Stroke thrombolysis: save a minute, save a day

Abstract

Background and purpose: Stroke thrombolysis is highly time-critical, but data on long-term effects of small reductions in treatment delays have not been available. Our objective was to quantify patient lifetime benefits gained from faster treatment.

Methods: Observational prospective data of consecutive stroke patients treated with intravenous thrombolysis in Australian and Finnish centers (1998-2011; n=2258) provided distributions of age, sex, stroke severity, onset-to-treatment times, and 3-month modified Rankin Scale in daily clinical practice. Treatment effects derived from a pooled analysis of thrombolysis trials were used to model the shift in 3-month modified Rankin Scale distributions with reducing treatment delays, from which we derived the expected lifetime and level of long-term disability with faster treatment.

Results: Each minute of onset-to-treatment time saved granted on average 1.8 days of extra healthy life (95% prediction interval, 0.9-2.7). Benefit was observed in all groups: each minute provided 0.6 day in old severe (age, 80 years; National Institutes of Health Stroke Scale [NIHSS] score, 20) patients, 0.9 day in old mild (age, 80 years; NIHSS score, 4) patients, 2.7 days in young mild (age, 50 years; NIHSS score, 4) patients, and 3.5 days in young severe (age, 50 years; NIHSS score, 20) patients. Women gained slightly more than men over their longer lifetimes. In the whole cohort, each 15 minute decrease in treatment delay provided an average equivalent of 1 month of additional disability-free life.

Conclusions: Realistically achievable small reductions in stroke thrombolysis delays would result in significant and robust average health benefits over patients' lifetimes. The awareness of concrete importance of speed could promote practice change.

Keywords: stroke; thrombolytic therapy.