Quantifying Intra-Arterial Verapamil Response as a Diagnostic Tool for Reversible Cerebral Vasoconstriction Syndrome
J Sequeiros, Jorge A. Roa, Ryan Sabotin, Sudeepta Dandapat, Santiago Ortega‐Gutiérrez, Enrique C. Leira, Colin P. Derdeyn, Girish Bathla, David Hasan, Edgar A. Samaniego
Abstract
<h3>BACKGROUND AND PURPOSE:</h3> There is mounting evidence supporting the benefit of intra-arterial administration of vasodilators in diagnosing reversible cerebral vasoconstriction syndrome. We prospectively quantified the degree of luminal diameter dilation after intra-arterial administration of verapamil and its accuracy in diagnosing reversible cerebral vasoconstriction syndrome. <h3>MATERIALS AND METHODS:</h3> Patients suspected of having intracranial arteriopathy on noninvasive imaging and referred for digital subtraction angiography were enrolled in a prospective registry. Intra-arterial verapamil was administered in vascular territories with segmental irregularities. The caliber difference (Caliber<sub>post</sub> − Caliber<sub>pre</sub>) and the proportion of caliber change ([(Caliber<sub>post</sub> − Caliber<sub>pre</sub>)/Caliber<sub>pre</sub>] × 100%) were used to determine the response to verapamil. The diagnosis of reversible cerebral vasoconstriction syndrome was made on the basis of clinical and imaging features at a follow-up appointment, independent of the reversibility of verapamil. Receiver operating characteristic curve analysis was performed to determine the best threshold. <h3>RESULTS:</h3> Twenty-six patients were included, and 9 (34.6%) were diagnosed with reversible cerebral vasoconstriction syndrome. A total of 213 vascular segments were assessed on diagnostic angiography. Every patient with a final diagnosis of reversible cerebral vasoconstriction syndrome responded to intra-arterial verapamil. The maximal proportion of change (<i>P </i>< .001), mean proportion of change (<i>P </i>= .002), maximal caliber difference (<i>P </i>= .004), and mean caliber difference (<i>P </i>= .001) were statistically different between patients with reversible cerebral vasoconstriction syndrome and other vasculopathies. A maximal proportion of change ≥32% showed a sensitivity of 100% and a specificity of 88.2% to detect reversible cerebral vasoconstriction syndrome (area under the curve = 0.951). The Reversible Cerebral Vasoconstriction Syndrome-2 score of ≥5 points achieved a lower area under the curve (0.908), with a sensitivity of 77.8% and a specificity of 94.1%. <h3>CONCLUSIONS:</h3> Objective measurement of the change in the arterial calibers after intra-arterial verapamil is accurate in distinguishing reversible cerebral vasoconstriction syndrome from other vasculopathies. A proportion of change ≥32% has the best diagnostic performance.