Background Primary balloon angioplasty (PBA) is an alternative treatment approach for intracranial atherosclerotic stenosis (ICAS); however, its efficacy may be compromised by arterial dissection or early elastic recoil after balloon dilation. This study aimed to explore the association between plaque characteristics on high-resolution magnetic resonance vessel wall imaging (HR-VWI) and failure of PBA for ICAS.

Methods We conducted a retrospective analysis of 113 patients with ICAS who underwent HR-VWI before endovascular treatment. Based on the presence of arterial dissection or early elastic recoil post-balloon dilation, patients were classified into the failed PBA (FPBA) group or the successful PBA (SPBA) group. Clinical and baseline HR-VWI characteristics were compared between the two groups. Multivariable analysis was used to investigate plaque features associated with the failure of PBA.

Results The FPBA and SPBA groups comprised 74 and 39 patients, respectively. Plaque eccentricity (83.78% vs 46.15%, P<0.001), negative remodeling (90.54% vs 48.72%, P<0.001), remodeling index (median 0.73 vs 0.90, P=0.001), and intraplaque hemorrhage (31.08% vs 5.13%, P=0.002) differed significantly between the FPBA and SPBA groups. Multivariable analysis indicated that higher frequency of plaque eccentricity (OR 14.03, 95% CI 3.42 to 57.62, P<0.001) and negative remodeling (OR 6.11, 95% CI 1.22 to 30.71, P=0.028) were independently associated with failure of PBA.

Conclusion Our findings showed that failure of PBA was associated with plaque eccentricity and negative remodeling. Analysis of plaque characteristics on baseline HR-VWI holds potential value for identifying arterial dissection or early elastic recoil after angioplasty in patients with ICAS.