This isn’t exactly “news” – or it shouldn’t be – because the basic underlying hypotheses for care in cerebral ischemia are: 1) identify or assume viable brain tissue, and 2) effectively reperfuse said tissue. So, of course, delays in 2 will lead to reductions in remaining viable 1 – the so-called “time is brain”.
This is a review of a mechanical thrombectomy registry, STRATIS, set up mostly just to record outcomes and usage in the “real world”. Registries are great for retrospective analysis fraught with bias, but, if high-quality evidence were cheap and easy to come by, we would have that instead. These authors performed an analysis associating onset-to-revascularization times with outcomes, stratifying their analysis by direct presentation to an endovascular center versus those requiring intra-hospital transfer. Unsurprisingly, onset-to-revascularization times are longer in those who presented to an outside facility prior to transfer. Unadjusted functional outcomes favored those with direct presentation (mRS 0-2 in 60.0% vs 52.2%), with no change in mortality. Statistical analysis of the impact of receiving tPA did not demonstrate any effect on outcomes.
So, yes, patients should be triaged in the field as best as possible to detect a large vessel stroke possibly amenable to intervention, and transported directly to capable centers. The only apparent negative impact is a delay to tPA, but the entire existence of the endovascular industry is predicated on the fact tPA just doesn’t work for large vessel strokes – the reperfusion rate is probably <10%, and it probably leads to increased post-procedural hemorrhage. There is essentially no value to stopping at the closest hospital just to give tPA when definitive therapy is delayed by, as these authors modeled, up to an hour and a half. The collateral circulation does usually give out eventually, so, while the magnitude of time-based treatment effect from this retrospective analysis isn’t reliable, it probably reflects some underlying truths – and stopping anywhere sooner is just a waste.
“Interhospital Transfer Prior to Thrombectomy is Associated with Delayed Treatment and Worse Outcome in the STRATIS Registry”
https://www.ncbi.nlm.nih.gov/pubmed/28943516