Clot Migration after Tenecteplase (TNK): A Potential Cause of Neurological Deterioration in Stroke Patients

Tenecteplase (TNK) has been increasingly adopted as an alternative to alteplase (tPA) for ischemic stroke due to its ease of administration and pharmacologic advantages. However, recent studies suggest TNK may be associated with a higher incidence of clot migration, potentially contributing to early neurologic deterioration.

To describe the incidence and clinical impact of clot migration following TNK administration in acute ischemic stroke patients.

We retrospectively reviewed consecutive patients treated with TNK at our Comprehensive Stroke Center between May and August 2023. Clot migration was defined as a change in thrombus position without full distal reperfusion. Neurologic deterioration was defined as an NIHSS increase ≥4 or new-onset deficit. All patients underwent pre- and post-TNK vascular imaging.

Among 53 patients treated with TNK, 12 (22.6%) experienced neurological deterioration. Clot migration was identified in 4 patients (8.3%) among those with confirmed vessel occlusion on baseline imaging (n = 48). All exhibited new occlusions in anatomically compatible sites and clinical worsening shortly after TNK. One patient required mechanical thrombectomy; the remaining 3 had distal occlusions or low NIHSS scores. At discharge, two patients had good outcomes (mRS ≤2), and two had poor outcomes (mRS >2).

Clot migration may contribute to early neurologic deterioration following TNK, particularly in posterior circulation strokes. Outcomes appear to depend on final clot location and clinical severity. As TNK becomes more widely used, increased awareness and early vascular imaging are critical for recognizing this phenomenon and guiding management.