Temporal Profile of Recanalization After Intravenous Tissue Plasminogen Activator
Selecting Patients for Rescue Reperfusion Techniques
This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
Background and Purpose— Intravenous thrombolysis in stroke achieves arterial recanalization in &50% of cases. Determining temporal profile of recanalization may address patient selection and potential benefits of further rescue reperfusion techniques.
Methods— We studied 179 consecutive intravenous tissue plasminogen activator (t-PA)–treated patients with intracranial artery occlusion. Continuous transcranial Doppler assessed recanalization (none-partial-complete) at 60 minutes (early), 120 minutes (delayed) after t-PA bolus, and 6 hours (late) from symptom onset. Outcomes were determined: National Institutes of Health Stroke Scale (NIHSS; 48-hour NIHSS) and 3-month modified Rankin Scale (mRS).
Results— On admission, 68% of patients presented proximal middle cerebral artery occlusion, median NIHSS 17. Early recanalization was complete for 30 patients (17%), partial for 50 (28%), and none for 99 (55%). Delayed recanalization was complete for 56 patients (31%), partial for 39 (22%), and none for 84 (47%). Although early flow improvement was observed in up to 45% of patients, only 19% of patients with persistent occlusion (11% of total) presented delayed recanalization (odds ratio [OR] delayed/early recanalization, 0.16; 95% CI, 0.085 to 0.304; P<0.001). Among patients with persistent occlusion at 2 hours, only 13 (7% of total) presented late flow improvement (OR late/early recanalization, 0.09; 95% CI, 0.043 to 0.196; P<0.001). The few patients with late recanalization presented comparable median 48-hour NIHSS to those with early/delayed recanalization (3 versus 4.5; P=0.9) and much lower than those with persistent occlusion after 6 hours (3 versus 15; P=0.005). At 3 months, the rate of mRS ≤2 was not statistically different between patients with early/delayed versus late recanalization (55% versus 86%; P=0.12) but was lower if occlusion persisted 6 hours after onset (22%; P<0.001).
Conclusion— The majority of t-PA-induced recanalizations occur during the first hour after treatment. Recanalizations during the following hours are rare but still related to clinical improvement if achieved within 6 hours from onset. Rescue reperfusion techniques should be considered if flow improvement is not observed 60 minutes after t-PA bolus.
- Received October 10, 2005.
- Revision received November 3, 2005.
- Accepted December 20, 2005.