Incidence of stroke, systemic embolism and bleeding events in patients without anticoagulation based on real-world data in Japan: a retrospective cohort study.

OBJECTIVES: To examine the incidence of stroke or systemic embolic events (SSEs) and bleeding events in untreated patients with non-valvular atrial fibrillation (NVAF) after widespread use of direct oral anticoagulant agents (DOACs). DESIGN: Multicentre, non-interventional, observational, retrospective cohort study using real-world data in Japan (2016-2018). SETTING: The Mie, Musashino University study of NVAF, which used the Mie-Life Innovation Promotion Center Database. This is a regional clinical database involving one university hospital and eight general hospitals in Mie Prefecture in Japan. PARTICIPANTS: Japanese patients with NVAF (n=7001). PRIMARY AND SECONDARY OUTCOME: The incidence of SSEs and bleeding events. RESULTS: A total of 7001 patients with NAVF were registered, and 53.0% were treated with DOACs, 10.6% were treated with warfarin and 36.4% had no treatment. Additionally, 29.5% of patients with a CHADS2 (congestive heart failure, hypertension, age≥75 years, diabetes, previous stroke or transient ischemic attack) score of 3-6 were untreated. In the no treatment group, the SSE rates by the CHADS2 score (0, 1, 2 and 3-6) were 1.4%, 1.4%, 3.2% and 8.0%, respectively. The rates of bleeding events by the CHADS2 score (0, 1, 2 and 3-6) in the no treatment group were 0.7%, 1.0%, 1.2% and 2.9%, respectively. A multivariate analysis of SSEs in components of the CHADS2 showed that the adjusted HRs were 2.32 for heart failure, 1.66 for an age ≥75 years, 1.81 for diabetes mellitus and 5.84 for prior stroke or transient ischaemic attack. CONCLUSIONS: Approximately one-third of the patients do not receive any anticoagulation in the modern DOAC era in Japan. The SSE rate increases by the CHADS2 score. The SSE rate is low in patients with a CHADS2 score <1, supporting no indication of anticoagulation in current guidelines. In patients with a CHADS2 score >1, the use of anticoagulant drug therapy is recommended because of a higher risk of stroke.

Analysis of drug adverse events in elderly patients based on the Japanese Adverse Drug Event Report Database.

WHAT IS KNOWN AND OBJECTIVE: Compared with the general adult population, pharmacokinetics and changes in drug responsiveness occur to a greater extent in the elderly. Interactions may occur between drugs used in combination to treat various diseases and may cause adverse events (AEs). We conducted a cross-sectional risk assessment of AEs in elderly patients based on information gathered from Japanese medical practices with the goal of obtaining information that will contribute to optimizing pharmacotherapy. METHODS: The Japanese Adverse Drug Event Report database was used to determine the incidence of AEs in elderly patients (aged 80 years or older) compared with patients aged less than 80 years old by evaluating the reporting odds ratio using the data obtained from reports. RESULTS AND DISCUSSION: Hypnotics and anxiolytics, as well as anticoagulants and theophylline, were identified as groups of drugs that warrant special attention in the elderly. Hypnotics and anxiolytics, especially those that are short-acting, tend to cause delirium and geriatric syndromes including falls and fractures. With respect to anticoagulants, no increase in the risk of bleeding was evident and the dose was believed to be properly adjusted; however, there was an increased risk of anemia. Theophylline toxicity tended to occur more frequently in the elderly, suggesting the need for drug monitoring. WHAT IS NEW AND CONCLUSION: Based on these cross-sectional studies, the evaluation of the risk of AEs for drugs commonly used in the elderly based on near real-world information was achieved.