When the one year results from the PARTNER US pivotal trial for Edwards Lifesciences. SAPIEN transcatheter aortic valve replacement (TAVR) device were announced last year at the American College of Cardiology (ACC) conference, they demonstrated the great potential for this technology to treat aortic stenosis. They also, however, indicated some concerns with the technology, namely the stroke risk. To Edwards Lifesciences relief, however, two-year results from this trial which were released this week at this year's ACC conference demonstrated no significant difference in stroke rates between TAVR and surgical aortic valve replacement in the PARTNER A arm of the trial. Furthermore, at two years there was no significant difference in mortality between the transcatheter approach and surgery.
These new results could be crucial for expanding the use of TAVR into a new subset of patients. As of early 2012, Edwards Lifesciences SAPIEN valve was only approved for use in patients considered too high risk to undergo surgery a decision that continues to be supported by positive results in these patients from the PARTNER B arm of the trial. The PARTNER A arm, however, examines patients who are surgical candidates even though their risk of complications is high. If TAVR can make headway into the surgical patient pool, the revenue potential will be huge the Food and Drug Administration's decision on approval in high-risk surgical candidates is anticipated in the upcoming months.
Expanding the patient population eligible for TAVR therapy was a hot topic at ACC.12, with multiple surgeons and interventionalists on both sides of the argument. Debates focused on the use of heart teams to select patients, how best to stratify patient risk, where the procedure should be performed, and what type of imaging should be used for the procedure.
Of note in the PARTNER A trial results was the importance of paravalvular leaks something infrequently seen in surgical valve replacement but often associated in TAVR which are shown to be an important predictor of mortality. This result and the previously mentioned debates demonstrate the early stage this therapy is at, with best practice for these procedures currently under study and in evolution. Furthermore, there remain exciting opportunities for new and improved devices to further improve this procedure and undoubtedly add more fuel to the debate about appropriate use of this technology.