The predictive role of CHA₂DS₂–VASc score between venous thromboembolism and ischemic stroke

a large-scale cohort study

Abstract

Purpose: 

This study aimed to explore the predictive role of CHA₂DS₂–VASc score between venous thromboembolism (VTE) and ischemic stroke.

Methods: 

The current study was analyzed from the in-patient claims data of the Taiwan National Health Insurance Research Database. We identified the patients diagnosed with VTE (for Study 1) or ischemic stroke (for Study 2) from 1 January 2000 to 31 December 2011 to observe the occurrence of ischemic stroke (for Study 1) and VTE (for Study 2), respectively. We used the CHA₂DS₂–VASc score to evaluate the risk of ischemic stroke among VTE patients (for Study 1) and to measure the risk of VTE among ischemic stroke patients (for Study 2). The predictive ability of CHA₂DS₂–VASc score was assessed by C-statistics based on Cox-regression analysis and receiver-operating characteristic (ROC) curve analysis.

Results: 

A total of 56 996 patients with VTE (Study 1), whereas a total of 688 556 patients with ischemic stroke (Study 2) were identified. The C-statistics of the CHA₂DS₂–VASc score for predicting ischemic stroke among VTE patients and for predicting VTE events in patients with ischemic stroke were 0.71 [95% confidence interval (CI) = 0.70–0.72] and 0.61 (95% CI = 0.60–0.62), respectively. Furthermore, among VTE patients, the area under the curve of ROC of CHA₂DS₂–VASc score predictive of ischemic stroke was 0.66 (95% CI = 0.65–0.67), whereas the area under the curve of ROC of the score predictive of VTE was 0.55 (95% CI = 0.54–0.55) in patients with ischemic stroke.

Conclusion: 

Our study is the first to concern the performance of CHA₂DS₂–VASc score in predicting the risk of ischemic stroke in VTE patients and the risk of VTE in ischemic stroke patients. Nevertheless, the performance of the score was modest, and the transportability of the score in these populations still needs to be defined.