Background: Arterial reocclusion has not been systematically studied despite the fact that 13% of patients in the National Institute of Neurological Diseases and Stroke rt-PA Trial deteriorated following initial improvement, suggesting that reocclusion might be responsible for poor clinical outcome in some of these patients.
Methods: Consecutive stroke patients treated with IV tissue plasminogen activator (TPA) within 3 hours and an M1 or M2 middle cerebral artery (MCA) occlusion on pre-TPA transcranial Doppler (TCD) were monitored up to 2 hours after TPA bolus. Reocclusion was defined as the Thrombolysis in Brain Ischemia flow decrease by >/=1 grades and no hemorrhage on repeat CT. The NIH Stroke Scale (NIHSS) and modified Rankin Scores (mRS) were obtained by a neurologist independently of TCD.
Results: Sixty patients with median prebolus NIHSS score of 16 (range 6 to 28, 90% with >/=10 points) had TPA bolus at 130 +/- 32 minutes (median 120 minutes, 58% within the first 2 hours). Recanalization was complete in 18 (30%), partial in 29 (48%), and none in 13 (22%) patients. Reocclusion occurred in 34% of patients with any initial recanalization (16/47): in 4 of 16 patients with complete recanalization (22%), and in 12 of 29 patients with partial recanalization (41%). Reocclusion was detected in four patients (25%) before TPA bolus, in three (19%) by 30 minutes after bolus, in three (19%) by the end of infusion, and in six (37%) by 60 to 120 minutes. Before reocclusion, those patients had earlier median timing of recanalization: 130 versus 180 minutes after stroke onset compared with those who recanalized without reocclusion (p = 0.01). Median prebolus NIHSS score in the reocclusion group was 13.5 versus 17 (rest, NS), whereas at 2 and 24 hours, their NIHSS scores were higher: 14 versus 9 and 16 versus 6 points (p </= 0.04). Deterioration followed by improvement by >/=4 NIHSS points occurred in 8 of 16 (50%) patients with reocclusion versus 10% (rest) (p < 0.05). In-hospital mortality was 25 versus 3% (p < 0.0001). At 3 months, good outcome (mRS score of 0 to 1) was achieved by 8% of patients with no recanalization, by 33% of patients with reocclusion, and by 50% of patients with stable recanalization (p </= 0.05), and mortality was 42% with no early recanalization, 33% after reocclusion, and 8% in patients with stable recanalization (p </= 0.05).
Conclusions: Early reocclusion occurs in 34% of TPA-treated patients with any initial recanalization, accounting for two-thirds of deteriorations following improvement. Reocclusion occurs more often in patients with earlier and partial recanalization, leading to neurologic deterioration and higher in-hospital mortality. However, patients with reocclusion have better long-term outcomes than patients without any early recanalization.