Investigation of the rimegepant effect on cerebral and extracerebral arteries during migraine attacks: a longitudinal magnetic resonance angiography study.

Migraine is a leading cause of disability worldwide, and triptans, the most widely used acute treatment, act through vasoconstriction and are contraindicated in patients with vascular disease. Rimegepant, a calcitonin gene-related peptide receptor antagonist, is proposed as a non-vasoconstrictive alternative, but its direct vascular effects during spontaneous migraine attacks have not been examined. This was a prospective, longitudinal study conducted at a single academic imaging centre between 12 January 2024 and 10 June 2025. Eighteen women aged 18-40 years with menstrually related migraine without aura were enrolled. Fifteen participants completed high-resolution 3 T magnetic resonance angiography during a spontaneous migraine attack before, and at 30 and 60 min after, administration of a single 75 mg oral dose of rimegepant. The primary outcome was change in arterial circumference of the cerebral artery and meningeal artery. Circumference was measured in millimetre and compared using paired samples t-tests. No significant vasoconstriction was observed in either artery following rimegepant administration. Cerebral artery circumference remained stable (baseline 8.13 ± 0.93 mm; 30 min 8.02 ± 0.84 mm, P = 0.404; 60 min 8.15 ± 0.90 mm, P = 0.918). Meningeal artery circumference showed no significant change (baseline 4.30 ± 0.83 mm; 30 min 4.47 ± 0.68 mm, P = 0.084; 60 min 4.35 ± 0.78 mm, P = 0.688). Rimegepant did not induce measurable constriction of cerebral or meningeal arteries during spontaneous migraine attacks. These findings support its vascular safety and indicate that effective migraine relief with calcitonin gene-related peptide receptor antagonists does not depend on vasoconstriction, in contrast to triptan therapy.