The overall performance of the Acurate neo2 THV in patients undergoing transcatheter aortic valve replacement (TAVR) across the full spectrum did not meet non-inferiority when compared to commercially available THVs. A post-hoc analysis demonstrated that approximately 20% of Acurate neo2 implants saw frame under expansion, which, if identified earlier, may have impacted outcomes. Furthermore, well-expanded implants yielded outcomes that were more similar to the commercial arm. Further data and studies may be needed to determine if the Acurate neo2 is non-inferior to commercially available THVs. It remains to be seen if the findings of this trial will be sufficient to result in FDA approval.

What question was the study supposed to answer? 

This study sought to compare the 1-year composite of all-cause mortality, stroke, or rehospitalization in patients undergoing TAVR with the self-expanding Acurate neo2 and commercially available THVs (SAPIEN and Evolut platforms) in an attempt to demonstrate non-inferiority. 

What did the study show? 

The 1-year analysis of patients enrolled in the multicenter randomized controlled trial demonstrated that the primary composite outcome of all-cause mortality, stroke, or rehospitalization was higher in TAVR patients receiving the Acurate neo2 THV compared to either a SAPIEN THV or Evolut THV (14.8% vs. 9.1%, posterior median difference = 6.6%, non-inferiority margin = 8.0%; therefore, non-inferiority was not achieved). The individual components of the composite were as follows: as all-cause mortality (5.0% vs. 3.9%), 
stroke (5.7% vs. 3.4%), and rehospitalization (5.3% vs. 3.5%). Interestingly, the investigators identified approximately 20% of Acurate neo2 THVs that were under expanded, and that demonstrated a numerically higher rate of the primary composite outcome (18.8% vs. 12.4%, p=0.05) and may have driven the results of the primary analysis. 

How good was the approach/methodology? 

The Acurate IDE Trial was a large-sized and well-designed multicenter randomized controlled trial seeking to demonstrate the non-inferiority of the Acurate neo2 THV compared to THVs that were commercially available for TAVR. One of the major limitations of enrollment was the fact that 72% of physicians implanting performed 5 of fewer Acurate neo2 TAVRs, with only 10% of implanters having performed at least 10 TAVRs using the Acurate neo2. Furthermore, sites on average saw 2-3 months between implants, perhaps highlighting the importance of a learning curve with this newer THV