ABCD2 and ABCD3-I scores in a TIA population with low stroke risk

Abstract

Abstract Background Several clinical risk scores have been developed to predict stroke risk after transient ischemic attack (TIA). We aimed to evaluate the ABCD3-I score and compare it with the ABCD2 score in short and long-term stroke risk prediction in our post TIA stroke risk study, MIDNOR TIA. Methods We performed a prospective, multicenter study in Central Norway from October, 2012, to July, 2015, enrolling 577 patients with TIA. In a subset of patients (n=305) we calculated the AUC statistics of the ABCD3-I score and compared this with the ABCD2 score at 1 week, 3 months and 1 year. To assess stroke occurrences, data obtained by telephone follow-up and registry data from the Norwegian Stroke Register was used. Results Three hundred and five patients had complete data for both ABCD3-I and ABCD2 scores. Within 1 week, 3 months and 1 year, 1.0% (n=3), 3.3% (n=10) and 5.2% (n=16) experienced a stroke, respectively. The AUCs for the ABCD3-I score were 0.72 (95% CI, 0.54 to 0.89) at 1 week (compared with ABCD2 score p =0.019), 0.66 (95% CI, 0.53 to 0.80) at 3 months ( p =0.11), and 0.68 (0.95% CI, 0.56 to 0.79) at 1 year ( p =0.39). Conclusions The ABCD3-I score had limited value in short term prediction of subsequent stroke after TIA and did not reliably discriminate between low and high-risk patients in long-term follow-up. The ABCD2 score did not predict subsequent stroke accurately at any time point. Since modern treatment regimens and a decrease in risk factors in the population have contributed to a generally lower stroke risk after TIA during the last years, the benefit of these clinical risk scores and their role in TIA management seems limited.