Predominantly mild thrombocytopenia, haematoma expansion and clinical outcomes in intracerebral haemorrhage

Abstract Introduction Evidence regarding the prognostic significance of thrombocytopenia in spontaneous intracerebral haemorrhage (ICH) remains limited and inconsistent. We investigated its associations with haematoma expansion (HE), functional outcomes and mortality. Patients and methods We retrospectively analysed prospectively collected data from consecutive patients with spontaneous ICH in a single-centre registry between August 2022 and March 2025. Thrombocytopenia was defined as an admission platelet count <150 × 109/L. HE was defined as a haematoma-volume increase >6 mL or >33% on follow-up noncontrast computed tomography. Poor functional outcome was defined as a modified Rankin Scale (mRS) score of 3–6 at 3 months. Associations were assessed using multivariable logistic regression, restricted cubic splines, ordinal regression and sensitivity analyses. Results Among 496 patients, 106 (21.4%) had thrombocytopenia; 368 were included in the HE analysis. After adjustment, thrombocytopenia showed no statistically significant association with HE (adjusted OR 0.97, 95% CI, 0.52–1.76; P = .920), 3-month poor functional outcome (adjusted OR 0.88, 95% CI, 0.46–1.66; P = .693), or 3-month mortality (adjusted OR 1.43, 95% CI, 0.70–2.89; P = .324). Restricted cubic spline analysis showed no statistically significant overall association and the test for nonlinearity was not statistically significant. Findings were similar across platelet-count categories, continuous haematoma-volume changes, ordinal mRS analyses and sensitivity analyses addressing imaging timing, early surgery, acute treatments and prior anticoagulant use. Discussion Admission thrombocytopenia showed no statistically significant association with HE, poor functional outcome, or mortality after ICH. Because few patients had platelet counts <100 × 109/L, these findings mainly apply to mild thrombocytopenia.