The Source for Neurovascular News and Education

April 19, 2019

 

Randomized trials are needed to clarify the role of IV thrombolysis in this setting, researchers say.

 

Some patients with acute ischemic stroke, particularly those who were not taking anticoagulation therapy beforehand, may benefit from receiving intravenous thrombolysis (IVT) before mechanical thrombectomy, according to new analysis of data from the ASTER trial.

 

But the researchers say limitations of their analysis, including potential selection bias for IVT therapy, means randomized trials are needed to confirm these findings.

 

“Several studies suggested that IVT may influence recanalization rate and clinical outcome after [mechanical thrombectomy],” write Florent Gariel, MD (University Hospital of Bordeaux, France), and colleagues. “However, its precise benefit remains under debate.”

 

Evidence suggests IVT may be particularly helpful in cases of distal emboli but could increase the risk of hemorrhage and result in delays during transportation to an endovascular-capable center, they explain.

 

Ninety-Day Mortality Lower With IVT

 

For the ASTER trial, 381 patients with acute ischemic stroke and large-vessel occlusion were randomized to first-line treatment with contact aspiration or stent retriever revascularization. For this post hoc analysis, published online recently in Stroke, the investigators looked at differences in 90-day favorable functional outcome (defined as an mRS ≤ 2) between the 250 patients who received IVT prior to mechanical thrombectomy and the 131 who did not.

 

After adjusting for age, hypertension, diabetes, admission NIHSS and ASPECTS scores, site of occlusion, and onset-to-puncture time, the investigators found no significant differences between those who did and did not receive IVT, with respect to 90-day favorable functional outcome, successful reperfusion rate, 24-hour improvement in NIHSS score, or hemorrhagic complication rate.

 

Adjusted 90-day mortality was lower among patients treated with IVT, however.

 

Outcomes by Use of IVT (With vs Without)

 

Adjusted Risk Ratio (95% CI)

P Value

90-Day mRS

1.27 (0.95-1.72)

0.11

mTICI 2b/3

1.05 (0.98-1.13)

0.16

24-Hour Mean Change in Baseline NIHSS Score

–0.8 (–2.7-1.1)

0.40

Hemorrhagic Complication Rate

1.10 (0.96-1.26)

0.18

90-Day Mortality

0.59 (0.39-0.88).

0.009

 

“The reason for not using IVT constitutes a major bias in the interpretation of the present data,” the study authors point out. “This may explain a higher morbi-mortality in the [mechanical thrombectomy]-alone group.

 

May Be More Beneficial in Nonanticoagulated Patients

 

A subgroup analysis of patients who were not treated with anticoagulant medication before stroke onset revealed that the use of IV thrombolysis prior to mechanical thrombectomy was associated with better functional outcome (adjusted RR 1.38; 95% CI 1.02-1.89; P = 0.0040), a higher successful recanalization rate after first-line strategy (adjusted RR 1.26; 95% CI 1.05-1.50; P = 0.0013), and a lower mortality rate (adjusted RR 0.58; 95% CI 0.36-0.93; P = 0.0023).

 

“Despite our results,” conclude the authors, “a randomized comparative study in patients eligible for IVT remains necessary to determine the exact impact of IVT in patients undergoing [mechanical thrombectomy]. This study should include patients in centers with comparable door-to-needle and door-to-groin times.”

 


Source:

Gariel F, Lapergue B, Bourcier R, et al. Mechanical thrombectomy outcomes with or without intravenous thrombolysis insight from the ASTER randomized trial. Stroke. 2018;Epub ahead of print.

 

Disclosures:

Gariel reports no relevant conflicts of interest.