The Placement of Aortic Transcatheter Valve (PARTNER) Trial

For several decades, surgical aortic valve replacement (sAVR) has been considered the therapeutic gold standard for the treatment of severe aortic stenosis (AS). Severe AS is a progressive disease with a long latency period, and despite significant strides in medical therapy for numerous other forms of cardiovascular disease, little progress has been made in medical therapy for AS. The mechanical effects of aortic valve obstruction induce burdensome hemodynamic consequences that are the sine qua non of severe AS. Thus, particularly in patients with comorbid conditions who are at high risk for complications with traditional sAVR, untreated AS was conventionally viewed as a terminal condition for patients refusing high-risk sAVR or those deemed not operative candidates by treating physicians.The publication of the 1-year outcomes from the 2 cohorts of the Placement of Aortic Transcatheter Valve (PARTNER) Trial1,2 has redefined this conventional wisdom. The PARTNER trial established the alternative use of a novel, less invasive procedure, transcatheter aortic valve replacement (tAVR), in the sickest patients with AS. In patients deemed at high risk for standard sAVR (cohort A), tAVR was associated with similar rates of 1-year all-cause mortality compared with sAVR (24.2% versus 26.8%; P =0.001 for noninferiority). In patients deemed not to be candidates for surgery (cohort B), tAVR was superior to standard therapy with reduced 1-year all-cause mortality (30.7% versus 50.7%; P <0.001). It is not often in clinical medicine that an early-stage less invasive technology demonstrates life-altering and life-saving impact on a common disease. Thus, it is instructive to examine several of the unique attributes of the landmark PARTNER trial that firmly established the evidence base for the role of tAVR in the treatment of AS. We focus here on a selected number of interesting facets of the trial from a clinical trialist's perspective.For …