Abstract W MP29: Stroke Severity and Thrombolysis-Induced Intracerebral Haemorrhage: Thrombolysis Practice and Outcomes in England and Wales at the Extremes of the NIHSS

Abstract

Background: The safety and outcomes of thrombolysis with intravenous tPA in patients with mild stroke or very severe stroke are still debated. We describe the use and outcomes from thrombolysis across the full range of stroke severity in England and Wales. Methods: The Sentinel Stroke National Audit Programme (SSNAP) is the prospective stroke register for England and Wales, with 100% population coverage. Data are entered by clinical teams using a secure online web portal. Symptomatic intracranial haemorrhage (SIH) was defined pragmatically (evidence on imaging plus clinical deterioration). Results: 58,769 ischaemic stroke patients were admitted from April 2013-March 2014, and 7598 (12.9%) received tPA; median NIHSS was 4 (IQR 2-9). Of the 6578 (86.9%) patients treated with tPA with documented NIHSS, 816 (12.4%) were mild (NIHSS 0-4) and 650 (10.0%) were very severe (NIHSS ≥ 22). The overall incidence of SIH was 4.0% (95% CI 3.5-4.5). Risk of SIH increased with stroke severity: 1.4% with NIHSS 0-4, 3.1% with NIHSS 5-14, 5.7% with NIHSS 15-21 and 8.8% with NIHSS ≥22. The association between NIHSS and SIH was similar across stroke onset-tPA times of 0-3 hrs, 3-4.5 hrs and >4.5 hrs. Compared to patients with NIHSS 5-14, patients with NIHSS 0-4 or NIHSS ≥22 had an adjusted odds ratio for SIH of 0.47 (0.3-0.9) and 2.6 (1.9-3.7) respectively. Outcomes in patients with NIHSS ≥22 treated with tPA were poor: 30 day mortality was 36% and 71% of survivors had a poor outcome (modified Rankin Scale score 3-5). Most patients (77%) with mild stroke treated with tPA had a good outcome (mRS 0-2) and 30day mortality was 2.4%. Conclusions: Thrombolysis in mild or very severe stroke is common practice in England and Wales. Risk of SIH following IV tPA is strongly related to stroke severity; the risk is significantly higher among severe strokes, for whom outcomes with tPA remain poor.