Pre-existing statin use and recurrence in relation to hematoma architecture of chronic subdural hematomas - A propensity score-matched analysis

Introduction: Chronic subdural hematoma (cSDH) affects increasing patient numbers annually, with postoperative recurrence rates of 5-33%. While atorvastatin shows efficacy as primary conservative treatment, the prognostic value of pre-existing statin use in surgical candidates remains unclear. Research question: This study examined associations between pre-existing statin therapy, hematoma architecture on computed tomography, and postoperative recurrence risk. Material and methods: This retrospective cohort study analyzed 564 consecutive patients surgically treated for cSDH at a tertiary center (2015-2023). Pre-existing statin use was documented and hematoma architecture classified into homogeneous, organized, sedimented, and subacute subtypes. The primary outcome was recurrence requiring reoperation. Multivariable logistic regression with hierarchical adjustment evaluated associations between statin use and recurrence, adjusting for demographics, comorbidities, medications, and hematoma characteristics. Interaction analyses tested whether statin effects varied by architecture. Propensity score matching (1:1, n = 252) reduced confounding. Results: Statin use was documented in 150 patients (26.6%). Recurrence occurred in 170 patients (30.1%): 32.9% in non-users versus 22.7% in users. Unadjusted analysis suggested protection (OR 0.599, p = 0.021), but this attenuated after adjusting for cardiovascular comorbidities (OR 0.649, p = 0.076) and became non-significant after full adjustment (OR 0.664, p = 0.109). Propensity matching corroborated findings (OR 0.736, p = 0.269). Hematoma architecture was the dominant predictor: organized hematomas showed 70% lower recurrence risk (OR 0.303, p < 0.001). No differential statin effects across subtypes were observed (p = 0.668). Discussion and conclusion: Pre-existing statin therapy shows no independent association with postoperative recurrence after adjusting for confounders and hematoma architecture. Prospective investigation of post-surgical statin initiation is warranted. Trial registration: The study was registered with the German Clinical Trials Register (DRKS00025280).