­­Should I stay or should I go? What revascularization treatment in large vessel occlusion stroke with low NIHSS?

Giuseppe Reale, Neurology Resident at Catholic University of the Sacred Heart, Rome. ESO – YSPR Committee

Endovascular treatment (EVT) is considered to be the standard of care for ischemic stroke due to proximal large vessel occlusion (LVO)1.

However, while the efficacy of intravenous thrombolysis (IVT) is proven regardless of the stroke severity2, the trials of thrombectomy published in 2015 enrolled very few patients with NIHSS <63 and, therefore, the benefit of EVT among patient with minor stroke due to LVO is still debated. This is not as marginal as it seems, considering that about 20% of ischemic strokes is associated with LVO and about 10% of LVO is associated with mild neurological symptoms4,5,6.

A recent observational study7 from the SITS-ISTR evaluated the frequency of non-hemorrhagic early neurological deterioration and three-months mRS in a population of 2553 LVO minor stroke patients treated with IVT. The Authors observed that non-hemorrhagic neurological deterioration, defined as an increase in NIH Stroke Scale score 4 at 24h, occurred more often among patients with LVO strokes (30% in case of internal carotid artery or tandem occlusion, 17% in case of extracranial carotid artery occlusion, 9% in case of middle cerebral artery M1 occlusion) versus 3% of non-LVO strokes. Moreover, in a regression model analysis, any occlusion site was an independent predictor of non-hemorrhagic early neurological deterioration. Finally, among patients with any occlusion and non-hemorrhagic early neurological deterioration, 77% had a mRS3 at three months.

At the moment no randomized controlled trial comparing IVT vs EVT in LVO stroke and NIHSS<6 is available. Data from non-randomized controlled studies are often conflicting. As an example, a recent retrospective study8 comparing immediate EVT versus best medical management (including rescue EVT in case of clinical deterioration) showed a superiority of the immediate EVT group in terms of outcomes. On the other side, a 2014 prospective observational study showed no difference in functional outcomes between intravenous thrombolysis and endovascular treatment groups, being the latter associated to a major risk of intracranial hemorrhage9.

In conclusion, LVO stroke seems to be linked to unfavorable outcomes (early neurological deterioration and death and disability), regardless of IVT. Being both the presence of any occlusion and the arterial occlusion site predictors of bad outcomes, vessel imaging in the acute phase might be considered even in the presence of mild symptoms. So, should I stay or should I go?

Hopefully, we will have more answers after randomized controlled trials.

References

  1. Powers WJ, Rabinstein AA, Ackerson T, et al. 2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association. Stroke. 2018 Jan 24 [Epub ahead of print].
  2. Emberson J, Lees KR, Lyden P, et al. Effect of treatment delay, age, and stroke severity on the effects of intraven- ous thrombolysis with alteplase for acute ischaemic stroke: a meta-analysis of individual patient data from randomised trials. Lancet. 2014;384:1929–1935.
  3. Rodrigues FB, Neves JB, Caldeira D, et al. Endovascular treatment versus medical care alone for ischaemic stroke: systematic review and meta-analysis. BMJ. 2016;353:i1754.
  4. Gur AY, Tanne D, Bornstein NM, et al. Stroke in the very elderly: characteristics and outcome in patients aged ≥85 years with a first-ever ischemic stroke. Neuroepidemiology. 2012;39:57–62.
  5. Rai AT, Seldon AE, Boo S, et al. A population-based incidence of acute large vessel occlusions and thrombectomy eligible patients indicates significant potential for growth of endovascular stroke therapy in the USA. J Neurointerv Surg. 2017;9:722–726.
  6. Scheitz JF, Abdul-Rahim AH, MacIsaac RL, et al. Clinical selection strategies to identify ischemic stroke patients with large anterior vessel occlusion: results from SITS-ISTR (Safe Implementation of Thrombolysis in Stroke International Stroke Thrombolysis Registry). Stroke. 2017;48:290–297.
  7. Mazya MV, Cooray C, Lees KR, et al. Minor stroke due to large artery occlusion. When is intravenous thrombolysis not enough? Results from the SITS International Stroke Thrombolysis Register. European Stroke Journal. 2018;3:29–38.
  8. Nagel S, Bouslama M, Krause LU, et al. Mechanical Thrombectomy in Patients With Milder Strokes and Large Vessel Occlusions. Stroke. 2018;49:2391-2397.
  9. Urra X, San Román L, Gil F, et al. Medical and endovascular treatment of patients with large vessel occlusion presenting with mild symptoms: an observational multicenter study. Cerebrovasc Dis. 2014;38:418-424.