Benefits of intravenous thrombolysis in acute ischemic stroke related to extra cranial internal carotid dissection. Dream or reality?

BACKGROUND: Small clinical series have reported the safety of intravenous thrombolysis in ischemic stroke related to extracranial internal carotid dissection. However, no studies specifically analyzing the effects on stroke outcome are available. Aims Our goal was to evaluate whether patients with ischemic stroke related to extracranial internal carotid dissection obtain any benefit from intravenous thrombolysis.

METHODS: Multicenter, prospective and observational study conducted in four university hospitals from the Madrid Stroke Network. Consecutive ischemic stroke patients who received intravenous thrombolysis were included, as well as patients with extracranial internal carotid dissection regardless of intravenous thrombolysis treatment. Stroke severity (NIHSS) and three-month outcome (modified Rankin Scale) were compared between the following groups: (1) intravenous thrombolysis-treated patients with ischemic stroke related to extracranial internal carotid dissection vs. other causes of stroke; (2) intravenous thrombolysis-treated extracranial internal carotid dissection patients vs. nonintravenous thrombolysis treated. Outcome was rated at three-months using the modified Rankin Scale. A good outcome was defined as a modified Rankin Scale score ≤2.

RESULTS: A total of 625 intravenous thrombolysis-treated patients were included; 16 (2·56%) had extracranial internal carotid dissection. Besides, 27 patients with extracranial internal carotid dissection and ischemic stroke who did not receive intravenous thrombolysis were also included. As compared with other etiologies, patients with extracranial internal carotid dissection were younger, had similar stroke severity and showed less improvement in their NIHSS score at Day 7 (1·38; (95% CI -3·77 to 6·54) vs. 6·81; (95% CI -5·99 to 7·63) P=0·004), but without differences in good outcomes at three-months (43·8% vs. 58·2%; NS). Extracranial internal carotid dissection intravenous thrombolysis-treated patients had more severe strokes at admission than those who were nonintravenous thrombolysis treated (median NIHSS: 15 vs. 7; P=0·031). Intravenous thrombolysis was safe in extracranial internal carotid dissection with no symptomatic hemorrhagic events; however, without differences in good outcome compared with the natural course of extracranial internal carotid dissection (nonintravenous thrombolysis treated) after adjustment for stroke severity (46·7% vs. 64·3%; NS).

CONCLUSIONS: As compared with other etiologies, stroke due to extracranial internal carotid dissection seems to obtain similar benefits from intravenous thrombolysis in outcome at three-months. Although intravenous thrombolysis is safe in stroke attributable to extracranial internal carotid dissection, no differences in outcome were found when comparing intravenous thrombolysis treated with nonintravenous thrombolysis-treated patients, even after adjustment for stroke severity.