CAS for Acute Stroke Feasible - But Controversial
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Carotid artery stenting (CAS) in the setting of acute stroke due to atherosclerotic extracranial occlusion is relatively safe and beneficial when performed within 6 hours of symptom onset, according to a small study published in the November 29, 2011, issue of the Journal of the American College of Cardiology.
For the retrospective analysis, Panagiotis Papanagiotou, MD, of Saarland University Hospital (Homburg, Germany), and colleagues evaluated data on 22 patients who presented at their institution between 2006 and 2010 with acute ischemic stroke due to atherosclerotic disease of the extracranial carotid artery.
The majority of patients received IV tPA within 3 hours of symptom onset (or, after publication of the European Co-operative Acute Stroke Study III, within 4.5 hours). This was followed by revascularization of the extracranial carotid with a self-expanding stent (typically Wallstent, Boston Scientific, Natick, MA). If no additional occlusion was present, a proximal protection device (WL Gore, Newark, DE) was used, when possible.
Next Step: Opening Intracranial Occlusions
After restoration of extracranial flow, an intracranial occlusion was seen in 85.7% of patients (n = 18). These lesions were treated by mechanical thrombectomy with the Penumbra system (Penumbra, Alameda, CA) or the Solitaire AB/FR stent-based recanalization system (ev3, Paris, France), with additional intra-arterial tPA (5-20 mg) in 10 patients. Intracranial recanalization to a TIMI score of at least 2 was achieved in 3 of 9 patients with the Penumbra system and in 9 of 9 patients with the Solitaire system.
The overall recanalization rate for both intracranial and extracranial occlusions was 63%. While extracranial recanalization was successful (TIMI 3 score) in all but 1 case, intracranial recanalization (TIMI score ≥ 2) was achieved in only about two-thirds of cases. At discharge, the mean NIH Stroke Scale (NIHSS) score had decreased by about 8 points, while at 90 days, 2 out of 5 patients were deemed to have a ‘good outcome,’ defined as a modified Rankin Scale score of 2 or lower (table 1).
Table 1. Angiographic and Clinical Outcomes
|
Before |
After |
Extracranial TIMI Score 3 |
0 |
95.5% |
Intracranial TIMI Score 2 or 3 |
9.1% |
63.6% |
Mean NIHSS Score |
18.5 |
10.2 (at discharge) |
Mean Rankin Scale Score ≤ 2 |
0 |
40.9% (at 90 days) |
The mortality rate at 90 days was 13.6%. In terms of safety, 18% (n = 4) suffered an intracranial hemorrhage within 72 hours of treatment. Three of these patients died from a large infection and swelling of the brain. In 2 patients, the intracranial hemorrhage was symptomatic, resulting in neurologic deterioration of more than 4 points on the NIHSS.
According to the authors, this is the third study to date examining CAS in acute stroke, showing overall a high rate of technical success and a satisfactory rate of favorable clinical outcomes. However, the 3 studies total only 62 patients.
CAS in Acute Stroke: Just Do It vs. Go Slow
In an accompanying editorial, Christopher J. White, MD, of Ochsner Medical Center (New Orleans, LA), underlines that stroke outcomes lag behind those for acute MI, where early reperfusion is a priority, in part due to a lack of stroke neurologists throughout the country.
“Acute carotid artery occlusive disease causes devastating strokes that do not respond well to IV tPA but are amendable to catheter-based therapy with CAS,” he writes. “This invites a larger pool of CAS-capable physicians including cardiologists, radiologists, vascular surgeons, neurosurgeons, and interventional neurologists to join stroke teams.”
But Philip M. Meyers, MD, a neurointerventionalist at Columbia University Medical Center (New York, NY), disagreed. A retrospective study of 22 stroke patients treated with carotid bifurcation stents hardly justifies Dr. White’s conclusion, he told TCTMD in a telephone interview.
“Occasionally—but only when necessary—carotid bifurcation stenting is performed on selected patients to treat acute ischemic stroke,” Dr. Meyers pointed out. “[So] it is not a novel concept.”
However, he said, current thinking among physicians who treat stroke is to avoid using a stent, when possible, “because of the need for strong antithrombotic agents and their associated risk for hemorrhage.”
Indeed, Dr. Papanagiotou and colleagues acknowledge that “aggressive anticoagulation, especially in combination with thrombolytics, may increase the risk of intracranial hemorrhage.”
In the end, Dr. Meyers said, this small study provides clinicians relatively little useful or new information in the face of ongoing multicenter international stroke trials enrolling hundreds of patients. “Although, it may eventually turn out that stenting is the right method to revascularize occluded cerebral arteries in acute ischemic stroke . . . there is currently no study that proves it is the right thing to do,” he noted.
“[Moreover,] there is some evidence that using strong antithrombotic agents such as GP IIb/IIIa inhibitors in acute stroke patients may be dangerous, and it is not the general direction of the main stroke trials,” he added.
“I want stroke treatment to advance as much as Dr. White, but we need to enroll stroke patients in the existing, well-conceived randomized trials to answer important questions about treatment in sequence,” Dr. Meyers concluded.
Study Details
Starting 24 hours after successful implantation, patients received 500 mg of IV aspirin and clopidogrel.
Sources:
- Papanagiotou P, Roth C, Walter S, et al. Carotid artery stenting in acute stroke. J Am Coll Cardiol. 2011;58:2363-2369.
- White CJ. Acute stroke treatment: Carotid ”stenters” to the rescue. J Am Coll Cardiol. 2011;58:2370-2371.
Disclosures
- Drs. Papanagiotou and Meyer report no relevant conflicts of interest.
- Dr. White reports receiving research support from Boston Scientific.
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