Introduction The characteristics and natural history of acute non-vitamin K antagonists oral anticoagulants (NOAC)-associated intracerebral haemorrhage (ICH) are largely unknown. We performed a comprehensive systematic review and meta-analysis to compare baseline ICH volume, haematoma expansion and clinical outcomes between NOAC-ICH versus vitamin K antagonists-ICH (VKA-ICH).

Methods We searched PubMed and conference abstracts for observational studies comparing baseline characteristics and outcomes in patients with NOAC-ICH versus VKA-ICH using an appropriate keyword/MeSH term search strategy. Data were extracted following PRISMA and MOOSE guidelines. The main outcome measures were mortality and unfavourable functional outcome (modified Rankin Score: 4–6) at discharge and at 3 months, as well as ICH volumes and haematoma expansion rates in the two groups. Random-effects models with DerSimonian-Laird weights were used for pooled estimates calculation.

Results Twelve studies including 393 NOAC-ICH and 3482 VKA-ICH were pooled in meta-analysis. There was no difference in mean ICH-volume between the two groups (standard mean difference: −0.24; 95% CI −0.52 to 0.04, p=0.093). The rates of haematoma expansion were comparable in NOAC-ICH versus VKA-ICH (OR: 0.76; 95% CI 0.49 to 1.19, p=0.236). We did not find any difference between patients with NOAC-ICH versus VKA-ICH in all-cause mortality at discharge (OR: 0.66; 95% CI 0.42 to 1.05, p=0.077) and unfavourable functional outcome at discharge (OR: 0.77; 95% CI 0.41 to 1.44, p=0.413). The 3-month outcome was also comparable between the two ICH groups. Moderate-to-substantial statistical heterogeneity was noted.

Conclusion Our results confirm that ICH volume, haematoma expansion, mortality and functional outcome appear to be similar for NOAC-ICH versus VKA-ICH. Large prospective cohorts and updated meta-analyses are needed to provide more precise estimates.