The PARTNER Trial: A New Paradigm for Treating Valvular Heart Disease

Summary

The Placement of AoRTic TraNscathetER Valve [PARTNER] Trial showed for the first time that transcatheter aortic valve implantation (TAVI), when used in inoperable patients with severe symptomatic aortic stenosis, is life-saving and the best therapeutic option compared with standard medical therapy. In high-risk (but operable) patients, no outcome differences were noted between TAVI and surgical replacement of the aortic valve.

  • Valvular Disease
  • Interventional Techniques & Devices

The Placement of AoRTic TraNscathetER Valve (PARTNER) Trial showed for the first time that transcatheter aortic valve implantation (TAVI), when used in inoperable patients with severe symptomatic aortic stenosis (AS), is life-saving and the best therapeutic option compared with standard medical therapy. In high-risk (but operable) patients, no outcome differences were noted between TAVI and surgical replacement of the aortic valve (SAVR). Of concern were the higher rates of stroke and complications with TAVI. Martin Leon, MD, Columbia University, New York, New York, USA, discussed the results and impact of the PARTNER trial [NCT00530894].

In the PARTNER trial, patients who were considered not suitable for SAVR (inoperable patients; n=358) were randomized (1:1) to either transfemoral TAVI (Edwards SAPIEN Transcatheter Heart Valve) or standard therapy. The primary study endpoint was all-cause mortality at 1 year. The coprimary endpoint was a composite of all-cause mortality and repeat hospitalization.

All-cause mortality at 1 year was 50.7% and 30.7% (HR, 0.51; 95% CI, 0.38 to 0.68; p<0.001) and 68.0% and 43.3% (HR, 0.56; 95% CI, 0.43 to 0.73; p<0.001) at 2 years for standard therapy and TAVI, respectively. The rate of the composite endpoint of death from any cause or repeat hospitalization was significantly (p<0.001) reduced with TAVI. Repeat hospitalizations were cut in half by TAVI (35%) versus standard care (72.5%). TAVI patients had significantly (p<0.001) improved NYHA class, which was sustained out to 2 years. Quality of life, as assessed with the Kansas City Cardiomyopathy Questionnaire (KCCQ), was also significantly improved [Reynolds MR. Circulation 2011]. TAVI was cost-effective (1.59-year improvement in life expectancy at an incremental cost of $50,000/life-year gained). At 30 days, TAVI was associated with a higher incidence of major strokes (5.0% vs 1.1% for standard therapy; p=0.06) and major vascular complications (16.2% vs 1.1%; p<0.001) [Leon MB et al. N Engl J Med 2010].

High-risk patients (n=699) were randomized to receive either transfemoral or transapical TAVI or SAVR. The primary study endpoint was all-cause mortality at 1 year. The rates of death from any cause were 24.2% and 26.8% at 1 year (TAVI and SAVR, respectively; p=0.62). Despite minimal differences in NYHA functional class, TAVI patients had an earlier recovery that was also evident on the 30-day 6-minute walk test and KCCQ scores, which also showed that transfemorally treated patients did much better at 1 month, while the transapically treated patients did worse. Transfemoral procedures were less expensive and improved quality of life, while the opposite was true of the transapical approach. Stroke rates were higher and vascular complications were significantly (p<0.001) more frequent with TAVI [Smith CR et al. N Engl J Med 2011].

The PARTNER trial showed that TAVI should be the standard of care for patients with AS who are not candidates for surgery, provided that comorbidities do not overwhelm the benefits of TAVI, thus preventing a meaningful improvement in quality of life. For high-risk patients, transcatheter and surgical procedures for aortic valve replacement were associated with similar rates of survival at 1 year. An increased risk of stroke, vascular complications, and major bleeding that was associated with transcatheter replacement is a concern in both patient populations.

Despite the great success of the PARTNER trial, the discussants expressed concern over “indication creep” (the use of TAVI to treat very or less sick patients), the use of this procedure in low-volume centers with poorer outcomes, and the evolution of technology that outpaces the ability of studies to evaluate safety and effectiveness. In general, the discussants recommend that careful attention be focused on patient selection with respect to life expectancy and noncardiac comorbidities that are unrelated to AS. Multidisciplinary heart teams should direct all aspects of the AS patient care. Increased experience of operators, improved devices (valves and delivery systems that are currently used in Europe), and new technologies for prevention of complications might reinforce the role of TAVI in the future.

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