Transcatheter Valves in Inoperable Patients at Two Years: PARTNER B

Shelley Wood

March 26, 2012

March 26, 2012 (Boston, Massachusetts) — Two-year outcomes in the PARTNER B trial, now published in the New England Journal of Medicine (NEJM), show that the reduction in death and hospitalization, along with reduced symptoms and improved hemodynamics seen with the Sapien transcatheter valve (Edwards Lifesciences) vs best medical care, are sustained out to two years [1].

"The risk of death by [transcatheter aortic-valve replacement] TAVR is reduced by approximately half in the first year and by the same magnitude in the survivors between year 1 and 2, suggesting there is a new survival advantage beyond the first year," Dr Raj R Makkar (Cedars-Sinai Heart Institute, Los Angeles, CA) told heartwire in an email.

Two-year outcomes for PARTNER B were presented at TCT 2011 in San Francisco, as reported by heartwire . The numbers reported in the NEJM are largely in line with the figures presented last fall.

The FDA approved the Sapien valve in November 2011, based on PARTNER B results.

By two years, 68% of patients in the medical group had died, compared with 43.3% in the TAVR group (p<0.001). Looking solely at cardiac deaths, 62.4% of the standard-care group died over the two years vs 31% in the TAVR group (p<0.001). Looking only at the death rate between years 1 and 2, 35.1% of standard-therapy patients who survived the first year died in year 2, compared with 18.2% of TAVR-treated patients.

"The numbers needed to treat at two years to reduce one all-cause death by TAVR was 4 and cardiac death was 3.2--these numbers are unprecedented; yet 43% mortality in the treated population suggests coexisting conditions in these patients should be taken into consideration while considering TAVR," Makkar added.

Investigators also looked at patients who crossed over to receive a transcatheter valve after the one-year mark--a total of 11 patients. Compared with those who didn't cross over, the mortality rate was halved, at 10% vs 21%. Functional improvements were also significantly better, and rates of hospitalizations for cardiac reasons significantly lower, among TAVI-treated patients.

In an analysis stratified by baseline Society of Thoracic Surgeons (STS) score, survival rates--not surprisingly--were best among patients with the lowest STS scores at baseline, compared with those with higher scores (denoting higher risk). According to Makkar, however, "no definite STS cutoff can be recommended at this time."

Importantly, given the attention paravalvular regurgitation is getting with the presentation of two-year PARTNER A results today, Makkar noted that while there was a trend toward increased cardiac mortality among patients with paravalvular leak, "this was not statistically significant, [and] in this patient population, comorbidities trump paravalvular leak [in terms of] the impact on death."

Makkar has disclosed receiving consulting fees, grant support, and lecture fees from Medtronic; grant support from St Jude Medical; and equity from Entourage Medical Technologies. Disclosures for the coauthors are listed in the paper.