BackgroundTransient ischemic attack (TIA) is a risk factor of stroke. Modern treatment regimens and changing risk factors in the population justify new estimates of stroke risk after TIA, and evaluation of the recommended ABCD2 stroke risk score.MethodsFrom October, 2012, to July, 2014, we performed a prospective, multicenter study in Central Norway, enrolling patients with a TIA within the previous 2 weeks. Our aim was to assess stroke risk at 1 week, 3 months and 1 year after TIA, and to determine the predictive value of the dichotomized ABCD2 score (0–3 vs 4–7) at each time point. We used data obtained by telephone follow-up and registry data from the Norwegian Stroke Register.ResultsFive hundred and seventy-seven patients with TIA were enrolled of which 85% were examined by a stroke specialist within 24 h after symptom onset. The cumulative incidence of stroke within 1 week, 3 months and 1 year of TIA was 0.9% (95% CI, 0.37–2.0), 3.3% (95% CI, 2.1–5.1) and 5.4% (95% CI, 3.9–7.6), respectively. The accuracy of the ABCD2 score provided by c-statistics at 7 days, 3 months and 1 year was 0.62 (95% CI, 0.39–0.85), 0.62 (95% CI, 0.51–0.74) and 0.64 (95% CI, 0.54–0.75), respectively.ConclusionsWe found a lower stroke risk after TIA than reported in earlier studies. The ABCD2 score did not reliably discriminate between low and high risk patients, suggesting that it may be less useful in populations with a low risk of stroke after TIA.Trial registrationUnique identifier: NCT02038725 (retrospectively registered, January 16, 2014).

Objectives. We aimed to evaluate the ABCD3-I score and compare it with the ABCD2 score in short- (1 week) and long-term (3 months; 1 year) stroke risk prediction in our post-TIA stroke risk study, MIDNOR TIA. Materials and Methods. We performed a prospective, multicenter study in Central Norway from 2012 to 2015, enrolling 577 patients with TIA. In a subset of patients with complete data for both scores ( n = 305 ), we calculated the AUC statistics of the ABCD3-I score and compared this with the ABCD2 score. A telephone follow-up and registry data were used for assessing stroke occurrence. Results. 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, 0.66 (95% CI, 0.53 to 0.80) at 3 months, and 0.68 (0.95% CI, 0.56 to 0.79) at 1 year. The corresponding AUCs for the ABCD2 score were 0.55 (95% CI, 0.24 to 0.86), 0.55 (95% CI, 0.42 to 0.68), and 0.63 (95% CI, 0.50 to 0.76). Conclusions. The ABCD3-I score had limited value in a short-term prediction of subsequent stroke after TIA and did not reliably discriminate between low- and high-risk patients in a long-term follow-up. The ABCD2 score did not predict subsequent stroke accurately at any time point. Since there is 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. Clinical Trial Registration. This trial is registered with NCT02038725 (retrospectively registered, January 16, 2014).

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.