Stent Retriever Leads to Procedural Success, Poorer Outcomes in Nonstandard Acute Stroke Patients

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In patients with acute stroke, use of a stent retriever thrombectomy device is associated with favorable outcome and low periprocedural complication rates. While technical success is similar between those who do vs. do not meet standard inclusion criteria for endovascular therapy, the latter have worse clinical results, according to an observational study published online November 21, 2013, ahead of print in Stroke.

Gerhard Schroth, MD, of the University of Bern (Bern, Switzerland), and colleagues looked at 227 patients from the Bernese Stroke Registry treated with the Solitaire FR stent retriever (ev3-Covidien, Irvine, CA) from January 2010 to November 2012. Patients were imaged prior to treatment with MRI (55.1%), CT (32.6%), or both (11.9%).

The study included patients who did (n = 81) and did not (n = 146) meet standard inclusion criteria. The latter were those with:

• Low or high baseline National Institutes of Health Stroke Scale (NIHSS) score
• ≥80 years of age
• Extensive ischemic signs in middle cerebral artery territory
• Time from symptom onset to endovascular intervention >8 hours

Vascular risk factors were similar between those who met the criteria and those who did not.

Favorable Safety, Procedural Outcomes

Overall, 105 patients (46.3%) were treated with the Solitaire device alone, while 122 (53.7%) were treated with additional techniques. Median procedure time was 44 minutes for the stent retriever alone vs. 114 minutes when multimodal endovascular therapy was employed.

In all but 2 patients, the Solitaire device was successfully deployed over the thrombus, with a median number of passes by the stent retriever of 1. Successful reperfusion was achieved in 70.9%.

Intraprocedural complications occurred in about one-third of patients, although these were clinically symptomatic in only 9 (4.0%). Symptomatic intracranial hemorrhage was seen in 9.7% of patients, while at 3 months clinical outcome was favorable (modified Rankin Scale 0-2) in 39.8%. Overall survival was 88.6%.

In multivariable analysis, independent predictors of favorable clinical outcome were:

• Successful reperfusion (P = 0.012)
• Higher ASPECT score (P = 0.037)
• Younger age (P < 0.001)
• Lower NIHSS score on admission (P < 0.001)
• Absence of diabetes (P = 0.018)

Compared with patients who met standard inclusion criteria, those who did not had similar rates of symptomatic intracranial complications but higher rates of symptomatic intracranial hemorrhage and at 3 months were less likely to have favorable outcomes or have survived (table 1).

Table 1. Outcomes for Patients With vs. Without Standard Inclusion Criteria

In the nonstandard group, the highest mortality rates occurred among patients age 80 and older (44.9%; P = 0.001), those with extensive ischemic lesions on initial imaging (42.6%; P < 0.001), and patients with high baseline NIHSS score (50.0%; P = 0.129). However, clinical outcome and mortality were similar in patients in whom endovascular treatment was performed at ≤ 8 hours after stroke onset and those with longer times after stroke onset.

Use in Nonstandard Patients Needs Further Investigation

According to the study authors, the findings are important since nonstandard patients generally constitute a large percentage of those treated at high-volume stroke centers. They note that reperfusion was just as successful in older patients as in younger patients, indicating “that age-related atherosclerotic changes do not influence technical success with the Solitaire.” However, favorable outcome and survival in patients at least 80 years of age were lower than in the younger cohort, they add. These results “warrant further research with a special focus on optimal patient selection,” the investigators say.

The finding that outcome and survival were no worse in patients treated more than 8 hours after symptom onset “is most likely the result of patient selection and emphasizes the importance of imaging for treatment decision,” Dr. Schroth and colleagues write. Additionally, they note that in more than half of patients, other endovascular techniques apart from the Solitaire were used to achieve final revascularization. “This emphasizes that traditional techniques such as intra-arterial thrombolysis or thromboaspiration still remain important complementary components of endovascular stroke treatment,” they say.

The authors conclude that favorable outcomes in the standard criteria patients support the preferential use of stent retrievers rather than older thrombectomy devices or isolated intra-arterial thrombolysis.

Study Details

Mean age was 68.2 ± 14.7 years, and median NIHSS score on admission was 16 (range 2-36).

 

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Source:
Gratz PP, Jung S, Schroth G, et al. Outcome of standard and high-risk patients with acute anterior circulation stroke after stent retriever thrombectomy. Stroke 2013;Epub ahead of print.

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