Are the results of intravenous thrombolysis trials reproduced in clinical practice? Comparison of observed and expected outcomes with the stroke-thrombolytic predictive instrument (STPI)

AIM

In patients with cerebral ischemia, intravenous (i.v.) recombinant tissue plasminogen activator (rt-PA) increases survival without handicap or dependency despite an increased risk of bleeding. This study evaluated whether the results of randomized controlled trials are reproduced in clinical practice.

METHOD

Data from a registry of consecutive patients treated by rt-PA at Lille University Hospital were retrospectively analyzed for outcomes, using modified Rankin Scale (mRS) scores, at 3 months. The observed outcomes were then compared with the probability of good (mRS 0-1) and of catastrophic (mRS 5-6) outcomes, as predicted by the stroke-thrombolytic predictive instrument (STPI).

RESULTS

Of the 1000 consecutive patients (469 male, median age 74 years, median baseline National Institutes of Health Stroke Scale 11, median onset-to-needle time 143min), 438 (43.8%) had a good outcome, 565 (56.5%) had an mRS score 0-2 or similar to their pre-stroke mRS, 155 (15.5%) died within 3 months and 74 (7.4%) developed symptomatic intracerebral hemorrhage according to ECASS-II (Second European-Australasian Acute Stroke Study) criteria. Of the 613 patients (61.3%) eligible for evaluation by the s-TPI, the observed rate of good outcomes was 41.3% (95% CI: 37.5-45.3%), while expected rates with and without rt-PA were 48.8% (95% CI: 44.8-52.7%) and 32.5% (95% CI: 28.8-36.2%), respectively; the observed rate of catastrophic outcomes was 17.0% (95% CI: 14.0-19.9%), while the expected rate was 19.2% (95% CI: 16.1-22.4%) with or without rt-PA.

CONCLUSION

In clinical practice, the rate of good outcomes is slightly lower than expected, according to the s-TPI, except for the most severe cases, whereas the rate of catastrophic outcomes is roughly similar. However, the rate of good outcomes is higher than predicted without treatment. This finding suggests that rt-PA is effective for improving outcomes in clinical practice.