Chinese Atrial Fibrillation Registry Research Articles

Association between the preprocedural serum potassium level and atrial fibrillation recurrence after catheter ablation

BackgroundThe association between serum potassium and atrial fibrillation (AF) recurrence after catheter ablation remains unclear. ObjectiveThe purpose of this study was to investigate whether preprocedural serum potassium influences AF recurrence in patients who underwent catheter ablation. MethodsWe used data of patients with AF who underwent de novo catheter ablation from the prospective Chinese Atrial Fibrillation Registry Study. Patients with prior ablation and without baseline serum potassium were excluded. The primary outcome was 1-year AF recurrence after a 3-month blanking period from the ablation procedure. Restricted cubic spline and Cox proportional models were used to compare outcomes across serum potassium categories. ResultsA total of 4838 patients with AF who underwent de novo catheter ablation was enrolled. At 1 year, AF recurrence occurred in 1347 patients (27.8%). The relationship between preprocedural serum potassium and 1-year AF recurrence after ablation presented as U shape (P for nonlinear = .048). Compared with the group of serum potassium within 4.41–4.60 mmol/L, the risk of AF recurrence increased significantly in the lowest serum potassium group (≤4.00 mmol/L) after multivariate analysis (hazard ratio [HR] 1.26; 95% confidence interval 1.06–1.51; P = .010). Other categories with lower or higher serum potassium levels including 4.01–4.20 mmol/L (HR 1.18), 4.21–4.40 mmol/L (HR 1.16), 4.61–4.80 mmol/L (HR 1.07), and ≥4.81 mmol/L (HR 1.11) showed nonsignificant higher recurrence risk. ConclusionThe relationship between preprocedural potassium and AF recurrence was U shaped, with an optimal potassium range (4.41–4.60 mmol/L). Lower potassium level is associated with increased AF recurrence risk after catheter ablation.

Catheter ablation versus medical therapy for atrial fibrillation with prior stroke history: a prospective propensity score-matched cohort study.

Patients with atrial fibrillation (AF) and prior stroke history have a high risk of cardiovascular events despite anticoagulation therapy. It is unclear whether catheter ablation (CA) has further benefits in these patients. AF patients with a previous history of stroke or systemic embolism (SE) from the prospective Chinese Atrial Fibrillation Registry study between August 2011 and December 2020 were included in the analysis. Patients were matched in a 1:1 ratio to CA or medical treatment (MT) based on propensity score. The primary outcome was a composite of all-cause death or ischemic stroke (IS)/SE. During a total of 4.1 ± 2.3 years of follow-up, the primary outcome occurred in 111 patients in the CA group (3.3 per 100 person-years) and in 229 patients in the MT group (5.7 per 100 person-years). The CA group had a lower risk of the primary outcome compared to the MT group [hazard ratio (HR) = 0.59, 95% CI: 0.47-0.74, P < 0.001]. There was a significant decreasing risk of all-cause mortality (HR = 0.43, 95% CI: 0.31-0.61, P < 0.001), IS/SE (HR = 0.73, 95% CI: 0.54-0.97, P = 0.033), cardiovascular mortality (HR = 0.32, 95% CI: 0.19-0.54, P < 0.001) and AF recurrence (HR = 0.33, 95% CI: 0.30-0.37, P < 0.001) in the CA group compared to that in the MT group. Sensitivity analysis generated consistent results when adjusting for time-dependent usage of anticoagulants. In AF patients with a prior stroke history, CA was associated with a lower combined risk of all-cause death or IS/SE. Further clinical trials are warranted to confirm the benefits of CA in these patients.

The ABC-Death Score for Mortality Prediction in Patients With Atrial Fibrillation Undergoing Catheter Ablation

BackgroundData on the performance of risk scores in predicting mortality risk after atrial fibrillation (AF) ablations are limited. ObjectivesThe purpose of this study was to investigate the associations of mortality with preablation biomarkers and evaluate the performance of age, biomarker, and clinical history (ABC)-death score in patients with AF undergoing catheter ablation. MethodsPatients with AF undergoing catheter ablations between 2013 and 2019 in the Chinese Atrial Fibrillation Registry were enrolled. Biomarkers associated with ABC-death score were quantified from baseline blood samples collected before AF ablation. Clinical outcomes were all-cause mortality and cardiac mortality. Discrimination, reclassification, clinical use, and calibration were further evaluated. ResultsWe identified 4,218 patients with AF undergoing catheter ablations. During a median follow-up period of 4.0 years, 119 patients died due to all causes, with 49 dying due to cardiac causes. Biomarker levels were all independently associated with an increased risk of all-cause death and cardiac death. The ABC-death score was superior to the CHA2DS2-VASc score in predicting all-cause death (C index 0.73 vs 0.63; P = 0.001) and cardiac death (C index 0.83 vs 0.71; P = 0.007). Reclassification analysis revealed significant reclassification improvements of the ABC-death score compared with the CHA2DS2-VASc (cardiac failure or dysfunction, hypertension, age ≥75 [doubled], diabetes mellitus, stroke [doubled]—vascular disease, age 65 to 74 years and sex category [female]) score. Decision curve analysis showed the greater net benefit of use of the ABC-death score. Calibration plots presented an overestimation of the observed mortality event rate by ABC-death score. ConclusionsPreablation biomarkers associated with ABC-death score were independently related to increased all-cause and cardiac mortality risk. Despite the overestimation of the event rate, the ABC-death score outperformed the CHA2DS2-VASc score in discriminating and reclassifying mortality risk, especially for cardiac mortality.

Identification of atrial fibrillation phenotypes at low risk of stroke in patients with CHA2DS2-VASc ≥2: Insight from the China-AF study.

Patients with atrial fibrillation (AF) are highly heterogeneous, and current risk stratification scores are only modestly good at predicting an individual's stroke risk. We aim to identify distinct AF clinical phenotypes with cluster analysis to optimize stroke prevention practices. From the prospective Chinese Atrial Fibrillation Registry cohort study, we included 4337 AF patients with CHA2 DS2 -VASc≥2 for males and 3 for females who were not treated with oral anticoagulation. We randomly split the patients into derivation and validation sets by a ratio of 7:3. In the derivation set, we used outcome-driven patient clustering with metric learning to group patients into clusters with different risk levels of ischemic stroke and systemic embolism, and identify clusters of patients with low risks. Then we tested the results in the validation set, using the clustering rules generated from the derivation set. Finally, the survival decision tree was applied as a sensitivity analysis to confirm the results. Up to the follow-up of 1 year, 140 thromboembolic events (ischemic stroke or systemic embolism) occurred. After supervised metric learning from six variables involved in CHA2 DS2 -VASc scheme, we identified a cluster of patients (255/3035, 8.4%) at an annual thromboembolism risk of 0.8% in the derivation set. None of the patients in the low-risk cluster had prior thromboembolism, heart failure, diabetes, or age older than 70 years. After applying the regularities from metric learning on the validation set, we also identified a cluster of patients (137/1302, 10.5%) with an incident thromboembolism rate of 0.7%. Sensitivity analysis based on the survival decision tree approach selected a subgroup of patients with the same phenotypes as the metric-learning algorithm. Cluster analysis identified a distinct clinical phenotype at low risk of stroke among high-risk [CHA2 DS2 -VASc≥2 (3 for females)] patients with AF. The use of the novel analytic approach has the potential to prevent a subset of AF patients from unnecessary anticoagulation and avoid the associated risk of major bleeding.

ABC-AF-Stroke score predicts thromboembolism in non-anticoagulated patients following successful atrial fibrillation ablation: a report from the Chinese Atrial Fibrillation Registry.

The age, biomarkers, and clinical history (ABC)-atrial fibrillation (AF)-Stroke score have been proposed to refine stroke risk stratification, beyond what clinical risk scores such as the CHA2DS2-VASc score can offer. This study aimed to identify risk factors associated with thromboembolism and evaluate the performance of the ABC-AF-Stroke score in predicting thromboembolism in non-anticoagulated AF patients following successful ablations. A total of 2692 patients who underwent successful ablations with discontinued anticoagulation after a 3-month blanking period in the Chinese Atrial Fibrillation Registry (CAFR) between 2013 and 2019 were included. Cox regression analysis was conducted to present the association of risk factors with thromboembolism risk. The ABC-AF-Stroke score was evaluated in terms of discrimination, including concordance index (C-index), net reclassification improvement (NRI) and integrated discrimination improvement (IDI), clinical utilization by decision curve analysis (DCA), and calibration by comparing the predicted risk with the observed annualized event rate. After a median follow-up of 3.5 years, 64 patients experienced thromboembolism events. Age, prior history of stroke/transient ischemic attack (TIA), high-sensitivity cardiac troponin T (cTnT-hs), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were independently associated with thromboembolism risk. The ABC-AF-Stroke score performed statistically significantly better than the CHA2DS2-VASc score in terms of C-index (0.67, 95% confidence interval [CI]: 0.59-0.74 vs. 0.60, 95% CI: 0.52-0.67, P = 0.030) and reclassification capacity. The DCA implied that the ABC-AF-Stroke score could identify more thromboembolism events without increasing the false positive rate compared to the CHA2DS2-VASc score. The calibration curve showed that the ABC-AF-Stroke score was well calibrated in this population. In this real-world study enrolling non-anticoagulated AF patients following successful ablations, age, prior history of stroke/TIA, level of NT-proBNP, and cTnT-hs were independently associated with an increased risk of thromboembolism. The ABC-AF-Stroke score was well-calibrated and statistically significantly outperformed the CHA2DS2-VASc score in predicting thromboembolism risk.

Analysis of dyslipidemia management status in atrial fibrillation patients with very high and high risk of atherosclerotic cardiovascular disease

Objective: To analyze the status of statins use and low-density lipoprotein cholesterol (LDL-C) management in patients with atrial fibrillation (AF) and very high/high risk of atherosclerotic cardiovascular disease (ASCVD) from Chinese Atrial Fibrillation Registry (CAFR). Methods: A total of 9 119 patients with AF were recruited in CAFR between January 1, 2015 to December 31, 2018, patients at very high and high risk of ASCVD were included in this study. Demographics, medical history, cardiovascular risk factors, and laboratory test results were collected. In patients with very high-risk, a threshold of 1.8 mmol/L was used as LDL-C management target and in patients with high risk, a threshold of 2.6 mmol/L was used as LDL-C management target. Statins use and LDL-C compliance rate were analyzed, multiple regression analysis was performed to explore the influencing factors of statins use. Results: 3 833 patients were selected (1 912 (21.0%) in very high risk of ASCVD group and 1 921 (21.1%) in high risk of ASCVD group). The proportion of patients with very high and high risk of ASCVD taking statins was 60.2% (1 151/1 912) and 38.6% (741/1 921), respectively. Attainment rate of LDL-C management target in patients with very high and high risk were 26.7% (511/1 912) and 36.4% (700/1 921), respectively. Conclusion: The proportion of statins use and attainment rate of LDL-C management target are low in AF patients with very high and high risk of ASCVD in this cohort. The comprehensive management in AF patients should be further strengthened, especially the primary prevention of cardiovascular disease in AF patients with very high and high risk of ASCVD.

AB-453070-3 VERY-EARLY SYMPTOMATIC RECURRENCE IS ASSOCIATED WITH INCREASED RISK OF LATE RECURRENCE AMONG ATRIAL FIBRILLATION PATIENTS AFTER RADIOFREQUENCY ABLATION

The effect of very-early (within 48 h) symptomatic recurrence (VESR) of atrial fibrillation (AF) after radiofrequency catheter ablation (RFCA) on late recurrence (LR) (after 3 months of RFCA) has been seldomly reported. To explore the relationship between VESR and LR among post-RFCA patients. We enrolled AF patients who registered in the Chinese Atrial Fibrillation Registry study and received the first RFCA procedure from June 2018 to December 2021 at Beijing Anzhen Hospital. Patients were divided into four groups based on VESR and early recurrence (ER) (from 48 h to 3 months after RFCA): group A (no VESR, no ER); group B (VESR but no ER); group C (ER but no VESR); and group D (both VESR and ER). Their clinical characteristics and risk of LR events were compared among groups. The study included 6887 patients; VESR was found in 330 (4.79% ) patients. The proportion of women in patients with VESR was higher (group B vs. group A: 40.65% vs. 32.03%, P=0.043; group D vs. group A: 39.13% vs. 32.03%, P=0.032), and the proportion of hypertensive patients was lower (group B vs. group A: 41.46% vs. 53.64%, P=0.007; group D vs. group A: 44.44% vs. 53.64%, P=0.009). With an average follow-up of 17.7 months, the Kaplan-Meier curve showed that LR risk in VESR patients was significantly higher than in other patients in both paroxysmal (log-rank, P<0.001) and persistent (log-rank, P<0.001) AF patients (P for interaction=0.118). In VESR patients, LR risk between group B and group D patients was significantly different (log-rank, P<0.001). Multivariate Cox regression showed that group B and group D were associated with increased risk of LR (HRB:A=2.161, P<0.001; HRD:A=7.401, P<0.001). In VESR patients, compared with the combination of variables in the APPLE score (Age, Persistent AF, imPaired eGFR, Left atrial diameter, left ventricular Ejection fraction), the combination of group and the APPLE score variables significantly improves AUC for predicting LR at 6 (73.2% vs. 58.2%, P<0.001), 12 (72.0% vs.60.5%, P<0.001), and 18 (69.2% vs. 50.3%, P=0.002) months. VESR is associated with increased risk of LR in both paroxysmal and persistent AF patients. Further, classification of VESR patients based on recurrence between 48 h and 3 months improves the prediction potential of LR risk in these patients.

Performance of the ABC-bleeding risk score for assessing major bleeding risk in Chinese patients with atrial fibrillation on oral anticoagulation therapy: A real-world study.

To evaluate performance of the ABC (Age, Biomarkers, Clinical history)-bleeding risk score in estimating major bleeding risk in Chinese patients with atrial fibrillation (AF) on oral anticoagulation (OAC) therapy in real-world practice. Data were collected from the Chinese Atrial Fibrillation Registry study (CAFR). Patients were stratified into low-, medium-, and high-risk groups based on ABC-bleeding risk score with 1-year major bleeding risk (<1%, 1-2%, and > 2%) and modified HAS-BLED score (≤1, 2, and > 2 points). Cox proportional-hazards (Cox-PH) models were used to determine the association of major bleeding incidence with bleeding scores. Harrell's C-index of the two scores were compared. Net reclassification improvement (NRI) and integrated discrimination improvement (IDI) at 1 year were employed to evaluate the reclassification capacity. The calibration curve was plotted to compare the predicted major bleeding risk using ABC-bleeding risk score with the observed annualized event rate. The decision analysis curves (DCA) were performed to show the clinical utilization of two scores in identifying major bleeding events. The study included 2,892 AF patients on OAC therapy. After the follow-up of 3.0 years, 48 patients had major bleeding events; the incidence of a bleeding event in the low-, medium-, and high-risk groups according to ABC-bleeding risk score was 0.31% (reference group, HR = 1.00),0.51% (HR = 1.83, 95%CI: 0.91-3.69, P = 0.09), and 1.49% (HR = 4.92, 95%CI: 2.34-10.30, P < 0.001), respectively. Major bleeding incidence had an independent association with growth differentiation factor 15 (GDF-15) level (HR = 2.16, 95%CI: 1.27-3.68, P = 0.005) after adjusting components of the HAS-BLED score and cTnT-hs level. The ABC-bleeding score showed a Harrell's C-index of 0.67 (95%CI: 0.60-0.75) in estimating major bleeding risk, which was non-significant compared to the modified HAS-BLED score (0.67 vs. 0.63; P = 0.38). NRI and IDI also revealed comparable reclassification capacity of ABC-bleeding risk score compared with HAS-BLED score (14.6%, 95%CI: -10.2%, 39.4%, P = 0.25; 0.2%, 95%CI -0.1 to 0.9%, P = 0.64). Cross-tabulation of the two scores showed that the ABC-bleeding score outperformed the HAS-BLED score in identifying patients with a high risk of major bleeding. The calibration curve showed that the ABC-bleeding risk score overestimated the observed major bleeding risk. DCA did not show any difference in net benefit when using either of the scores. This study verified the value of the ABC-bleeding risk score in assessing major bleeding risk in Chinese patients with AF on OAC therapy in real-world practice. Despite the overestimation of major bleeding risk, ABC-bleeding score performed better in stratifying patients with a high risk than the modified HAS-BLED score. Combining the two scores could be a clinically practical strategy for precisely stratifying AF patients, especially those at a high risk of major bleeding, and further supporting the optimization of OAC treatment.

Outcome of catheter ablation for paroxysmal atrial fibrillation in patients with stable coronary artery disease.

Atrial fibrillation (AF) and stable coronary artery disease (SCAD) frequently coexist. This study aimed to assess the long-term outcome of catheter ablation in patients with paroxysmal AF and SCAD. In total, 12,104 patients with paroxysmal AF underwent catheter ablation in the Chinese Atrial Fibrillation Registry between 2011 and 2019 were screened. A total of 441 patients with SCAD were matched with patients without SCAD in a 1:4 ratio. The primary endpoint was AF recurrence after single ablation. The composite secondary endpoints were thromboembolism, coronary events, major bleeding, all-cause death. Over a mean follow-up of 46.0±18.9 months, the recurrence rate in patients with SCAD was significantly higher after a single ablation (49.0%vs. 41.9%, p=.03). The very late recurrence rate of AF in the SCAD group was also significantly higher than that in the control group (38.9%vs. 31.2%;p=.04). In multivariate analysis, adjusted with the female, smoking, duration of AF, previous thromboembolism, COPD, and statins, SCAD was independently associated with AF recurrence (adjusted HR, 1.19 [1.02-1.40], p=.03). The composite secondary endpoints were significantly higher in the SCAD group (12.70%vs. 8.54%, p=.02), mainly due to thromboembolism events (8.16%vs. 4.41%, p<.01). SCAD significantly increased the risk of recurrence after catheter ablation of paroxysmal AF. The incidence of thromboembolic events after catheter ablation of paroxysmal AF in the patients with SCAD was significantly higher than that in those without SCAD.

The relationship between fasting blood glucose level and thromboembolism events in patients with non-valvular atrial fibrillation

Objective: To explore the relationship between fasting blood glucose level and thromboembolism events in patients with non-valvular atrial fibrillation (NVAF). Methods: This was an observational study based on data from a multicenter, prospective Chinese atrial fibrillation registry cohort, which included 18 703 consecutive patients with atrial fibrillation (AF) in 31 hospitals in Beijing from August 2011 to December 2018. Patients were divided into 5 groups according to status of comorbid diabetes and fasting glucose levels at admission: normal blood glucose (normal glucose group), pre-diabetes group, strict glycemic control group, average glycemic control group and poor glycemic control group. Patients were followed up by telephone or outpatient service every 6 months. The primary follow-up endpoint was thromboembolic events, including ischemic stroke and systemic embolism. The secondary endpoint was the composite endpoint of cardiovascular death and thromboembolic events. Kaplan-Meier survival analysis and multifactorial Cox regression were used to analyze the correlation between fasting glucose levels and endpoint events. Results: The age of 18 703 patients with NVAF was (63.8±12.0) years, and there were 11 503 (61.5%) male patients. There were 11 877 patients (63.5%) in normal blood glucose group, 2 023 patients (10.8%)in pre-diabetes group, 1 131 patients (6.0%) in strict glycemic control group, 811 patients in average glycemic control group and 2 861 patients(4.3%) in poor glycemic control group. Of the 4 803 diabetic patients, 1 131 patients (23.5%) achieved strict glycemic control, of whom 328 (29.0%) were hypoglycemic (fasting blood glucose level<4.4 mmol/L at admission). During a mean follow-up of (51±23) months (up to 82 months), thromboembolic events were reported in 984 patients (5.3%). The survival curve analysis of Kaplan Meier showed that the incidence rates of thromboembolic events in normal glucose group, pre-diabetes group, strict glycemic control group, average glycemic control group and poor glycemic control group were 1.10/100, 1.41/100, 2.09/100, 1.46/100 and 1.71/100 person-years, respectively (χ²=53.0, log-rank P<0.001). The incidence rates of composite endpoint events were 1.86/100, 2.17/100, 4.08/100, 2.58/100, 3.16/100 person-years (χ²=72.3, log-rank P<0.001). The incidence of thromboembolic events and composite endpoint events in the other four groups were higher than that in the normal blood glucose group (P<0.001). Multivariate Cox regression analysis showed that compared with normal glucose group, the risk of thromboembolism increased in pre-diabetes group(HR=1.23, 95%CI 1.00-1.51, P=0.049), strict glycemic control group(HR=1.32, 95%CI 1.06-1.65, P=0.013) and poor glycemic control group(HR=1.26, 95%CI 1.01-1.58, P=0.044). Conclusion: Both high or low fasting glucose may be an independent risk factor for thromboembolic events in patients with NVAF.

Efficacy and safety of non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation and hypertrophic cardiomyopathy

Objective: To evaluate the efficacy and safety of non-vitamin K antagonist oral anticoagulants (NOAC) in patients with atrial fibrillation (AF) and hypertrophic cardiomyopathy (HCM). Methods: This study was a prospective cohort study. The data of this study were based on the Chinese Atrial Fibrillation Registry (CAFR) Study, which was a prospective, multicenter registry study. The CAFR Study enrolled inpatients and outpatients with AF from 31 hospitals. Patients with AF and HCM were selected from August 2011 to December 2018. The patients were divided into NOAC-treated group and warfarin-treated group. General clinical data, echocardiographic results and treatment options were collected and compared between the two groups. Patients were followed up every 6 months; outcome events included effective endpoint events(thromboembolism)and safety endpoint events(major bleeding). The incidence of endpoint events in both groups was calculated and compared. Cox proportional hazards regression models and Kaplan-Meier survival analysis were performed to determine the association between NOAC use and endpoint events. Results: A total of 393 patients were included (average age: (60.5±11.8) years, 252 men (64.1%)). There were 133 (34.0%) patients in the NOAC-treated group and 260 (66.0%) patients in the warfarin-treated group. Compared with the warfarin-treated group, the patients in the NOAC-treated group had a higher proportion of paroxysmal AF, catheter ablation of AF, a lower proportion of hypertension, ischemic stroke/transient ischemic attack (TIA), lower heart rate, lower usage rate of angiotensin-converting enzyme inhibitors(ACEI)/angiotensin receptor blockers(ARB), β-blockers, non-dihydropyridine calcium channel blockers(NDH-CCB)(P<0.05). There were no significant differences on the echocardiographic results, including interventricular septal thickness, left ventricular posterior wall thickness, left ventricular end-diastolic diameter, left atrial diameter, left ventricular ejection fraction(P>0.05). After a follow-up of 42 (24, 60)months, the incidence rates of thromboembolism were 1.63 and 2.10 events per 100 person-years for NOAC-and warfarin-treated group, and those of major bleeding were 0.66 and 1.03 events per 100 person-years. Kaplan-Meier survival analysis showed survival rates free from endpoint events were similar between NOAC-treated group and warfarin-treated group(thromboembolism-free survival comparison, P=0.476; major bleeding-free survival comparison, P=0.855). Cox multivariate regression analysis revealed that there was no significant difference on risk of thromboembolism(HR=1.21, 95%CI: 0.42-3.50, P=0.720) and major bleeding(HR=1.50, 95%CI: 0.27-8.41, P=0.642) between NOAC-treated and warfarin-treated group. Conclusion: Patients with AF and HCM can be safely and effectively treated with NOAC.

Associations of anemia with death and major bleeding in patients with atrial fibrillation: A report from the Chinese Atrial Fibrillation Registry Study

BackgroundAnemia is a common comorbidity in patients with atrial fibrillation (AF). Reports on the association of anemia and adverse events in patients with AF, especially from Asia, are limited.Methods and ResultsBased on data from the Chinese Atrial Fibrillation Registry Study (CAFR), a total of 18,106 AF patients enrolled between August 2011 and December 2018 had hemoglobin (Hb) values recorded at baseline. Patients were classified into three groups according to Hb levels: 15,606 patients (86.2%) into the no anemia group (male Hb≥130 g/L; female Hb≥120 g/L), 1800 (9.9%) with mild anemia (male 110≤Hb<129 g/L; female 110≤Hb<119 g/L), and 700 (3.9%) with moderate to severe anemia (Hb≤109 g/L). Multivariable Cox regression models were used to determine if anemia was independently associated with all‐cause death, cardiovascular death, or major bleeding, after adjusting for confounders.Anemia was present in 13.8% of the population at baseline. During a median follow‐up of 4.01 years, the incidences of all‐cause death (1.8, 4.9, and 8.9 per 100 person‐years), cardiovascular death (1.0, 2.9, and 4.5 per 100 person‐years), and major bleeding (0.5, 0.6, and 0.7 per 100 person‐years) were gradually accentuated in patients with no anemia, mild anemia, and moderate to severe anemia, respectively. Compared with patients with no anemia, those with anemia had higher risks for all‐cause death (mild anemia; adjusted hazard ratio [HR]: 1.22, 95% confidence interval [CI]: 1.08–1.38; moderate to severe anemia; adjusted HR: 1.53, 95% CI: 1.31–1.77); and cardiovascular death (mild anemia; adjusted HR: 1.29, 95% CI: 1.10–1.52; moderate to severe anemia; adjusted HR: 1.27, 95% CI: 1.03–1.57), but not for major bleeding. The association between anemia and all‐cause death was similar among subgroups stratified by sex, kidney function, anticoagulant, or ablation therapy.ConclusionsAnemia was associated with increased risks of all‐cause death, cardiovascular death, but no major bleeding in AF patients. The effect of anemia correction on the prognosis of patients with AF requires further study.

Chronic kidney disease and risks of adverse clinical events in patients with atrial fibrillation

BACKGROUNDChronic kidney disease (CKD) is highly prevalent in patients with atrial fibrillation (AF). However, the association between CKD and clinical consequences in AF patients is still under debate.METHODSWe included 19,079 nonvalvular AF patients with available estimated glomerular filtration rate (eGFR) values in the Chinese Atrial Fibrillation Registry from 2011 to 2018. Patients were classified into no CKD (eGFR ≥ 90 mL/min per 1.73 m2), mild CKD (60 ≤ eGFR < 90 mL/min per 1.73 m 2), moderate CKD (30 ≤ eGFR < 60 mL/min per 1.73 m 2), and severe CKD (eGFR < 30 mL/min per 1.73 m 2) groups. The risks of thromboembolism, major bleeding, and cardiovascular mortality were estimated with Fine-Gray regression analysis according to CKD status. Cox regression was performed to assess the risk of all-cause mortality associated with CKD. RESULTSOver a mean follow-up of 4.1 ± 1.9 years, there were 985 thromboembolic events, 414 major bleeding events, 956 cardiovascular deaths, and 1,786 all-cause deaths. After multivariate adjustment, CKD was not an independent risk factor of thromboembolic events. As compared to patients with no CKD, those with mild CKD, moderate CKD, and severe CKD had a 45%, 47%, and 133% higher risk of major bleeding, respectively. There was a graded increased risk of cardiovascular mortality associated with CKD status compared with no CKD group: adjusted hazard ratio [HR] was 1.34 (95% CI: 1.07−1.68,P = 0.011) for mild CKD group, 2.17 (95% CI: 1.67−2.81,P < 0.0001) for moderate CKD group, and 2.95 (95% CI: 1.97−4.41, P < 0.0001) for severe CKD group, respectively. Risk of all-cause mortality also increased among patients with moderate or severe CKD. CONCLUSIONSCKD status was independently associated with progressively higher risks of major bleeding and mortality, but didn’t seem to be an independent predictor of thromboembolism in AF patients.

Integrated Care of Atrial Fibrillation Using the ABC (Atrial fibrillation Better Care) Pathway Improves Clinical Outcomes in Chinese Population: An Analysis From the Chinese Atrial Fibrillation Registry.

Background: “Atrial fibrillation Better Care” (ABC) pathway has been proposed to improve the management of patients suffered from atrial fibrillation (AF). This integrated or holistic management approach comprise of three aspects, including “A” Avoid stroke or Anticoagulation; “B” Better symptom control with rate or rhythm control strategies; “C” Cardiovascular risk factor and Concomitant diseases management. We aimed to confirm the beneficial evidence of ABC pathway compliance in a Chinese AF cohort.Method and Results: From the Chinese Atrial Fibrillation registry (CAFR) dataset, a total of 19,187 non-valvular AF patients were enrolled, of which 4.365 (22.8%) were ABC pathway compliant (ABC compliance group). During a median follow-up of 4.1 ± 1.8 years, The incident rate of all-cause death in ABC compliance group and non-ABC compliance group is 2.7 and 1.1 per 100 person-year (p < 0.001), the incident rate of ischemic stroke is 1.3 and 0.8% per 100 person-year (p < 0.001), the incident rate of composite outcome, which consist of all-cause death, ischemic stroke and intracranial hemorrhage, is 3.8 and 1.9 per 100 person-year (p < 0.001). On Cox multivariable analysis, ABC pathway shows an independently association with reduction of all-cause death [hazard ratio (HR) = 0.82; 95% confidence interval (CI) = 0.70–0.95] and the composite outcome (HR 0.86, 95% CI 0.76–0.96). The increasingly components of ABC integrated care compliance is associated with lower risk of all-cause death and composite events.Conclusion: In a large cohort of Chinese AF patients, ABC pathway compliance shows an independently association with reduction of all-cause death and composite outcome of all-cause death, ischemic stroke and intracranial hemorrhage. Better compliance of ABC integrated care contributes to lower HR for adverse events.

Renin–angiotensin system inhibitors and clinical outcomes in patients with atrial fibrillation and heart failure: a propensity score-matched study from the Chinese Atrial Fibrillation Registry

ObjectiveThe effect of renin–angiotensin system inhibitors (RASIs) in patients with heart failure (HF) and atrial fibrillation (AF) remains unclear. This study aimed to investigate associations between RASI use and all-cause mortality and cardiovascular outcomes in patients with AF and HF.MethodsUsing data from the China Atrial Fibrillation Registry study, we included 938 patients with AF and HF with a left ventricular ejection fraction <50%. Cox regression models for RASIs vs. non-RASIs with all-cause mortality as the primary outcome were fitted in a 1:1 propensity score-matched cohort. A sensitivity analysis was performed by using a multivariable time-dependent Cox regression model. As an internal control, we assessed the relation between β-blocker use and all-cause mortality.ResultsDuring a mean follow-up of 35 months, the risk of all-cause mortality was similar in RASI users compared with non-users (hazard ratio: 0.92; 95% confidence interval: 0.67–1.26). Similar results were obtained in the sensitivity analysis. In contrast, β-blocker use was associated with significantly lower all-cause mortality in the same population.ConclusionsRASI use was not associated with better outcomes in patients with AF and HF in this prospective cohort, which raises questions about their value in this specific subset.Trail Registration: ChiCTR-OCH-13003729.

Evaluation of medical quality and treatment trends of nonvalvular atrial fibrillation in Beijing inpatients.

The quality of care presented to AF cases in tertiary and non-tertiary hospitals in China remains obscure and needs further investigation. Therefore, we examined the compliance with quality measures (QMs) and clinical performance measures (PMs) that were proposed by the ACC/AHA in 2016 in a Chinese adult population with nonvalvular atrial fibrillation (AF). We also investigated the changes in patients' characteristics, treatment plans, and quality of provided care at different time-points [2011-2016]. We used the datasets from two registry-based studies in Beijing, including the Chinese Atrial Fibrillation Registry (CHINA-AF) investigation. From August 2011 to July 2016, an overall number of 13,439 nonvalvular AF cases were included. Our primary outcome was to determine the compliance rate with two PMs [oral anticoagulant (OAC) use and prothrombin time international normalized ratio (INR)] and six QMs (beta-blocker, ACEI-ARB, and the inappropriate prescription of antiarrhythmic drugs, Sotalol, antiplatelet and OAC, and non-dihydropyridine calcium channel antagonist) over a period of 5 years [2011-2016]. Also, the difference in compliance between tertiary and non-tertiary hospitals was investigated. The compliance with PMs and QMs was variable between tertiary and non-tertiary hospitals. In tertiary hospitals, the total number of inpatient beds was >500, and each bed was equipped with >1.03 health technical personnel and >0.4 nurses. In non-tertiary hospitals, the available beds capacity was <500, and each bed corresponded with 0.7-0.88 health technical personnel and >0.4 nurses. The compliance rates with OAC use steadily increased from 2011-2015 in tertiary hospitals (35%, 35.9%, 37.9%, 45%, and 49%, P<0.001). In non-tertiary hospitals, INR follow-up of warfarin use increased significantly over the years, with rates of 36.2%, 60.5%, 71.6%, 64.3%, and 81.5% (P=0.04), respectively. In terms of QMs, the compliance with the six measure sets was quite similar among tertiary and non-tertiary hospitals avoiding any significant difference over the years (P>0.05). We noted an improvement in medical quality regarding the use of OAC, especially in tertiary hospitals. Meanwhile, the compliance rates of INR follow-up improved in non-tertiary hospitals. However, the compliance rates of other performance and QMs are still low, which are in need of improvement.

Incidence and predictors of hospitalization in patients with atrial fibrillation: results from the Chinese atrial fibrillation registry study

BackgroundPatients with atrial fibrillation (AF) underwent a high risk of hospitalization, which has not been paid much attention to in practice. Therefore, we aimed to assess the incidence, causes and predictors of hospitalization in AF patients.MethodsFrom August 2011 to December 2017, a total number of 20,172 AF patients from the Chinese Atrial Fibrillation Registry (China-AF) Study were prospectively selected for this study. We described the incidence, causes of hospitalization by age groups and sex. The Fine-Gray competing risk model was employed to identify predictors of first all-cause and first cause-specific hospitalization.ResultsAfter a mean follow-up of 37.3 ± 20.4 months, 7,512 (37.2%) AF patients experienced one or more hospitalizations. The overall incidence of all-cause hospitalization was 24.0 per 100 patient-years. Patients aged < 65 years were predominantly hospitalized for AF (42.1% of the total hospitalizations); while patients aged 65–74 and ≥ 75 years were mainly hospitalized for non-cardiovascular diseases (43.6% and 49.3%, respectively). We found patients complicated with heart failure (HF)[hazard ratio (HR) 1.10, 95% confidence interval (CI) 1.02–1.18], established coronary artery disease (CAD) (HR 1.24, 95%CI 1.17–1.33), ischemic stroke/transient ischemic attack (TIA) (HR 1.22, 95%CI 1.15–1.30), diabetes (HR 1.14, 95%CI 1.08–1.20), chronic obstructive pulmonary disease (COPD) (HR 1.28, 95%CI 1.02–1.62), gastrointestinal disorder (HR 1.37, 95%CI 1.21–1.55), and renal dysfunction (HR 1.24, 95%CI 1.09–1.42) had higher risks of hospitalization.ConclusionsMore than one-third of AF patients included in this study were hospitalized at least once during over 3-year follow-up. The main cause for hospitalization among the elderly patients (≥ 65 years) is non-cardiovascular diseases rather than AF. Multidisciplinary management of comorbidities should be advocated to reduce hospitalization in AF patients older than 65 years old.Clinical Registryhttp://www.chictr.org.cn/showproj.aspx?proj=5831. Unique identifier: ChiCTR-OCH-13003729. The registration date is October 22, 2013.

Mild Renal Dysfunction and Risk of Thromboembolism and Bleeding in Patients with Atrial Fibrillation: The Chinese Atrial Fibrillation Registry Study

Abstract Objective: Previous studies indicated that patients with atrial fibrillation (AF) and moderate-to-severe chronic kidney disease (CKD) are at a higher risk of thromboembolism and bleeding during anticoagulation. Whether mild CKD is associated with an increased risk of thromboembolism and bleeding in AF patients remains unknown. This study aimed to evaluate the impact of mild CKD on thromboembolism and major bleeding among patients with AF. Methods: Baseline serum creatinine was available in 17,559 of 25,512 patients enrolled in the China-AF study between August 2011 and December 2018. After excluding those who underwent AF ablation or with moderate-to-severe CKD, 7191 non-valvular AF patients (2059 with mild CKD and 5132 with normal renal function) with regular follow-up for at least 6 months were included. Primary outcomes were the time to the first occurrence of thromboembolic and major bleeding events. Results: Over a mean follow-up of (44.4 ± 23.4) months, 639 thromboembolism and 231 major bleeding events occurred. The crude incidence rates of thromboembolism were higher in the mild CKD group than that of the normal renal function group (3.0/100 person-years vs. 2.2/100 person-years, P &lt; 0.0001), while the crude incidence rates of major bleeding were comparable between the two groups (1.0/100 person-years vs. 0.8/100 person-years, P = 0.076). After multivariate analyses, mild CKD was not associated with an increased risk of thromboembolism (HR = 1.05, 95% CI: 0.89–1.25, P = 0.547) or major bleeding (HR = 1.11, 95% CI: 0.84–1.47, P = 0.476). Conclusions: Mild CKD was not an independent risk factor of thromboembolism or major bleeding in patients with AF.

Effect of family history of atrial fibrillation on recurrence after atrial fibrillation ablation: A report from the Chinese Atrial Fibrillation Registry Study.

To evaluate the impact of family history of atrial fibrillation (FAF) on postablation atrial tachyarrhythmia (AT) recurrence. All the 8198 patients undergoing initial AF ablation registered in the Chinese Atrial Fibrillation Registry study were analyzed. FAF was defined as having first-degree relatives diagnosed as AF at age 65 years or younger, and before the time the case in this study was diagnosed. Cox proportional hazards models were used to evaluate the impact of FAF on postablation AT recurrence. Age, sex, body mass index, AF type, history of congestive heart failure, hypertension, diabetes mellitus, prior stroke/transient ischemic attack/systemic embolism, vascular diseases, use of contact force-sensing catheter, and completion of high school were adjusted. The definition of AT recurrence was any documented AF, atrial flutter, or AT lasting more than or equal to 30 s after 3 months blanking period. After a mean follow-up of 26.2 ± 19.6 months, 318 out of the 645 patients (49.3%) with FAF and 3339 out of the 7553 patients (44.2%) without FAF experienced AT recurrence, corresponding to annual recurrence rates of 22.8% and 20.2%, respectively. Patients with FAF had a significant higher risk of AT recurrence (adjusted hazard ratio 1.129, 95% confidence interval 1.005-1.267) in multivariable analysis. Moreover, FAF had a significant higher impact on AT recurrence in the subgroup of patients diagnosed with AF at age 50 years or younger (p for interaction = .036). FAF is a risk factor for postablation AT recurrence. This is especially true in those with AF diagnosed at 50 years or younger.

Catheter ablation for atrial fibrillation is associated with reduced risk of mortality in the elderly: a prospective cohort study and propensity score analysis.

BackgroundIt is unclear whether catheter ablation (CA) for atrial fibrillation (AF) affects the long-term prognosis in the elderly. This study aims to evaluate the relationship between CA and long-term outcomes in elderly patients with AF.MethodsPatients more than 75 years old with non-valvular AF were prospectively enrolled between August 2011 and December 2017 in the Chinese Atrial Fibrillation Registry Study. Participants who underwent CA at baseline were propensity score matched (1:1) with those who did not receive CA. The outcome events included all-cause mortality, cardiovascular mortality, stroke/transient ischemic attack (TIA), and cardiovascular hospitalization.ResultsOverall, this cohort included 571 ablated patients and 571 non-ablated patients with similar characteristics on 18 dimensions. During a mean follow-up of 39.75 ± 19.98 months (minimum six months), 24 patients died in the ablation group, compared with 60 deaths in the non-ablation group [hazard ratio (HR) = 0.49, 95% confidence interval (CI): 0.30-0.79, P = 0.0024]. Besides, 6 ablated and 29 non-ablated subjects died of cardiovascular disease (HR = 0.25, 95% CI: 0.11–0.61, P = 0.0022). A total of 27 ablated and 40 non-ablated patients suffered stroke/TIA (HR = 0.79, 95% CI: 0.48–1.28, P = 0.3431). In addition, 140 ablated and 194 non-ablated participants suffered cardiovascular hospitalization (HR = 0.84, 95% CI: 0.67–1.04, P = 0.1084). Subgroup analyses according to gender, type of AF, time since onset of AF, and anticoagulants exposure in initiation did not show significant heterogeneity.ConclusionsIn elderly patients with AF, CA may be associated with a lower incidence of all-cause and cardiovascular mortality.