Comorbidities Influence Three-Year Survival With Sapien TAVI: PARTNER B

Reed Miller

October 25, 2012

MIAMI — New results from the PARTNER B trial of the Edwards Lifesciences Sapien transcatheter aortic valve in inoperable patients shows that the mortality benefit of the device persists at least three years and that the survival prognosis in patients undergoing transcatheter aortic-valve implantation (TAVI) correlates to the severity of their comorbidities at the time of implant [1,2].

Here at TCT 2012, Dr E Murat Tuzcu (Cleveland Clinic, OH) presented the three-year follow-up data from PARTNER B showing that all of the major benefits of TAVI vs standard therapy shown at a previous time point--measured by all-cause mortality, cardiovascular mortality, repeat hospitalization, and functional status--are sustained out to three years.

As reported by heartwire , PARTNER B compared Sapien with standard care in patients who were too ill to withstand surgery. PARTNER B initially randomized 179 patients to TAVI with Sapien and 179 to standard therapy. By the three-year follow-up, all but 19 of the control patients had either died or been "censored" because they received a Sapien valve, while there were 80 patients left in the TAVI group.

The Kaplan Meier estimated rates of death at three years were 54.1% in the TAVI patients and 81% percent in the standard-therapy group (p<0.0001), and the rates of cardiovascular death were 41.4 % and 74.5%, respectively (p<0.0001). By comparison, at two years, 68% of patients in the standard-therapy control group had died, compared with 43.3% in the TAVI group (p<0.001), and cardiovascular death was 62.4% in the standard-care group vs 31% in the TAVI group (p<0.001).

The rates of mortality plus stroke at three years were 80.9% in the control group and 57.5% in the TAVI group, a 23.4% difference. The additional risk of stroke with TAVI vs standard therapy grew slightly between the two- and three-year follow up, as the stroke rate in the TAVI group grew from 13.7% to 15.7% while it stayed flat at 5.5% in the standard-therapy group, but neither of the two strokes during year three in the TAVI group were device-related, Tuzcu said. Also, rehospitalization rates at three years were 75.7% in the control group and 43.3% in the TAVI group, a difference of 33.4% (p<0.0001).

Echocardiography studies by the PARTNER core lab showed no increase in the average transvalvular gradient or any decrease in the average effective orifice area of the valves.

Risk Score Predicts Survival With TAVI But Not Standard Therapy

The three-year PARTNER B data show that TAVI makes the biggest difference in patients with fewer or less severe comorbidities, as measured by baseline Society of Thoracic Surgeons (STS) score. In patients with an initial STS score from 0 to 4.9, mortality at three years was 100% in the control group and 33.2% in the TAVI group. For scores from 5 to 14.9, mortality was 77.5% and 55.2% for the control and TAVI groups, respectively, and for STS scores over 15, the three-year mortality rates were 86.6% and 65.8%.

"These data underscore the importance of patient selection before TAVI and the need for aggressive management of illnesses after TAVI, because when we stratified mortality according to STS score, we were quite surprised that the higher STS scores in the standard treatment groups were somewhat irrelevant," he said. "It doesn't matter what your STS score is if you are not treated by TAVI, but if you are treated with TAVI, it makes an impact."

Because patient selection is critical to success, Tuzcu emphasized the importance of the oft-promoted "heart-team" approach to aortic-valve repair. "We should not promote one procedure, we should promote a program of taking care of high-risk valvular heart disease patients--this may be surgical treatment, percutaneous treatment, or optimization of the patient's clinical status in the critical care unit, balloon valvuloplasty, or a wise solution to the patient's concomitant problems," he said. "We should not perceive what is accomplished with the PARTNER program only as a success with the procedure, but rather how the program can be established with multiple disciplines."

Tuzcu has no financial disclosures; he is a member of PARTNER Trial executive committee.