Gastrointestinal Bleeding From Oral Anticoagulant Therapy Among Japanese Patients With Atrial Fibrillation Identified From the SAKURA Atrial Fibrillation Registry.

BACKGROUND: In the Japanese clinical setting, the prevalence, potential cofounders of gastrointestinal (GI) bleeding from anticoagulant therapy, including direct oral anticoagulants (DOACs) and warfarin, and prognosis after GI bleeding are unclear.Methods and Results:We examined about GI bleeding from anticoagulant therapy using data from the SAKURA AF Registry, a prospective multicenter registry in Japan. Among 3,237 enrollees, 48.8% (n=1,561) were warfarin users and 51.2% (n=1,676) DOAC users. GI bleeding was identified in 68 patients (2.1%). No incidental differences in GI bleeding were observed between the DOAC and warfarin users (32 [1.9%] patients [0.67 events per 100 person-years] vs. 36 [2.3%] patients [0.75 events per 100 person-years], respectively; P=0.43). Multivariate Cox proportional hazard model analysis revealed that creatinine (hazard ratio [HR] 1.379, 95% confidence interval [CI] 1.091-1.743 P=0.007) and hemoglobin (HR 0.814, 95% CI 0.705-0.941, P=0.005) remained independent determinants of GI bleeding. Patients experiencing GI bleeding events had a higher risk of all-cause death (18%) than those without GI bleeding (6%) (P=0.045). CONCLUSIONS: GI bleeding was strongly associated with anemia and renal impairment. Patients experiencing GI bleeding had higher risk for all-cause death than those without GI bleeding.

Prognostic Value of Serum N-Terminal Pro-Brain Natriuretic Peptide Level over Heart Failure for Stroke Events and Deaths in Patients with Atrial Fibrillation.

Atrial fibrillation (AF) and heart failure (HF) often coexist. The aims of this study were to explore the factors associated with the serum levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), and the association between prognosis and a history of HF or the serum NT-proBNP level in Japanese patients with AF.The present sub-study was based on the SAKURA AF Registry, a Japanese multicenter observational registry that included 3267 AF patients (median follow-up period: 39 months). All the patients were receiving warfarin or any of four direct oral anticoagulants. Serum NT-proBNP levels were available for 2417 patients, and the median value was 508 (interquartile range 202-1095) pg/mL at the time of enrollment. Log NT-proBNP was associated with non-paroxysmal AF, creatinine clearance > 60 mL/minute, history of HF and ischemic heart disease, antiarrhythmic drug use, anemia, being elderly female, and history of AF ablation. The relative risk of adverse clinical events, except major bleeding, was significantly higher in the highest NT-proBNP quartile as compared to the lowest quartile (adjusted hazard ratios: 2.87 for death, 2.39 for stroke), but a history of HF was associated only with a higher incidence of all-cause death.Concomitant HF was associated with a higher mortality, but the high NT-proBNP was associated with higher mortality and stroke events. In Japanese AF patients receiving anticoagulant treatment, high serum NT-proBNP levels predict the risk for both stroke events and deaths, and intensive follow-up is needed in such patients.

Clinical Outcomes of Off-Label Dosing of Direct Oral Anticoagulant Therapy Among Japanese Patients With Atrial Fibrillation Identified From the SAKURA AF Registry.

BACKGROUND: Off-label dosing of direct oral anticoagulants (DOACs) is encountered clinically among patients with atrial fibrillation (AF), although data on the clinical outcomes of over- and under-dosing are lacking in Japan. Methods and Results: We examined the clinical outcomes of off-label DOAC dosing using the SAKURA AF Registry, a prospective multicenter registry in Japan. Among 3,237 enrollees, 1,676 under any of the 4 DOAC regimens were followed up for a median of 39.3 months: 746 (45.0%), appropriate standard-dose; 477 (28.7%), appropriate low-dose; 66 (4.0%), over-dose; and 369 (22.2%) under-dose. Compared with the standard-dose group, patients in the under- and over-dose groups were significantly older and had a higher stroke risk. After multivariate adjustment, stroke/systemic embolism (SE) and death events were equivalent between the standard- and under-dose groups, but major bleeding events tended to be lower in the under-dose group (hazard ratio [HR] 0.474, P=0.0739). Composite events (stroke/SE, major bleeding, or death) were higher in the over-dose than in the standard-dose group (HR 2.714, P=0.0081). CONCLUSIONS: Clinical outcomes were not worse for under-dose than for standard-dose users among patients with different backgrounds. Over-dose users, however, were at higher risk for all clinical events and required careful follow-up. Further studies are needed to clarify the safety and effectiveness of off-label DOAC dosing in Japan.

Oral anticoagulant use and clinical outcomes in elderly Japanese patients: findings from the SAKURA AF Registry.

Direct-acting oral anticoagulants (DOACs) are widely used in aged Japanese patients with atrial fibrillation (AF), but outcome data for such patients are limited. We compared outcomes between 1895 (58.5%) patients aged < 75 years (non-elderly), 1078 (33.3%) 75-84 years (elderly) and 264 (8.2%) ≥ 85 years (very elderly) enrolled in a prospective multicenter registry. Kaplan-Meier analysis (median follow-up: 39.3 months) revealed a significantly high incidence of stroke/systemic embolism (SE) among the very elderly relative to that among the non-elderly or elderly (3.2 vs. 1.2 and 1.5 events per 100 patient-years, p < 0.001). Major bleeding in the non-elderly group was significantly infrequent relative to that among the elderly or very elderly group (1.1 vs. 1.6 vs. 1.8 events, p = 0.033). After multivariate adjustment, the stroke/SE incidence was comparable between DOAC and warfarin users, regardless of age, but major bleeding decreased significantly among very elderly DOAC users (adjusted HR 0.220, 95% CI 0.042-0.920). The greater increasing incidence of stroke/SE than major bleeding as patients age suggests that stroke prevention should outweigh the bleeding risk when anticoagulants are being considered for aged patients. Our data indicated that DOACs can be a therapeutic option for stroke prevention in very elderly patients.

Three-Year Clinical Outcomes Associated With Warfarin vs. Direct Oral Anticoagulant Use Among Japanese Patients With Atrial Fibrillation　- Findings From the SAKURA AF Registry.

BACKGROUND: Although direct oral anticoagulants (DOACs) are widely used in Japanese patients with atrial fibrillation (AF), large-scale investigations into their use, with suitable follow-up times and rates, are lacking. Methods and Results: The SAKURA AF Registry is a prospective multicenter registry created to investigate therapeutic outcomes of oral anticoagulant (OAC) use in Japanese AF patients. We conducted a study involving 3,237 enrollees from 63 institutions in the Tokyo area being treated with any of 4 DOACs (n=1,676) or warfarin (n=1,561) and followed-up for a median of 39.3 months (range 28.5-43.6 months). Analyses of 1- and 2-year follow-up data available for 3,157 (97.5%) and 2,952 (91.2%) patients, respectively, showed no significant differences in rates of stroke or systemic embolism (SE), major bleeding, and all-cause mortality for DOAC vs. warfarin users (1.2 vs. 1.8%/year, 0.5 vs. 1.2%/year, and 2.1 vs. 1.7%/year, respectively). Under propensity score matching, the incidence of stroke or SE (P=0.679) and all-cause death (P=0.864) remained equivalent, but the incidence of major bleeding was significantly lower (P=0.014) among DOAC than warfarin users. CONCLUSIONS: A high follow-up rate allowed us to obtain reliable data on the status of OAC use and therapeutic outcomes among AF patients in Japan. Warfarin and DOACs appear to yield equivalent 3-year stroke and all-cause mortality rates, but DOACs appear to reduce the risk of major bleeding.

Low alanine aminotransferase levels are independently associated with mortality risk in patients with atrial fibrillation.

Extremely low alanine aminotransferase (ALT) may reflect aging, frailty, sarcopenia, and malnutrition in several cardiovascular diseases, but the association between low ALT and patient characteristics, cardiovascular and all-cause mortality is not well investigated in the population with atrial fibrillation. We conducted a post hoc analysis of a prospective, observational multicenter study. Patients with nonvalvular AF in the SAKURA AF Registry (n = 3156) were classified into 3 tertiles according to baseline ALT: first (ALT ≤ 15 U/L, n = 1098), second (15 < ALT < 23 U/L, n = 1055), and third (ALT ≥ 23 U/L, n = 1003). The first tertile had an older age; lower body mass index (BMI); higher prevalence of heart failure; and lower hemoglobin, total cholesterol, and triglycerides (all P < 0.05). During median 39.2 months follow-up, the first tertile had significantly higher incidences of cardiovascular and all-cause mortality (log-rank P < 0.001). Lower ALT was significantly associated with the incidence of cardiovascular and all-cause mortality, even after adjusting for clinically relevant factors (P < 0.05). Low ALT may reflect aging, sarcopenia, and malnutrition and be independently associated with a high risk of all-cause mortality in patients with AF.

University hospitals, general hospitals, private clinics: Place-based differences in patient characteristics and outcomes of AF-A SAKURA AF Registry Substudy.

BACKGROUND: Relations between characteristics and outcomes of patients in Japan with atrial fibrillation (AF) and the type of medical facility providing their outpatient care are unclear. METHODS AND RESULTS: We compared patient characteristics and outcomes between 2 university hospitals (n=1178), 20 general hospitals (n=1308), and 41 private clinics (n=751) (follow-up: 39.3 months) in the prospective SAKURA AF Registry. Private clinic patients were significantly older than university hospital and general hospital patients (73.4±9.2 vs. 70.3±9.8 and 72.6±8.9 years; p<0.001), and these patients' CHADS2 scores were significantly lower than general hospital, but higher than university hospital patients (1.8±1.1 vs. 2.0±1.2 and 1.6±1.1; p<0.001). The Kaplan-Meier incidences of stroke/systemic embolism (SE) (1.72 vs. 1.58 vs. 0.84 events per 100 patient-years; p=0.120), a cardiovascular event (4.09 vs. 2.44 vs. 1.40; p<0.001), and death were higher (2.39 vs. 2.21 vs. 1.24; p=0.015) for university and general hospital patients than for private clinic patients; the incidences of major bleeding were equivalent (1.78 vs. 1.33 vs. 1.16; p=0.273). After multivariate adjustments, this trend persisted. CONCLUSIONS: Adverse clinical events at small to large hospitals appear to be higher than those at private clinics, suggesting that careful attention for preventing stroke/SE and cardiovascular events should be paid to patients at a university or general hospital.

Impact of the Fibrosis-4 Index on Risk Stratification of Cardiovascular Events and Mortality in Patients with Atrial Fibrillation: Findings from a Japanese Multicenter Registry.

BACKGROUND: Liver diseases drive the development and progression of atrial fibrillation (AF). The Fibrosis-4 (FIB4) index is a non-invasive scoring method for detecting liver fibrosis, but the prognostic impact of using it for AF patients is still unknown. Herein, we evaluated using the FIB4 index as a risk assessment tool for cardiovascular events and mortality in patients with AF. METHODS: We performed a post-hoc analysis of a prospective, observational multicenter study. A total of 3067 patients enrolled in a multicenter Japanese registry were grouped as first tertile (FIB4 index < 1.75, n = 1022), second tertile (1.75 ≤ FIB4 index < 2.51, n = 1022), and third tertile (FIB4 index ≥ 2.51, n = 1023). RESULTS: The third tertile had statistically significant results: older age, lower body mass index, increased heart failure prevalence, and lower clearances of hemoglobin and creatinine (all p < 0.05). During the follow-up period, incidences of major bleeding, cardiovascular events, and all-cause mortality were significantly higher for the third tertile (all p < 0.05). After multivariate adjustment, the third tertile associated independently with cardiovascular events (HR 1.72; 95% CI 1.31-2.25) and all-cause mortality (HR 1.43; 95% CI 1.06-1.95). Adding the FIB4 index to a baseline model with CHA2DS2-VASc score improved the prediction of cardiovascular events and all-cause mortality, as shown by the significant increase in the C-statistic (all p < 0.05), net reclassification improvement (all p < 0.001), and integrated discrimination improvement (all p < 0.001). A FIB4 index ≥ 2.51 most strongly associated with cardiovascular events and all-cause mortality in AF patients with high CHADS2 scores (all p < 0.001). CONCLUSIONS: The FIB4 index is independently associated with risks of cardiovascular events and all-cause mortality in AF patients.

Relationship between the Renal Function and Adverse Clinical Events in Patients with Atrial Fibrillation: A Japanese Multicenter Registry Substudy.

BACKGROUND: Atrial fibrillation (AF) and chronic kidney disease (CKD) often coexist, but the real-world data after approval of direct oral anticoagulants (DOACs) are still lacking in Japan. We investigated the association of the baseline renal function and adverse clinical events and risk of adverse clinical events with DOACs compared to warfarin for each renal functional level in Japanese AF patients. METHODS: The present substudy was based on the SAKURA AF Registry, a Japanese multicenter observational registry (median follow-up period: 39 months). The creatinine clearance (CrCl) values were estimated by the Cockcroft-Gault formula, and divided into normal renal function, and mild and moderate-severe CKD (CrCl ≥ 80, 50-79, <50 mL/min). RESULTS: In the SAKURA AF Registry, the baseline CrCl data were available for 3242 patients (52% for DOAC and 48% for warfarin user). The relative risk of adverse clinical events was significantly higher in the patients with a CrCl < 50 mL/min as compared to those with a CrCl ≥ 80 mL/min (adjusted HRs: 2.53 for death, 2.53 for cardiovascular [CV] events, 2.13 for strokes, and 1.83 for major bleeding). Risks of all adverse clinical events were statistically even between DOAC and warfarin users for each renal function level. CONCLUSION: Moderate-severe CKD was associated with a higher mortality, CV events, strokes, and major bleeding than normal renal function. The safety and effectiveness of DOACs over warfarin were similar for each renal function level. By a worsening renal function, the incidence of adverse clinical events increased, especially deaths and CV events as compared to strokes and major bleeding.

Different determinants of vascular and nonvascular deaths in patients with atrial fibrillation: A SAKURA AF Registry substudy.

BACKGROUND: The incidence and causes of death among patients in Japan treated for atrial fibrillation (AF), a major determinant of strokes and death, with direct oral anticoagulants (DOACs) are unclear. This study's aim was two-fold: to compare the incidence and causes of death between DOAC and warfarin users in Japan and to identify the factors associated with vascular and nonvascular death in the Japanese AF population. METHODS: The study was based on the SAKURA AF registry, in which clinical events were tracked in 3267 enrollees from 63 institutions for 2-4 years. Enrollees included warfarin users (n=1577) and users of any of 4 DOACs (n=1690). The incidence, cause, and major determinants of death were analyzed. RESULTS: During a median 39.3-month follow-up, 200 patients died, with most succumbing to cardiac death (25%), malignancies (21%), or respiratory infections (20%). There was no significant difference in deaths from any cause between warfarin and DOAC users (108 vs. 92 patients, p=0.34). An age ≥75 years was found to be a major determinant of death, but the relative risk (vs. <75 years) was greater for nonvascular death (hazard ratio: 2.85 and 4.97 for age 75-84 and ≥85 years, respectively) than vascular death (2.14 and 2.98 for 75-84 and ≥85 years, respectively). Heart failure, renal dysfunction, and the type of institution were major determinants of vascular death, and a male sex, weight <50kg, and anemia were major determinants of nonvascular death. CONCLUSIONS: The results of our AF registry-based study, in which two thirds of the enrolled patients succumbed to cardiac death, malignancies, or respiratory infections within 2- 4 years and use of DOACs rather than warfarin did not reduce the mortality, indicated that a management of AF that includes prophylaxis for vascular and nonvascular events in addition to strokes is warranted.

Worsening renal function, adverse clinical events and major determinants for changes of renal function in patients with atrial fibrillation: a Japanese multicenter registry substudy.

Objective: To explore factors related to changing renal function and the prognostic effect of worsening renal function in patients with atrial fibrillation (AF). Methods: The present substudy was based on the SAKURA AF Registry, a Japanese multicenter prospective observational registry that includes 3267 AF patients from 63 institutions in the Tokyo area. Worsening renal function was defined as an estimated glomerular filtration rate (eGFR) decrease equaling more than 20% of the patient's baseline eGFR. Results: During a median 39.3 month follow-up period, patients' eGFR decreased annually by a mean value of 1.07 mL/min/1.73 m2. Multivariable analysis showed that age ≥75 years, body weight ≤50 kg, a history of heart failure and initially preserved renal function (creatinine clearance [CrCl] ≥ 60 mL/min) were significantly associated with a decrease in eGFR, whereas a history of AF ablation was associated with a maintain in eGFR. The 194 patients with worsening renal function were at significantly increased risk of death, stroke and major bleeding (adjusted hazard ratios [HRs]: 2.06, 1.97 and 2.23, respectively). Conclusion: Age ≥75 years, body weight ≤50 kg, a history of heart failure and initially preserved renal function appear to promote renal dysfunction in patients with AF, but a history of AF ablation seems to have a favorable effect. Worsening renal function seems to increase AF patients' risk of adverse clinical events. Renal function can decline quickly; thus, early intervention including AF ablation is warranted.

Adverse clinical events in Japanese atrial fibrillation patients with and without coronary artery disease-findings from the SAKURA AF Registry.

Background: Although atrial fibrillation (AF) and coronary artery disease (CAD) are increasing in prevalence in Japan, real-world data regarding clinical outcomes in Japanese AF patients with CAD are limited.Methods: The SAKURA AF Registry is a prospective multi-center registry created to investigate outcomes of oral anticoagulant (OAC) use in Japanese AF patients. A study was conducted involving 3237 enrollees from 63 Tokyo-area institutions who were followed up for a median of 39.3 months. Clinical adverse events were compared between the patients accompanied with (n = 312) and without CAD (n = 2925).Results: The incidence of cardiovascular events and all-cause mortality rates were significantly higher among patients with CAD than among those without CAD (5.98 vs 2.52 events per 100 patient-years, respectively, p < 0.001; 3.27 vs 1.94 deaths per 100 patient-years, respectively, p = 0.012), but there was no difference in strokes/transient ischemic attacks or systemic embolisms (1.70 vs 1.34). After a multivariate adjustment, CAD remained a risk factor for cardiovascular events (hazard ratio [HR] = 1.57, 95% confidence interval [CI] = 1.08-2.25, p = 0.018). Among CAD patients, the propensity score-adjusted risk for major bleeding was significantly decreased among direct oral anticoagulant (DOAC) users in comparison to that among warfarin users (HR = 0.29, 95% CI = 0.07-0.94, p = 0.04), but other adverse clinical events did not differ significantly between these two groups.Conclusions: CAD did not appear to be a major determinant of strokes/TIAs, major bleeding, or all-cause mortality, but appeared to increase the risk of cardiovascular events in Japanese AF patients. The risk of major bleeding in CAD patients appeared to decrease when a DOAC rather than warfarin was administered. The data suggested that patients with AF and concomitant CAD require careful management and follow-up to reduce cardiovascular risks, and DOACs may be a better choice over warfarin when considering the risk of major bleeding.

Deposition of 137Cs in Rokkasho, Japan and its relation to Asian dust.

Biweekly atmospheric depositions of (137)Cs were measured in Rokkasho, Aomori, Japan from March 2000 to March 2006 to study recent (137)Cs deposition. Although the deposition level was generally lower than the detectable limit, deposition samples collected in spring occasionally had measurable levels of (137)Cs. The annual (137)Cs deposition from 2001 to 2005 was 0.04-0.69 Bq m(-2) with a mean value of 0.27 Bq m(-2). Depositions of insoluble Al, Fe and Ti were strongly correlated with the (137)Cs deposition, suggesting that suspension of soil particles was the main source of the recent (137)Cs deposition. Asian dust events were coincident with some of the significant (137)Cs depositions in spring. It was found that the ratios of (137)Cs/Al and Fe/Al could be used as indices for discriminating Asian dust from suspension of the local surface soil. Backward trajectory analysis suggested southern Mongolian and northeastern China regions as sources of the significant (137)Cs depositions.

Current use of direct oral anticoagulants for atrial fibrillation in Japan: Findings from the SAKURA AF Registry.

BACKGROUND: Large-scale investigations on the use of oral anticoagulants including direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF) have not included Japanese patients. METHODS: We established the multicenter SAKURA AF Registry to support prospective observational research on the status of anticoagulation treatment, especially with DOAC, for AF in Japan. We enrolled 3266 AF patients treated with warfarin (n=1577) or any of 4 DOACs (n=1689) from 63 institutions (2 cardiovascular centers, 13 affiliated hospitals or community hospitals, and 48 private clinics) in the Tokyo area. RESULTS: We conducted our first analysis of the registry data, and although we found equivalent mean age between the DOAC and warfarin users (71.8±9.5 vs. 72.3±9.4 years, p=0.2117), we found a slightly lower risk of stroke (CHADS2 score of 0 or 1 [46.9% vs. 39.4%, p<0.0001]) and significantly better creatinine clearance in DOAC users (70.4±27 vs. 65.6±25.7 mL/min, p<0.0001). Importantly, we documented under-dosing in 32% of warfarin users and inappropriate-low-dosing in 19.7-27.6% of DOAC users. CONCLUSIONS: Our initial analysis of the SAKURA AF Registry data clarified the real-world use of anticoagulants, which includes DOACs and warfarin in Japan. The DOAC users were at a lower risk for stroke than the warfarin users. In 20-30% of DOAC users, the dose was inappropriately reduced.

Environmental gamma-ray dose rate in Aomori Prefecture, Japan.

Japan's first commercial nuclear fuel cycling facilities, including a spent nuclear fuel reprocessing plant, are now under construction in Rokkasho, Aomori Prefecture (prefecture--an area of administration similar to a county in the U.S.). The reprocessing plant is due to be completed by 2004. We surveyed indoor and outdoor environmental gamma-ray dose rates throughout Aomori Prefecture from 1992 to 1996 to get background data before operation of the plant. Glass dosimeters were used to measure cumulative gamma-ray dose rate. The outdoor gamma-ray dose rates were measured at 109 locations in the prefecture. The indoor gamma-ray dose rates were measured at 81 locations, which were generally in a dwelling near the location of an outdoor measurement. The contribution of radionuclides in the ground to the outdoor dose rate was estimated by using in-situ gamma-ray spectrometry with a germanium detector. The spectra were measured at 20 locations used for the glass dosimeter measurements. The outdoor gamma-ray dose rate was higher in the Tsugaru area (western part of the prefecture) than in the Nanbu area (eastern part). Means of the dose rate were 28, 31, and 25 nGy h(-1) for the whole prefecture and Tsugaru and Nanbu areas, respectively. The dose rates in winter were lower than those in the other seasons due to the shielding effect of snow on the ground. Mean contributions of uranium series, thorium series and 40K to the dose rates were 7.7, 8.2, and 9.3 nGy h(-1), respectively. The indoor dose rate was generally higher than the outdoor one, and the mean ratio of indoor to outdoor dose rates was 1.42. Means of indoor gamma-ray dose rate were 41, 37, and 43 nGy h(-1) for the whole prefecture and Tsugaru and Nanbu areas, respectively. The average effective dose rate to people in the prefecture was estimated to be 0.24 mSv y(-1).

Inventories of 239+240Pu, 137Cs, and excess 210Pb in sediments from freshwater and brackish lakes in Rokkasho, Japan, adjacent to a spent nuclear fuel reprocessing plant.

We investigated the vertical profiles of (239+240)Pu, (137)Cs, and excess (210)Pb ((210)Pb(ex)) in sediment core samples obtained from two freshwater lakes and two brackish lakes situated near the first commercial spent nuclear fuel reprocessing plant in Rokkasho, Japan, before the final test of the plant using actual spent nuclear fuel. The inventory of (239+240)Pu in those lakes was larger than that in soil in Rokkasho, which indicated the inflow of (239+240)Pu from the catchment area in addition to direct deposition on the lake surfaces. The (137)Cs inventory in sediments of the brackish lakes was lower than that in the soil, which showed that part of the (137)Cs was removed from the sediments by the brackish water or that it was not deposited into the sediments, because of the high solubility of Cs in brackish water. The (137)Cs inventory in sediments of the freshwater lakes was higher than that of the brackish lakes, and comparable with that in soil except for one core sample out of four. The (239+240)Pu/(137)Cs ratio in freshwater lake sediments was higher than that in soil, and that indicated that part of the (137)Cs was lost from the sediments. The low inventory of (137)Cs may be attributable to competition for absorption sites in sediments with ammonium ions formed in the reducing environment which occurs from summer to fall in the sediments. Those data will be used as background data on the artificial radionuclides in the lakes to assess the effect of released radionuclides on their concentrations.