Optimized Hemodynamic Assessment to Predict Stroke Risk in Vertebrobasilar Disease: Analysis From the VERiTAS Study
Authors: See Alfred P. , Pandey Dilip K. , Du Xinjian , Rose‐Finnell Linda , Charbel Fady T. , Derdeyn Colin P. , Amin‐Hanjani Sepideh , Richardson DeJuran , Xie Hui , Thulborn Keith , Flanner Michael P. , Ganin Hagai , Ruland Sean , Grysiewicz Rebecca , Khaja Aslam , Pedelty Laura , Testai Fernando , Ong Archie , Epstein Noam , Muqtadar Hurmina , Watson Karriem , Mlinarevich Nada , Hillmann Maureen , Elkind Mitchell S. V. , Hirsch Joy , Dashnaw Stephen , Meyers Philip M. , Willey Josh Z. , McNeill‐Simaan Edwina , Perez Veronica , Canaan Alberto , Paulino‐Hernandez Wayna , Zipfel Gregory J. , Vo Katie , Foster Glenn , Ford Andria , Nassief Abdullah , Bradley Abbie , Serna‐Northway Jannie , Kraus Kristi , Shiwani Lina , Hantler Nancy , Liebeskind David S. , Alger Jeffrey , Godinez Sergio , Saver Jeffrey L. , Ali Latisha , Kim Doojin , Tenser Matthew , Froehler Michael , Raychev Radoslav , Song Sarah , Ovbiagele Bruce , Abcede Hermelinda , Adamczyk Peter , Rao Neal , Yallapragada Anil , Modir Royya , Hinman Jason , Tansy Aaron , Calderon‐Arnulphi Mateo , Sheth Sunil , Noorian Alireza , Ng Kwan , Liang Conrad , Gadhia Jignesh , Smith Hannah , Avila Gilda , Avelar Johanna , Silver Frank L. , Mikulis David , Fierstra Jorn , Hlasny Eugen , Casaubon Leanne K. , Vergouwen Mervyn , Martin del Campo J. C. , Jaigobin Cheryl S. , Astorga Cherissa , Kalman Libby , Kramer Jeffrey , Vaughan Susan , Owens Laura , Richardson DeJuran , Thulborn Keith R. , Caplan Louis R. , Gorelick Philip B. , Kasner Scott E. , Kissela Brett , Turan Tanya N. , Aletich Victor , Jacobs Tom P. , Janis Scott 
Published: June 2020

Background

Atherosclerotic vertebrobasilar disease is a significant etiology of posterior circulation stroke. The prospective observational
VER
i
TAS
(Vertebrobasilar Flow Evaluation and Risk of Transient Ischemic Attack and Stroke) study demonstrated that distal hemodynamic status is a robust predictor of subsequent vertebrobasilar stroke risk. We sought to compare predictive models using thresholds for posterior circulation vessel flows standardized to age and vascular anatomy to optimize risk prediction.

Methods and Results

VER
i
TAS
enrolled patients with recent vertebrobasilar transient ischemic attack or stroke and ≥50% atherosclerotic stenosis/occlusion in vertebral and/or basilar arteries. Quantitative magnetic resonance angiography measured large‐vessel vertebrobasilar territory flow, and patients were designated as low or normal flow based on a prespecified empiric algorithm considering distal territory regional flow and collateral capacity. For the present study, post hoc analysis was performed to generate additional predictive models using age‐specific normalized flow measurements. Sensitivity, specificity, and time‐to‐event analyses were compared between the algorithms. The original prespecified algorithm had 50% sensitivity and 79% specificity for future stroke risk prediction; using a predictive model based on age‐normalized flows in the basilar and posterior cerebral arteries, standardized to vascular anatomy, optimized flow status thresholds were identified. The optimized algorithm maintained sensitivity and increased specificity to 84%, while demonstrating a larger and more significant hazard ratio for stroke on time‐to‐event analysis.

Conclusions
These results indicate that flow remains a strong predictor of stroke across different predictive models, and suggest that prediction of future stroke risk can be optimized by use of vascular anatomy and age‐specific normalized flows.