Dr. Thourani Presents PARTNER 2 Results: TAVR also Compares Well with Minimally Invasive Surgery

February 2012

During transcatheter aortic valve replacement (TAVR), the SAPIEN™ transfemoral transcatheter heart valve—made of cow tissue—is mounted on a wire mesh, fed through a small incision in the chest wall or groin with a catheter, and placed where it is needed. Last year, the results of the multi-center Edwards LifeSciences PARTNER 1 SAPIEN™ trial, which established TAVR as a viable, non-surgical alternative to traditional, open-heart surgery or medication therapy in high-risk patients with aortic stenosis, influenced the FDA's approval of the new valve. Emory was one of the highest volume centers that participated in the trial.

In a new sub-analysis presented at the Society of Thoracic Surgeons (STS) annual meeting in Ft. Lauderdale, FL, researchers showed that TAVR is not only as effective as the alternative minimally invasive technique, but may also be safer in the short term. The results were presented by Emory cardiothoracic surgeon Dr. Vinod Thourani, who shared PI duties with Emory cardiologist Dr. Vasilis Babaliaros for the Emory University Hospital-based site of the national study.

The Emory team compared 341 TAVR patients with 250 patients receiving full-sternotomy surgery and 49 receiving either minimally invasive mini-thoracotomy or partial sternotomy to access the heart. Mean age (about 84 years) and Society of Thoracic Surgeons (STS)-predicted mortality risk (about 11%) were equivalent across groups.

While mortality was equivalent between TAVR and full-sternotomy at 30 days, minimally invasive surgery showed a higher death rate, though the difference was not statistically significant. Major vascular complications were higher with TAVR, while other endpoints such as rehospitalization and stroke were equivalent between all groups. On multivariable analysis adjusted for STS score, full-sternotomy surgery did not show increased mortality at 30 days compared with TAVR, though minimally invasive surgery did. At one year, however, neither full-sternotomy surgery nor minimally invasive surgery was associated with increased mortality compared with TAVR.

"Overall, both TAVR and surgical aortic valve replacement provide excellent results in high-risk patients," Dr. Thourani noted, "though early mortality is higher in those patients undergoing minimally invasive surgery. However, one-year mortality was not significantly different among groups, underscoring that in this high-risk patient population, careful preoperative consideration for operative strategy should be performed."

Dr. Thourani admitted that the study's scope didn't allow for conclusions as to why minimally invasive surgery patients did worse at 30 days. "We need to do more investigation on mini vs. full sternotomy," he says. "We've uncovered that something is going on between the two and a randomized study is needed to tease that out."

However, Dr. Thourani believes the similarity in one-year outcomes between the three methods once again vindicates the viability of TAVR. "It's what we found with the original PARTNER trial, in that most of the discrepancies equaled out after a year, and there are certain advantages with minimally invasive or endovascular-based therapy in high-risk patients, such as not having to open the chest and faster patient recovery."