Prediction of long-term recurrent ischemic stroke: the added value of non-contrast CT, CT perfusion, and CT angiography

Abstract

The aim of this study was to evaluate whether the addition of brain CT imaging data to a model incorporating clinical risk factors improves prediction of ischemic stroke recurrence over 5 years of follow-up. Methods A total of 638 patients with ischemic stroke from three centers were selected from the Dutch acute stroke study (DUST). CT-derived candidate predictors included findings on non-contrast CT, CT perfusion, and CT angiography. Fiveyear follow-up data were extracted from medical records. We developed a multivariable Cox regression model containing clinical predictors and an extended model including CT-derived predictors by applying backward elimination. We calculated net reclassification improvement and integrated discrimination improvement indices. Discrimination was evaluated with the optimism-corrected c-statistic and calibration with a calibration plot. Results During 5 years of follow-up, 56 patients (9%) had a recurrence. The c-statistic of the clinical model, which contained male sex, history of hyperlipidemia, and history of stroke or transient ischemic attack, was 0.61. Compared with the clinical model, the extended model, which contained previous cerebral infarcts on non-contrast CT and Alberta Stroke Program Early CT score greater than 7 on mean transit time maps derived from CT perfusion, had higher discriminative performance (c-statistic 0.65, P = 0.01). Inclusion of these CT variables led to a significant improvement in reclassification measures, by using the net reclassification improvement and integrated discrimination improvement indices. Conclusion Data from CT imaging significantly improved the discriminatory performance and reclassification in predicting ischemic stroke recurrence beyond a model incorporating clinical risk factors only.

Recurrence of ischaemic stroke using epidemiology and neuroimaging: A retrospective study in Gansu Province

“…Although stroke has a variety of clinical symptoms, the use of neuroimaging in patient examination, diagnosis, and treatment is a major theme in modern IS care, and neuroimaging is widely used to assess vascular patency and tissue vitality. For instance, data from CT imaging have significantly improved the discriminatory performance and reclassification for predicting IS recurrence beyond a model incorporating clinical risk factors only [ 15 , [18] , [19] , [20] ]. Regional data in China revealed that the rate of neuroimaging diagnosis and hospitalisation of stroke patients have increased significantly over the past three decades, with an annual increase of 4.0% and 11.2%, respectively [ 21 ].…”