Recent silent infarcts do not increase the risk of haemorrhage after intravenous thrombolysis

Haemorrhagic transformation (HT) is one of the main risks of intravenous thrombolysis (IVT) for acute ischaemic stroke. Contraindications serve to exclude patients at high risk of HT after IVT. One of these contraindications is a stroke within the preceding 3 months. It is unclear if this contraindication should include recent clinically silent infarcts (RSIs). The aim of this study was to investigate whether RSIs are associated with a higher risk of HT and a worse clinical outcome after IVT for acute ischaemic stroke.

In a retrospective monocentric cohort study, all patients who received IVT for acute ischaemic stroke based on magnetic resonance imaging were assessed over 5 years. RSIs were defined as lesions with diffusion restriction and positive signal on fluid attenuated inversion recovery sequences. Patients with RSIs (RSI+) were compared to patients without RSIs (RSI-) regarding HT after IVT and clinical outcome.

In all, 981 patients who had received IVT for acute ischaemic stroke demonstrated by magnetic resonance imaging were identified. RSIs were detected in 115 patients (11.5%). HT after IVT was observed in 32 (28.3%) RSI+ and 56 (25.8%) RSI- patients (P = 0.624). Symptomatic intracerebral haemorrhage was noted in two (1.8%) RSI+ and five (2.3%) RSI- patients (P = 1.000). No differences in clinical outcome were observed.

The detection of RSIs in patients treated with IVT for acute ischaemic stroke was not associated with a higher risk of HT or a worse clinical outcome. The results of this study argue against considering RSIs as a contraindication for IVT.