Letter by Hill et al Regarding Article, “A Cost-Utility Analysis of Mechanical Thrombectomy as an Adjunct to Intravenous Tissue-Type Plasminogen Activator for Acute Large-Vessel Ischemic Stroke”

Intravenous thrombolysis in acute ischemic stroke: standard and potential future applications

Acute ischemic stroke is a medical emergency requiring urgent treatment. Randomized clinical trial and Phase IV data have provided unequivocal evidence that intravenous thrombolysis with recombinant tissue plasminogen activator (rt-PA) improves early functional outcomes by restoring brain perfusion. Moreover, these studies have shed substantial light on the factors which are associated with more favorable outcome with tPA and are related to the highest benefit-to-risk ratio. Stroke physicians should consider vascular imaging techniques to aid decision making with thrombolytic therapy. The presence of intracranial occlusion is the target of treatment with early recanalization being the goal. Successful use of intravenous thrombolysis depends on a sound understanding of the decision-making process and organization of the treating team who strives for early treatment initiation and strict adherence to the protocol. Intravenous rt-PA within 4.5 h of onset should now be a standard treatment of acute disabling ischemic stroke throughout the world. This review also summarizes intravenous thrombolysis contraindications as well as the safety of novel reperfusion therapies including tenecteplase, sonothrombolysis and the combination of alteplase with direct thrombin inhibitors or glycoprotein IIb/IIIa receptor antagonists.

Drivers of costs associated with reperfusion therapy in acute stroke: the Interventional Management of Stroke III Trial

BACKGROUND AND PURPOSE

The Interventional Management of Stroke (IMS) III study tested the effect of intravenous tissue-type plasminogen activator (tPA) alone when compared with intravenous tPA followed by endovascular therapy and collected cost data to assess the economic implications of the 2 therapies. This report describes the factors affecting the costs of the initial hospitalization for acute stroke subjects from the United States.

METHODS

Prospective cost analysis of the US subjects was treated with intravenous tPA alone or with intravenous tPA followed by endovascular therapy in the IMS III trial. Results were compared with expected Medicare payments.

RESULTS

The adjusted cost of a stroke admission in the study was $35 130 for subjects treated with endovascular therapy after intravenous tPA treatment and $25 630 for subjects treated with intravenous tPA alone (P<0.0001). Significant factors related to costs included treatment group, baseline National Institutes of Health Stroke Scale, time from stroke onset to intravenous tPA, age, stroke location, and comorbid diabetes mellitus. The mean cost for subjects who had routine use of general anesthesia as part of endovascular therapy was $46 444 when compared with $30 350 for those who did not have general anesthesia. The costs of embolectomy for IMS III subjects and patients from the National Inpatient Sample cohort exceeded the Medicare diagnosis-related group payment in ≥75% of patients.

CONCLUSIONS

Minimizing the time to start of intravenous tPA and decreasing the use of routine general anesthesia may improve the cost-effectiveness of medical and endovascular therapy for acute stroke.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00359424.

Cost-effectiveness of two endovascular treatment strategies vs intravenous thrombolysis

OBJECTIVE

To assess the cost-effectiveness of endovascular treatment against intravenous thrombolysis (IVT) when varying assumptions concerning its effectiveness.

METHODS

We developed a health economic model including a hypothetical population consisting of patients with ischemic stroke, admitted within 4.5 h from onset, without contraindications for IVT or intra-arterial treatment (IAT). A decision tree and life table were used to assess 6-month and lifetime costs (in Euros) and effects in quality-adjusted life years treatment with IVT alone, IAT alone, and IVT followed by IAT if the patient did not respond to treatment. Several analyses were performed to explore the impact of considerable uncertainty concerning the clinical effectiveness of endovascular treatment.

RESULTS

Probabilistic sensitivity analysis demonstrated a 54% probability of positive incremental lifetime effectiveness of IVT-IAT vs IVT alone. Sensitivity analyses showed significant variation in outcomes and cost-effectiveness of the included treatment strategies at different model assumptions.

CONCLUSIONS

Acceptable cost-effectiveness of IVT-IAT compared to IVT will only be possible if recanalization rates are sufficiently high (>50%), treatment costs of IVT-IAT do not increase, and complication rates remain similar to those reported in the few randomized studies published to date. Large randomized studies are needed to reduce the uncertainty concerning the effects of endovascular treatment.

Intravenous thrombolysis and endovascular therapy for acute ischemic stroke with internal carotid artery occlusion: a systematic review of clinical outcomes

BACKGROUND AND PURPOSE

Strokes secondary to acute internal carotid artery (ICA) occlusion are associated with extremely poor prognosis. The best treatment approach to acute stroke in this setting is unknown. We sought to determine clinical outcomes in patients with acute ischemic stroke attributable to ICA occlusion treated with intravenous (IV) systemic thrombolysis or intra-arterial endovascular therapy.

METHODS

Using the PubMed database, we searched for studies that included patients with acute ischemic stroke attributable to ICA occlusion who received treatment with IV thrombolysis or intra-arterial endovascular interventions. Studies providing data on functional outcomes beyond 30 days and mortality and symptomatic intracerebral hemorrhage (sICH) rates were included in our analysis. We compared the proportions of patients with favorable functional outcomes, sICH, and mortality rates in the 2 treatment groups by calculating χ(2) and confidence intervals for odds ratios.

RESULTS

We identified 28 studies with 385 patients in the IV thrombolysis group and 584 in the endovascular group. Rates of favorable outcomes and sICH were significantly higher in the endovascular group than the IV thrombolysis-only group (33.6% vs 24.9%, P=0.004 and 11.1% vs 4.9%, P=0.001, respectively). No significant difference in mortality rate was found between the groups (27.3% in the IV thrombolysis group vs 32.0% in the endovascular group; P=0.12).

CONCLUSIONS

According to our systematic review, endovascular treatment of acute ICA occlusion results in improved clinical outcomes. A higher rate of sICH after endovascular treatment does not result in increased overall mortality rate.