Despite higher initial costs, treating patients with acute ischemic stroke with a stent retriever plus tissue-type plasminogen activator was economically dominant over the long term compared with tPA alone, according to an economic substudy of the SWIFT-PRIME trial.
SWIFT-PRIME was one of several studies showing that prompt treatment with latest-generation intra-arterial therapy improved 90-day outcomes in patients with acute ischemic stroke. Unlike some other studies of intra-arterial therapy, in SWIFT-PRIME, all patients also had confirmed large-vessel anterior circulation occlusion and were treated with the same technology — a stent retriever (Solitaire, Medtronic/Covidien).
Theresa I. Shireman, PhD, from the Center for Gerontology and Health Care Research, Brown University School of Public Health in Providence, Rhode Island, and colleagues conducted a prospective economic substudy simultaneous with SWIFT-PRIME to determine in-trial costs, post-trial costs and estimated life expectancy for surviving patients assigned the stent retriever plus tPA or tPA alone.
To estimate post-trial costs and life expectancy, the researchers used a model based on data from SWIFT-PRIME and a contemporary cohort of individuals who survived ischemic stroke.
Shireman and colleagues found that mean index hospitalization costs were $45,761 for the stent retriever group and $28,578 for the tPA group (difference, $17,183; P < .001), with much of the difference coming from initial procedure costs.
Between discharge and 90 days, mean costs were $11,270 for the stent retriever group and $16,174 for the tPA group (difference, –$4,904; P = .014), but total 90-day costs were higher for the stent retriever group ($57,031 vs. $44,752; P < .001), according to the researchers.
However, because of higher utility values, in-trial quality-adjusted life years were higher in the stent retriever group (0.131 vs. 0.105; P = .005).
When the researchers calculated lifetime projections, they found that use of a stent retriever plus tPA was linked to significant gains in quality-adjusted life years (6.79 vs. 5.05) and savings of $23,203 per patient compared with tPA alone.
Shireman and colleagues found the stent retriever plus tPA strategy was economically dominant over the tPA–alone strategy in 90% of bootstrap replicates.
The long-term calculations “were consistent in multiple sensitivity and subgroup analyses,” the researchers wrote.
“These findings suggest that for patients similar to those enrolled in SWIFT-PRIME, a treatment strategy of [stent retriever plus tPA] is highly cost-effective and likely economically dominant compared with tPA,” Shireman and colleagues wrote. – by Erik Swain
The study was funded by Medtronic. Shireman reports no relevant financial disclosures. Please see the full study for a list of all other researchers’ relevant financial disclosures.