A model that includes quality of life (QoL) in its assessment predicted with moderate discrimination patients who likely would have poor outcomes after undergoing transcatheter aortic valve replacement (TAVR), according to results published online May 23 in Circulation.
Suzanne V. Arnold, MD, MHA, of Saint Luke’s Mid America Heart Institute in Kansas City, Mo., and colleagues used data from the PARTNER (Placement of AoRtic TraNscathetER Valves) trial to develop and validate a tool to identify patients whose benefit from TAVR was likely to be suboptimal. PARTNER was the pivotal trial for approval of the Sapien (Edwards Lifesciences) device for patients with severe aortic stenosis. The trial include two cohorts: inoperable and high risk.
“[I]n this elderly population of patients, often with extensive comorbidity and impaired health status, it is likely that prolonged survival alone (without improved QoL) would not be viewed as a desirable outcome,” Arnold et al wrote. “Therefore, any definition of a successful outcome of TAVR (and conversely, of a poor outcome) must consider survival and QoL.”
Their study assessed clinical factors and QoL at baseline, six months and 12 months after randomization. Their primary analysis focused on outcomes at six months. They defined a poor outcome as death, a summary score of less than 45 on the Kansas City Cardiomyopathy Questionnaire or a decrease of more than 10 points from the baseline score. They also looked at one-year outcomes using an alternative definition.
They randomly assigned two-thirds of the 2,137 TAVR patients to a derivation group and one third to a validation group. At six months, 19 percent of the patients had died, 12 percent had very poor QoL and 2 percent had worsened QoL. They determined that shorter distance on a walking test and higher mean aortic valve gradients were associated with poor outcomes. Clinical factors included oxygen-dependent chronic lung disease, renal dysfunction, cardiac arrhythmias and cognitive decline.
The c-index in the model was 0.66, which they described as moderate discrimination, and calibration was good. In the validation group, the c-index was 0.64 and in the calibration was reasonable. The model identified 211 patients with a more than 50 percent likelihood of a poor outcome after TAVR at six months and 178 patients with a more than 70 percent likelihood of a poor outcome at one year.
“Such information could help inform clinical decision making for patients and their physicians when considering TAVR and could also help patients and their families set realistic expectations when they choose to undergo TAVR,” Arnold and colleagues proposed.
They cautioned that the model’s discrimination was only moderate, but despite that limitation it could be useful in practice.