Serial measurement of biomarkers and the risk of stroke or systemic embolism and bleeding in patients with atrial fibrillation in ENGAGE AF-TIMI 48

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
K Oyama ◽  
R Giugliano ◽  
D Berg ◽  
C Ruff ◽  
M Tang ◽  
...  

Abstract Background Patients with atrial fibrillation (AF) have progressive cardiac structural changes that may be manifest by biomarkers of myocardial injury and hemodynamic stress. Baseline values of hsTnT (high-sensitivity troponin T), and NT-proBNP (N-terminal pro-brain natriuretic peptide) are associated with stroke risk and GDF-15 (growth differentiation factor-15) is associated with bleeding risk in patients with AF. However, the variability of these biomarkers over time and their associations with stroke or systemic embolism events (S/SEE) and bleeding in patients with AF remain unclear. Purpose We examined whether patients with AF demonstrate detectable changes in these biomarkers over 12 months and whether such changes from baseline to 12 months are associated with the subsequent risk of S/SEE (hsTnT, NT-proBNP) and bleeding (GDF-15). Methods ENGAGE AF-TIMI 48 was a multinational randomized trial of the oral factor Xa inhibitor edoxaban in patients with atrial fibrillation and a CHADS2 score ≥2. We performed a nested prospective biomarker study in 6062 patients, analyzing hsTnT, NT-proBNP, and GDF-15 at baseline and 12 months. Event rates were estimated and displayed with annualized event rates after 12 months. Results Of 6062 patients, hsTnT was dynamic in 46.9% (≥2 ng/L change), NT-proBNP in 51.9% (≥200 pg/L change), GDF-15 in 45.6% (≥300 pg/L change) between baseline and 12 months. In addition, 7.7% in hsTnT shifted from low->high categories, 9.4% in NT-proBNP from low->high, 10.6% in GDF-15 from low->high over 12 months (Figure). Elevated hsTnT (≥14 ng/L) and NT-proBNP (≥900 pg/L) either at baseline or at 12 months were independently associated with higher rates of subsequent S/SEE, and elevated GDF-15 (≥1800 pg/L) either at baseline or at 12 months were independently associated with higher rates of subsequent bleeding (P<0.001 for each). In a Cox regression model, the absolute changes in log2-transformed hsTnT and NT-proBNP were associated with increased risk of S/SEE (adj-HR, 1.75; 95% CI, 1.38–2.23; p<0.001, and adj-HR, 1.31; 95% CI, 1.11–1.55; p=0.002, respectively) and log2-transformed GDF-15 with bleeding (adj-HR, 1.42; 95% CI, 1.04–1.92; p=0.025). Analyzed in a categorical manner (Figure), patients who increased hsTnT or NT-proBNP between baseline and 12 months or had high hsTnT or NT-proBNP at both timepoints were at higher risk for S/SEE (adj-HR 1.87 and 1.50 for hsTnT; adj-HR 1.80 and 2.59 for NT-proBNP, respectively). Patients with persistently elevated GDF-15 appeared to be at higher risk for bleeding (adj-HR,1.35) (Figure). Conclusions Serial assessment of hsTnT, NT-proBNP, and GDF-15 revealed a substantial proportion of patients with AF had dynamic values. Patients with either persistently elevated or dynamic values were at higher risk of adverse clinical outcomes. Those biomarkers may play a role in personalizing preventive strategies in patients with AF based on risk. Change in biomarkers and event rate Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Daiichi Sankyo Pharma Development

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M Akao ◽  
T Yamashita ◽  
S Suzuki ◽  
K Okumura

Abstract Background Randomized clinical trials demonstrated the efficacy and safety of apixaban in preventing stroke in patients with atrial fibrillation (AF). However, data on patients with low creatinine clearance (CCr), especially CCr 15–29 mL/min, are limited. Methods The J-ELD AF Registry is a large-scale, multicenter prospective observational study of Japanese non-valvular AF patients aged ≥75 years taking on-label dose (standard dose of 5 mg bid or reduced dose of 2.5 mg bid) of apixaban. The enrollment period was from September 2015 to August 2016, and the observation period for each patient was 1 year. The entire cohort (3,015 patients from 110 institutions) was divided into three CCr subgroups: CCr ≥50 mL/min (n=1,165, 38.6%), CCr 30–49 mL/min (n=1,395, 46.3%), and CCr 15–29 mL/min (n=455, 15.1%). Results Most patients (74.3%) in the CCr ≥50 group received the standard apixaban dose, and most (97.4%) in the CCr 15–29 group received the reduced apixaban dose. The average age was 79.2 years for the CCr ≥50 group, 82.5 years for the CCr 30–49 group, and 85.6 years for the CCr 15–29 group. The lower CCr value group included more female patients, had lower body weight, and less cases of paroxysmal AF, as well as more cases of heart failure, peripheral artery disease, and myocardial infarction as comorbidities. The CHA2DS2-VASc and HAS-BLED scores were 4.2±1.2 and 2.4±0.8 for the CCr ≥50 group, 4.5±1.2 and 2.4±0.8 for the CCr 30–49 group, and 4.9±1.2 and 2.4±0.7 for the CCr 15–29 group, respectively. Kaplan Meier curves for cumulative incidence of events are shown in Figure. The event incidence rates (/100 person-years) were 1.76, 1.39, and 1.67 for stroke or systemic embolism (log rank p=0.762), 1.39, 1.93, and 3.13 for bleeding requiring hospitalization (log rank p=0.159), 1.75, 2.76, and 7.87 for total deaths (log rank p<0.001), and 0.46, 0.84, and 2.62 for cardiovascular deaths (log rank p<0.001), in the CCr ≥50 group, CCr 30–49 group, and CCr 15–29 group, respectively. After adjusting for confounders by Cox regression analysis, CCr 15–29 was an independent risk for total death [hazard ratio (HR) 3.22, 95% confidence interval (CI) 1.68–6.17, with reference to the CCr ≥50 group] and cardiovascular death [HR 3.18, 95% CI 1.06–9.56], but not for stroke or systemic embolism [HR 0.94, 95% CI 0.40–2.24], or bleeding requiring hospitalization [HR 2.00, 95% CI 0.93–4.28]. Conclusions The incidence of events in each CCr value group was comparable for stroke or systemic embolism and bleeding requiring hospitalization, and significantly higher for total deaths and cardiovascular deaths only in the CCr 15–29 group, in Japanese non-valvular AF patients aged ≥75 years. Cumulative incidence rates of events Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Bristol-Myers Squibb


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M Proietti ◽  
M Vitolo ◽  
S Harrison ◽  
G.A Dan ◽  
A.P Maggioni ◽  
...  

Abstract Introduction Frailty is a major health determinant for cardiovascular disease. Thus far, data on frailty in patients with atrial fibrillation (AF) are limited. Aims To evaluate frailty in a large contemporary cohort of European AF patients, the relationship with oral anticoagulant (OAC) prescription and with risk of all-cause death. Methods We analyzed patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. A 38-items frailty index (FI) was derived from baseline characteristics according to the accumulation of deficits model proposed by Rockwood and Mitnitsky. All-cause mortality was the primary study outcome. Results Out of the 11096 AF enrolled patients, data for evaluating frailty were available for 6557 (59.1%) patients who have been included in this analysis (mean [SD] age 68.9 [11.5], 37.7% females). Baseline median [IQR] CHA2DS2-VASc and HAS-BLED were 3 [2–4] and 1 [1–2], respectively. At baseline, median [IQR] FI was 0.16 (0.12–0.23), with 1276 (19.5%) patients considered “not-frail” (FI<0.10), 4033 (61.5%) considered “pre-frail” (FI 0.10–0.25) and 1248 (19.0%) considered “frail” (FI≥0.25). Age, female prevalence, CHA2DS2-VASc and HAS-BLED progressively increased across the FI classes (all p<0.001). Use of OAC progressively increased among FI classes; after adjustments FI was not associated with OAC prescription (odds ratio [OR]: 1.09, 95% confidence interval [CI]: 0.98–1.19 for each 0.10 FI increase). Conversely, FI was directly associated with vitamin K antagonist (VKA) use (OR: 1.26, 95% CI: 1.18–1.34 for each 0.10 FI increase) and inversely associated with non-VKA OACs (NOACs) use (OR: 0.82, 95% CI: 0.77–0.88). FI was significantly correlated with CHA2DS2-VASc (Rho= 0.516, p<0.001). Over a median [IQR] follow-up of 731 [704–749] days, there were 569 (8.7%) all-cause death events. Kaplan-Meier curves [Figure] showed an increasing cumulative risk for all-cause death according to FI categories. A Cox multivariable analysis, adjusted for age, sex, type of AF and use of OAC, found that increasing FI as a continuous variable was associated with an increased risk of all-cause death (hazard ratio [HR]: 1.56, 95% CI: 1.40–1.73 for each 0.10 FI increase). An association with all-cause death risk was found across the FI categories (HR: 1.71, 95% CI: 1.23–2.38 and HR: 2.88, 95% CI: 2.02–4.12, respectively for pre-frail and frail patients compared to non-frail ones). FI was also predictive of all-cause death (c-index: 0.660, 95% CI: 0.637–0.682; p<0.001). Conclusions In a European contemporary cohort of AF patients the burden of frailty is significant, with almost 1 out of 5 patients found to be “frail”. Frailty influenced significantly the choice of OAC therapy and was associated with (and predictive of) all-cause death at follow-up. Kaplan-Meier Curves Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Since the start of EORP programme, several companies have supported it with unrestricted grants.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
Y.M Cha ◽  
M.D Metzl ◽  
R.C Canby ◽  
E.M Fruechte ◽  
M Duggal ◽  
...  

Abstract Introduction Chronic right ventricular pacing (RVP) has been associated with dyssynchrony, leading to increased mortality. However, there have been discrepancies in previous reports in the effect of RVP levels. Objective To sub-stratify mortality risk by age for different RVP level groups within a large real-world ICD cohort. Methods Optum® de-identified electronic health records were linked to the Medtronic Carelink data to identify dual chamber ICD recipients (2007–2017). RVP level was based on median daily pacing during the first 90 days post-implant and categorized either into groups with a cutoff of 40%, or with groups of 0–9%, 10–19%, 20–29%, 30–39%, 40–49%, and 50–100%. The endpoint was death more than 90 days post-implant. Kaplan-Meier survival curves, log-rank tests, and Cox regression were used to analyze the relationship between RVP and risk of death. Results Among 14,832 ICD patients (median age 67; 74.0% male), there were 2,602 deaths within 10 years after implant. In unadjusted comparisons, high RVP (>40%) increased the risk of death relative to low RVP (≤40%) (p<0.001). This effect remained significant in older cohort (≥67 years old at implant) (p<0.001), but not in younger cohort (<67 years old) (p=0.955) (Figure). After controlling for age, gender, pacing mode, MI, SCA, HF hospitalization, diabetes, and renal dysfunction, similar or increased risk was associated with higher pacing groups relative to the 0–9% pacing group in the older cohort, but not in the younger cohort. Conclusions Our data from a large contemporaneous real-world source suggests that older age or characteristics associated with age make patients more sensitive to chronic RVP effects. These results help reconcile differences observed in prior studies. Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Medtronic, Inc.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M Thind ◽  
W Zareba ◽  
D Atar ◽  
H Crijns ◽  
J Zhu ◽  
...  

Abstract Background/Introduction The use of antiarrhythmic drugs in patients with chronic kidney disease (CKD) is complex because impaired renal clearance can cause increased drug levels, and risk of intolerance or adverse events. Since CKD commonly co-occurs with atrial fibrillation/atrial flutter (AF/AFL), it is important to establish efficacy and safety for such drugs when used in AF/AFL patients with CKD. Purpose To evaluate the efficacy and safety of dronedarone in patients with AF or AFL across different levels of renal function. Methods This post hoc analysis evaluated pooled data from two multicentre, double-blind, randomised (2:1) trials of rhythm control with dronedarone 400 mg twice daily vs placebo. Primary endpoint was time to first recurrence of AF or AFL. Renal function (estimated glomerular filtration rate [eGFR]) was assessed with the CKD-Epidemiology Collaboration equation. Patients were grouped by eGFR strata. Log-rank testing and Cox regression were used to compare time to events between treatment groups. Results Most (85%) patients had mild or mild-to-moderate decrease in eGFR (Table 1). Median time to first AF recurrence was significantly longer in the dronedarone vs placebo group for all eGFR subgroups except the 30–44 mL/min group (Figure 1), where the trend was consistent; however, the small population size may have precluded meaningful analyses in this subgroup. Serious adverse events, deaths, and treatment discontinuations did not differ notably between each group irrespective of eGFR strata. Conclusions This analysis confirms the efficacy and safety of dronedarone in patients with AF across a wide spectrum of renal function. Figure 1 Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Sanofi


Author(s):  
Alexander P. Benz ◽  
Ziad Hijazi ◽  
Johan Lindbäck ◽  
Stuart J. Connolly ◽  
John W. Eikelboom ◽  
...  

Background: The novel ABC (Age, Biomarkers, Clinical History) scores outperform traditional risk scores for stroke, major bleeding and death in patients with atrial fibrillation (AF) receiving oral anticoagulation. To refine their utility, the ABC-AF scores needed to be validated in patients not receiving oral anticoagulation. Methods: We measured plasma levels of the ABC biomarkers (N-terminal pro-B-type natriuretic peptide, cardiac troponin-T and growth-differentiation factor-15) to apply the previously developed ABC-AF scores in patients with AF receiving aspirin (n=3,195) or aspirin and clopidogrel (n=1,110) in two large clinical trials. Calibration was assessed by comparing estimated with observed one-year risks. Cox-regression models were used for recalibration. Discrimination was evaluated separately for the aspirin only and the overall cohort (n=4,305). Results: The ABC-AF-stroke score yielded a c-index of 0.70 (95% confidence interval [CI] 0.67-0.73) in both cohorts. The ABC-AF-bleeding score had a c-index of 0.76 (95% CI 0.71-0.81) in the aspirin only cohort and 0.73 (95% CI 0.69-0.77) overall. Both scores were superior to risk scores recommended by current guidelines. The ABC-AF-death score yielded a c-index of 0.78 (95% CI 0.76-0.80) overall. Calibrated in patients receiving oral anticoagulation, the ABC-AF-stroke score underestimated, and the ABC-AF-bleeding score overestimated the risk of events in both cohorts. These scores were recalibrated for prediction of absolute event rates in the absence of oral anticoagulation. Conclusions: The biomarker-based ABC-AF scores showed better discrimination than traditional risk scores and were recalibrated for precise risk estimation in patients not receiving oral anticoagulation. They can now provide improved decision support regarding treatment of an individual patient with AF.


2016 ◽  
Vol 115 (03) ◽  
pp. 663-677 ◽  
Author(s):  
Pasquale Ambrosino ◽  
Antonio Dello Russo ◽  
Michela Casella ◽  
Elena Tremoli ◽  
Claudio Tondo ◽  
...  

SummaryWe performed a meta-analysis about the prevalence of left atrial thrombus (LAT) in patients with atrial fibrillation (AF) undergoing trans-esophageal echocardiography (TEE). Studies reporting on LAT presence in AF patients were systematically searched in the PubMed, Web of Science, Scopus and EMBASE databases and the pooled LAT prevalence was evaluated as weighted mean prevalence (WMP). Seventy-two studies (20,516 AF patients) showed a LAT WMP of 9.8 % (95 %CI: 7.6 %-12.5 %). LAT presence was associated with a higher age (mean difference: 2.56, 95 %CI: 1.49–3.62), and higher prevalence of female gender (OR: 1.35, 95 %CI: 1.04–1.75), hypertension (OR: 1.78, 95 %CI: 1.38–2.30), diabetes mellitus (OR: 1.86, 95 %CI: 1.33–2.59) and chronic heart failure (OR: 3.67, 95 %CI: 2.40–5.60). Overall, LAT patients exhibited a higher CHADS2-score (mean difference 0.88, 95 %CI: 0.68–1.07) and a higher risk of stroke/systemic embolism (OR: 3.53, 95 %CI: 2.24–5.56) compared with those without LAT. A meta-regression showed an inverse association between LAT prevalence and the presence of anticoagulation (Z-value: −7.3, p< 0.001). Indeed, studies in which 100 % of patients received oral anticoagulation reported a 3.4 % WMP of LAT (95 %CI: 1.3 %–8.7 %), whereas studies in which 0 % of patients received anticoagulation showed a LAT WMP of 7.4 % (95 %CI: 2.3 %–21.5%). Our data suggest that LAT is present in ≈10 % of AF patients, and is associated with a 3.5-fold increased risk of stroke/systemic embolism. Interestingly, LAT is also reported in some of patients receiving anticoagulation. The implementation of the screening of LAT in AF patients before cardioversion/ablation could be useful for the prevention of vascular events.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
C Wassberg ◽  
G Batra ◽  
N Hadziosmanovic ◽  
E Hagstrom ◽  
H White ◽  
...  

Abstract Background Psychosocial burden is associated with increased risk of cardiovascular (CV) events in patients with stable coronary heart disease (CHD). The underlying mechanisms linking psychosocial burden and CHD are unclear and might be explained by studying biomarkers known to be associated with CV risk. Methods 15,608 patients in the STABILITY trial completed a questionnaire on to what extent they were feeling down, had loss of interest, experienced financial stress and if they were living alone. Levels of high-sensitivity (hs) C-reactive protein (hs-CRP), interleukin-6 (IL-6), hs-troponin T (hs-TnT) and N-terminal pro-B type natriuretic peptide (NT-proBNP) were assessed at baseline. Associations between levels of psychosocial burden (sometimes, often/always vs. never/rarely) and biomarkers were evaluated in a linear model where geometric mean ratio of the log-transformed biomarker were calculated. Results Adjusted associations (age, gender and established CV risk factors) are presented in the table. Conclusion Psychosocial burden in patients with stable CHD was independently associated with elevated biomarkers. The underlying association is likely to be complex and involve multiple pathways. Funding Acknowledgement Type of funding source: Private company. Main funding source(s): The STABILITY study was funded by GlaxoSmithKline. Roche Diagnostics, Rotkreuz, Switzerland, supported the research by providing the GDF-15 assay free of charge.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
H.K Yaggi ◽  
B Eliasson ◽  
T Kasai ◽  
N Marx ◽  
B Zinman ◽  
...  

Abstract Background/Introduction Obstructive sleep apnoe (OSA) and type 2 diabetes (T2D) occurs more frequently in persons with obesity, and both OSA and T2D are associated with metabolic disturbances that increases the risk for cardiovascular disease (CVD). In EMPA-REG OUTCOME, a randomized placebo-controlled outcome trial involving 7020 patients with T2D and CVD, the sodium glucose co-transporter (SGLT)-2 inhibitor empagliflozin reduced HbA1c, systolic blood pressure, waist circumference, and weight, and also reduced the risk of 3-point major adverse CV events (3P- MACE) by 14%, CV death by 38% and hospitalization for heart failure (HHF) by 35%. Purpose We investigated incidence rates of CV, HHF, and mortality outcomes in patients with or without OSA at baseline, and the treatment effect of empagliflozin, in EMPA-REG OUTCOME. Methods The trial included patients from 42 countries with T2D (with HbA1c 7.0–9.0% for drug-naïve patients and 7.0–10.0% for those on stable glucose-lowering therapy), established CVD, and estimated glomerular filtration rate &gt;30 mL/min/1.73 m2. Patients were randomised (1:1:1) to receive empagliflozin 10 mg, empagliflozin 25 mg, or placebo once daily in addition to standard of care. All CV outcomes were independently adjudicated and events were pooled for the 10 and 25mg doses. In this post-hoc analysis, OSA were assessed based on investigator reports using MedDRA 18.0 and incidence rates for outcomes were reported by adjusted event-rates per 100 patient-years. Analysis of effects on outcomes were performed using Cox regression models with multivariable adjustments. Results Of 7020 patients with T2D and CVD, OSA was reported in 391 (5.6% [placebo 5.4%; pooled empagliflozin doses 5.7%]. Compared with patients without OSA at baseline, those with OSA were more frequent males (82.9% vs 70.8%), living in region North-America (63.2% vs 17.3%), and had more obesity (BMI ≥35 kg/m2: 55.2% vs 18.2%) and more coronary artery disease (88.0 vs 74.9%). Over a median 3.1 years, individuals with OSA at baseline relative to those without OSA in the placebo group, experienced 1.3–2.0 fold higher event rates for 3P-MACE (OSA vs no OSA: 6.49 vs 4.27/100-patient-year), CV death (2.57 vs 1.99), HHF (2.71 vs 1.38) and all-cause mortality (4.29 vs 2.78). Empagliflozin improved CV, HHF, and mortality outcomes regardless of presence of OSA at baseline (p-for interactions &gt;0.05 [Figure 1]). Conclusions In this post-hoc exploratory analysis, patients with OSA had higher frequency of events for 3P-MACE, HHF and mortality. The cardio-protective effects of empagliflozin was consistent in those with and without OSA at baseline. Figure 1. Sleep apnea and empagliflozin Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Boehringer Ingelheim and Eli Lilly Diabetes Alliance


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
T Yamashita ◽  
C.C Wang ◽  
Y.-H Kim ◽  
R De Caterina ◽  
P Kirchhof ◽  
...  

Abstract Background The prevalence of atrial fibrillation (AF) and the need for appropriate anticoagulation increase with age. The benefit/risk profile of direct oral anticoagulants such as edoxaban in elderly population with AF in regular clinical practice is therefore of particular interest. Purpose Analyses of Global ETNA-AF data were performed to report patient characteristics, edoxaban treatment, and 1-year clinical events by age subgroups. Methods Global ETNA-AF is a multicentre, prospective, noninterventional program conducted in Europe, Japan, Korea, Taiwan, and other Asian countries. Demographics, baseline characteristics, and 1-year clinical event data were analysed in four age subgroups. Results Of 26,823 patients included in this analysis, 50.4% were ≥75 years old and 11.6% were ≥85 years. Increase in age was generally associated with lower body weight, lower creatinine clearance, higher CHA2DS2-VASc and HAS-BLED scores, and a higher percentage of patients receiving the reduced dose of 30 mg daily edoxaban. At 1-year, rates of ISTH major bleeding and ischaemic stroke were generally low across all age subgroups. The proportion of intracranial haemorrhage within major bleeding events was similar across age groups. All-cause mortality increased with age more than cardiovascular mortality. Conclusion Data from Global ETNA-AF support the safety and effectiveness of edoxaban in elderly AF patients (including ≥85 years) in routine clinical care with only a small increase in intracranial haemorrhage. The higher all-cause mortality with increasing age is not driven by cardiovascular causes. Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Daiichi Sankyo


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Smoczynska ◽  
H.D.M Beekman ◽  
R.W Chui ◽  
S Rajamani ◽  
M.A Vos

Abstract Background Atrial fibrillation (AF) is the most common cardiac arrhythmia treated in clinical practice. Structural remodeling is characterized by atrial enlargement and contributes to the therapeutic resistance in patients with long-standing AF. Purpose To study the atrial arrhythmogenic and echocardiographic consequences induced by volume overload in the complete chronic atrioventricular block (CAVB) dog. Methods Echocardiographic and electrophysiological data was obtained in 14 anaesthetized Mongrel dogs, in acute AV-block (AAVB), after 6 weeks of CAVB (CAVB6) and CAVB10. Left atrial (LA) volume was determined with 2D echocardiography by using the biplane method. An electrocardiogram and monophasic action potentials (MAP) at the right atrial (RA) free wall were recorded. Atrial effective refractory period (AERP) was determined by continuous programmed electrical stimulation (PES) of 20 beats with a cycle length of 400 ms and an extrastimulus with decremental design until refractoriness was reached. A continuous PES protocol of 20 beats with an extrastimulus 5 ms longer than the AERP was applied for 150 seconds to trigger AF. After 5 min without arrhythmias, autonomic neuromodulation was performed by intravenous infusion (IV) of acetylcholine (1,5μg/kg/min to 6,0μg/kg/min) for 20 min followed by prompt IV infusion of isoprenaline (3μg/min) until the atrial heart rate increased by 20 bpm. PES with an extrastimulus was repeated for 150 seconds to induce AF. Results LA volume increased from 13.7±3.2 ml at AAVB to 20.5±5.9 ml* at CAVB6, and 22.7±6.0 ml* at CAVB10 (Fig. 1A). AERP was similar at AAVB, CAVB6, and CAVB10 (115.8±11.9, 117.3±11.7, and 106.8±12.1 ms respectively). Repetitive AF paroxysms of &gt;10 seconds were induced in 1/14 (7%) dogs at AAVB, 1/11 (9%) at CAVB6, and 5/10 (50%)* at CAVB10 (*p&lt;0.05) upon PES (Fig. 1B). Combined neuromodulation and PES did not increase the AF inducibility rate, but prolonged the longest episode of AF in the inducible dogs from 55±49 seconds to 236±202 seconds* at CAVB10 (Fig. 1C). LA volume was higher in inducible dogs 25.0±4.9 ml compared to 18.4±4.2 ml in non-inducible dogs at CAVB10. Conclusion Sustained atrial dilation forms a substrate for repetitive paroxysms of AF. Neuro-modulation prolongs AF episode duration in susceptible dogs. This animal model can be used to study structural remodeling of the atria and possible therapeutic advances in the management of AF. Figure 1 Funding Acknowledgement Type of funding source: Private company. Main funding source(s): Amgen Research


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