The Effect of Methamphetamine Use on Radiographic Vasospasm Following Angiogram-Negative Subarachnoid Hemorrhage: A Preliminary Retrospective Analysis

<b>Introduction:</b> The effect of methamphetamine use on angiogram-negative subarachnoid hemorrhage (ANSAH) outcomes has not been examined. Herein, our goal is to evaluate the effect of methamphetamine use on radiographic vasospasm following ANSAH. Methods: This is a retrospective cohort analysis that was performed between 2011 and 2022 among consecutive ANSAH patients presenting to our institution. Methamphetamine positivity (MP) was defined as presence of methamphetamine on urine toxicology and/or by patient report. Outcomes of interest included radiographic vasospasm, clinical vasospasm, and discharge home and were evaluated using multivariate logistic regressions. Results: 101 patients met inclusion criteria and had a median Hunt and Hess score of 2 (range 1-4). Eight (7.9%) MP patients were younger (47.5 ± 3.3 v. 60.8 ± 1.2 years, <i>p</i> = 0.004) than methamphetamine-negative patients. In univariate analysis, MP patients were nearly 12 times more likely to experience radiographic vasospasm (odds ratio (OR) 11.6; 95%: confidence interval (CI): 1.4-98.3; <i>p</i> = 0.008) but there was no significant difference in clinical vasospasm or discharge home (<i>p</i> > 0.05). In multivariate analysis, MP was associated with increased radiographic vasospasm (OR 18.8; 95%CI: 1.7-210.5, <i>p</i> = 0.017) but not clinical vasospasm (OR: 5.1; 95%CI: 0.9-28.7; <i>p</i> = 0.063) or discharge home (OR: 1.3; 95%CI: 0.1-15.6; <i>p</i> = 0.843) Conclusions: Methamphetamine-positive ANSAH patients have increased odds of radiographic vasospasm compared to MN patients. While limited by sample size, this preliminary study adds to our understanding of the increased risk of radiographic vasospasm following ANSAH for patients who use methamphetamine. Future multi-center prospective registry studies should include methamphetamine history as this may modulate vasospasm risk.