High platelet count and embolic fragments or stenosis at the thrombectomy site predicts poorer outcomes, new data show.
High platelet count on admission and residual embolic fragments or stenosis after successful thrombectomy for acute stroke are risk factors for early restenosis, which is associated with poorer outcome. These are the main findings of a study published online September 18, 2018, ahead of print in Stroke.
Even when mechanical thrombectomy for acute ischemic stroke results in successful recanalization, write Pascal J. Mosimann, MD (Bern University Hospital, Switzerland), and colleagues, 3% to 9% of patients experience reocclusion of the target vessel.
“Because rapid, sustained, and complete reperfusion is the most important modifiable prognostic factor for a favorable clinical outcome, we aimed to identify the prevalence and predictors of early reocclusion within 48 hours after an initially successful endovascular thrombectomy within a prospective cohort of consecutive patients with acute ischemic stroke from a single center,” Mosimann et al note.
For the study, they followed 711 patients with ischemic stroke who achieved successful reperfusion, defined as an mTICI 2b/3, following thrombectomy. All patients included in the analysis underwent MR or CT angiography at 24 to 48 hours.
Early reocclusion was seen in 16 successfully reperfused patients (2.3%) with a median time to diagnosis of 20 hours from thrombectomy. The presence of early reocclusion was an independent predictor of unfavorable outcome at 90 days, defined as an mRS ≤ 2, with an adjusted odds ratio of 0.13 (95% CI 0.03-0.57).
Identifying Risk Factors Could Lead to Prevention
In multivariate analysis, predictors of early reocclusion were: higher platelet count on admission, prestroke functional dependency, as well as stroke of undetermined or other specified pathogenesis, based on Transparency and Openness Promotion Guidelines (TOAST) classification.
Suggestive Predictors of Early Reocclusion
|
|
Adjusted OR |
95% CI |
|
High Platelet Count on Admission |
1.01 |
1.01-1.02 |
|
Prestroke Dependence |
7.12 |
1.49-34.03 |
|
TOAST: Unknown Pathogenesis |
7.19 |
1.10-47.05 |
|
TOAST: Other Pathogenesis |
36.50 |
4.47-298.11 |
When residual embolic fragments or stenosis at the thrombectomy site were added to the logistic regression model, discrimination between patients with and without reocclusion improved significantly, with an area under the curve of 0.955 vs 0.854 (P = 0.023).
“Swift identification of these risk factors [for early restenosis] may allow prompt corrective measures towards sustained recanalization, including immediate repeated thrombectomy, which may improve outcome,” conclude the study authors.
Notably, the number of stent retriever passes, use of distal aspiration catheters, or other interventional parameters did not influence the risk of early restenosis.
Mossiman and colleagues observe that steps must be taken to avoid missing residual debris or an underlying plaque that could lead to early reocclusion.
“[C]areful reinspection of the original occlusion site on the past angiographic run is advised,” they say. “Adjustment of contrast/windowing levels, pixel shift, and zoom in the region of interest, followed by another run in different projections or 10 minutes later may be necessary, especially after tentative corrective measures have been applied, such as spasmolytic therapy, intensified antiplatelet medication, or PTA/stenting.”
Source:
Mosimann PJ, Kaesmacher J, Gautschi D, et al. Predictors of unexpected early reocclusion after successful mechanical thrombectomy in acute ischemic stroke patients. Stroke 2018;Epub ahead of print.
Disclosures:
Mosimann reports receiving research grants from SNSF to study new therapeutic options for cerebral aneurysms.
