• Interventional Techniques & Devices
• Cardiology Clinical Trials
• Valvular Disease

Transcatheter aortic valve implantation (TAVI) is the recommended treatment for “inoperable” patients with severe aortic stenosis (AS), based on the 1-year results of the PARTNER trial [NCT00530894; Leon MB et al. NEJM 2010]. The objective of this PARTNER trial analysis, presented by Raj R. Makkar, MD, Cedars-Sinai Medical Center, Los Angeles, California, USA, was to evaluate the clinical outcomes of TAVI compared with standard therapy at 2 years in patients with inoperable AS (PARTNER Cohort B).

The PARTNER Cohort B randomized 358 inoperable patients with symptoms of severe AS to transfemoral TAVI (n=179) versus standard therapy (n=179). Included patients were NYHA class II or higher and had severe AS (echo valve area of <0.8 cm² [EOA index < 0.5 cm²], mean gradient >40 mm Hg or jet velocity >4.0 m/s) and a >50% risk of death or serious irreversible morbidity with surgical aortic valve replacement as assessed by a cardiologist and two surgeons). The primary endpoint was all-cause mortality over the length of the trial. Other key endpoints were: cardiac mortality, rehospitalization, stroke, NYHA functional class, days alive and out of the hospital, echoderived valve area, transvalvular gradients, paravalvular aortic regurgitation, and mortality outcomes that were stratified by STS score.

Eleven patients crossed over from standard therapy to TAVI between 1 and 2 years. All-cause mortality (intention to treat; ITT), including crossover patients, was significantly lower at 2 years for patients who were treated with TAVI versus standard therapy (67.6% vs 43.3%, respectively; HR=0.57; 95% CI, 0.44 to 0.75; p<0.0001). Censoring of the crossover patients did not qualitatively change the results.

A landmark analysis was performed among the survivors at 1 year to ascertain whether there was incremental benefit between Years 1 and 2. Among the 1-year survivors, mortality was 18.2% with TAVI versus 35.1% with standard therapy (HR=0.58; 95% CI, 0.37 to 0.92; p=0.019).

Cardiovascular (CV) mortality (ITT, crossover patients censored) was 31.0% with TAVI versus 62.4% with standard therapy (HR=0.44; 95% CI, 0.32 to 0.60; p=0.0001). The rate of repeat hospitalizations (ITT) was 35.0% in the TAVI group versus 72.5% in the standard therapy group (HR=0.41; 95% CI, 0.30 to 0.58; p=0.0001). The days alive out of the hospital was 699 with TAVI versus 355 with standard therapy (p=0.0003). TAVI improved NYHA functional status and decreased Class III/IV symptoms versus standard therapy (17% vs 64%; p<0.001).

There were more neurological events with TAVI versus standard therapy (16.2% vs 5.5%, respectively; p=0.003). The incidence of stroke at 2 years was 13.8% in the TAVI group versus 5.5% in the standard therapy group (HR=2.79; 95% CI, 1.25 to 6.22; p=0.009). After 30 days, differences in stroke frequency were largely due to increased hemorrhagic strokes in TAVI patients.

In patients who were not suitable for surgery, TAVI was superior to standard therapy, with incremental benefit from 1 to 2 years, markedly reducing the rates of all-cause mortality, CV mortality, and repeat hospitalization, with improved NYHA functional status and decreased Class III/IV heart failure symptoms. Importantly, TAVI patients had significantly increased rates of stroke. TAVI was most beneficial in patients without extreme clinical comorbidities.

Dr. Makkar concluded that the 2-year data continue to support the role of TAVI as standard of care for symptomatic patients with AS who are not surgical candidates.

• © 2011 MD Conference Express