Few recent large-scale studies have evaluated the risks and benefits of continuing oral anticoagulant (OAC) therapy after catheter ablation (CA) for atrial fibrillation (AF). This study evaluated the status of continuation of OAC therapy and the association between continuation of OAC therapy and thromboembolic and bleeding events according to the CHADS₂ score. This retrospective study included data from the Japanese nationwide administrative claims database of patients who underwent CA for AF between April 2014 and March 2021. Patients without AF recurrence assessed by administrative data of the treatment modalities were divided into two groups according to continuation of OAC therapy 6 months after the index CA. The primary outcomes were thromboembolism and major bleeding after a landmark period of 6 months. After inverse probability of treatment weighting analysis, the association between OAC continuation and outcomes was determined according to the CHADS₂ score. Among 231 374 patients included, 69.7%, 21.6%, and 8.7% had CHADS₂ scores of ≤1, 2, and ≥3, respectively. Of these, 71% continued OAC therapy at 6 months. The OAC continuation rate was higher in the high CHADS₂ score group than that in the low CHADS₂ score group. Among all patients, 2451 patients (0.55 per 100 person-years) had thromboembolism and 2367 (0.53 per 100 person-years) had major bleeding. In the CHADS₂ score ≤1 group, the hazard ratio of the continued OAC group was 0.86 [95% confidence interval (CI): 0.74–1.01, P = .06] for thromboembolism and was 1.51 (95% CI: 1.27–1.80, P < .001) for major bleeding. In the CHADS₂ score ≥3 group, the hazard ratio of the continued OAC group was 0.61 (95% CI: 0.46–0.82, P = .001) for thromboembolism and was 1.05 (95% CI: 0.71–1.56, P = 0.81) for major bleeding. This observational study suggests that the benefits and risks of continuing OAC therapy after CA for AF differ based on the patient’s CHADS₂ score. The risk of major bleeding due to OAC continuation seems to outweigh the risk reduction of thromboembolism in patients with lower thromboembolic risk. Status of the continuation of OAC therapy and the association between the continuation of OAC therapy and thromboembolic and bleeding events according to the CHADS₂ score. AF, atrial fibrillation; CA, catheter ablation; HR, hazard ratio; OAC, oral anticoagulant.

Aims/Introduction: The purpose of the present study was to quantify errors in the diagnosis of diabetes for use in the national database, using a sufficient population size.Materials and methods: A claims database constructed by the JMDC (Tokyo, Japan), using standardized disease classifications and anonymous record linkage, was used in this validation study. We included patients with health insurance claims data from April 2005 to March 2019 in the JMDC claims database. We excluded patients without a record of specific health checkups in Japan. Sample size calculation was based on a 5% prevalence of diabetes and 0.4% absolute accuracy (i.e., 1,250,000 individuals), to calculate the sensitivity, specificity, positive predictive value and negative predictive value.Results: In total, 2,999,152 patients were included in this study, of which 165,515 were classified as having diabetes based on specific health checkups (validation cohort prevalence of 5.5%). The newly devised algorithm had three elements – the diagnosis‐related codes for diabetes without suspected flag, the medication codes for diabetes and then these two codes on the same record – and yielded a sensitivity of 74.6%, positive predictive value of 88.4% and Kappa Index of 0.80 (the highest values).Conclusions: In future claims database studies, our validated algorithms will be useful as diagnostic criteria for diabetes.

Aims/Introduction: Although the epidemiological relationship between hypoglycemia and increased risk of acute coronary syndrome (ACS) has been well established, the time period for increased risk of ACS after a severe hypoglycemic episode remains unknown. The present study aimed to determine the ACS risk after a severe hypoglycemic episode.Materials and Methods: We carried out a retrospective population‐based cohort study based on national claims data in Japan. We retrieved data of diabetes patients aged ≥35 years collected from April 2014 to March 2016. The absolute risk of ACS was defined as the occurrence of an emergency percutaneous coronary intervention after a severe hypoglycemic episode.Results: In total, data of 7,909,626 patients were included in the analysis. The absolute risk of ACS was 2.9 out of 1,000 person‐years in all patients. ACS risk in patients with severe hypoglycemic episodes was 3.0 out of 1,000 person‐years. Severe hypoglycemic episodes increased the absolute risk of ACS in patients aged ≥70 years, but not in patients aged <70 years. The absolute risk of ACS was 10.6 out of 1,000 person‐years within 10 days of a severe hypoglycemic episode. There was a significant trend between shorter duration after an episode and higher ACS risk.Conclusions: Severe hypoglycemia was associated with an increased risk of ACS in elderly diabetes patients. ACS risk increased with a shorter period after a severe hypoglycemic episode, suggesting that severe hypoglycemia leads to an increased risk of ACS in diabetes patients. These findings show that it is important to avoid severe hypoglycemia while treating diabetes, particularly in elderly patients.

Aim/Introduction: Although immune checkpoint inhibitor‐related type 1 diabetes mellitus (ICI‐T1DM) is a rare condition, it is of significant concern globally. We aimed to elucidate the precise incidence, risk factors, and impact of ICI‐T1DM on survival outcomes.Materials and Methods: The study is a large retrospective cohort study, performed using the DeSC Japanese administrative claims database comprising 11 million patients. The database population is reportedly similar to the entire population of Japan. Patients administered ICI between 2014 and 2022 were enrolled in the study, including 21,121 patients. The risk factors for ICI‐T1DM development and their characteristics were evaluated by logistic regression analysis. Development of a new irAE after the day following the first administration of ICI was set as the study outcome.Results: ICI‐T1DM was observed in 102 (0.48%) of the 21,121 patients after ICI initiation. PD‐(L)1 and CTLA‐4 combination therapy was associated with an increased risk of ICI‐T1DM compared with PD‐1 monotherapy (odds ratio [OR], 2.36; 95% confidence interval [CI], 1.21–4.58; P = 0.01). Patients with a prior diagnosis of diabetes mellitus (OR, 1.59; 95% CI, 1.03–2.46; P = 0.04) or hypothyroidism (OR, 2.48; 95% CI, 1.39–4.43; P < 0.01) also exhibited an increased risk of ICI‐T1DM. The Kaplan–Meier analysis revealed that patients with ICI‐T1DM showed higher survival rates than those without (log‐lank test, P < 0.01). Multivariable Cox regression analysis demonstrated that ICI‐T1DM development was associated with lower mortality (hazard ratio, 0.60; 95% CI, 0.37–0.99; P = 0.04).Conclusions: Collectively, the results of this study demonstrate the precise incidence and risk factors of ICI‐T1DM. The development of ICI‐T1DM, like other irAEs, is associated with higher survival rates.

Aim: This study aimed to determine whether there is an association between influenza and new‐onset type 1 diabetes.Materials and methods: This population‐based retrospective cohort study used data from the National Database of Health Insurance Claims and Specific Health Check‐ups of Japan. Influenza was defined based on drug prescriptions and the onset of type 1 diabetes was defined using specific medical codes indicating a diagnosis of type 1 diabetes. The incidence rate ratio of new‐onset type 1 diabetes within 180 days after an influenza diagnosis was calculated and it was compared with that at other times using Poisson regression and generalized estimating equations. Sensitivity analyses were performed to confirm the robustness of this finding.Results: The data of 10,400 patients with new‐onset type 1 diabetes were analyzed, including 2,196 (952 male 1,244 female) patients diagnosed with influenza between 1 September 2014 and 31 August 2017. Although only patients with type 1 diabetes were included, adjusted analysis showed that individuals had a 1.3‐fold (95% confidence interval: 1.15–1.46) higher risk of developing type 1 diabetes in the first 180 days after influenza diagnosis than that at other times.Conclusions: In this Japanese population‐based cohort, the risk of new‐onset type 1 diabetes may increase after the diagnosis of influenza. These results, which must be confirmed in other populations, suggest that influenza may be a causal factor for new‐onset type 1 diabetes. The molecular mechanisms underlying the potential etiological relationship between influenza and type 1 diabetes should be elucidated.