Association of beta blocker use with new-onset heart failure and mortality in atrial fibrillation without pre-existing heart failure: the Fushimi AF registry

Background

Heart failure (HF) is one of the major complications in atrial fibrillation (AF). We previously reported that not a few AF patients without pre-existing HF (defined as prior HF hospitalization, New York Heart Association functional class≥2, or left ventricular ejection fraction (LVEF)<40%) subsequently developed new-onset HF. Beta blockers are the established therapy for HF, but it remains unclear whether beta blockers prevent new-onset HF and improve outcomes in AF patients without preexisting HF.

Methods

In the Fushimi AF registry, 778 of 3,262 patients without pre-existing HF were receiving beta blockers at baseline. We investigated the incidence of new-onset HF defined as cardiac death or HF hospitalization, and all-cause death in a propensity-matched cohort (N=1,198; mean age, 71 years; 39% female; mean LVEF, 66%). Additionally, annual follow-up prescription data before the onset of events were collected in 294 of patients with beta blockers and 395 of those without beta blockers. We also investigated the association of starting or stopping beta blockers with the incidence of new-onset HF and all-cause death.

Results

During the median follow-up of 5.8 years, new-onset HF and all-cause death occurred in 77 (12.9%) and 118 (19.7%) of patients with beta blockers, and 70 (11.7%) and 131 (21.9%) of those without beta blockers, respectively. Incidence of new-onset HF was comparable between patients with and without beta blockers (Figure 1), and incidence of all-cause death was also comparable between the two groups (Figure 2). In exploratory subgroup analyses, there was no interaction in the association of beta blockers with the incidence of events, except for pulse rate for new-onset HF and left atrial size for all-cause death. Hazard ratio of beta blockers for new-onset HF tended to be lower in patients with higher pulse rates (>84 bpm) (Figure 1), and that for all-cause death was lower in those without left atrial enlargement (Figure 2). Of patients with follow-up prescription data, beta blockers were stopped in 55 (18.7%) and started in 97 (24.6%) patients, respectively. Patients with starting beta blockers had higher pulse rate (78.5±17.3 vs 74.9±13.9 bpm; p=0.03) and more symptomatic AF (58.8% vs 46.0%; p=0.03) compared to those without starting beta blockers, while there was no difference in baseline characteristics between those with and without stopping beta blockers. During the follow-up, the incidences of new-onset HF and all-cause death were also comparable between the patients with and without stopping beta blockers and those with and without starting beta blockers.

Conclusion

Beta blockers were not associated with the incidence of new-onset HF and all-cause death in AF patients without pre-existing HF. However, the exploratory subgroup analyses suggested the existence of subjects who may benefit from beta blockers.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Boehringer Ingelheim, Bayer Healthcare, Pfizer, Bristol-Myers Squibb, Astellas Pharma, AstraZeneca, Daiichi Sankyo, Novartis Pharma, MSD, Sanofi-Aventis, and Takeda Pharmaceutical.

Clinical characteristics and outcomes of atrial fibrillation patients with peripheral artery disease: the Fushimi AF Registry

Background

Atrial fibrillation (AF) represents the common arrhythmia and increases the risk of thromboembolism. Risk assessment for thromboembolism is important for the management of AF patients. Peripheral artery disease (PAD) is identified as a risk factor for thromboembolism in CHA2DS2-VASc score. However, there are little data on clinical characteristics and cardiovascular events of AF patients with PAD.

Purpose

In this study, we investigated the clinical characteristics and outcomes of AF patients with PAD.

Methods

The Fushimi AF Registry, a community-based prospective survey, was designed to enroll all of the AF patients who visited the participating medical institutions in Fushimi-ku, Kyoto, Japan. The inclusion criterion of the registry is the documentation of AF at 12-lead electrocardiogram or Holter monitoring at any time, and there are no exclusion criteria. We started to enroll patients from March 2011 and follow up data including prescription status were available in 4,464 patients from March 2011 to August 2021. Median follow-up period was 1,848 days.

Results

Of 4,464 patients, 183 patients had PAD (4.1%; PAD group). The mean age was higher in PAD group than no-PAD group (PAD group vs. no-PAD group: 76.7 vs. 73.5; p<0.01). Patients with PAD had more co-morbidities such as stroke, systemic embolism, congestive heart failure, hypertension, diabetes mellitus, dyslipidemia coronary artery disease and chronic kidney disease than those without PAD. Thus, CHADS2 score, CHA2DS2-VASc score and HAS-BLED score were higher in PAD group than no-PAD group (2.81 vs. 2.00; p<0.01, 5.17 vs. 3.30; p<0.01, 2.42 vs. 1.71; p<0.01, respectively). The proportion of patients with oral anticoagulant was similar between the two groups and the proportion of patients with antiplatelet drug was higher in PAD group than no-PAD group (59.0% vs. 55.6%; p=0.36, 62.9% vs. 24.7%; p<0.01, respectively). The incidences of all-cause death, cardiac death and myocardial infarction were higher in PAD group than no-PAD group (11.4 vs. 4.6 per 100 person-years; log-rank p<0.01, 1.7 vs. 0.8 per 100 person-years; log-rank p<0.01, 1.2 vs. 0.2 per 100 person-years; log-rank p<0.01). However, the incidence of stroke or systemic embolism was similar between the two groups (2.9 vs. 2.2 per 100 person-years, log-rank p=0.19). Finally, the incidence of composite of cardiac death, stroke, systemic embolism or myocardial infarction was higher in PAD group than no-PAD group (6.0 vs. 3.0 per 100 person-years; log-rank p<0.01).

Conclusion

AF patients with PAD had significantly higher risk for death and cardiac events, whereas the incidence of thromboembolism was similar between AF patients with and without PAD.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Japan Agency for Medical Research and Development

Association of cardiothoracic ratio with heart failure hospitalization in patients with atrial fibrillation: the Fushimi AF Registry

Background

Chest radiography is the most common diagnostic imaging test in clinical medicine, and the cardiothoracic ratio (CTR) is a readily available and non-invasive tool with which to assess the volume status and cardiomegaly. However, it remains unknown whether CTR on chest radiography is associated with the incidence of HF hospitalization in AF patients remains unclear.

Methods

The Fushimi AF Registry is a community-based prospective survey of AF patients in Fushimi-ku, Kyoto, Japan. The inclusion criterion of the registry is the documentation of AF at 12-lead electrocardiogram or Holter monitoring at any time, and there are no exclusion criteria. We started to enroll patients from March 2011, and follow-up data were available for 4,489 patients by the end of August 2021. In the present study, 3,727 patients with available data of CTR were examined. We divided the patients into two groups according to their CTR at baseline; Higher group (CTR ≥50.0%, n=2,696) and Lower group (CTR <50.0%, n=1,031), and compared the clinical background and outcomes between the two groups.

Results

The proportion of female was grater in Higher group, and the patients in Higher group were older. The patients in Higher group had higher prevalence of HF, hypertension and chronic kidney disease. During the median follow-up of 3,033 days, in Kaplan-Meier analysis, the incidence rates of HF hospitalization were higher in Higher group (Higher group: 2.5% per person-year vs. Lower group: 1.1%; p<0.01). Multivariate Cox proportional hazards regression analysis revealed that higher CTR (≥50.0%) was an independent determinant of the incidence of HF hospitalization. Furthermore, when we divided the patients into four groups based on the quartile of CTR; Q1 (CTR<49.0%), Q2 (49.0≤CTR<53.8%), Q3 (53.8≤CTR<59.0%), Q4 (59.0%≤CTR), the incidence of HF hospitalization was more frequent in patients with higher CTR, regardless of the presence or absence of prior hospitalization for HF (Figure).

Conclusion

In Japanese AF patients, patients with higher CTR had significantly higher incidence of HF hospitalization, regardless of the prevalence of prior hospitalization for HF.

Funding Acknowledgement

Type of funding sources: None.

Echocardiographic parameters of left atrial structure and function in elderly patients with atrial fibrillation, and clinical outcomes at 2 years: the ANAFIE echocardiographic substudy

Background

Previous studies have shown an association between echocardiographic parameters of cardiac structure and function and prognosis in patients with atrial fibrillation (AF). However, only limited data are available for elderly patients (age, ≥75 years).

Purpose

The All Nippon Atrial Fibrillation In the Elderly (ANAFIE) Registry (UMIN000024006) was a prospective, multicenter, observational study which collected real-world data on the clinical status and prognosis of 33,062 Japanese patients aged ≥75 years and with non-valvular AF (NVAF). A prospective substudy of 1,474 patients who underwent transthoracic echocardiography at baseline was conducted to investigate relations between echocardiographic parameters of left atrial structure and function and clinical outcomes at 2 years.

Methods

Cumulative incidences and adjusted hazard ratios (HRs) of clinical outcomes were calculated using Kaplan–Meier analysis and the Cox proportional-hazards model, respectively. The data were analysed by left atrial volume index (LAVi) category, left atrial emptying fraction (LAEF) category, and direct oral anticoagulant (DOAC) use vs warfarin (WF) use. Cardiovascular (CV) events was a composite of stroke, myocardial infarction (MI), cardiac interventions, heart failure (HF) hospitalization, CV death. Cardiac events was a composite of MI, cardiac intervention, HF hospitalization, and CV death.

Results

Baseline characteristics were mean age of 80.7 years; male, 59.2%; paroxysmal AF, 45.9%; mean CHA2DS2-VASc score, 4.3; mean HAS-BLED score, 1.9; median LAVi, 48.7 mL/m2; median LAEF, 26.6%; comorbidity or history of HF, 32.2%; oral anticoagulant use, 92.7%; DOAC use, 68.7%; and WF use, 24.0%. Incidences (/100 patient-years) and HRs (95% CIs) for each clinical outcome according to LAVi and LAEF category are summarized in Table. Compared with patients with LAEF >45.0% (n=224), those with LAEF ≤45.0% (n=1,213) were at higher risk of CV events (2.19 [1.13–4.27], p=0.021) and HF hospitalization (2.25 [1.02–4.96], p=0.045). Risk of all-cause death was higher in patients with LAVi >48.0 mL/m2 (n=656) than in those with LAVi ≤48.0 mL/m2 (n=621) (1.69 [1.00–2.83], p=0.048). In the subgroups with LAEF ≤45.0% or LAVi >48.0 mL/m2, patients receiving a DOAC had significantly lower risk of cardiac events, CV events, and HF hospitalization than patients receiving warfarin.

Conclusion

In elderly Japanese patients with NVAF, those with LAEF ≤45.0% are at higher risk of CV events and HF hospitalization, and those with LAVi >48.0 mL/m2 are at higher risk of all-cause death. Thus, the higher risk differs between patients with LAEF ≤45.0% and those with LAVi >48.0 mL/m2.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Daiichi Sankyo Co., Ltd.

The association of left ventricular ejection fraction with incident heart failure in patients with atrial fibrillation

Background

Atrial fibrillation (AF) increases the risk of incident heart failure (HF). Left ventricular ejection fraction (LVEF) is an important prognostic parameter in patients with HF. However, little is known regarding the association of LVEF with incident HF in patients with AF.

Purpose

The aim of this study is to investigate the relationship between LVEF at enrollment and incidence of HF hospitalization during follow-up period in patients with AF.

Methods

The Fushimi AF Registry is a community-based prospective survey of patients with AF in Fushimi-ku, Kyoto, Japan. The inclusion criterion of the registry is the documentation of AF at 12-lead electrocardiogram or Holter monitoring at any time, and there are no exclusion criteria. We started to enroll patients from March 2011, and follow-up data were available for 4,489 patients by the end of August 2021. In the present study, we investigated 3,544 patients with the data of LVEF at enrollment. We divided the patients into 4 groups stratified by LVEF (reduced LVEF [LVEF <40%], mildly reduced LVEF [LVEF: 40–49%], slightly reduced LVEF [LVEF: 50–59%], and normal LVEF [LVEF ≥60%]), and compared the backgrounds and outcomes between these 4 groups.

Results

Of 3,544 patients, the mean age was 73.6±10.7 years, 1,420 (40%) were female, 1,781 (50%) were paroxysmal AF, and 1,085 (30%) had pre-existing HF. The mean CHADS2 and CHA2DS2-VASc scores were 2.1±1.3 and 3.4±1.7, respectively. The mean LVEF at enrollment was 63±12% (reduced LVEF: 197 [6%], mildly reduced LVEF: 250 [7%], slightly reduced LVEF: 532 [15%] and normal LVEF: 2,565 [72%], respectively). Patients with lower LVEF demonstrated lower prevalence of female and paroxysmal AF, and had a higher CHADS2 and CHA2DS2-VASc scores (all P<0.01). A total of 605 patients were hospitalized for HF during the median follow-up period of 5.5 years, corresponding to an annual incidence of 3.4% per person-year. Kaplan-Meier curves demonstrated that LVEF at enrollment could stratify the incidence of HF hospitalization during follow-up in patients with AF (Picture 1). Multivariable Cox regression analysis revealed that lower LVEF strata were significantly associated with the increased risk of HF hospitalization even after adjustment by age, sex, type of AF and CHA2DS2-VASc score (Picture 1). An increased risk of HF hospitalization was observed even in patients with mildly reduced LVEF (adjusted hazard ratio: 2.56, 95% CI: 1.99–3.29) as well as in those with slightly reduced LVEF (adjusted hazard ratio: 1.79, 95% CI: 1.45–2.22) compared with those with normal LVEF. These results were also the case in AF patients without pre-existing HF (Picture 2).

Conclusion

LVEF at enrollment could stratify the incidence of HF hospitalization in patients with AF, suggesting the importance of measuring LVEF in all patients with AF. Even mildly (LVEF: 40–49%) or slightly (LVEF: 50–59%) reduced LVEF was independently associated with the risk of incident HF in patients with AF.

Funding Acknowledgement

Type of funding sources: None.

The relationship between diastolic blood pressure and the risk of cardiovascular events in patients with atrial fibrillation whose systolic blood pressure was treated to less than 130 mmHg

Background

Hypertension is one of the major risk factors of cardiovascular events in patients with atrial fibrillation (AF). Low diastolic blood pressure (DBP) has been reported to be associated with the incidence of cardiovascular events, but current guidelines recommend an intensive blood pressure target of less than 130/80 mmHg for AF patients taking oral anticoagulants without mentioning the lower limits of DBP.

Methods

The Fushimi AF Registry is a community-based prospective survey of AF patients in a city of Japan. Follow-up data were available in 4,472 patients, and hypertensive patients who received prescription of any antihypertensive agents and whose systolic blood pressure was treated to less than 130 mmHg were available were examined (n=1,319). We divided the patients into four groups according to their DBP at baseline; G1 (DBP<60 mmHg, n=349), G2 (60≤DBP<70, n=434), G3 (70≤DBP<80, n=386) and G4 (80≤DBP, n=150), and compared the clinical background and outcomes among groups.

Results

The proportion of female was grater in G1 group, and the patients in G1 group were older. During the median follow-up of 2,458 days, in Kaplan-Meier analysis, the incidence rates of cardiovascular events (composite of cardiac death, ischemic stroke, systemic embolism, non-fatal myocardial infarction and heart failure hospitalization during follow up) were the highest in G1 group and the lowest in G3 group (G1: 7.2% per person-year vs. G2: 4.9% vs. G3: 2.2% vs. G4: 4.4%; p<0.01). Multivariate Cox proportional hazards regression analysis revealed that DBP was an independent determinant of cardiovascular events (G1 vs. G3; hazard ratio (HR): 1.96, 95% confidence intervals (CI): 1.39–2.76, G2 vs. G3; HR: 1.79, 95% CI: 1.28–2.50, G4 vs. G3; HR: 1.56, 95% CI: 0.99–2.45) (Figure 1). When we examined the association of DBP according to 10 mmHg increment, patients with excessively low DBP (<50 mmHg) had significantly higher incidence of cardiovascular events than patients with DBP of 70–79 mmHg (HR: 2.80, 95% CI: 1.81–4.33), and DBP exhibited J curve association with higher incidence of cardiovascular events (Figure 2).

Conclusion

In Japanese AF patients whose systolic blood pressure was treated to less than 130 mmHg, patients with excessively low DBP had significantly higher incidence of cardiovascular events, and DBP exhibited J curve association with higher incidence of cardiovascular events.

Funding Acknowledgement

Type of funding sources: None.

Real-world clinical outcomes and anticoagulant therapy in elderly non-valvular atrial fibrillation patients with heart failure: sub-analysis of the ANAFIE Registry

Background

Atrial fibrillation (AF) and heart failure (HF) are bidirectionally correlated; the more severe the NYHA classification, the higher the incidence rate of atrial fibrillation, and vice versa. HF is included in the items of CHA2DS2-VASc score used to calculate stroke risk in patients with AF, and is itself a risk factor for thromboembolism in such patients. Anticoagulant management in AF patients with HF is thus a key concern that remains to be sufficiently examined, especially in elderly patients aged ≥75 y.

Purpose

The All Nippon Atrial Fibrillation In the Elderly (ANAFIE) Registry enrolled more than 30,000 elderly (≥75 y) patients with non-valvular AF (NVAF), aiming to produce real-world data on their clinical status and prognosis. This sub-analysis of the ANAFIE Registry assessed the 2-year outcomes and status of anticoagulant treatment in elderly NVAF patients with HF.

Methods

A total of 32,275 patients from the ANAFIE Registry were divided into two groups according to whether they had HF (HF group and reference group). The incidence rates and adjusted hazard ratios (HR) of clinical outcomes were determined using Kaplan-Meier analysis and the Cox proportional-hazards model, respectively.

Results

A total of 20,159 (62.5%) patients were included in the reference group, and 12,116 (37.5%) in the HF group. Compared with the reference group, the HF group had higher mean age (82.4 vs 80.9 y), female ratio (46.6% vs 40.4%), non-paroxysmal AF (69.8% vs 50.8%), and had lower mean CrCL (43.3 vs 51.6 mL/min). In the HF group, the rate control drugs were frequently used (50.1% vs 35.8%), and the rhythm control drugs were less used (14.2% vs 22.7%) than in the reference group. More patients in the HF group were using anticoagulants (93.9% vs 91.6%; warfarin (WF), 29.6% vs 23.0%; direct oral anticoagulants (DOAC), 64.2% vs 68.5%) than those in the reference group. The HF group had a numerically higher incidence of stroke or systemic embolic events (SEE) (3.28% vs 2.84%, HR 0.96, p=0.558) and major bleeding (2.35% vs 1.79%, HR 1.14, p=0.130) than the reference group, but the differences were not statistically significant. The HF group had a significantly higher incidence rate of HF requiring hospitalization (12.99% vs 4.59%, HR 1.94, p<0.001) and all-cause mortality (9.83% vs 5.21%, HR 1.32, p<0.001). In the HF group, patients receiving DOAC had significantly lower incidence rates for major bleeding, HF requiring hospitalization, and all-cause mortality than those receiving WF, while there was no difference for stroke/SEE between both groups.

Conclusions

Elderly NVAF patients with HF had higher risk of HF requiring hospitalization and mortality than those without. Differences were seen in the incidence rates of major bleeding, HF requiring hospitalization, and all-cause mortality between patients on DOAC and those on WF. This study will explore relevant factors affecting clinical outcomes in elderly NVAF patients with HF.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Daiichi Sankyo Co., Ltd.

Previous pacemaker therapy was not associated with the risk of clinical events in patients with atrial fibrillation: the Fushimi AF Registry

Background

Patients with atrial fibrillation (AF) occasionally require pacemaker implantation. Meanwhile, patients with implanted pacemaker are occasionally found to have subclinical AF and develop clinical AF. However, little is known about the clinical outcomes of AF patients with implanted pacemaker.

Purpose

We aimed to investigate the clinical outcomes in AF patients undergoing previous pacemaker therapy.

Methods

The Fushimi AF Registry is a community-based prospective survey of the AF patients in a city of Japan. Follow-up data including prescription status were available for 4,447 patients. After exclusion of patients with implantable cardioverter defibrillator and cardiac resynchronization therapy, we investigated 293 AF patients with pacemaker implantation at baseline. We performed propensity score-matching analysis to assess the impact of pacemaker therapy in AF patients.

Results

Of a total cohort, patients with pacemaker were more often female (51.2% vs. 39.7%; p<0.01) and older (78.0 vs. 73.3 years of age; p<0.01). Patients with pacemaker were more likely to have pre-existing heart failure (33.1% vs. 26.6%; p<0.01), valvular heart disease (22.9% vs. 16.8%; p<0.01), chronic kidney disease (48.8% vs. 34.7%; p<0.01), and history of performing direct current cardioversion (7.2% vs. 3.1%; p<0.01), compared with patients without pacemaker. Mean CHA2DS2-VASc score was higher in patients with pacemaker (3.80 vs. 3.34; p<0.01). Patients with pacemaker were more often prescribed oral anticoagulants (62.1% vs. 55.2%; p=0.02), verapamil (13.3% vs. 9.4%; p=0.03), and loop diuretics (30.7% vs. 21.8%; p<0.01). Using propensity score-matching, 291 patients with pacemaker and 291 without pacemaker were matched and baseline characteristics were comparable. The median follow-up period was 1,819 days. All-cause death occurred in 91 patients with pacemaker (6.0 /100 person-years) and 79 patients without pacemaker (5.9 /100 person-years), with a hazard ratio (HR) for patients with pacemaker of 1.01 (95% confidence interval [CI], 0.75 to 1.37; p=0.93). Furthermore, HR of cardiac death for patients with pacemaker was 1.00 (95% CI, 0.23 to 4.32; p=0.99), that of stroke or systemic embolism was 0.69 (95% CI, 0.44 to 1.07; p=0.10) and that of hospitalization for heart failure was 0.94 (95% CI, 0.65 to 1.37; p=0.76).

Conclusion

We identified that patients undergoing previous pacemaker therapy were not associated with the incidence of various adverse clinical events in Japanese AF patients.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Boehringer Ingelheim, Bayer Healthcare, Pfizer, Bristol-Myers Squibb, Astellas Pharma, AstraZeneca, Daiichi Sankyo, Novartis Pharma, MSD, Sanofi-Aventis, Takeda Pharmaceutical, and the Practical Research Project for Life-Style related Diseases including Cardiovascular Diseases and Diabetes Mellitus from Japan Agency for Medical Research and Development.

Association of the degree of thrombocytopenia with cause of death in patients with atrial fibrillation: the Fushimi AF Registry

Background

Thrombocytopenia is sometimes found in routine blood tests and is associated with an increased risk of mortality in general population. We have previously reported that atrial fibrillation (AF) patients with thrombocytopenia have a higher mortality than those without thrombocytopenia. However, association of the degree of thrombocytopenia with cause of death in AF patients is unknown.

Purpose

We aimed to investigate the association of baseline platelet count with cause of death including cardiac death, intracranial death, malignancy, infection, extracranial bleeding death, renal failure death, respiratory failure death and undetermined death.

Methods

The Fushimi AF Registry was designed to enroll all of the AF patients in Fushimi-ku, Kyoto. Fushimi-ku is densely populated with a total population of 283,000 and is assumed to represent a typical urban community in Japan. We started to enroll patients from March 2011, and follow-up data with baseline platelet counts less than 150,000/μL were available in 853 patients by the end of September 2020. We divided them into 3 groups according to baseline platelet level: Mild thrombocytopenia (100,000–149,999/μL, n=703), Moderate thrombocytopenia (50,000–99,999/μL, n=120), and Severe thrombocytopenia (<50,000/μL, n=30).

Results

In the entire cohort, the mean age was 76 years, 34% were women, the mean body weight and body mass index was 59.3 kg and 22.9 kg/m2, and the median platelet count were 121,000/μL (interquartile range 109,000 to 141,000/μL). Compared to Mild thrombocytopenia, patients with Moderate or Severe thrombocytopenia were more likely to have chronic kidney disease (42.2% vs 54.2% vs 73.3%, p=0.0003), have higher HAS-BLED score (1.90 vs 2.14 vs 2.00, p=0.047) and lower hemoglobin (12.8g/dL vs 11.7g/dL vs 11.2g/dL, p<0.0001) and were less often prescribed anti platelet drugs. Age, sex, body weight, systolic blood pressure, previous stroke, previous major bleeding, hypertension, diabetes mellitus, CHADS2 score and CHA2DS2-VASc score were comparable between three groups. During the median follow-up period, the incidence rate (per 100 person-years) of all-cause death was 6.82 vs 15.27 vs 9.64. (p<0.001) On univariate analysis, the incidence of all-cause death was higher in Moderate group than Mild group. (HR: 2.15; 95% CI 1.61–2.87, p<0.0001), but there was no significant difference between Mild and Severe groups. (HR: 1.44; 95% CI 0.78–2.64, p=0.243). The incidence of cardiac death was comparable between three groups. (Mild vs Moderate: HR 0.65; 95% CI 0.15–2.75, p=0.56, Mild vs Severe: HR 1.11; 95% CI 0.15–8.23, p=0.92) Regarding other causes of death such as intracranial bleeding, extracranial bleeding, malignancy, infection, renal failure, respiratory failure and undetermined cause, there was no significant difference.

Conclusion

Mortality was higher according to the degree of thrombocytopenia in AF patients, but the cause of death was not different among three groups.

Funding Acknowledgement

Type of funding sources: None.

Exploration of electrocardiographic and echocardiographic findings to screen transthyretin amyloid cardiomyopathy in patients with mild left ventricular hypertrophy

Background

The transthyretin amyloid cardiomyopathy (ATTR-CM), a common condition in the elderly, is a life-threatening disease; however, it is treatable. The early accurate diagnosis is, therefore, an important key to improve the patient's outcomes. Electrocardiography and echocardiography are instant diagnostic tools with red flags for the screening of the ATTR-CM. In fact, ATTR-CM often mimics left ventricular hypertrophy (LVH), and the differential diagnosis is difficult to establish. Thus, the characteristics of cardiac amyloidosis may be obscured in ATTR-CM patients with mild LVH, possibly making the disease difficult to diagnose. Therefore, in this study, the effect of LVH on the occurrence of electrocardiographic and echocardiographic parameters for ATTR-CM was investigated, and their incremental value over the age for the screening of ATTR-CM in the patients with mild LVH was recorded.

Methods

This study retrospectively studied 319 consecutive nonischemic LVH patients with a sinus rhythm who underwent detailed diagnostic tests. The light chain-associated amyloidosis was an exclusion criterion. The mean left ventricular wall thickness (MWT) <12 mm was defined as mild LVH, while MWT ≥12 mm was defined as moderate to severe LVH. The ATTR-CM was diagnosed with biopsy or 99 mTc-PYP scintigraphy. The elderly were defined as people aged ≥65 years in males and ≥70 years in females, according to the literature. Each electrocardiographic and echocardiographic parameter was binarized with an external cut-off point to increase the external validity, being the incremental benefit of each parameter over age for identifying ATTR-CM assessed using a receiver operating characteristic curve analysis and comparisons of the area under the curve (AUC).

Results

Fourteen patients (8%) among the 170 patients with mild LVH had ATTR-CM, while 27 patients (18%) among the 149 patients with moderate to severe LVH had ATTR-CM. The patients with mild LVH had fewer electrocardiographic and echocardiographic parameters, showing a significant difference between ATTR-CM and non-ATTR-CM patients than those with moderate to severe LVH (Table 1). Among several binarized parameters, the voltage-to-mass ratio, E/A ratio, the global longitudinal strain, and also the relative apical sparing pattern demonstrated additive value for identifying the ATTR-CM over aging (Table 2). In addition, the discriminative ability of the propensity score calculated from these four variables and age was considered excellent for the screening of ATTR-CM (AUC = 0.98).

Conclusion

The patients with mild LVH appear to have fewer electrocardiographic and echocardiographic specific findings of the ATTR-CM compared to patients with moderate to severe LVH. However, several red flags may be useful for screening ATTR-CM even in patients with a mild LVH.

Funding Acknowledgement

Type of funding sources: None. Table 1Table 2

Predictors and risk model for heart failure hospitalization in atrial fibrillation patients without pre-existing heart failure: the Fushimi AF Registry

Background

Atrial fibrillation (AF) increases the risk of hospitalization for heart failure (HF), as well as that of thromboembolism. The strategy for prediction of thromboembolism has been well-established; however, little focus has been placed on the risk stratification for and prevention of HF hospitalization in AF patients.

Purpose

The aim of this study is to investigate the predictors and risk model of HF hospitalization in non-valvular AF patients without pre-existing HF.

Methods

The Fushimi AF Registry is a community-based prospective survey of AF patients in Fushimi-ku, Kyoto, Japan. The inclusion criterion of the registry is the documentation of AF at 12-lead electrocardiogram or Holter monitoring at any time, and there are no exclusion criteria. We started to enroll patients from March 2011, and follow-up data were available for 4,472 patients by the end of October 2020. From the registry, we excluded patients without a pre-existing HF (defined as having one of the following; prior hospitalization for HF, New York Heart Association class ≥2, or left ventricular ejection fraction [LVEF] <40%), and those with valvular AF (mitral stenosis or prosthetic heart valve). Among 3,188 non-valvular AF patients without pre-existing HF, we explored the risk factors for the HF hospitalization during follow-up period. The risk model for predicting HF hospitalization was determined by the cumulative numbers of risk factors which were significant on multivariate analysis.

Results

The mean age was 72.4±10.8 years, 1197 were female and 1787 were paroxysmal AF. The mean CHADS2 and CHA2DS2-VASc scores were 1.7±1.2 and 2.9±1.6, respectively. During the median follow-up period of 5.1 years, HF hospitalization occurred in 285 (8.9%), corresponding to an annual incidence of 1.8 events per 100 person-years. In multivariable Cox regression analysis, advanced age (≥75 years), valvular heart disease, coronary artery disease, reduced LVEF (<60%), chronic obstructive pulmonary disease (COPD) and anemia were independently associated with the higher incidence of HF hospitalization (all P<0.001) (Picture 1). A risk model based on these 6 variables could stratify the incidence of HF hospitalization during follow-up period (log-rank; P<0.001) (Picture 2). Patients with ≥3 risk factors had an 11-fold higher incidence of HF hospitalization compared with those not having any of these risk factors (hazard ratio: 11.3, 95% confidence interval: 7.0–18.4; P<0.001).

Conclusions

Advanced age, coronary artery disease, valvular heart disease, reduced LVEF, COPD and anemia were independently associated with the risk of HF hospitalization in AF patients without pre-existing HF. There was good prediction for endpoint of HF hospitalization using these 6 variables, providing the opportunities for the implementation of strategies to reduce the incidence of HF among AF patients.

Funding Acknowledgement

Type of funding sources: None.

Left atrial dysfunction still exists in patients who obtain normal left atrial volume after successful ablation of atrial fibrillation

Introduction

Atrial fibrillation (AF) promotes left atrial (LA) remodeling and vice versa. LA volume index (LAVI) ≥34 mL/m2 is an established cut-off value for identifying an enlarged left atrium. Catheter ablation has become an established therapy for AF and provides a reduction of LA volume by maintaining sinus rhythm (reverse remodeling). However, the definition of LA reverse remodeling after AF ablation is undetermined.

Purpose

We hypothesized that patients with LA dilatation who obtain normal LA volume (LAVI <34 mL/m2) after AF ablation would have better long-term outcomes than those who do not. Furthermore, we investigated whether patients with a normal LA volume could also obtain normal LA function with AF ablation.

Methods

We enrolled 140 AF patients with baseline LAVI ≥34 mL/m2, without AF recurrence for 1 year after the initial AF ablation. We acquired conventional and speckle-tracking echocardiographic parameters within 24 h and at 1 year after the procedure. Late recurrence was defined as AF recurrence >1 year after the initial ablation. To define the normal range of LA function, age-and sex-matched 140 controls without a history of AF were also enrolled.

Results

After restoration of sinus rhythm, overall LA structural and functional parameters were significantly improved, and 75 patients (54%) had normal LA volume at the time of follow-up (Table). During a median follow-up of 44 (31–61) months, 32 patients (23%) experienced a late recurrence of AF. Patients who obtained normal LA volume after AF ablation had fewer late recurrences than those who did not (P<0.01) (Figure). However, LA functional abnormalities still existed in AF patients, even if LA volume was normalized as in controls (Table).

Conclusion

Patients who obtain normal LA volume have better long-term outcomes of AF ablation than those who do not. Although AF ablation promotes beneficial effects on LA structure and function, LA function cannot be normalized even in patients who obtain normal LA volume after successful ablation. Thus, physicians should carefully consider long-term follow-up and residual AF risks, regardless of sinus rhythm restoration by catheter ablation.

Funding Acknowledgement

Type of funding sources: None.

Left ventricular longitudinal shortening at cardiac base as a determinant of left atrial reservoir function in cardiac amyloidosis

Objective

To investigate a mechanistic determinant of left atrial (LA) reservoir function in patients presenting left ventricular (LV) hypertrophy, and clarify diagnostic and prognostic values of LA reservoir strain in patients with cardiac amyloidosis (CA).

Methods

Three-hundred sixty patients (median age: 68 years, male gender: 65%) with left ventricular hypertrophy (LVH) assessed by echocardiography were retrospectively included. The LVH etiologies were diagnosed by any of biopsy, cardiac magnetic resonance imaging or 99mTc-PYP scintigraphy. LV segmental longitudinal strain was estimated from apical three views, and LA reservoir strain was measured from an apical 4-chamber view.

Results

The LVH etiologies were confirmed with CA in 81 patients, hypertensive heart disease in 87 patients, hypertrophic cardiomyopathy in 143 patients, and miscellaneous disorders in 49 patients. The median (25th, 75th percentile) value of LV ejection fraction was 59% (48–67). LV basal longitudinal strain and LA reservoir strain were significantly reduced in patients with CA compared with those with other etiologies; LV basal strain: 5.4% (3.9–8.7) vs. 11.9% (9.3–14.6), LA reservoir strain: 9.2% (6.3–12.3) vs. 17.5% (11.3–24.1), p<0.01 respectively. LV basal strain was significantly correlated with LA reservoir strain in patients with CA (r=0.57, p<0.01) and in those with other etiologies (r=0.45, p<0.01). The area under the receiver-operating characteristic curves of LA reservoir strain and E/e' (0.78 and 0.74) to identify CA etiology were significantly larger than that of LA volume index (0.62) (p<0.01). During the follow-up period (median 2.9 years), 53 patients experienced heart failure hospitalization. The Cox regression model including age, gender, LV ejection fraction, E/e' and LA reservoir strain showed that male gender (hazard ratio: 0.46, p=0.03), E/e' (hazard ratio: 1.04, p<0.01) and LA reservoir strain (hazard ratio: 0.94, p<0.01) independently predicted heart failure hospitalization.

Conclusions

The decrease of LV longitudinal shortening at cardiac base could worsen LA reservoir function especially in patients with CA. LA reservoir strain might be an alternative measure to identify CA etiology and have a predictive value of heart failure hospitalization in patients with LV hypertrophy.

Funding Acknowledgement

Type of funding sources: None.

Gastrointestinal stromal tumour lacking mutations in the KIT and PDGFRA genes in a cat

Molecular subtyping in gastrointestinal stromal tumours is a useful method for predicting the efficacy of treatment using tyrosine kinase inhibitors in humans. However, owing to the paucity of reports on mutational analyses, the association between genetic mutations and the therapeutic response to tyrosine kinase inhibitors remains unclear in feline gastrointestinal stromal tumours. In this report, we describe the case of a cat with a gastrointestinal stromal tumour which was unresponsive to tyrosine kinase inhibitors. A mutational analysis revealed that the cat lacked mutations in both the KIT and platelet-derived growth factor receptor-alpha (PDGFRA) genes. Our findings are consistent with the fact that KIT/PDGFRA wild-type gastrointestinal stromal tumours are less responsive to tyrosine kinase inhibitors in humans. This signifies the need for further evaluation and possibly individualised treatment for gastrointestinal stromal tumours in cats on the basis of mutational analyses.

Epidemiology and clinical characteristics of childhood TB identified using active and passive case finding

BACKGROUND: Childhood TB cases can be found using passive case finding (PCF), i.e., by diagnosing children presenting with symptoms, or using active case finding (ACF), i.e., by identifying children with TB through contact tracing. Our study determined epidemiologic, clinical, and radiographic differences between these groups.DESIGN/METHODS: Retrospective cohort study of children aged 0-19 years diagnosed with TB from January 1, 2012 to December 31, 2019 at a U.S. TB clinic, comparing clinical, radiographic, microbiologic, and epidemiological characteristics of children identified using PCF and ACF.RESULTS: Of 178 eligible patients, 99 (55.6%) were diagnosed using PCF. Children identified using PCF were older (mean 8.9 vs. 6.1 years, P = 0.003), more often non-US-born (OR 2.29, 95% CI 1.12-4.67), had more extrapulmonary disease (44.4% vs. 3.8%, OR 20.27, 95% CI 5.98-68.64) and severe intrathoracic findings (39.4% vs. 10.1%, OR 5.77, 95% CI 2.50-13.29). Children identified using ACF were often asymptomatic, had isolated hilar/mediastinal adenopathy, but had more availability of drug susceptibility data from a link to a source case.CONCLUSION: Children identified using PCF had more severe manifestations, while those identified using ACF had greater availability of drug susceptibility data. Clinicians should be aware that clinical and radiographic presentations in children identified using PCF and those identified using ACF differ, and that the latter may be eligible for shorter treatment regimens.

A multicenter cohort study of osimertinib compared with afatinib as first-line treatment for EGFR-mutated non-small-cell lung cancer from practical dataset: CJLSG1903

Background

FLAURA, the prospective trial of osimertinib as a first-line therapy compared with first-generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), did not show superior survival benefit for osimertinib in either the subgroup of Asians or the subgroup with the L858R mutation. In addition, the superiority of osimertinib compared with second-generation EGFR-TKI is thus far unclear.

Patients and methods

We reviewed the clinical data of all consecutive patients who were treated with osimertinib or afatinib as first-line therapy between May 2016 and October 2019 from 15 institutions in Japan. We defined the groups based on first-line EGFR-TKI as the afatinib group and the osimertinib group. Outcomes included time to discontinuation of any EGFR-TKI (TD-TKI), overall survival (OS), and time to treatment failure, with propensity score analysis carried out as an exploratory analysis in the survival and subgroup analyses.

Results

A total of 554 patients were enrolled. Data on 326 patients in the osimertinib group, and 224 patients in the afatinib group were analyzed. TD-TKI adjusted by propensity score in the afatinib and osimertinib groups was 18.6 months (95% confidence interval 15.8 to 22.0) and 20.5 months (95% confidence interval 13.8 to not reached), respectively, without significant difference (P = 0.204). OS adjusted by propensity score favored the afatinib group with a significant difference (P = 0.018). Subgroup analysis with propensity score showed that patients with L858R and without brain metastasis had superior survival benefit with afatinib compared with osimertinib (P < 0.001).

Conclusions

TD-TKI in the afatinib group was not significantly prolonged compared with the osimertinib group in the practical data. In the exploratory analysis of patients with L858R-mutated non-small-cell lung cancer without brain metastasis, afatinib showed more benefit in OS over osimertinib.

•

The large-scale practical data of 550 patients who were treated with osimertinib or afatinib as first-line therapy were analyzed.

•

The superiority of osimertinib compared with afatinib could not be demonstrated in all populations.

•

Osimertinib therapy showed effectiveness in patients with brain metastasis.

•

Afatinib therapy showed potential benefit in patients with L858R mutation and without brain metastasis.

Clinical significance of the relative apical sparing pattern of longitudinal strain in patients with cardiac amyloidosis

Background

The relative apical sparing pattern (RASP) of left ventricular (LV) longitudinal strain (LS) is frequently associated with cardiac amyloidosis (CA). However, some patients with CA do not show the RASP, and their clinical characteristics have not been fully clarified. We sought to investigate the clinical significance of RASP in patients with CA.

Methods

One hundred consecutive CA patients who were diagnosed by biopsy or myocardial pyrophosphate scintigraphy and evaluated for RASP (mean age: 76 years, male: 77%, LV mean wall thickness: 13.5 mm, light-chain [AL] type: 33 cases, transthyretin [TTR] type: 67 cases) were retrospectively enrolled. The RASP was semi-quantitatively and quantitatively assessed. Semi-quantitative RASP was defined as reduction of LS (≥−10%) in ≥5 (of 6) basal segments relative to preserved LS (&lt;−15%) in ≥1 apical segment. Quantitative RASP was calculated according to the following formula: Quantitative RASP = [Average apical LS] / [Average basal LS + Average mid LS]. We adapted three validated thresholds (&gt;1.00, &gt;0.90, and &gt;0.87) according to the literature.

Results

Semi-quantitative and binalized quantitative RASP (&gt;1.00, &gt;0.90, and &gt;0.87) were observed in 55, 55, 63, and 65 patients, respectively. RASP in each definition was more prevalent in the TTR group than in the AL group. Additionally, RASP was significantly associated with higher LV wall thickness even after adjustment for the CA subtypes (all, p&lt;0.05, Figure). After the RASP assessment, 35 all-cause deaths and 26 cardiac deaths were observed during the follow-up period (median, 1.1 years). Although these events were significantly associated with poor nutrition, lower blood pressure, higher New York Heart Association class, and the AL group, no association was found with RASP and LV wall thickness.

Conclusions

The incidence of RASP is low in the case of thin LV wall thickness in CA patients, which may indicate the difficulty of early diagnosis of CA using RASP in patients with mild LV hypertrophy. The prognostic prediction using RASP may be challenging in this cohort.

Figure 1

Funding Acknowledgement

Type of funding source: None

Cyclin dependent kinase 1 (CDK1) positively regulates cardiac hypertrophy and fibrosis via TGF-beta pathway

Background

Transforming growth factor beta (TGF-β) critically mediates cardiac fibrosis by transforming fibroblasts to myofibroblasts in pathological conditions. Cyclin dependent kinases (CDKs), cell cycle-regulating proteins, are known to be intimately involved in cardiac fibrosis. Among CDK isoforms, CDK1 is essential for cell cycle progression and cell division. It is reported some interphase CDKs such as CDK4 or CDK6 were involved in cardiac fibrosis, however, detailed mechanisms of cardiac fibrosis through CDK1 and its interactions with TGF-β in cardiac fibrotic process haven't been elucidated. We hypothesize that CDK1 is involved in cardiac fibrotic process via TGF-β pathway and its suppression decreases TGF-β expression and transformation to myofibroblasts from fibroblasts presenting antifibrotic effect.

Methods and results

Isolated neonatal rat cardiac fibroblasts were treated with angiotensin II (ANG II, 1 μM, 24 h) or phosphate-buffered saline (PBS). ANG II increased CDK1 and TGF-β in cardiac fibroblasts, by 97% and 292%, respectively (p&lt;0.05). Administration of Ro-3306, a specific CDK1 inhibitor (1 μM, 24 h), suppressed TGF-β protein levels in ANG II-treated cardiac fibroblasts by 58% (p&lt;0.05). Similarly, knockdown of CDK1 by RNA silencing also inhibited ANG II-induced increases in TGF-β in cardiac fibroblasts by 39% (p&lt;0.05). ANG II increased alpha-smooth muscle actin (α-SMA), which is a marker of myofibroblasts, and knockdown of CDK1 significantly suppressed it by 49% (p&lt;0.05). In vivo study, 11-week-old male C57BL/6J mice were administered ANG II continuously with infusion pump, at a dose of 1000 ng/kg/min, for a week. Also, Ro-3306 was intraperitoneally injected at a dose of 2 mg/kg/day, every other day, for a week. First, Ro-3306 attenuated ANG II-mediated cardiac hypertrophy indicated by heart weight and echocardiographic parameter as to left ventricular wall thickness. Second, CDK1 and TGF-β expression were significantly augmented in ANG II-infused mice by 404% and 113%, respectively (p&lt;0.05). Injection of Ro-3306 suppressed TGF-β protein levels by 48%, although the difference wasn't statistically significant (p=0.09). Finally, histopathological examination (Masson's trichrome stain) demonstrated remarkable repression of ANG II-induced cardiac fibrosis by Ro-3306.

Conclusions

CDK1 positively controls cardiac fibrotic process by regulating transformation to cardiac myofibroblasts from fibroblasts via TGF-β pathway. It also presents an antihypertrophic effect on ANG II stimulation. CDK1 is a potential therapeutic target of cardiac fibrosis and hypertrophy.

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): KAKENHI

Derivation and validation of a novel score to detect heart failure with preserved ejection fraction in patients with atrial fibrillation: the Fushimi AF registry

Background

Heart failure with preserved ejection fraction (HFpEF) is an important comorbidity of atrial fibrillation (AF). However, it is sometimes difficult to detect HFpEF among AF patients with preserved EF, since AF and HF share similar symptoms.

Purpose

The aim of this study was to identify factors associated with having HFpEF in AF patients with preserved EF, and derive a new score for HFpEF in AF patients.

Methods

The Fushimi AF Registry is a community-based prospective survey of the AF patients in Fushimi-ku, Kyoto, Japan. Follow-up data were available for 4,466 patients, and 3,083 patients had preserved EF (≥50%). Of the 3,083 patients, 444 had prior HF hospitalization at baseline and we defined these patients as HFpEF. We examined the factors associated with having HFpEF, and derived a new score for detecting HFpEF in AF patients. Thereafter, we validated this score in patients without prior HF hospitalization.

Result

The mean age of the patients with EF ≥50% was 73.6 years, and 41.3% were female. Compared with the patients without prior HF hospitalization, HFpEF patients were older, more often female, less in body weight, had more heart disease (valvular heart disease, cardiomyopathy, old myocardial infarction, and coronary artery disease), chronic kidney diseases (CKD), anemia (Hb &lt;11 g/dL), sustained AF (persistent or permanent), left atrial enlargement (&gt;45 mm), and dilation of cardio-thoracic ratio (CTR) (&gt;54%) at baseline. In multivariate analysis, heart diseases, CKD, sustained AF, dilatation of CTR, left atrial enlargement, and anemia were significantly associated with HFpEF (Table 1). We derived a new score to diagnose HFpEF in AF patients (2 points for heart diseases, 1 point for CKD, sustained AF, dilatation of CTR, left atrial enlargement, and anemia; range 0 to 7 points). In a receiver-operating characteristic curve, optimal cut-off point for detecting HFpEF was 3 (Figure 1). We validated this score in patients without prior hospitalization for HF (n=2,639). Of these, 298 patients had HF symptoms of NYHA 2–4 (Symptomatic-HF), and 2,341 patients had neither prior HF hospitalization nor HF symptoms (No-HF). Notably, 207 patients (69.5%) in symptomatic-HF group and 748 patients (32.0%) in No-HF group were classified into HFpEF based on this new score. Furthermore, patients diagnosed as HFpEF by this score had higher incidence of new hospitalization for HF during the follow-up in both symptomatic-HF group and No-HF group. (Figure 2).

Conclusion

We derived a new score to diagnose HFpEF in AF patients based on the presence of prior HF hospitalization (2 points for heart diseases, 1 point for CKD, sustained AF, dilatation of CTR, left atrial enlargement, and anemia). In patients without prior HF hospitalization, sizable number of patients had high HFpEF score (≥3), and those patients showed higher incidence of new HF hospitalization.

Funding Acknowledgement

Type of funding source: None

Utility of scoring system including relative apical sparing pattern for screening cardiac amyloidosis in patients with left ventricular hypertrophy

Background

Cardiac amyloidosis (CA) is an infiltrative disease mimicking left ventricular hypertrophy (LVH), although its prognosis is poorer than other diseases with LVH. Moreover, because CA is treatable, appropriate screening for CA is an important area of study for clinicians to prevent and treat the disease. Several imaging predictors of CA have been reported so far;. in particular, deformation parameters such as relative apical sparing patterns of longitudinal strain (RASP) may diagnose CA with better precision than conventional parameters. Accordingly, we hypothesized that the inclusion of deformation parameters into the established diagnostic parameters would permit derivation of a risk score for CA screening in patients with LVH. Thus, we aimed to 1) investigate the incremental benefits of deformation parameters over established diagnostic parameters for CA screening in patients with LVH; 2) determine the risk score to screen CA patients with LVH using all of these variables; and 3) externally validate the score.

Methods

We retrospectively studied 295 consecutive non-ischemic patients with LVH who underwent echocardiography as well as the detailed work-up for LVH (biopsy, technetium pyrophosphate scintigraphy (99mTc-PYP) or cardiac magnetic resonance imaging) (median age, 67 years; MWT, 12 mm). CA was diagnosed by biopsy or 99mTc-PYP. The base model consisted of age (≥65 [male], ≥70 [female]), low voltage in electrocardiography, and posterior wall thickness ≥14 mm in reference to previous studies. Continuous echocardiographic variables were binarized by the use of generally accepted external cutoff points to avoid best clinical scenario. Incremental benefits were assessed using receiver operating characteristic curve analysis and area under the curve (AUC) comparison. Multiple logistic regression analysis was performed to determine the risk score. The score was then validated in the external validation sample (N=178, median age, 70 years; MWT, 12 mm).

Results

CA was observed in 54 patients (18%) and of the several echocardiographic parameters studied, only RASP demonstrated a significant incremental benefit for the screening of CA over the base model (Figure A). After multiple logistic regression analysis in the prediction of CA with 4 variables (RASP and basal model components), each was assigned a numeric value based on its relative effect (Figure B). The incidence rate of CA clearly increased as the sum of the risk score increased (Figure C). The score had good discrimination ability, with an AUC of 0.87, a total score of ≥2 with 70% sensitivity and 90% specificity. Similarly, the discrimination ability of the score in the validation cohort was sufficient (AUC = 0.87).

Conclusion

Overall, we determined a simple risk score including RASP to screen CA. This score takes into account 4 common parameters used in daily practice, and therefore, has potential utility in risk stratification and management of patients with LVH.

Figure 1

Funding Acknowledgement

Type of funding source: Private hospital(s). Main funding source(s): Kitaishikai

Clinical outcomes of Japanese atrial fibrillation patients with combined valvular heart disease: the Fushimi AF Registry

Background

We previously reported that valvular heart disease (VHD) was not at the significant risk of stroke/systemic embolism (SE), but was associated with an increased risk of hospitalization for heart failure (HF) in Japanese atrial fibrillation patients. However, the impact of combined VHD on clinical outcomes has been little known.

Purpose

The aim of this study is to investigate the prevalence of combined VHD and its clinical characteristics and impact on outcomes such as stroke/SE, all-cause death, cardiac death and hospitalization for HF.

Method

The Fushimi AF Registry is a community-based prospective survey of AF patients in one of the wards of our city which is a typical urban district of Japan. We started to enroll patients from March 2011, and follow-up data were available for 4,466 patients by the end of November 2019. In the entire cohort, echocardiography data were available for 3,574 patients. 68 AF patients with prosthetic heart valves were excluded and we compared clinical characteristics and outcomes between 488 single VHD (103 Aortic valve disease (AVD), 315 mitral valve disease (MVD), 70 tricuspid valve disease (TVD)) and 158 combined VHD (46 AVD and MVD, 11 AVD and TVD, 66 MVD and TVD, 35 AVD and MVD and TVD).

Result

Compared with single VHD, patients with combined VHD were older (combined vs. single VHD: 78.5 vs. 76.0 years, respectively; p&lt;0.01), more likely to have persistent/permanent type AF (73.4% vs. 63.9%, p=0.02) and prescription of warfarin (63.1% vs. 53.8%, p=0.04). Combined VHD was less likely to have diabetes mellitus (13.9% vs. 23.6%, p=0.01) and dyslipidemia (26.6% vs. 40.4%, p&lt;0.01). Sex, body weight, hypertension, pre-existing HF were comparable between the two groups.

During the median follow-up of 1,474 days, the incidence rate of stroke/SE was not significantly different between the two groups (1.58 vs. 1.89 per 100 person-years, respectively, log rank p=0.10). The incidence rate of all-cause death (7.35 vs. 5.33, p=0.65), cardiac death (1.20 vs. 0.99, p=0.91) and hospitalization for HF (5.55 vs. 4.43, p=0.53) were also not significantly different. We previously reported AVD had significant impacts on cardiac adverse outcomes in AF patients, and we further analyzed event rates between combined VHD including AVD (AVD and MVD/TVD) and without AVD (MVD and TVD). Combined VHD with AVD group had higher incidence rate of all-cause death (10.7 vs. 5.79, p=0.03) than that without AVD group. However, the incidence rate of stroke/SE (1.98 vs. 1.56, p=0.59), cardiac death (0.98 vs. 1.14, p=0.68), hospitalization for HF (8.03 vs. 5.38, p=0.17) were not significantly different between the two groups.

Conclusion

As compared with single VHD, the risk of stroke/SE, all-cause death, cardiac death and hospitalization for HF in combined VHD was not significantly different. Among patients with combined VHD, those having AVD had higher incidence rate of all-cause death than those without AVD.

Figure 1

Funding Acknowledgement

Type of funding source: None

The relationship between diastolic blood pressure and the risk of cardiovascular events in patients with atrial fibrillation: the Fushimi AF registry

Background

Hypertension is one of the major risk factors of cardiovascular events in patients with atrial fibrillation (AF). However, relationship between diastolic blood pressure (DBP) and cardiovascular events in AF patients remains unclear.

Methods

The Fushimi AF Registry is a community-based prospective survey of AF patients in Japan. Follow-up data were available in 4,466 patients, and 4,429 patients with available data of DBP were examined. We divided the patients into three groups; G1 (DBP&lt;70 mmHg, n=1,946), G2 (70≤DBP&lt;80, n=1,321) and G3 (80≤DBP, n=1,162), and compared the clinical background and outcomes between groups.

Results

The proportion of female was grater in G1 group, and the patients in G1 group were older and had higher prevalence of heart failure (HF), diabetes mellitus (DM), chronic kidney disease (CKD). Prescription of beta blockers was higher in G1 group, but that of renin-angiotensin system-inhibitors and calcium channel blocker was comparable. During the median follow-up of 1,589 days, in Kaplan-Meier analysis, the incidence rates of cardiovascular events (composite of cardiac death, ischemic stroke and systemic embolism, major bleeding and HF hospitalization during follow up) were higher in G1 group and G3 group than G2 group (Figure 1). When we divided the patients based on the systolic blood pressure (SBP) at baseline (≥130 mmHg or &lt;130 mmHg), the incidence of rates of cardiovascular events were comparable among groups. Multivariate Cox proportional hazards regression analysis including female gender, age (≥75 years), higher SBP (≥130 mmHg), DM, pre-existing HF, CKD, low left ventricular ejection fraction (&lt;40%) and DBP (G1, G2, G3) revealed that DBP was an independent determinant of cardiovascular events (G1 group vs. G2 group; hazard ratio (HR): 1.40, 95% confidence intervals (CI): 1.19–1.64, G3 group vs. G2 group; HR: 1.23, 95% CI: 1.01–1.49). When we examined the impact of DBP according to 10 mmHg increment, patients with very low DBP (&lt;60 mmHg) (HR: 1.50,95% CI:1.24–1.80) and very high DBP (≥90 mmHg) (HR: 1.51,95% CI:1.15–1.98) had higher incidence of cardiovascular events than patients with DBP of 70–79 mmHg (Figure 2). However, when we examined the impact of SBP according to 20 mmHg increment, SBP at baseline was not associated with the incidence of cardiovascular events (Figure 3).

Conclusion

In Japanese patients with AF, DBP exhibited J curve association with higher incidence of cardiovascular events.

Funding Acknowledgement

Type of funding source: None

Adverse outcomes after worsening renal function in patients with atrial fibrillation: the Fushimi AF Registry

Background

Patients with atrial fibrillation (AF) commonly coexist with chronic kidney disease (CKD). Non-vitamin K antagonist oral anticoagulants (NOAC) are recommended for stroke prevention in patients with non-valvular atrial fibrillation (AF), and worsening renal function (WRF) as well as CKD is an important issue in using NOAC. However, little is known about the clinical outcomes of patients after WRF.

Purpose

We aimed to investigate outcomes after WRF in AF patients.

Methods

The Fushimi AF Registry is a community-based prospective survey of the AF patients in our city. Follow-up data including prescription status were available for 4,441 patients. Of them, 1,890 patients who have baseline and at least 1 follow-up creatinine clearance (CrCl) measurements, estimated by the Cockcroft-Gault formula, were analyzed in the present study. WRF was defined as a decrease of ≥20% from baseline CrCl measurement at any time point during follow-up. We evaluated demographics and outcomes after WRF in AF patients.

Results

During the median follow-up period of 2,194 days, mean CrCl decrease of 2.2 ml/min/year was observed and WRF occurred in 981 patients (51.9%). Patients with WRF were significantly more often female (with vs. without WRF; 40.3% vs. 35.4%; p=0.03), older (73.4 vs. 71.1 years of age; p&lt;0.01), more often paroxysmal type (49.9% vs. 47.1%; p&lt;0.01), and more likely to have prior stroke (17.9% vs. 12.7%; p&lt;0.01), heart failure (30.8% vs. 24.8%; p&lt;0.01), diabetes (31.7% vs. 27.1%; p=0.03), and coronary artery disease (19.9% vs. 12.1%; p&lt;0.01) than those without WRF. Co-existing of CKD and mean CrCl at baseline were comparable (37.4% vs. 36.9%; p=0.82, 65.3 vs. 63.5 ml/min; p=0.66, respectively). Mean CHA2DS2-VASc score was significantly higher in WRF patients (3.55 vs. 3.03; p&lt;0.01). On landmark analysis, all-cause mortality occurred in 135 patients (8.6 /100 person-years) after WRF and 82 patients (1.7 /100 person-years) without WRF, with an adjusted hazard ratio (HR) of 6.33 (95% confidence interval [CI], 4.33–9.50; p&lt;0.01), adjusted by sex, age, body weight, serum creatinine, type of AF, oral anticoagulant prescription and comorbidities. Stroke or systemic embolism occurred in 45 patients after WRF (3.0 /100 person-years) and 78 (1.7 /100 person-years) patients without WRF (adjusted HR 1.60 [95% CI, 1.04–2.49; p=0.03]) (Figure).

Conclusions

AF patients after WRF had higher incidence of various adverse events.

Incidence of Adverse Outcomes

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): The Practical Research Project for Life-Style related Diseases including Cardiovascular Diseases and Diabetes Mellitus from Japan Agency for Medical Research and Development. Boehringer Ingelheim, Bayer Healthcare, Pfizer, Bristol-Myers Squibb, Astellas Pharma, AstraZeneca, Daiichi-Sankyo, Novartis Pharma, MSD, Sanofi-Aventis, and Takeda Pharmaceutical.

Clinical impact of regression from sustained to paroxysmal atrial fibrillation: the Fushimi AF registry

Background

Atrial fibrillation (AF) commonly progresses from paroxysmal type to sustained type in the natural course of the disease, and we previously demonstrated that the progression of AF was associated with increased risk of clinical adverse events. There are some patients, though less frequently, who regress from sustained to paroxysmal AF, but the clinical impact of the regression of AF remains unknown.

Purpose

We sought to investigate whether regression from sustained to paroxysmal AF is associated with better clinical outcomes.

Methods

Using the dataset of the Fushimi AF Registry, patients who were diagnosed as sustained (persistent or permanent) AF at baseline were studied. Conversion of sustained AF to paroxysmal AF during follow-up was defined as regression of AF. Major adverse cardiac events (MACE) were defined as the composite of cardiac death, stroke, and hospitalization for heart failure (HF). Event rates were compared between the patients with and without regression of AF. In patients with sustained AF at baseline, predictors of MACE were identified using Cox proportional hazards model.

Results

Among 2,253 patients who were diagnosed as sustained AF at baseline, regression of AF was observed in 9.0% (202/2,253, 2.0 per 100 patient-years) during a median follow-up of 4.0 years. Of these, 24.3% (49/202, 4.6 per 100 patient-years) of the patients finally recurred to sustained AF during follow-up. The proportion of asymptomatic patients was lower in patients with regression of AF than those without (with vs without regression; 49.0% vs 69.5%, p&lt;0.01). The percentage of beta-blocker use at baseline was similar between the two groups (37.2% vs 33.8%, p=0.34). The prevalence of patients who underwent catheter ablation or electrical cardioversion during follow-up was higher in patients with regression of AF (catheter ablation: 15.8% vs 5.5%; p&lt;0.01, cardioversion: 4.0% vs 1.4%; p&lt;0.01, respectively). The rate of MACE was significantly lower in patients with regression of AF as compared with patients who maintained sustained AF (3.7 vs 6.2 per 100 patient-years, log-rank p&lt;0.01). Figure shows the Kaplan-Meier curves for MACE, cardiac death, hospitalization for heart failure, and stroke. In patients with sustained AF at baseline, multivariable Cox proportional hazards model demonstrated that regression of AF was an independent predictor of lower MACE (adjusted hazard ratio [HR]: 0.50, 95% confidence interval [CI]: 0.28 to 0.88, p=0.02), stroke (HR: 0.51, 95% CI: 0.30 to 0.88, p=0.02), and hospitalization for HF (HR: 0.50, 95% CI: 0.29 to 0.85, p=0.01).

Conclusion

Regression from sustained to paroxysmal AF was associated with a lower incidence of adverse cardiac events.

Funding Acknowledgement

Type of funding source: None

Plasma natriuretic peptide level is an independent determinant of major clinical outcomes in atrial fibrillation patients without heart failure: the Fushimi AF Registry

Background

Atrial fibrillation (AF) increases the risk of death, stroke/systemic embolism and heart failure (HF). Plasma natriuretic peptide (NP) level is an important prognostic marker in HF patients. However, little is known regarding the prognostic significance of plasma NP level in AF patients without HF.

Purpose

The aim of this study is to investigate the relationship between plasma NP level and clinical outcomes such as all-cause death, stroke/systemic embolism and HF hospitalization during follow-up period in AF patients without HF.

Methods

The Fushimi AF Registry is a community-based prospective survey of AF patients in our city. The inclusion criterion of the registry is the documentation of AF at 12-lead electrocardiogram or Holter monitoring at any time, and there are no exclusion criteria. We started to enroll patients from March 2011, and follow-up data were available for 4,466 patients by the end of November 2019. From the registry, we excluded 1,220 patients without a pre-existing HF (defined as having one of the following; prior hospitalization for HF, New York Heart Association class ≥2, or left ventricular ejection fraction &lt;40%). Among 3,246 AF patients without HF, we investigated 1,189 patients with the data of plasma BNP (n=401) or N-terminal pro-BNP (n=788) level at the enrollment. We divided the patients according to the quartile of each plasma BNP or NT-pro BNP level and compared the backgrounds and outcomes between these 4 groups stratified by plasma NP level.

Results

Of 1,189 patients, the mean age was 72.1±10.2 years, 454 (38%) were female and 684 (58%) were paroxysmal AF. The mean CHADS2 and CHA2DS2-VASc score were 1.6±1.1 and 2.9±1.5, respectively. Oral anticoagulants were prescribed in 671 (56%) at baseline. The median (interquartile range) BNP and N-terminal pro-BNP level were 84 (38, 176) and 500 (155, 984) pg/ml, respectively. Patients with high plasma NP level were older, and demonstrated lower prevalence of paroxysmal AF, higher CHADS2 and CHA2DS2-VASc scores and higher prevalence of chronic kidney disease and oral anticoagulants prescription (all P&lt;0.01). A total of 165 all-cause death, 114 stroke/systemic embolism and 103 HF hospitalization occurred during the median follow-up period of 5.0 years. Kaplan-Meier curves demonstrated that higher plasma NP level was significantly associated with the incidences of all-cause death, stroke/systemic embolism and HF hospitalization in AF patients without HF (Figure 1A). Multivariable Cox regression analysis revealed that plasma NP level could stratify the risk of clinical outcomes even after adjustment by type of AF, CHA2DS2-VASc score, chronic kidney disease and oral anticoagulant prescription (Figure 1B).

Conclusion

Plasma NP level is a significant prognostic marker for all-cause death, stroke/systemic embolism and HF hospitalization in AF patients without HF, suggesting the importance of measuring plasma NP level in AF patients even without HF.

Figure 1

Funding Acknowledgement

Type of funding source: None

Impact of right ventricular contractile reserve on exercise capacity in patients with heart failure: clinical application of low-load exercise stress echocardiography

Background

The peak oxygen uptake (VO2) evaluated by the cardiopulmonary exercise test (CPX) is an established marker of exercise capacity in patients with heart failure (HF). In particular, peak VO2 &lt;14 ml/kg/min is used to be one of the criteria for heart transplantation. However, given exercise intolerance in patients with HF, it is difficult for refractory HF patients to reach sufficient exercise load. A recent report has highlighted significant impact of right ventricular (RV) function on mortality and urgent heart transplantation. Taken together, we hypothesized that the assessment of RV function was helpful to predict exercise capacity by using low-load exercise stress echocardiography (low-load ESE) in patients with HF.

Purpose

We evaluated whether RV dysfunction assessed by the low-load ESE determined a low peak VO2 &lt;14 ml/kg/min in patients with HF.

Methods

We studied 67 consecutive hospitalized patients with HF (mean age, 65 years; 75% male; mean LV ejection fraction, 36%) who underwent ESE and CPX after stabilized HF condition, and the time interval of CPX and ESE tests was within 48 hours. CPX was performed using an upright cycle ergometer by a ramp protocol, while ESE was performed using ergometer in semi-supine position and the workload was generally increased by 25 watts every 3 minutes. The low-load ESE was defined as the 25 watts exercise. The increments of RV s' velocity at tricuspid annulus and RV strain in the free wall were considered as a preservation of RV contractile reserve. Among the study population, 26 patients were performed right heart catheterization and RV dP/dt/Pmax was estimated as an invasive marker of RV contractility.

Results

The achieved intensity of exercise was 50.4±21.0 watts, and all patients completed the low-load ESE. The invasive study showed that the change of RV s' velocity during the low-load ESE significantly correlated with RV dP/dt/Pmax (r=0.706, p&lt;0.001). As shown in Figure, the non-invasive parameters of RV contractile reserve during the low-load ESE were significantly correlated with peak VO2 (RV s' velocity: r=0.787, p&lt;0.001; RV strain: r=0.244, p=0.047). ROC analysis showed that the change of RV s' velocity during the low-load ESE correctly identified patients with peak VO2 &lt;14 ml/kg/min (AUC=0.95, sensitivity 92.3%, specificity 85.2%). In terms of inter- and intra-observer variabilities, ICCs of the change of RV s' velocity were 0.86 and 0.96, and ICCs of the changes of RV strain were 0.63 and 0.70, respectively.

Conclusion

The change of RV s' velocity during the low-load ESE could determine exercise tolerance in patients with HF. The assessment of RV contractile reserve might be clinically useful to discriminate high risk HF patients.

Figure 1

Funding Acknowledgement

Type of funding source: None

Incremental benefits of echocardiographic indices over clinical parameters for screening cardiac amyloidosis in patients with left ventricular hypertrophy

Background

Cardiac amyloidosis (CA), characterized by amyloid protein deposition in the heart, is a treatable disease. Although left ventricular (LV) wall thickness is the most established imaging predictor for CA, several echocardiographic indices including deformation parameters also contribute to the screening of CA. However, it is unclear whether additive values of echocardiographic indices have greater benefit over the conventional clinical predictors for the screening of CA. Therefore, we sought to compare the incremental benefits of echocardiographic indices over the clinical parameters for the screening of CA and externally validate their incremental benefits.

Methods

We retrospectively studied 295 consecutive patients (median age, 67 years; male, 65%; mean LV wall thickness (MWT), 12 mm) with LV hypertrophy who underwent echocardiography as well as the detailed work-up for myocardium (Biopsy, technetium pyrophosphate scintigraphy (99mTc-PYP) or cardiac magnetic resonance imaging). CA was diagnosed through biopsy or 99mTc-PYP. The clinical model considers patients' age and the low-voltage in electrocardiography in reference to previous studies. Continuous echocardiographic variables were represented in binary through generally accepted external cutoff points. The incremental benefits of the echocardiography findings over the clinical model were assessed using with the help of both receiver-operated characteristic curve analysis and comparison of area under the curves. Furthermore, these incremental benefits were validated in the external validation sample (median age, 70 years; male, 69%; MWT, 12 mm).

Results

Among the enrolled patients, CA was observed in 18% of cases. Table presents the results of this study. Of the echocardiographic parameters, relative apical sparing pattern (RASP) was the greatest contributor for improvement of diagnostic accuracy of the clinical model. The next greatest contributor was LV wall thickness, followed by left atrial reservoir strain (LAS), E/e', left atrial volume index, ejection fraction strain ratio, and pericardial effusion, respectively. Similarly, RASP, LV wall thickness, global longitudinal strain, ejection fraction, LAS, and granular sparkling showed significant incremental benefit in the validation cohort. Only mean wall thickness, LV wall thickness, LAS, E/e' and RASP consistently improved the diagnostic accuracy of the clinical model.

Conclusion

During the screening process, adding LV wall thickness, LAS, and RASP to the clinical parameters may be useful for the accurate diagnosis of CA in patients with LV hypertrophy.

Figure 1

Funding Acknowledgement

Type of funding source: None

Feasibility study of a compact heavy ion source for investigation of laboratory magnetospheric plasma

We are developing a laser ion source to provide a high brightness multi-charged heavy ion beam as a part of the heavy ion beam probe system, which will be used to diagnose plasma potential in the Ring Trap 1 device at the University of Tokyo. As a probe beam, Nb²⁺ was selected, and a detailed laser irradiation condition was explored. It was found that the laser power density of 1.2 × 10⁹ W/cm² gives the maximum particle number of Nb²⁺ per laser energy from a niobium foil target. Essential ablation plasma parameters to design the laser ion source were also obtained. The expected beam current was more than 12 mA/cm², with a pulse width of 3.1 µs at 200 mm away from the target.

Optimization of laser-target parameters for the production of stable lithium beam

A laser ion source coupled with a radio frequency quadrupole linac accelerator is being proposed as a suitable system for the production of a low energy, high-current stable lithium beam. In order to maximize the lithium yield, plasmas generated by laser ablation of different materials based on lithium (Li, LiOH, and LiNbO₃) have been characterized by using a Faraday cup and an electrostatic ion analyzer in the time of flight configuration. A wide range of laser power density has been investigated (10⁹-10¹² W/cm²) using two Nd:YAG lasers operating at different wavelengths (1064 nm and 532 nm), pulse durations (6 ns and 17 ns), and maximum energies (1400 mJ and 210 mJ). This paper outlines the pros and cons of the investigated materials by studying how the ion energy, yields, and charge state distributions are modified when the laser power density is changed. Considerable attention has been paid to the higher charge states of oxygen, which may occur with the same mass-to-charge ratio of Li³⁺. The analysis has evidenced that LiNbO₃ represents a valid target since it allows minimizing the O⁶⁺/⁷Li³⁺ ratio down to 2.5% by using a laser power density of 1.8 × 10¹⁰ W/cm². For such a condition, a Li³⁺ current of 1.4 mA/cm² has been measured.

P176 Left ventricular diastolic function by gated myocardial perfusion SPECT strongly reflects NT-ProBNP

Background

The importance of left ventricle diastolic dysfunction (LVDD) has been recognized widely, as it is well established that heart failure with preserved ejection fraction has a poor prognosis. Furthermore, N-terminal pro–B-type natriuretic peptide (NT-ProBNP) is used as a marker of heart failure. However, the association between LVDD and NT-proBNP is unclear. 

Purpose

The aim of this study was to clarify the association between LVDD and NT-ProBNP. 

Methods

In this study, an index based on gated myocardial perfusion SPECT using CardioREPO software for the diagnosis of LVDD was used. Out of the 171 patients who underwent myocardial perfusion imaging (MPI) between January 2015 and December 2018, 163 individuals (116 men and 47 women) completed MPI and NT-ProBNP. Patients were classified into 4 groups: NT-ProBNP levels below 125 pg/ml (n = 52), NT-ProBNP levels 125 to 400 pg/ml (n = 33), NT-ProBNP levels 400 to 900 pg/ml (n = 23), and NT-ProBNP levels over 900 pg/ml (n = 37). CardioREPO parameters (peak filling rate　(PFR), 1/3 mean filling rate (MFR), and time to peak filling rate/R-R (TTPFR)) were compared between the 4 NT-ProBNP groups. 

Results

Of the 163 patients, 55 had LVDD. The PFR and 1/3MFR were associated with LVDD. There was a statistically significant difference in PFR and 1/3 MFR between the NT-ProBNP levels below 125 pg/ml group and the NT-ProBNP levels 400 to 900 pg/ml group (PFR = 2.51+/-1.11 vs. 1.80+/-0.65, p = 0.001; 1/3 MFR = 1.41+/-0.55 vs. 1.06+/-0.47, p = 0.006, Table).

Conclusions

The MPI indices obtained by CardioREPO software were useful in the diagnosis of LVDD. The evaluation of LVDD by MPI correlated with NT-Pro BNP level is thought to have a clinical utility in the diagnosis and management of LVDD.

Variable: NT-ProBNP 　 0-125 (n = 52) 125-400 (n = 33) 400-900 (n = 23) 900- (n = 37) p Age 66 ± 11 72 ± 11 68 ± 17 70 ± 12 0.133 Male 40 (77%) 22 (12%) 18 (78%) 23 (62%) 0.36 Left ventricular diastolic dysfunction 8 (15%) 4 (12%) 10 (43%) 27 (73%) &lt;0.001 E/A 0.9 ± 0.3 0.8 ± 0.2 1.1 ± 0.7 1.4 ± 0.9 (35) &lt;0.001 E/e" 10.27 ± 3.69 (20) 8.83 ± 3.56 (10) 12.46 ± 3.75 (12) 20.25 ± 8.30 (25) &lt;0.001 rest-PFR /s 2.51 ± 1.11 2.06 ± 0.58 2.16 ± 0.65 1.80 ± 0.65 0.001 rest-1/3 MFR /s 1.41 ± 0.55 1.19 ± 0.41 1.16 ± 0.50 1.06 ±0.47 0.008 rest-TTPFR ms 177 ± 53 181 ± 69 198 ± 80 166 ± 85 0.38 rest-TTPFR / R-R 　 0.19 ± 0.06 0.20 ± 0.11 0.21 ±0.09 0.21 ± 0.15 0.92

96Zr beam production for isobar experiment in relativistic heavy ion collider

To investigate the chiral magnetic effect, ⁹⁶Zr and ⁹⁶Ru beams were accelerated at the relativistic heavy ion collider (RHIC) during Run-18 at Brookhaven National Laboratory. The ⁹⁶Zr beam was provided from the electron beam ion source (EBIS) injector, which consists of a laser ion source, an EBIS high charge state ion breeder, a 300 keV/u radio frequency quadrupole, and a 2 MeV/u interdigital H type drift tube linear accelerator (IH-DTL). The natural abundance of ⁹⁶Zr is only 2.8% with about 50% of ⁹⁰Zr. To obtain a sufficient beam current, Zr material enriched to about 60% of ⁹⁶Zr was used. The only available form of the enriched material was zirconium oxide (ZrO₂) powder, which was not well suited for a laser ion source target. We studied and established a sintering technique of the ZrO₂ powder to make a solid sample which could be installed into the laser ion source. The singly charged Zr was produced in a laser ablation plasma, extracted, and delivered to the EBIS to be ionized further to ⁹⁶Zr¹⁶⁺. We optimized the laser irradiation condition, the EBIS confinement time, and transport through the RF linacs to maximize the performance of the injector. The total number of shots provided from the laser ion source for injection into the EBIS was 489 910. The EBIS facility provided a 192 MeV stable beam of ⁹⁶Zr¹⁶⁺ ions to the booster ring of alternating gradient synchrotron (AGS) for further acceleration and stripping in the AGS/RHIC complex, allowing for successful data acquisition at the Solenoidal Tracker at the RHIC.