The Role of Angiotensin-Converting Enzyme Inhibitors in Patients with Chronic Subdural Hematoma: A Scandinavian Population-Based Multicenter Study

To investigate the role of angiotensin converting enzyme (ACE) inhibitors in the recurrence of chronic subdural hematoma (cSDH) after burr hole surgery. A retrospective review was conducted of a Scandinavian multicenter, population-based cohort of 1252 adults with cSDH who underwent with burr hole surgery between January 1, 2005, and December 31, 2010. The risk of cSDH recurrence was assessed in users of ACE inhibitors, users of angiotensin II receptor blockers (ARBs), and those without ACE inhibitor treatment (no ACE inhibitor group) using univariable and multivariable regression analyses. The cohort included 98 (7.8%) ACE inhibitor users and 63 (5%) ARB-only users. The recurrence rate was 16.3% (n = 16) in the ACE inhibitor group, compared with 13.3% (n = 153) in the no ACE inhibitor group (P = 0.39) and 14.3% (n = 9) in the ARB group (P = 0.73). When comparing groups, age (P = 0.01), Charlson Comorbidity Index (P = 0.01), use of platelet inhibitors (P = 0.001) and use of anticoagulants (P = 0.01) differed between the ACE inhibitor and no ACE inhibitor groups. Only age differed significantly between the ACE inhibitor and ARB groups (P = 0.03). In the analyses adjusted for differences in baseline characteristics, ACE inhibitor treatment did not influence the risk of recurrence (odds ratio, 1.2; 95% confidence interval, 0.7–2.2; P = 0.46). In this population-based study, the use of ACE inhibitors was not associated with the risk of recurrence following burr hole surgery for cSDH. •Recently, conflicting reports have emerged suggesting that angiotensin-converting enzyme (ACE) inhibitors may or may not influence the risk of chronic subdural hematoma (cSDH) recurrence. Lack of power or inability to adjust for likely confounding factors likely influence the results in those previous studies.•In a large Scandinavian multicenter population-based cohort, we investigated the risk of cSDH recurrence in users of ACE inhibitors, users of angiotensin II receptor blockers, and those without ACE inhibitor treatment (no ACE inhibitor group) using univariable analyses and adjusting for baseline differences using a regression analysis.•After adjusting for differences in the baseline characteristics using a regression model, ACE inhibitor treatment did not influence risk for recurrence (odds ratio, 1.2; 95% confidence interval, 0.7–2.2; P = 0.46). Thus, our results argue against any significant effect of ACE inhibitors on cSDH recurrence, and other adjuvant treatment should