Is mechanical clot removal or disruption a cost-effective treatment for acute stroke?

Abstract

Background and purpose: It is unclear whether the costs and risks of mechanical therapies make them cost-effective. We examined whether interventions such as mechanical clot removal or disruption with angioplasty are cost-effective for acute ischemic stroke compared with best medical therapy.

Materials and methods: We performed a cost-utility analysis of patients with acute stroke due to large intracranial artery occlusion presenting beyond the 3-hour window for IV tPA. Model inputs for the mechanical arm were derived from Multi MERCI trial data and a recent meta-analysis. For best medical therapy, we used rates of spontaneous recanalization, ICH, and functional outcomes based on a systematic literature review. Discounted QALYs were determined by using the Markov modeling for 65-year-old patients with acute ischemic stroke.

Results: On the basis of a systematic literature review, we modeled an 84% rate of recanalization with mechanical intervention and a 6.3% rate of symptomatic ICH. For best medical therapy, we modeled a spontaneous recanalization rate of 24% with a 2% rate of symptomatic ICH. Mechanical therapies were associated with a $7718 net cost and a gain of a 0.82 QALYs for each use, thus yielding a net of $9386/QALY gained. In sensitivity analyses, results were dependent on the rates of recanalization, symptomatic ICH rates, and costs of treatment.

Conclusions: On the basis of available data, mechanical therapies in qualified patients with acute stroke beyond the window for IV tPA appear to be cost-effective. However, the inputs are not derived from randomized trials, and results are sensitive to several assumptions.

Fig 1.

Decision tree used to compare cost-effectiveness of aggressive NIR treatment with the best medical therapy for a patient presenting with acute ischemic stroke within 8 hours of symptom onset but beyond the 3-hour window for IV tPA.

Fig 2.

Univariate sensitivity analyses of recanalization rates over an appropriate range of uncertainty for those undergoing NIR treatment (A) and best medical therapy (B). Arrows indicate base-case values for NIR treatment (84%) and best medical therapy (24%). Rates that lead to a net of <$50,000/QALY gained are usually considered cost-effective (bold dashed line).

Fig 3.

Univariate sensitivity analyses of symptomatic ICH rates with NIR treatment (A) and best medical therapy (B). Arrows indicate base-case values (6.3% for NIR and 2% for best medical therapy). Rates that lead to a net of <$50,000/QALY gained are usually considered cost-effective.

Fig 4.

Monte Carlo simulation of all input variables (except age and discount rate). The oval represents the 95% CI of the distribution of cost-effectiveness of the intervention, all of which is <$50,000/QALY as represented by the diagonal dashed line.