Two-year mortality rates after SAVR better than STS risk models predict

Elderly patients with aortic stenosis who underwent surgical aortic valve replacement (SAVR) had a two-year all-cause mortality rate of 4.1 percent, according to an analysis of a randomized trial.

The mortality rate was similar to patients who underwent transcatheter aortic valve replacement (TAVR) and lower than the Society of Thoracic Surgeons (STS) risk models had predicted.

Lead researcher Vinod H. Thourani, MD, of Emory University in Atlanta, presented the results on Jan. 24 during a news conference at the STS annual meeting in Houston.

The researchers examined the PARTNER 2A trial, which evaluated the safety and efficacy of the Sapien XT TAVR valve system (Edwards Lifesciences) compared with SAVR in intermediate-risk patients. Thourani disclosed he is a consultant for Edwards Lifesciences.

The FDA has approved the Sapien XT for inoperable and high-risk patients with severe aortic stenosis, for aortic valve-in-valve procedures and for pulmonic valve replacement procedures.

This analysis included 937 severe aortic stenosis, intermediate-risk patients who enrolled in the study from December 2011 to November 2013 and had a surgical valve implanted. The mean age was 82 years old, while 55 percent of patients were males, approximately 25 percent had a prior coronary bypass surgery, 10 percent had a previous stroke and 12 percent had a previous pacemaker implanted.

Thoruani said patients were considered to be intermediate-risk if they had an STS predicted score between 4 and 8. The mean STS score was 5.8. Thourani said in a news release that approximately 15 percent of patients undergoing SAVR in the U.S. are intermediate-risk.

The two-year all-cause mortality rate was 4.1 percent, while the two-year in-hospital stroke rate was 5.4 percent. The mortality rate was lower than what the STS predicted, but the stroke rate was two times higher than what the STS predicted. Thourani noted that previous studies had no neurological assessments when evaluating strokes, so the previous stroke rates could have been underestimated.

“The time-related events demonstrated a period of high early mortality, followed by a more consistent risk over the next two years,” Thourani said.

Thourani added that minimally invasive AVR did not result in higher mortality or stroke rates compared with full sternotomy. In addition, patients with severe prosthesis-patient mismatch (PPM) after AVR had a similar two-year mortality rate compared with those who did not have severe PPM. One-third of the patients were in the PPM group and had a surgical valve that was too mall.

“From this adjudicated, prospectively collected data in the contemporary era, SAVR can be performed in intermediate-risk elderly patients with mortality commensurate with the national benchmarks,” Thourani said. “Continued surveillance to these patients remains extremely important.”