Study sheds light on the 'Lazarus phenomenon'

Intra-arterial administration of thrombolytic therapy (mainly tissue-plasminogen activator [t-PA]) has demonstrated significant and immediate clinical improvement, dubbed the "Lazarus phenomenon," in about one-fourth of patients with acute ischemic stroke. Factors associated with the Lazarus phenomenon are a shorter time to treatment, a high reperfusion score, and formation of good pial collaterals.

Intra-arterial delivery of t-PA directly into a clot, which has not been approved by FDA, was studied in 108 consecutive acute stroke patients presenting within 6 hours of symptom onset (patients with basilar artery thrombosis were treated within 24 hours of symptom onset). For this study, the Lazarus phenomenon was defined as a decrease in the National Institutes of Health (NIH) Stroke Scale score of ≥50% within 24 hours of treatment.

Arteriograms were reviewed to assess reperfusion on the basis of thrombolysis in cerebral infarction (TICI) score and to assess pial collateral formation. A TICI score of 0 designated no reperfusion to the affected region; a maximum score of 3 designated complete reperfusion to the affected territory. A score of 1 designated reperfusion <50%, and a score of 2 designated reperfusion of >50% to the affected territory but without complete recanalization.

Patients who experienced the Lazarus phenomenon were treated a mean of 198 minutes from symptom onset, compared with 299 minutes for those who did not experience significant and immediate improvement (P=.0002).

Another significant factor was pial collateral formation: 92.3% of those who experienced the Lazarus phenomenon had good pial collaterals, compared with 59.7% of those who did not experience the Lazarus phenomenon (P=.0022).

"Patients with brisk collaterals and who get in quickly have a much better chance at a dramatic outcome," Dr Christoforidis said. Approximately 50% of the patients with good pial collaterals who were treated in <270 minutes experienced the Lazarus phenomenon. In contrast, none of the patients with poor collaterals who were treated >270 minutes after symptom onset had this type of improvement.

TICI reperfusion score was also related to outcome. Half of the patients with TICI 2 or 3 reperfusion who were treated in <270 minutes experienced the Lazarus phenomenon; about one-fourth of patients with TICI 2 or 3 reperfusion who were treated >270 minutes also had rapid and significant improvement; of the patients with TICI 0 or 1 reperfusion, <10% experienced the Lazarus phenomenon.

Patients who experienced the Lazarus phenomenon improved by a median of 10 points on the NIH Stroke Scale in the first 24 hours, and improved by 0 points between the first 24 hours and hospital discharge. The majority of significant clinical improvement occurred within the first 24 hours, Dr Christoforidis said.