Statins Reduce Wall Enhancement at Vessel Wall MRI in Unruptured Vertebrobasilar Dissecting Aneurysms: A Randomized Controlled Trial

Background Vertebrobasilar dissecting aneurysms (VBDAs) are important causes of stroke. Aneurysm wall enhancement at vessel wall (VW) MRI is a marker of inflammation. Previous studies have shown that statins may reduce inflammation in intracranial saccular aneurysms, but their effect on VBDAs remains unknown. Purpose To evaluate the effect of 6-month atorvastatin treatment on VBDA wall enhancement on VW MRI scans. Materials and Methods Participants with unruptured VBDAs were enrolled in this open-label, randomized controlled trial from July 2021 to January 2023 and randomized 1:1 to the daily 20 mg atorvastatin group or control group. VBDAs were imaged with VW MRI at baseline and at the 6-month follow-up. The primary end point was the change in aneurysm wall enhancement measured by the quantitative wall enhancement index (WEI) and three-dimensional wall enhancement volume rate (WEVR). The secondary outcomes were changes in aneurysm size or morphology and inflammation-related circulating biomarkers. All outcome analyses were performed using appropriate tests for categorical and continuous variables. Results A total of 40 participants were included (mean age, 52 years ± 11 [SD]; 34 men). In the statin group, both the WEI and WEVR of the aneurysm wall decreased at 6 months compared with those at baseline. The change in WEI was -0.3 in the statin group but 0.1 in the control group (<i>P</i> < .001). Similarly, the change in WEVR was -15.1% in the statin group but 5.3% in the control group (<i>P</i> < .001). Additionally, the circulating plasma levels of C-reactive protein, tumor necrosis factor α, interleukin-6, and interleukin-1β improved in the atorvastatin group compared with the control group (all <i>P</i> < .05). The atorvastatin group also showed slowed progression of intramural hematoma (304.0 mm³ vs 100.3 mm³; <i>P</i> = .006). No change in aneurysm size was detected in both groups. Conclusion Atorvastatin use decreased VBDA wall enhancement on VW MRI scans compared with the control group. ClinicalTrials.gov Identifier: NCT04943783 © RSNA, 2025 <i>Supplemental material is available for this article.</i> See also the editorial by Mohajer and Chernyak in this issue.