Prediction of response to cardiac resynchronization therapy using cardiac magnetic resonance imaging in non-ischemic dilated cardiomyopathy

Background

Cardiac resynchronization therapy (CRT) is a well-established therapy for symptomatic heart failure with reduced ejection fraction, but the response is different for individuals. Although many modalities have been conducted to predict CRT response, cardiac magnetic resonance (CMR) to predict CRT response has still insufficient usefulness.

Purpose

We determine whether the parameters including late gadolinium enhancement (LGE) identified in CMR could act as predictors of CRT response.

Methods

We retrospectively investigated 124 patients with non-ischemic dilated cardiomyopathy who underwent CMR before CRT implantation between Jan 2010 and July 2021 in a single center. CRT response was defined as a decrease in left ventricular end-systolic volume (LVESV) >15% on echocardiography after at least 3 months after CRT implantation.

Results

Among the study population (mean age 65.7±11.2 years, mean EF 25±6.5%, 50% of female), 85 (69%) patients were defined as CRT responder. The CRT responders had more left bundle branch block (LBBB) compared with non-responders [79 (92.9%) vs. 23 (59.0%), p<0.001], but there was a no difference of QRS duration (158.7 vs 165.0ms, p=0.054) between two groups. CMR analysis showed that there were no significant differences in the left ventricular (LV) chamber volume and LV ejection fraction between CRT-responder and non-responder. However, the right ventricular (RV) chamber volume was smaller (RV end-diastolic volume index, 86.3 vs 103.5 ml/m2, p=0.039; RV end-systolic volume index, 49.3 vs 68.5 ml/m2, p=0.013) and the RV ejection fraction (RVEF) was higher (46.9 vs 37.6%, p=0.002) in CRT-responders compared with non-responders. The LGE on CMR was more shown in non-responders than in CRT-responders [33 (84.6%) vs 45 (52.9%), p<0.001]. In CMR parameters, RV dysfunction (RVEF <45%) [Odds ratio (OR), 0.21 (0.05–0.93), p=0.045] and LGE [OR, 0.21 (0.05–0.58), p=0.01] were significantly associated with poor CRT response.

Conclusions

The presence of LGE and RV dysfunction on CMR were associated with poor CRT response in patients with non-ischemic dilated cardiomyopathy. Further investigation with CMR for pre-CRT patients is needed to support these results.

Funding Acknowledgement

Type of funding sources: None.

Association of usual walking with mortality in oldest old adults aged 85 years and older: a nationwide senior cohort study

Background

Current guidelines recommend moderate to vigorous intensity physical activity (MVPA) for health benefit in adults. However, it is difficult to meet the recommended minimum MVPA in “oldest old” aged over 85. Although walking is simple and easy exercise for oldest old, research on the association between walking and mortality in oldest old are lacking.

Purpose

To investigate the association between walking and the risk of all-cause and cardiovascular mortality among older adults aged 85 years and older.

Methods

7047 participants aged 85 or older underwent the Korean National Health Screening Program, including self-administered questionnaire for physical activity. Reported frequency per week of walking for at least 30 minutes increment was used to classify hours of walking per week. We computed multivariable-adjusted hazard ratios for walking and mutually adjusted for MVPA in relation to all-cause and cardiovascular mortality.

Results

The proportions of participants who engaged in walking, moderate- and vigorous-intensity physical activity were 42.5% (2996/7047), 14.7% (1037/7047) and 11.0% (773/7047), respectively. Only 7.6% (538/7047) of participants met the guidelines recommended minimum MVPA. Compared to inactive individuals, those who walked at least 1 hour per week had lower all-cause (HR 0.60 [95% CI, 0.50–0.74]) and cardiovascular mortality risk (HR 0.61 [95% CI, 0.42–0.89]). Walking 1 hour per week was still significant associated with reduction of risk for all-cause (HR 0.50 [95% CI, 0.40–0.61]) and cardiovascular mortality (HR 0.46 [95% CI, 0.30–0.70]) among participants who reported only walking without any MVPA.

Conclusions

1 hour a week of walking might be of benefit for all-cause and cardiovascular mortality in aged over 85 years, even without MVPA. Promoting walking may be a way to help oldest old avoid inactivity and encourage an active lifestyle for all-cause and cardiovascular mortality risk reduction.

Funding Acknowledgement

Type of funding sources: None.

Blunted atrial reverse remodeling a year after catheter ablation for atrial fibrillation and their long-term rhythm outcome

Background

Although active rhythm control by atrial fibrillation (AF) catheter ablation (AFCA) reduces left atrial (LA) dimension, blunted atrial reverse remodeling can be observed in patients with significant atrial myopathy. We explored the characteristics and long-term outcomes of AF patients who showed blunted atrial reverse remodeling despite no AF recurrence within a year after AFCA.

Methods

Among a total of 2,756 patients with AFCA, we included 1,685 patients (74.8% male, 60.2±10.1 years old, 54.5% paroxysmal AF) who underwent both baseline and 1-year follow-up echocardiogram, baseline LA>40mm, and did not recur within a year. We divided them into tertile groups (T1–T3) based on one-year percent change of LA dimension after propensity matching for age, sex, AF type, and baseline LA dimension. We also investigated the patients' genetic characteristics with blunted LA reverse remodeling (T1) using a genome-wide association study (GWAS).

Results

Patients with blunted LA reverse remodeling (T1, n=424) were independently associated with body mass index (OR 1.082 [1.010–1.160], p=0.025), LA peak pressure (OR 1.010 [1.002–1.019], p=0.019), LA wall thickness (OR 0.448 [0.252–0.789], p=0.006), LA voltage (OR 0.651 [0.463–0.907], p=0.012), and pericardial fat volume (OR 1.004 [1.001–1.008], p=0.014). Throughout 65.9±37.4 months of follow-up, the incidence of AF recurrence a year after the procedure was significantly higher in the T1 group than in T2 or T3 groups (Log-rank p<0.001). Among 894 patients with GWAS, ATXN1, XPO7, KRR1_PHLDA1, ZFHX3, and their polygenic risk score were associated with blunted LA reverse remodeling.

Conclusions

Patients with blunted LA reverse remodeling after AFCA were independently associated with low LA voltage, thin wall thickness, high LA pressure, and fat volume, and have a genetic background. Long-term clinical recurrence a year after AFCA was higher in this patient group with suspicious atrial myopathy.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Health and WelfareNational Research Foundation of Korea

Oral anticoagulation therapy in atrial fibrillation patients with advanced chronic kidney disease: CODE-AF Registry

Background and objectives

Advanced chronic kidney disease (CKD), including end-stage renal disease (ESRD) on dialysis, increases thromboembolic risk among patients with atrial fibrillation (AF). This study examined the comparative safety and efficacy of direct-acting oral anticoagulant (DOAC) compared to warfarin or no OAC among AF patients with advanced CKD or ESRD on dialysis.

Methods

Using data from the COmparison study of Drugs for symptom control and complication prEvention of AF (CODE-AF) registry, 260 non-valvular AF patients with advanced CKD (defined as estimated glomerular filtration rate [eGFR] <3 0ml/min per 1.73 m2) or ESRD on dialysis were enrolled from June 2016 to July 2020. The study population was categorized into DOAC, warfarin, and no OAC group, and differences in major or clinically relevant non-major (CRNM) bleeding, stroke/systemic embolism (SE), myocardial infarction/critical limb ischemia (CLI), and death were assessed.

Results

During a median 24 months of follow-up, major or CRNM bleeding risk was significantly reduced in the DOAC group compared to the warfarin group (hazard ratio [HR] 0.21, 95% confidence interval [CI] 0.05 to 0.95, p=0.042). In addition, the risk of composite adverse clinical outcome (major or CRNM bleeding, stroke/SE, myocardial infarction/CLI, and death) was significantly reduced in the DOAC group compared to the no OAC group (HR 0.32, 95% CI 0.11 to 0.96, p=0.043).

Conclusion

Among AF patients with advanced CKD or ESRD on dialysis, DOAC was associated with a lower risk of major or CRNM bleeding compared to warfarin and a lower risk of composite adverse clinical outcome compared to no OAC.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Korean Healthcare Technology R&D project funded by the Ministry of Health & Welfare (HI15C1200, HC19C0130)

Effects of early recurrence and extra-PV triggers on long-term recurrence after catheter ablation for atrial fibrillation

Background

Although early recurrence (ER) within 3 months after atrial fibrillation (AF) catheter ablation (AFCA) was recently reported to be a reliable predictor of late recurrence (LR), the mechanism is not clear.

Purpose

We explored the characteristics of patients with ER and compared the long-term late recurrence (LR) pattern depending on the existence of extra-pulmonary vein trigger (ExPV-trigger).

Methods

Among 3643 patients who underwent de novo AFCA, we included 1249 patients (59.2±11.0 years old, 31.3% persistent AF) who underwent isoproterenol provocation and regular follow-up over three years after AFCA. We evaluated the risk factors for ER and compared the patients with ER alone (10.1%), LR alone (16.6%), and ER+LR (15.9%), and the outcome of repeat procedure.

Results

Overall ER (ER alone and ER+LR) was independently associated with persistent AF (OR 1.58 [1.16–2.14], p=0.003), extra-PV triggers (OR 2.80 [1.90–4.13], p<0.001), and empirical extra-PV ablation (OR 1.54 [1.15–2.07], p=0.004). Overall LR (LR alone and ER+LR) risk was significantly higher in the ER with ExPV-trigger group than in ER without ExPV-trigger or no ER groups (Log-rank p<0.001). The rhythm outcome of the second procedure did not differ between ER+LR and LR alone groups (Log-rank p=0.160), but was worse in the ER+LR ExPV-trigger than in ER+LR without ExPV-trigger or LR alone groups (Log-rank p=0.005).

Conclusion

ER was independently associated with LR after de novo AFCA. ExPV-trigger played crucial roles in ER and LR after de novo AFCA and worse rhythm outcome after redo AFCA.

Funding Acknowledgement

Type of funding sources: None.

Effect of the epicardial fat volume on the outcomes after a left atrial posterior wall isolation in addition to pulmonary vein isolation in patients with persistent atrial fibrillation

Background

While the effect of a circumferential pulmonary vein isolation (CPVI) alone is unsatisfactory, that of an additional electrical posterior wall box isolation (POBI) is controversial in persistent atrial fibrillation (PeAF) patients. Increased epicardial adipose tissue (EAT) is associated with higher recurrence rates after AF catheter ablation (AFCA).

Purpose

We investigated the possible effects of a POBI on rhythm outcomes with varying EAT volumes.

Methods

We included 1,187 patients with PeAF undergoing a de novo AFCA (79.6% male, median age 60 years) into two groups including those receiving a CPVI alone (n=687) and those an additional POBI (n=500). The rhythm outcomes at two years post-AFCA were compared in subgroups stratified by the total EAT volume using propensity overlap weighting.

Results

A reduced total EAT volume was linearly associated with more favorable rhythm outcomes for an additional POBI treatment than for a CPVI alone (P for interaction=0.002). Among the patients with smaller EAT volumes (≤116.23 ml, the median value, n=594), an additional POBI was associated with a reduced AF recurrence risk as compared to a CPVI only (weighted hazard ratio [HR] 0.74, 95% confidence interval [CI] 0.56–0.99; weighted log-rank P=0.039). In contrast, among the remaining 593 patients with greater EAT volumes (>116.2 3mL), there was no difference in the AF recurrence risk between an additional POBI and CPVI alone (weighted HR 1.13, 95% CI 0.84–1.52; weighted log-rank P=0.410). Among 185 patients with a repeat ablation, the POBI reconnection rate tended to be higher in the large EAT group (75.0%) than small EAT group (55.4%, P=0.060).

Conclusion

While PeAF patients with a smaller EAT volume averted AF recurrence by an additional POBI after the CPVI, no benefit of the POBI was observed in those with a greater EAT volume. The EAT volume might identify AF patients likely to benefit from linear ablation in addition to the CPVI.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Korean Ministry of Science, ICT & Future Planning (MSIP)Korean Ministry of Health and Welfare

Resting heart rate and cardiovascular outcomes in patients with atrial fibrillation: CODE-AF registry

Funding Acknowledgements

Type of funding sources: None.

Background

The prognostic significance of resting heart rate and its therapeutic target in atrial fibrillation (AF) is uncertain.

Purpose

The aim of this study was to investigate the relationships between resting heart rate and cardiovascular outcomes in patients with AF.

Methods

A total of 8,886 patients with AF was included from the COmparison study of Drugs for symptom control and complication prEvention of AF (CODE-AF) registry. Patients were categorized according to baseline heart rate, and cardiovascular outcomes were accessed during a median follow-up of 30 months. The primary outcome was a composite of cardiovascular death, hospitalization due to heart failure, and myocardial infarction/critical limb ischemia.

Results

Compared to heart rate ≥100 beats per minute (bpm), heart rate 80-99 bpm was associated with the lowest risk of primary outcome (adjusted hazard ratio [HR] 0.56, 95% confidence interval [CI] 0.40-0.79, p=0.001). In subgroup of patients with heart failure with preserved ejection fraction (HFpEF), heart rate between 80-99 bpm was associated with reduced risk of primary outcome compared to heart rate ≥100 bpm (HR 0.40, 95% CI 0.16-0.98, p=0.045). However, in patients with heart failure with reduced ejection fraction (HFrEF), there was no association between resting heart rate and cardiovascular outcomes (P for interaction 0.001).

Conclusion

Resting heart rate was associated with cardiovascular outcomes in patients with AF, and those with a resting heart rate between 80-99 bpm had the lowest risk of adverse events. The impact of resting heart rate on adverse events persisted in patients with concomitant HFpEF but was not apparent in those with concomitant HFrEF.

Association of ZFHX3 genetic polymorphisms and extra-pulmonary vein triggers in patients with atrial fibrillation who underwent catheter ablation

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Health and Welfare, National Research Foundation of Korea (NRF)

Abstract

Background

The ZFHX3 gene (16q22) is the second most highly associated gene with atrial fibrillation (AF) and is related to inflammation and fibrosis.

Purpose

We hypothesized that ZFHX3 is associated with extra-pulmonary vein (PV) triggers, left atrial (LA) structural remodeling, and poor rhythm outcomes of AF catheter ablation (AFCA).

Methods

We included 1782 patients who underwent a de novo AFCA (73.5% male, 59.4±10.8 years old, 65.9% paroxysmal AF) and genome-wide association study and divided them into discovery (n=891) and replication cohorts (n=891). All included patients underwent isoproterenol provocation tests and LA voltage mapping. We analyzed the ZFHX3, extra-PV trigger-related factors, and rhythm outcomes.

Results

Among 14 single-nucleotide polymorphisms (SNPs) of ZFHX3, rs13336412, rs61208973, rs2106259, rs12927436, and rs1858801 were associated with extra-PV triggers. In the overall patient group, extra-PV triggers were independently associated with the ZFHX3 polygenic risk score (PRS) (OR 1.65 [1.22-2.22], p=0.001, model 1) and a low LA voltage (OR 0.74 [0.56-0.97], p=0.029, model 2). During 49.9±40.3 months of follow-up, clinical recurrence of AF was significantly higher in patients with extra-PV triggers (Log-rank p<0.001, HR 1.89 [1.49-2.39], p<0.001, model 1), large LA dimensions (Log-rank p<0.001, HR 1.03 [1.01-1.05], p=0.002, model 2), and low LA voltages (Log-rank p<0.001, HR 0.73 [0.61-0.86], p<0.001, model 2) but not the ZFHX3 PRS (Log-rank p=0.819).

Conclusions

The extra-PV triggers had significant associations with both ZFHX3 genetic polymorphisms and acquired LA remodeling. Although extra-PV triggers were an independent predictor of AF recurrence after AFCA, the studied AF risk SNPs intronic in ZFHX3 were not associated with AF recurrence.

Comparative effectiveness of early rhythm control versus rate control for cardiovascular outcomes according to sex in patients with atrial fibrillation

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Health & Welfare, Republic of Korea

Background

Rhythm control is associated with better cardiovascular outcomes than usual care among patients recently diagnosed with atrial fibrillation (AF). However, there are limited data on the outcomes of AF ablation according to sex. The purpose of this study was to evaluate gender differences in the effects of early rhythm control compared to rate control on the primary composite outcome of cardiovascular death, ischaemic stroke, hospitalisation for heart failure (HF), or myocardial infarction.

Methods

We conducted a retrospective population-based cohort study including 22635 patients with AF newly treated with rhythm control (antiarrhythmic drugs or ablation) or rate control in 2011-2015 from the Korean National Health Insurance Service database. Propensity overlap weighting was used.

Results

Among patients with early AF treatment (initiated within 1 year since diagnosis), compared with rate control, rhythm control was associated with a similar lower risk of the primary composite outcome both women (weighted incidence rate per 100 person-years: 8.68 in rhythm control vs. 10.3 in rate control; hazard ratio [HR] 0.79, 95% confidence interval [CI] 0.69 to 0.90; P<0.001) and men (weighted incidence rate per 100 person-years: 6.33 in rhythm control vs. 8.32 in rate control; HR 0.77, 95% CI 0.67 to 0.88; P<0.001). However, the effective initiation time for rhythm control therapy was within 6 and 11 months after AF diagnosis in female and male patients, respectively. Moreover, the effective times for other outcomes were different between genders (hospitalization for HF; female within 2 months, male within 9 months/ ischemic stroke; female within 11 months, male immediately).

Conclusions

Early initiation of rhythm control was associated with a lower risk of primary outcome in both genders. However, the effective rhythm control treatment initiation time for primary outcome, stroke and HF-related admission was different in both genders. For rhythm control treatment to be effective, women should start treatment earlier than men.

Genetic predisposition according to the age at the onset of atrial fibrillation

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Ministry of Health and Welfare National Research Foundation of Korea (NRF)

Background

Although atrial fibrillation (AF) is a heritable disease, multiple comorbid factors, including aging, contribute to its development.

Purpose

We investigated the association between a weighted genetic risk score (wGRS) for AF and the age at onset.

Methods

We included 1,968 patients with AF (Yonsei AF Ablation cohort) and 5,486 controls from the Korean Genome Epidemiology Study (KoGES). After 1:1 matching, 1,416 patients and 1,416 controls were included in the analyses. The age of AF onset was determined by the first electrocardiogram (ECG) documentation.

Results

We selected nine previously reported AF-associated single-nucleotide polymorphisms (SNPs). Among nine proven AF-associated SNPs, 4 genes (PRRX1, PPFIA4, PITX2, and ZFHX3) were independently associated with the age at the onset of AF (p<0.05), but no associated genes were found in the controls. In the quartile and multivariate analyses, the lower quartile age at the onset of AF had a higher wGRS (p<0.001), and a younger age at the onset of AF was independently associated with the wGRS (β -0.29 [-0.57--0.01], p=0.045), but that association was not observed in the control cohort. Contrarily, the higher quartile of the wGRS group had a younger age of AF onset (p<0.001), and the wGRS was independently associated with the age at onset of AF (β -0.02 [-0.03--0.01], p=0.002). In the subgroup analyses, these age-wGRS associations were significant in males (p<0.001) and in those without heart failure (p<0.001) or strokes (p<0.001).

Conclusions

AF-associated genetic loci significantly contributed to the age at the onset of AF, as determined by the first ECG.

Learning curve of left bundle branch area pacing with standard stylet-driven pacing leads: a single center prospective observational study in Korea

Funding Acknowledgements

Type of funding sources: None.

Background

Although cardiac pacing is an essential therapy for bradycardia, conventional right ventricular pacing (CRVP) can cause electrical-mechanical dyssynchrony. Left Bundle Branch Area Pacing (LBBAP) is a new conduction system pacing strategy that includes a normal conduction system and therefore maintains synchronous ventricular contraction. Most of the experience with LBBAP is done in a lumen-less lead with fixed helix design, and this device is not available in sometimes.

Purpose

This study aimed to evaluate the learning curve of LBBAP using standard stylet-driven lead with extendable helix design.

Methods

This study enrolled patients who underwent permanent cardiac pacemaker implantation at a University Hospital in South Korea from December 2020 to October 2021. LBBAP was performed with a 5.6Fr stylet-driven pacing lead with an extendable helix. The learning curve was assessed by analyzing fluoroscopy time and procedure time.

Results

In 65 patients who underwent LBBAP during the observation period, mean fluoroscopy time and procedural time were 17.1 ± 17.2 minutes and 64.2 ± 33.5 minutes, respectively in this study. The learning curve for achieving LBBAP appears to plateau after around 24th case with a progressive reduction in procedure time. This is a significantly shorter period of time when compared to the previously reported learning curves of his bundle pacing (30-50cases), previously developed conduction system pacing strategy.

Conclusion

During initial experience with LBBAP, fluoroscopy and procedural time continue to improve with operator experience. For physicians who are experienced at cardiac pacemaker implantation, the steepest part of the learning curve of LBBAP appears to be over the first 20-25 cases.

Management and clinical outcome of patients with atrial fibrillation stratified by the 4S-AF scheme for structured characterization of atrial fibrillation: data from CODE-AF registry

Background

Recently, 4S-AF scheme consisting of four essential domains requiring for integrated management of atrial fibrillation (AF), including stroke prevention, symptom severity, severity of AF burden, and substrate for AF, has been proposed for the structured characterization of AF.

Purpose

To classify patients with AF applying 4S-AF scheme, evaluate how rhythm control and stroke prevention strategies were applied according to the 4S-AF scheme, and analyze the association between 4S-AF scheme score and the risk of clinical outcome, composite of stroke and admission for heart failure in patients with AF.

Methods

Using the data from the COmparison study of Drugs for symptom control and complication prEvention of Atrial Fibrillation (CODE-AF) registry from June 2015 to October 2020, we identified patients with AF who had information about 4S. The 4S-AF scheme score was calculated by stroke risk (truly low risk patients = 0; otherwise = 1), symptom severity (no symptom = 1; presence of symptom = 1), severity of AF burden (paroxysmal = 0, persistent = 1, and long-persistent to permanent = 2), substrate for AF (add 1 if >75 years; no comorbidity=1, 1 comorbidity = 1, 2 or more comorbidities = 2; left atrial anteroposterior diameter <40mm = 0, 40 to <50mm = 1, and ≥50mm = 2). Treatment strategies, including rhythm control and anticoagulation, were analyzed according to the 4S-AF scheme score. The risk for a composite of stroke and admission for heart failure was evaluated according to the 4S-AF scheme score during follow-up.

Results

Among 8199 patients with AF, the 4S-AF scheme scores of 0, 1, 2, 3, 4, 5, and ≥6 were 2.5%, 5.6%, 9%, 17.1%, 20.1%, 17.6%, and 28%, respectively. Patients with higher scores were tended to be older, had higher CHA2DS2-VASc score, included less proportion of paroxysmal AF, and showed larger left atrial size (Table). According to 4S-AF scheme, physicians preferred to apply a rhythm control strategy through both performing catheter ablation and prescribing antiarrhythmic agents in patients with lower 4S-AF scheme score (Figure). Oral anticoagulation rates were higher in patients with higher 4S-AF scheme score owing to higher CHA2DS2-VASc scores of these patients (Figure). The incidence rates of composite clinical outcomes were increased with increasing in 4S-AF scheme score (Figure). When grouping 4S-AF scheme score 0 and 1 as group A, 2 to 4 as group B, 5 as group C, and 6 as group D, group B, C, and D were associated with a higher risk of the composite clinical outcomes by 3.4, 7.9 and 11.5-fold compared to group A, respectively (Figure).

Conclusions

The 4S-AF scheme score was well-associated with the risk of stroke and admission for heart failure in patients with AF. Although the 4S-AF scheme might be already reflected in clinical practice when physicians determined the rhythm control and stroke prevention strategies for their AF patients, more systematic approach should be utilized for better clinical outcomes in patients with AF.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This study was supported by a research grant from the Korean Healthcare Technology R&D project funded by the Ministry of Health & Welfare (HI15C1200, HC19C0130).

Survival among ischemic and non-ischemic heart failure patients with primary implantable cardioverter defibrillator therapy in Korea: a nationwide cohort study

Background

Concerns still exist about the efficacy of prophylactic implantable electrocardiogram defibrillators (ICD) in patients with non-ischemic heart failure (HF). We evaluated the mortality and predictors of mortality in patients with prophylactic ICD implantation for ischemic and non-ischemic HF.

Methods

From 2008 to 2017, 1097 patients (667 non-ischemic; 430 ischemic) with prophylactic ICD implantation who were aged 19 years or older were identified from the Korean National Health Insurance Service database. We used propensity score overlap weighting to correct for differences between two groups.

Results

Compared with non-ischemic HF patients, ischemic HF patients were older (67.0±10.1 years vs. 61.8±14.2), more often male (71.4% vs. 63.7%), and had more comorbidities. During a median follow-up of 37.3 months (interquartile range (IQR), 14.2–53.8 months), all-cause death was higher in unweighted ischemic than non-ischemic HF patients (10.9 and 6.4 per 100 person-years, hazard ratio [HR] 1.74, 95% confidence interval [CI] 1.38–2.20, p<0.001). However, after weighting, annual all-cause mortality rate was similar in both groups (9.5 vs. 8.8 per 100 person-years) without difference in the risk of all-cause death (HR 1.08, 95% CI 0.68–1.71, p=0.755). Older age and chronic kidney disease were independent predictors of all-cause mortality in both groups. There was also no difference in cardiac and non-cardiac mortality between weighted non-ischemic and ischemic HF groups.

Conclusions

All-cause, cardiac and non-cardiac mortality were similar between non-ischemic and ischemic HF patients undergoing prophylactic ICD implantation. Our findings support the current guidelines recommendation for primary-prevention ICD in HFrEF patients with ischemic and non-ischemic HF.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Korean Healthcare Technology R&D project funded by the Ministry of Health and Welfare

Clinical and electrophysiological characteristics of extra-pulmonary vein triggers in patients who underwent catheter ablation for atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

Extra-pulmonary vein (PV) triggers play significant roles in atrial fibrillation (AF) recurrence after AF catheter ablation (AFCA).

Purpose

We explore the clinical and electrophysiological characteristics of extra-PV triggers in de novo and repeat-AFCA procedure.

Methods

We included 2,151 patients who had de novo AFCA and 319 repeat AFCA (female 28.0%, 59.1 ± 10.8 years old, paroxysmal AF 65.1%) those underwent post-procedural isoproterenol (ISO) provocation tests. We analysed the clinical, electrophysiological, and procedure-related factors associated with extra-PV triggers.

Results

Extra-PV triggers were documented in 11.9% (1.19 ± 0.42 foci) after de novo-AFCA and 27.0% (1.37 ± 0.65 foci) after repeat-AFCA (p = 0.004). LA volume index (OR 1.02 [1.01-1.03], p = 0.004), history of vascular disease (OR 0.55[0.31-0.91], p = 0.028) and Lead I amplitude of electrocardiogram (OR <0.01 [<0.01-0.62], p = 0.032) were independently associated with the existence of extra-PV triggers in de-novo procedure. Women (OR 1.84 [1.03-3.25], p = 0.037) and LA appendage volume (OR 1.04 [1.01-1.07] p = 0.027) were independently associated with extra-PV triggers during the redo-mapping procedure. Septum (28.4%), coronary sinus (24.0%), and superior vena cava (19.6%) were common extra-PV foci, and septal foci were more commonly found in repeat mapping (38.4% vs. 25.0%, p = 0.025). Among 65 patients who showed extra-PV at the repeat procedures, 19 (29.2%) matched with previous focal or empirical extra-PV ablation sites and 9 (13.8%) were multiple or unmappable sites. AF recurrence rates were significantly higher in both patients with extra-PV triggers after de novo procedures (Log-rank P <0.001; HR 1.93 [1.58-2.36], p= <0.001) and repeat procedures (Log-rank P <0.001, HR 1.87 [1.29-2.70], p= <0.001).

Conclusion

ISO provoked extra-PV triggers commonly found in AF patients with significant remodelling and previous empirical or focal extra-PV ablations. Existence of extra-PV triggers were independently associated with poorer rhythm outcome after both de novo and repeat AFCA. Denovo AF ablation outcome OverallExtra-PV triggers (-)Extra-PV triggers (+)p-value(n = 2151)(n = 1895)(n = 256)Age, yrs58.98 ± 10.9558.73 ± 11.0360.76 ± 10.200.006Male, (%)1550 ( 72.1)1389 ( 73.3)161 ( 62.9)0.001Follow up duration, month50.30 (37.71)51.65 (37.95)40.71 (34.58)<0.001Early recurrence (%)579 ( 27.8)455 ( 24.9)124 ( 48.4)<0.001Clinical recurrence (%)699 ( 33.6)584 ( 32.0)115 ( 44.9)<0.001Abstract Figure. AF free survival according to Extra PVT

Antiarrhythmic drug responders among patients with recurrent atrial fibrillation after catheter ablation

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): The Ministry of Health and Welfare The National Research Foundation of Korea (NRF)

Backgroud

Sinus rhythm (SR) can be maintained with antiarrhythmic drugs (AADs) in a considerable number of patients with recurrent atrial fibrillation (AF) after AF catheter ablation (AFCA).

Purpose

We explored the characteristics and long-term outcomes of patients who maintained clinically acceptable rhythm control with AADs for 2 years.

Methods

Among 2,935 consecutive AAD-resistant patients who underwent a de novo AFCA, we included 512 recurrent patients (73.0% men, 59.2 ± 10.5 years old, 56.4% paroxysmal AF) who were followed up for over 2 years under AAD medications.

Results

In total, 218 patients remained in SR (AAD-responders[2-yrs], 42.6%) and 294 had recurrent AF among whom, 162 underwent repeat procedures (redo-AFCA[AAD failure-2-yrs]). We also compared the AAD-responders[2-yrs] with 40 patients who underwent AFCA before AADs (redo-AFCA[Before AAD]). AAD-responders[2-yrs] were independently associated with an old age (odds ratio [OR] 1.02 [1.00-1.04] p = 0.037), paroxysmal AF (OR 1.51 [1.04-2.19] p = 0.003), and a delayed recurrence timing of > 18 months (OR 1.52 [1.04-2.22] p = 0.032). When comparing the AAD-responder[2-yrs] and redo-AFCA[AAD failure-2-yrs] groups, the recurrence pattern showed a convergence after 7 years. The overall rhythm outcome was better in the redo-AFCA[Before AAD] group than AAD group (log rank p = 0.013).

Conclusion

Among the patients with recurrent AF after AFCA, over 40% remained in SR with AADs for 2 years, especially those who were old, those with a paroxysmal type, and those who had a delayed recurrence timing of >18 months after the de novo procedure. UnivariateMultivariateOdds Ratio(95% CI)p valueOdds Ratio(95% CI)p valueAge1.02 (1.00-1.04)0.0231.02 (1.00-1.04)0.037Female1.64 (1.11-2.42)0.0141.29 (0.85-1.95)0.236PAF1.58 (1.11-2.26)0.0121.51 (1.04-2.19)0.030Time to recurrence after the initial AFCA >18mo*1.59 (1.11-2.30)0.0131.52 (1.04-2.22)0.032LA dimension, mm0.99 (0.96-1.02)0.360LV ejection fraction, %1.03 (1.01-1.06)0.0111.02 (0.997-1.046)0.081Heart failure0.65 (0.34-1.24)0.192Hypertension1.18 (0.83-1.67)0.358Diabetes1.01 (0.65-1.71)0.844Stroke or TIA0.96 (0.56-1.66)0.879Vascular disease1.43 (0.88-2.31)0.151Logistic regression analysis for AAD responders Abstract Figure. K-M analysis of AF-free survival rate

Computational modeling for antiarrhythmic drugs for atrial fibrillation according to the genotypes

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by a grant [HI19C0114] from the Ministry of Health and Welfare. Additionally, the work was funded by grants [NRF-2019R1C1C100907512], and [NRF-2020R1A2B01001695] from the Basic Science Research Program run by the National Research Foundation of Korea (NRF) under the Ministry of Science, ICT & Future Planning (MSIP).

Background

The efficacy of antiarrhythmic drugs (AAD) can vary in patients with atrial fibrillation (AF) and the PITX2 gene affects the responsiveness of AADs. We explored the virtual AAD (V-AAD) responses between wild-type and PITX2+/- deficient AF conditions by realistic in-silico AF modeling.

Methods

We tested the V-AADs in AF modeling integrated with patients’ 3D-computed tomography and 3D-electroanatomical mapping, acquired in 25 patients (68% male, 59.8 ± 9.8 years old, 32.0% paroxysmal type). The ion currents for the PITX2+/- deficiency and each AAD (amiodarone, sotalol, dronedarone, flecainide, and propafenone) were defined based on previous publications.

Results

We compared the wild-type and PITX2+/- deficiency in terms of the action potential duration (APD90), conduction velocity (CV), maximal slope of restitution (Smax), and wave-dynamic parameters, such as the dominant frequency (DF), phase singularities (PS), and AF termination rates according to the V-AADs. The PITX2+/- deficient model exhibited a shorter APD90 (p < 0.001), a lower Smax (p < 0.001), mean DF (p = 0.012), PS number (p < 0.001), and a longer AF cycle length (AFCL, p = 0.011). Five V-AADs changed the electrophysiology in a dose dependent manner. AAD-induced AFCL lengthening (p < 0.001) and reductions in the CV (p = 0.033), peak DF (p < 0.001) and PS number (p < 0.001) were more significant in PITX2+/- deficient than wild-type AF. PITX2+/- deficient AF was easier to terminate with class IC AADs than the wild-type AF (p = 0.018).

Conclusions

The computational modeling-guided AAD test was feasible for evaluating the efficacy of multiple AADs in patients with AF. AF wave-dynamics and electrophysiological characteristics are different among the PITX2 deficient and the wild-type genotype models. BaselineChanges after AADClass ICClass IIIWild-typePITX2+/-p-valueWild-typePITX2+/-p-valueWild-typePITX2+/-p-valueWild-typePITX2+/-p-valueAPD90, (ms)243.7 ± 33.8184.4 ± 15.5<0.00138.2 ± 37.343.4 ± 56.20.223275.9 ± 43.5219.0 ± 39.2<0.001284.9 ± 32.8233.8 ± 71.4<0.001CV, (m/s)0.78 ± 0.320.70 ± 0.210.347-0.15 ± 0.18-0.20 ± 0.260.0330.63 ± 0.320.53 ± 0.300.0270.60 ± 0.360.43 ± 0.33<0.001Mean Smax0.787 ± 0.280.531 ± 0.18<0.0010.005 ± 0.260.115 ± 0.24<0.0010.828 ± 0.310.694 ± 0.320.0030.768 ± 0.320.608 ± 0.27<0.001Mean AFCL, (ms)146.96 ± 24.61164.78 ± 22.730.01122.62 ± 24.5537.92 ± 32.72<0.001165.44 ± 36.96190.85 ± 35.61<0.001169.05 ± 25.26203.35 ± 34.78<0.001Peak DF, (Hz)10.68 ± 2.9711.82 ± 3.340.211-2.98 ± 4.94-5.46 ± 4.66<0.00110.01 ± 4.397.23 ± 4.20<0.0016.30 ± 4.325.80 ± 4.070.301Mean DF, (Hz)6.80 ± 0.886.22 ± 0.710.012-1.95 ± 2.44-2.20 ± 1.990.2065.75 ± 1.784.53 ± 2.00<0.0014.14 ± 2.393.69 ± 2.000.077PS Number, (N)101086 ± 9608814150 ± 24778<0.001-59322 ± 99288-7409 ± 27856<0.00150579 ± 6523611568 ± 21868<0.00132951 ± 558643524 ± 8302<0.001PS Life Span, (ms)109.36 ± 113.90102.24 ± 226.640.889-24.87 ± 72.06-41.38 ± 126.350.073103.36 ± 180.6868.05 ± 162.790.14871.91 ± 141.8655.99 ± 217.970.454Table. Effects of AADs in the Wild-type and PITX2+/- Deficiency groupAbstract Figure. Wild-type vs. PITX2+/- baseline model

Malnutrition and risk of procedural complication in patients with atrial fibrillation undergoing catheter ablation

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Health and Welfare of Korea Ministry of Science, ICT & Future Planning of Korea

Background

Malnutrition is common in the elderly, even in developed countries, and increases mortality.

Purpose

 To investigate the prevalence and prognostic value of malnutrition among patients with atrial fibrillation (AF) which is a type of metabolic disease.

Methods

We included 3,239 patients (age 58.5 ± 10.8 years, 73.2% male, 67.7% paroxysmal type) undergoing de novo AF catheter ablation (AFCA) between 2009 and 2020. Nutritional status was assessed using controlling nutritional status (CONUT) score. The associations between malnutrition and the risk of AFCA complications or long-term rhythm outcome were evaluated by multivariable logistic regression.

Results

Among 3,239 patients, 1,005 (31.0%) patients had malnutrition; 991 (30.6%) with mild (CONUT scores 2-4) and 14 (0.4%) with moderate-to-severe (CONUT scores ≥5) malnutrition. Overall complication rates after AFCA were 3.3% in normal nutrition, 4.2% in mild malnutrition, and 21.4% in moderate to severe malnutrition, respectively (P for trend = 0.031). Major complication rates were 1.9%, 2.6%, and 14.3% in normal nutrition, mild malnutrition, and moderate to severe malnutrition (P for trend = 0.042). After multivariable adjustment, moderate-to-severe malnutrition status was associated with increased risks of overall (OR 8.215 [2.199-30.691], P = 0.002) and major (OR 7.392 [1.568-34.837], P = 0.011) complications compared with normal nutrition. However, CONUT score did not affect the long-term rhythm outcome during the mean follow-up of 40 (interquartile range 18-74) months (log-rank P = 0.760).

Conclusion

Malnutrition is common in patients undergoing AFCA. Those with moderate-to-severe malnutrition status were at substantially higher risk of complications after AFCA. Abstract Figure. Overall and major complication rates

Sex differences in mapping and rhythm outcomes of a repeat atrial fibrillation ablation

Funding Acknowledgements

Type of funding sources: None.

Introduction

The risk of procedure-related complications and rhythm outcomes differ between men and women after atrial fibrillation catheter ablation (AFCA). We evaluated whether consistent sex differences existed in mapping and rhythm outcomes in repeat ablation procedures.

Methods

Among 3,282 patients in the registry, we analysed 443 consecutive patients (24.6% female, 58.5 ± 10.3 years old, 61.5% paroxysmal AF) who underwent a second AFCA. We compared the clinical factors, mapping, left atrial (LA) pressure, complications, and long-term clinical recurrences after propensity score matching.

Results

The LA volume index (43.1 ± 18.6 vs. 35.8 ± 11.6 ml/m2, p < 0.001) was higher, but LA dimension (40.0 ± 6.8 vs. 41.6 ± 6.3mm, p = 0.018), LA voltage (0.94 ± 0.55 vs. 1.20 ± 0.68 mV, p = 0.002), and pericardial fat volume (89.5 ± 43.1 vs. 122.1 ± 53.9 cm3, p < 0.001) lower in women with a repeat ablation than in their male counterparts. The pulmonary vein (PV) reconnections were lower (58.7% vs. 74.9%, p = 0.001), but the proportion of extra-PV triggers (27.5% vs. 17.0%, p = 0.026) and elevated LA pulse pressures (79.7% vs. 63.7%, p = 0.019) was significantly higher in women than men. There was no significant sex difference in the procedure-related complication rate (4.6% vs. 4.2%, p = 0.791). During a 31(8∼60) month median follow-up, clinical recurrences were significantly higher in women after both the de novo procedure (log rank p = 0.039, antiarrhythmic drug [AAD]-free log rank p < 0.001) and second procedure (log rank p = 0.006, AAD-free log rank p = 0.093). A female sex (HR 1.51 [1.06-2.15], p = 0.023), non-paroxysmal AF (HR 1.78 [1.30-2.34], p < 0.010), and extra-PV triggers (HR 1.88 [1.28-2.75], p = 0.001) were independently associated with clinical recurrences after repeat procedures.

Conclusions

During the repeat AFCA procedures, PV reconnections were lower in women than men, and the existence of extra-PV triggers and an LA pressure elevation was more significant, which resulted in poor rhythm outcomes.

Artificial intelligence-predicted poor responders to catheter ablation for atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Introduction

Although atrial fibrillation (AF) catheter ablation is effective for rhythm control, in some patients it is hard to maintain sinus rhythm in spite of repeated AF catheter ablation (AFCA) procedures and anti-arrhythmic drugs (AADs). We explored the pre-procedural predictors for poor responders to AFCA and tested whether artificial intelligence (AI) assists the prediction of poor responders in the independent cohort by determining the invasive parameters.

Methods

Among 1,214 patients who underwent AFCA and regular rhythm follow-up for 56.2 ± 33.8 months (59 ± 11 years, 73.5% male, 68.6% paroxysmal AF), we differentiated 92 poor responders defined as those with sustained AF despite repeat AFCAs, AADs, or electrical cardioversion. Using the Youden index, we identified advanced LA remodeling with lower LA voltage under 1.109mV. AI model, which was derived from development cohort using medical record, was applied to predict LA voltage <1.109mV in the independent cohort (n = 634, poor responders = 24) using a grad-cam score.

Results

The patients with lower LA voltage under 1.109mV showed significantly poorer rhythm outcomes (Log-rank p < 0.001). We determined invasive parameter LA voltage by using the multiple variables (age, female sex, AF type, CHA2DS2VASc score, LA dimension, E/em, hemoglobin, PR interval) and achieved relatively good prediction power of AI for LA voltage <1.109mV (AUC = 0.734, sensitivity 0.729, specificity 0.643) in the test cohort. In the independent cohort, the AI model showed good discrimination power for poor responders (AUC 0.751, p < 0.001) by estimating LA voltage, which is an invasive variable. The patients with predicted lower LA voltage (grad-cam score <0) showed poorer rhythm outcome after active rhythm control (Log-rank p < 0.001)

Conclusions

The patients with advanced atrial remodeling with low LA voltage, which can be predicted by an AI, showed significantly higher recurrence of AF after AFCA with AADs or cardioversion. AI may assist to select these poor responder patients before the AFCA procedure. Abstract Figure.

Left atrial wall stress and the outcome of catheter ablation for atrial fibrillation: artificial intelligence-based prediction of clinical outcome

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction: Left atrial (LA) wall stress (LAW-str) may contribute to the mechanism of atrial fibrillation (AF).

Purpose

We explored the clinical characteristics and the rhythm outcome of AF depending on LAW-str among the patients who underwent AF catheter ablation (AFCA). We also tested whether artificial intelligence (AI) properly estimate LAW-str without invasive parameters.

Methods

We included 2223 patients (72.8% male, 59.0 [52.0–67.0] years old, 28.7% with persistent AF [PeAF]) who underwent radiofrequency catheter ablation (RFCA). LAW-str was calculated by the Law of Laplace using LA diameter (echocardiogram), peak LA pressure, and mean LA wall thickness (computed tomography) measured by customized software. Based on the quartile (Q1–4) or AI-estimated values of LAW-str, we compared clinical characteristics and rhythm outcome.

Results

LAW-str was independently associated with PeAF (p < 0.001), diabetes (p = 0.012) and vascular disease (p = 0.002), body mass index (p < 0.001), E/Em (p < 0.001), and mean LA voltage (p < 0.001). During 26.0 (12.0–52.0) months follow-up, clinical recurrence of AF was significantly higher in the Q4 of LAW-str group (log rank p = 0.001). LAW-str was independently associated with clinical recurrence after AFCA (HR 1.001 [1.000–1.002], p = 0.013). AI-based model using non-invasive parameters predicted Q4 of LAW-str with area under the curve (AUC) 0.734, which was similar to logistic regression based predictive model using all data including invasive parameters (AUC 0.726). Patients in Q4 of LAW-str showed consistently worse rhythm outcome regardless of the type of AF, sex, or AI-based prediction (p = 0.039).

Conclusions

The LAW-str seems to be associated with rhythm outcome of AFCA and AI can predict this complex parameter with moderate accuracy. TableMultivariateβ (95% CI)PPersistent AF31.08 (21.77-40.39)<0.001Diabetes mellitus15.36 (3.35-27.38)0.012Vascular disease22.27 (8.4-36.14)0.002Body mass index2.91 (1.53-4.29)<0.001E/Em4.95 (3.87-6.02)<0.001Mean LA voltage-22.24 (-27.96–16.52)<0.001Linear regression analysis for clinical variables predictive of LA wall stress (10^3 dyn/cm2).Abstract Figure. AF recurrence by LAW-str, AI-prediction

Long-term outcomes of empirical extra-pulmonary vein linear ablation in patients with persistent atrial fibrillation

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): This work was supported by grants [HI18C0070] and [HI19C0114] from the Korea Health 21 R&D Project, Ministry of Health and Welfare, and a grant [NRF-2020R1A2B01001695] from the Basic Science Research Program run by the National Research Foundation of Korea (NRF).

Background

Although extra-pulmonary vein (PV) left atrial (LA) linear ablation has been performed during catheter ablation (CA) of persistent atrial fibrillation (PeAF), the long-term efficacy and safety of this procedure have not yet been verified.

Purpose

We investigated whether an anterior line (AL) and posterior box ablation (POBA) in addition to circumferential PV isolation (CPVI) improves the rhythm without worsening the LA function in PeAF patients.

Methods

We retrospectively compared the additional AL + POBA and CPVI alone groups in 604 patients with PeAF who underwent regular rhythm follow-ups (16.9%; males 79.3%, 58.5 ± 10.7 years of age) after propensity score matching. The primary endpoint was AF recurrence after single procedures and secondary endpoints were the cardioversion rate, response to anti arrhythmic drugs, LA changes, and re-conduction rates of the de-novo ablation lesion set.

Results

After a mean follow-up of 45.2 ± 33.6 months, the clinical recurrence rate did not significantly differ between the two groups (log-rank p = 0.554) despite longer procedure times in the AL + POBA group (p < 0.001). Atrial tachycardia recurrences (p = 0.001) and the cardioversion rates after ablation (p < 0.001) were higher in the AL + POBA group than CPVI group. AL + POBA was associated with better rhythm outcomes in patients with large anterior LA volume indices (p for interaction 0.037) and low mean LAA(left atrial appendage) voltages (p for interaction 0.019). In repeat procedures, the LA pulse pressure elevation was significant after the AL + POBA.

Conclusion

In patients with PeAF, an AL + POBA in addition to the CPVI did not improve the rhythm outcomes nor influence the long-term safety, and lead to more extended procedures. Procedure outcomes OverallAL + POBACPVIp-value(n = 604)(n = 302)(n = 302)Procedure time, min190.8 ± 62.6226.9 ± 49.4154.6 ± 52.8<0.001Ablation time, sec5079 ± 19566420 ± 13723738± 1475<0.001Overall complications24 (4.0)13 (4.3)11 (3.6)0.835Early recurrence, n (%)277 (45.9)129 (42.7)148 (49.0)0.142Recurrence type AT, n (% in early recur)77 (27.8)51 (39.5)26 (17.6)<0.001Clinical recurrence within 1-year, n(%)116 (19.2)52 (17.2)65 (21.5)0.256Recurrence type AT, n (% in clinical recur)60 (23.1)46 (30.7)14 (12.7)0.001Cardioversion, n (% in total recur/ % overall)105 (40.4/17.4)74 (49.3/24.5)31 (28.1/10.3)<0.001POBA, posterior box ablation; AL, anterior line; CPVI, circumferential pulmonary vein isolation; AT, atrial tachycardia;Abstract Figure. Long term ablation outcome

The reduction of body mass index and risk of incidence of cardiovascular events in the elderly population

Funding Acknowledgements

Type of funding sources: None.

Introduction

Obesity is known to be risk factor for incidence of cardiovascular (CV) events. However, the association between the reduction of body mass index (BMI) and incidence of cardiovascular event is not well established in elderly Asian population.

Methods

From the National Health Insurance Service-Senior (≥60 years) cohort from 2002 to 2013, 13,038 participants over 75 years old without baseline comorbidities (mean age: 78.4 ± 3.2 years 5243 (40.2%) male) were included in this study. We measured the change of BMI from first to second visit for health check-up within mean 23.6 ± 5.8months of follow-up. We categorized the reduction of BMI as five group according to the amount of change in BMI in overall patients (group 1: BMI change <-10%, group 2: -10%≤BMI change<-3%, group 3: -3% ≤ BMI change < 3%, group 4: 3% ≤BMI change < 10%, group 5: 10% ≤BMI change). We investigated the influence of change in BMI on the incidence of new-onset AF, stroke, acute myocardial infarction (MI), and CV mortality

Results

In the overall patients, new-onset AF, stroke, acute MI, and CV death was occurred in the 494 patients (3.5%), 775 patients (5.9%), 16 patients (0.1%), and 458 patients (3.5%) respectively. The Kaplan-Meier curve showed significant cumulative incidence rate of CV death in group 1 (Log rank p < 0.001). The multivariate cox regression after adjusting for compound clinical covariates showed the risk of stroke (HR 1.43, 95% CI [1.09-1.89], p = 0.01) and CV death (HR 2.06, 95% CI [1.49-2.84] were significant higher in the group 1 as compared with group 3. In the high BMI (≥25) group, the risk of AF was significant higher in the group 5 as compared with group 3 (HR 2.38, 95% CI [1.02-5.54], p = 0.04). In contrast, the risk of stroke (HR 1.70, 95% CI [1.07-2.71], p = 0.02) and CV death (HR 3.27, 95% CI [1.66-6.41], p < 0.001) was significant higher in the group 1 than in group 3.

Conclusions

In the elderly Asian population over 75 years old, the reduction of body weight affected worse effect on the incidence of stroke and CV death in overall patient and high BMI (≥25) group. It needs careful consideration to reduce BMI in the elderly Asian population even with high BMI (≥25) for purpose of CV events.

Early mortality and complications associated with catheter ablation of atrial fibrillation: analysis of the entire procedure in Korea from 2007 to 2016

Funding Acknowledgements

Type of funding sources: None.

Background

There is limited data regarding the early mortality and adverse outcomes from catheter ablation of atrial fibrillation (AF) in Korea. The aim of this study was to examine the early mortality and frequency of adverse outcomes associated with AF catheter ablation from 2006 to 2016 in Korea.

Methods

From 2006 to 2016 in the Korean National Health Insurance Service database, 11,893 individuals underwent catheter ablation for AF. We investigated the frequency of complications and early mortality associated with AF ablation and comorbidities that led to adverse outcomes after AF ablation.

Results

Out of all 11,893 procedures, early mortality occurred in 38 cases (0.32%). Annual trends in AF procedural complications occurring during index admission for AF ablation decreased from 9.25% in 2006 to 6.49% in 2016 (P for trend = 0.004). The early mortality rate after AF ablation had remained unchanged between 2006 and 2016. After adjustment for age, comorbidities, and medication, procedural complications (adjusted odds ratio[aOR]: 16.1; P < 0.001), age (aOR: 1.25; P = 0.024), history of hemorrhagic stroke (aOR: 4.74; P = 0.019), and less experience with AF ablation of the hospital (aOR: 2.85; P = 0.024) were associated with early mortality. Among procedural complications, atrioesophageal fistula (aOR: 199.8; P < 0.001), access site complications (aOR: 6.08; P = 0.005), complete heart block (aOR: 11.3; P = 0.029), pneumothorax (aOR: 62.0; P < 0.001), and procedure related pneumonia (aOR: 39.0; P < 0.001) were associated with early mortality.

Conclusions

Procedural complications, history of hemorrhagic stroke, and less experience with AF ablation of the hospital were predictors of early mortality. Out of all complications, atrioesophageal fistual, procedure related pneumonia, and in-hospital stroke were related to early mortality. Adequate management of complications may contribute to reducing the number of early mortalty rates following AF ablation. Abstract Figure. Trend of early mortality after ablation

Incidence of atrial fibrillation in cancer patients according to cancer type

Background and objectives

The prevalence of both atrial fibrillation (AF) and cancer are increasing especially in the elderly. The occurrence of AF in cancer may be related to comorbidities of patients, cancer treatment, or a direct tumor effect. The objectives of this study were to investigate the incidence of AF according to cancer type.

Methods

From the Korean National Health Insurance Service elderly (NHIS-elderly) cohort (age >60), we identified 67,077 patients with newly diagnosed cancer and without previous AF. Incidence rates of new onset AF were evaluated.

Results

The mean age of the cancer patients was 75.1 year and 53.5% were males. During a median follow-up period of 25 months, the incidence rate of AF among overall cancer patients was higher than that of age-sex matched non-cancer population (1.42 vs. 0.69 per 100 person-years, respectively). Compared with solid cancer, the risk of incident AF in patients with hematologic cancer was significantly higher (hazard ratio [HR]: 1.53, 95% confidence interval [CI]: 1.39–1.72, p<0.001). Among patients with solid cancer, thoracic (lung cancer, esophageal cancer, mediastinal cancer, etc.) and breast cancer was associated with a higher risk of AF incidence compared with other solid cancer (HR: 1.64, 95% CI: 1.53–1.76, p<0.001).

Conclusions

Cancer was associated with an increased incidence of AF. Hematologic cancer was associated with higher risk of AF incidence than solid cancer. Among solid cancer, thoracic and breast cancer was most strongly associated with the risk of AF incidence.

Funding Acknowledgement

Type of funding source: None

The mortality outcome after implantable cardioverter-defibrillator implantation according to indication for implantation and underlying etiology: a Nationwide Cohort study

Background and objectives

There are few nationwide data about the mortality outcome after implantable cardioverter-defibrillator (ICD) implantation. The aim of this study was to evaluate the mortality outcome after ICD implantation according to indication for implantation (primary vs. secondary prevention) and underlying etiology (non-ischemic vs. ischemic heart disease) with a nationwide cohort data of Korea.

Methods

During the period from January 1, 2008 to December 31, 2017, 3,558 patients (mean age, 67.7±11.4 years) with newly-implanted ICD who were aged 19 years or older were identified by 50-percents random sampling from the Korean National Health Insurance Service database.

Results

Patients with primary and secondary prevention ICD were 1,097 (30.8%) and 2,461 (69.2%), respectively. Patients with non-ischemic and ischemic heart disease were 2,487 (69.9%) and 1,071 (30.1%), respectively. Overall all-cause mortality was 20.4% during the follow-up period (mean 24 months). The mortality rates in patients with primary and secondary prevention ICD were 26.2% and 17.9%, respectively. The mortality rates in patients with non-ischemic and ischemic heart disease were 16.1% and 30.4%, respectively. In Kaplan-Meier estimates of survival according to both indication for implantation and underlying etiology, the best prognostic group was patients with secondary prevention ICD and having non-ischemic etiology. The worst prognostic group was patients with primary prevention ICD and having ischemic etiology. The survival probability was below 50% (45.2%) 5 years after ICD implantation in patients with primary prevention ICD and having ischemic etiology.

Conclusions

In Korean nationwide data, patients with primary prevention ICD and having ischemic etiology show the worst prognosis. About half of these patients died of any cause within five years.

Funding Acknowledgement

Type of funding source: None

Benefit of high cardiovascular health for incident cardiovascular events and mortality in elderly population

Background

There is consistent evidence of the association between ideal cardiovascular health and lower incident cardiovascular disease (CVD); however, most studies used a single measure of cardiovascular health.

Purpose

To examine the association of change in cardiovascular health with subsequent incident CVD and mortality in elderly population.

Methods

In the Korea National Health Insurance Service-Senior (≥60 years) cohort, 312,736 participants who received national health check-ups between 2005–2012 were assessed for eligibility. Using the 7metrics of the American Heart Association (nonsmoking; and ideal levels of body mass index, physical activity, diet, blood pressure, fasting blood glucose, and total cholesterol), participants with 0 to 2, 3 to 4, and 5 to 7 ideal metrics were categorized as having low, moderate, and high cardiovascular health. Change in cardiovascular health over 2 years between 2005 and 2006 was considered.

Results

The study population included 162,149 participants without prior CVD or malignancy (median age at baseline, 69 [IQR 66–73] years; 91,408 [56.2%] women), of whom 59,887 had data about cardiovascular health change. Over a median follow-up of 5.8 (5.5–8.0) years, 5346 incident CVD events and 6035 death occurred. In multivariable analysis and compared with individuals with persistently low cardiovascular health (consistently low group, 7.9% of participants; CVD incident rate per 1000 person-years, 21.1 [95% CI, 19.4–23.0]), a lower CVD risk was observed in the consistently moderate group (38.7% of participants; absolute rate difference per 1000 person-years, −4.8 [95% CI, −5.5 to −4.1]; HR, 0.77 [95% CI, 0.70–0.85]), the moderate to high group (11.6% of participants; absolute rate difference per 1000 person-years, −7.7 [95% CI, −8.8 to −5.5]; HR, 0.62 [95% CI, 0.55–0.70]), the high to moderate group (11.2% of participants; absolute rate difference per 1000 person-years, −7.2 [95% CI, −8.3 to −5.9]; HR, 0.64 [95% CI, 0.56–0.72]), and the consistently high group (11.3% of participants; absolute rate difference per 1000 person-years, −10.2 [95% CI, −11.2 to −9.1]; HR, 0.51 [95% CI, 0.44–0.58]). A lower mortality risk was observed in the consistently moderate group, the moderate to high group, and the high to moderate or high groups.

Conclusion

Among a group of elderly participants without CVD, there was benefit of moderate or high cardiovascular health for incident cardiovascular events and mortality.

Funding Acknowledgement

Type of funding source: None

Catheter ablation can improve survival with the reduction of heart failure in frail patients with atrial fibrillation

Background

It is unclear whether catheter ablation is beneficial in frail patients with AF.

Purpose

This study aimed to evaluate whether catheter ablation reduces death and other outcomes in real-world frail patients with atrial fibrillation (AF).

Methods

Out of 801,710 patients with AF in the Korean National Health Insurance Service database from 2006 to 2015, 1,411 frail patients underwent AF ablations. The Hospital Frailty Risk Score were calculated retrospectively. Inverse probability of treatment weighting (IPTW) was used to categorize ablation and non-ablation frail groups.

Results

After IPTW, the two cohorts had similar background characteristics. During a median follow-up of 4.7 years (interquartile range: 2.2–7.8), the risk of death in frail patients with ablations was reduced by 65% compared to frail patients without ablations (2.0 and 6.4 per 100 person-years, respectively; hazard ratio [HR] 0.35; 95% confidence interval [CI] 0.25–0.50; P<0.001). Ablations were related with a lower incidence and risk of heart failure admission (1.8 and 3.1 per 100 person-years, respectively; HR 0.66, 95% CI 0.44–0.98; P=0.042) and acute myocardial infarction (0.2 and 0.6 per 100 person-years, respectively; HR 0.30, 95% CI 0.15–0.62; P=0.001). However, the risk of stroke did not change after ablation.

Conclussion

Ablation may be associated with lower incidences of death, heart failure, and acute myocardial infarction in real-world frail patients with AF, supporting the role of AF ablation in these patients. The effect of frailty risk on the outcome of ablation should be evaluated in further studies.

Funding Acknowledgement

Type of funding source: None

Risk for stroke and systemic embolism in patients with atrial fibrillation and heart failure according to heart failure type

Introduction

Risk for stroke and systemic embolism (SE) in patients with atrial fibrillation (AF) and heart failure (HF) with mid-range (mr) ejection fraction (EF) is not well known.

Methods

Total 10,780 patients (age, 66.8±11.1 years; men, 64.7%) with AF were included in a prospective, multicenter AF registry. The patients were grouped into four according to HF type: no-HF, HF with preserved EF (HFpEF), HFmrEF, and HF with reduced EF (HFrEF). Baseline characteristics, cumulative incidence and hazard ratios for stroke/SE, major bleeding, and mortality were compared among the four groups.

Results

Proportion of patients with HF was 10.3%: HFpEF, 43.7%; HFmrEF, 23.6%; HFrEF, 32.7%. CHA2DS2-VASc score was significantly higher in the HFpEF, HFmrEF, and HFrEF groups than the no-HF group (4.0±1.7, 3.8±1.8, 3.5±1.8, and 2.5±1.6, respectively). Oral anticoagulants were administered in 83.6% of patients with CHA2DS2-VASc score ≥1. Annual incidence of stroke/SE was 2.0% in HFpEF group, 0.6% in HFmrEF group, 1.1% in HFrEF group, and 0.7% in no-HF group for 23.0±9.5 months of follow-up period. Cumulative incidence of stroke/SE was significantly higher in the HFpEF group than the no-HF and HFmrEF groups (p<0.001 and p=0.042, respectively; Figure). Risk for stroke/SE was significantly higher in the HFpEF group than the no-HF group [hazard ratio, 1.929; 95% confidence interval, 1.171–3.179, p=0.010]. There were no significant differences in risk for stroke/SE in the HFmrEF and HFrEF groups, compared with the no-HF group. There were no significant differences in major bleeding and mortality among the groups.

Conclusions

Risk for stroke/SE is highest in HFpEF and lowest in HFmrEF in patients with AF and HF.

Figure 1

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): National Research Foundation of Korea

Outcomes of cardiac resynchronization therapy with or without a defibrillator in patients with nonischemic cardiomyopathy in Korea: a nationwide cohort study

Background

Randomized control trials comparing the effectiveness of cardiac resynchronization therapy devices, with (CRT-D) or without (CRT-P) a defibrillator, are scarce in heart failure patients. Patients with nonischemic dilated cardiomyopathy (NICM) may be at lower risk for ventricular arrhythmias compared with those with ischemic cardiomyopathy. In addition, NICM has been identified as a predictor of positive response to CRT. The aim of this study was to investigate the impact of an additional implantable cardioverter-defibrillator over CRT in Korean patients with NICM.

Methods

During the period from January 1, 2008 to December 31, 2017, 533 NICM patients (mean age, 65.7±12.2 years, male 53.6%) with newly-implanted CRT-P (n=71) or CRT-D (n=462) who were aged 19 years or older were identified by 50-percents random sampling from the Korean National Health Insurance Service database.

Results

Compared with patients receiving CRT-P, those receiving CRT-D were younger (65.3±12.3 vs. 68.3±11.6 years, p=0.038), more likely to be male (56.1% vs. 38.0%, p=0.005), and have an admission history of congestive heart failure (93.9% vs. 87.3%, p=0.041). Over the mean follow-up period of 21 months,114 cases in the CRT-D group and 24 cases in the CRT-P group died, with annualized mortality rates of 14.9 and 17.2 per 100 person-years, respectively. Kaplan-Meier estimates of event-free survival showed that there was no difference in mortality between CRT-D and CRT-P groups (p=0.343). In multivariate analysis, factors associated with mortality were chronic kidney disease, atrial fibrillation, and older age. With regard to death or heart failure hospitalization, heart failure death, and non-cardiac death, there were no difference between the two groups.

Conclusions

Among Asian patients with NICM with indications for CRT, death, death or heart failure hospitalization, heart failure death, and non-cardiac death were not different between CRT-D and CRT-P groups.

Funding Acknowledgement

Type of funding source: None

Elevation of pulse pressure in middle age is associated with the risk of dementia: data from a population-based cohort

Aims

Pulse pressure (PP) is a well-known risk factor for cardiovascular disease. However, the association between the PP and dementia is not well identified. This study aimed to determine the effect of PP on the risk of dementia development in different age subgroups using a longitudinal, population-based, and stroke-free cohort from the general population.

Methods

The association of PP with the development of incident dementia was assessed from January 1, 2005, to December 31, 2013, in 433,154 participants without a history of dementia or stroke from the Korea National Health Insurance Service-Health Screening cohort. The diagnosis of dementia was defined using the 10th revision of the International Classification of Disease codes.

Results

The mean age of the cohort was 55.7±9.2 years, 45.7% were women. Hypertension was 23.6%. The mean systolic and diastolic blood pressure of the entire cohort were 125.9±16.6 and 78.4±10.7 mmHg, respectively. Mean PP was 47.5±10.9 mmHg. In the middle-age group (40 to 50 year-old), increasing of 10 mmHg of PP was associated with incident dementia after adjusting mean blood pressure and clinical variables with a hazard ratio (HR) of 1.21 (95% confidence interval [CI]: 1.19–1.23, p<0.001). The association was still significant even after censoring for stroke (HR: 1.16, 95% CI: 1.08–1.22, p<0.001). In the older population, elevation of PP was not associated with dementia development (HR: 0.98, 95% CI: 0.95–1.01, p=0.247)

Conclusion

PP was associated with increased risk of dementia only in middle-aged population beyond that of mean arterial pressure.

Funding Acknowledgement

Type of funding source: None

Intense cardiac-targeted small extracellular vesicles-mediated delivery of RAGE siRNA attenuates inflammation in rat myocarditis model

Background

Despite advances in the field and new therapeutics being developed, heart disease remains the leading cause of mortality worldwide. Small extracellular vesicles (sEV) are 30–150 nm in diameter and ferry RNA and proteins to cells. sEV are a natural carrier of many signaling molecules and play an important role in heart disease. However, the high probability of off-target effects associated with these carriers is a major barrier to translation into clinical application.

Purpose

Our aim was to evaluate whether sEVs engineered to express potent cardiac targeting peptides (CTPs) could deliver siRNA to the heart and exert a therapeutic effect.

Methods

We use vectors encoding LAMP2B (sEV) or CTP-LAMP2B (PsEV) into HEK 293 cells expressing. sEVs were purified from culture media of HEK 293 cells by serial centrifugation followed by tangential flow filtration (TFF) system. sEV and PsEV were loaded with siRNAs by Exo-Fect™ exosome transfection reagent, and were treated into H9C2 rat cardiomyocyte. TNF-alpha were then added to the cells to induce inflammation. And sEVs were intravenously injected into myocarditis rat. Inflammation factors of in vitro and in vivo inflammation model were identified by western blot. Echocardiographic examination was also performed in rat.

Results

The successful development of PsEVs was analyzed by Western blot and TEM. We observed a 4 fold increase from that of the previously developed sEVs in H9C2 cells and a 200% increase in cardiac-specific delivery without toxicity in rat model. AGE is involved in proinflammatory/pro-apoptotic processes. To block RAGE, we loaded RAGE siRNA (siRAGE) in sEV that had high expression of PsEV. Characteristics of sEVs were maintained despite siRNA load.In inflammatory cell models and rat disease models, PsEV-treated groups significantly reduced molecular levels associated with inflammatory responses such as RAGE, IL-6, TNF-alpha, COX2, HMGB1, and p-p65 / p65.

Conclusions

Our results suggest that PsEV can potentially serve as a treatment delivery vehicle for heart disease.

Scheme

Funding Acknowledgement

Type of funding source: None

P4758Label adherence of non-vitamin K antagonist oral anticoagulants and clinical outcomes in patients with atrial fibrillation: A nationwide study

Background

Dose adjustment of non-vitamin K antagonist oral anticoagulants (NOACs) is indicated in some patients with atrial fibrillation (AF), based on selected patient factors or concomitant medications.

Purpose

We assessed the frequency of label adherence of NOAC dosing among AF patients and the associations between off-label NOAC dosing and clinical outcomes in real-world clinical practice.

Methods

We evaluated 53,649 AF patients treated with a NOAC using Korean National Health Insurance Service database during the period from January 2013 to December 2016. NOAC doses were classified as either underdosed or overdosed, consistent with U.S. Food and Drug Administration labeling. Cox proportional hazards regression was performed to investigate the effectiveness and safety outcomes including stroke or systemic embolism, major bleeding, and all-cause mortality.

Results

Overall, 16,757 NOAC-treated patients (31.2%) were underdosed, 4,492 were overdosed (8.4%), and 32,400 (60.4%) were dosed appropriately according to drug labeling. Compared with patients with label adherence, those who were underdosed or overdosed were older (71±8 and 75±7 years of age vs. 70±9 years of age, respectively; p<0.001), more likely female (39% and 53% vs. 38%, respectively; p<0.001), and had higher CHA2DS2-VASc scores (4.6±1.7 and 5.3±1.7 vs. 4.5±1.8, respectively; p<0.001). NOAC overdosing was associated with increased risk for stroke or systemic embolism (5.76 vs. 4.03 events/100 patient-years, p<0.001), major bleeding (4.77 vs. 2.94 events/100 patient-years, p<0.001), and all-cause mortality (5.43 vs. 3.05 events/100 patient-years, p<0.001) compared with label-adherent use.

Figure 1

Conclusion

In routine clinical practice, a significant proportion (almost 2 in 5) of AF patients received NOAC doses inconsistent with drug labeling. NOAC overdosing is associated with increased risk for stroke or systemic embolism, major bleeding, and all-cause mortality in Asian patient with AF.

P1012Radiofrequency catheter ablation of accessory pathways at the site of prior valve surgery

Background

Radiofrequency catheter ablation (RFCA) for accessory pathways (APs) at the site of prior valve surgery remains challenging. We aimed to clarify the factors associated with successful RFCA for such APs.

Methods

Upon reviewing a RFCA registry and previous case reports, we included nine patients who underwent RFCA of APs at the site of prior valve surgery (total-VS group; age, 34.0 [24.5–45.0] years; men, 4/9) and 196 patients who underwent RFCA of APs with no history of valve surgery (no-VS group; age, 40.5 [23.0–54.0] years; men, 114/196). Electrophysiological features, procedural details, and outcomes were examined.

Results

AP exhibited decremental conduction in four of nine patients in the total-VS group. The number of RFCA attempts was significantly higher in the total-VS group than in the no-VS group (10.0 [4.5–14.5] vs 2.0 [1.0–3.0]; p<0.001). In four patients who underwent mitral valve surgery, successful RFCA was achieved using the transaortic approach, coronary sinus approach, or bipolar ablation. In three patients who underwent tricuspid valve surgery, successful RFCA was achieved using the above-prosthetics or trans-prosthetics approach. In two patients, RFCA failed. The trans-prosthetics approach and bipolar ablation technique were effective. The transaortic and coronary sinus approaches were occasionally effective. The transseptal approach was ineffective. Based on the success rate and accessibility, we suggest a stepwise approach to RFCA of APs at the site of prior mitral or tricuspid valve surgery (Figure).

Stepwise approach to AP at valve surgery

Conclusions

Successful RFCA of APs at the site of prior valve surgery can be achieved by detailed mapping of the areas both above and below the prosthetic valve, as well as by ensuring effective radiofrequency energy delivery using various catheter approaches and RFCA techniques.

P5660Clinical impact of polycythemia on cardiovascular outcome from the general population: a nationwide cohort study

Background

Although adverse effect of anemia had been reported, effect of polycythemia on cardiovascular outcome from the general population had not been revealed yet.

Methods

We included 451,107 subjects who received national health examinations from the Korean National Health Insurance Service-based National Sample Cohort from 2009–2013. Medical records were screened from January 2002 to investigate the subjects' disease-free baseline period. They were followed until December 2013. We divided male and female subjects into four categories each based on hemoglobin level (normal, moderate to severe and mild anemia, polycythemia) to assess each outcome.

Results

During 1,735,964 person·years, 12,107 major adverse cardiovascular and cerebrovascular events (MACCE), 862 incident acute myocardial infarction (MI), 5,850 incident ischemic stroke, and 2,430 incident atrial fibrillation (AF) were observed. Compared to normal hemoglobin range group, polycythemia group showed higher MACCE (HR=1.23 [1.12–1.35] in male, HR=1.79 [1.20–2.67] in female, each p<0.001), incident MI (HR=1.37 [1.05–1.79] in male, HR=3.46 [1.06–14.00] in female, each p<0.001), incident ischemic stroke (HR=1.27 [1.10–1.46] in male, HR=1.72 [1.02–2.91] in female, each p<0.001), and incident AF (HR=1.46 [1.21–1.74] in male, HR=2.13 [1.03–4.77] in female, each p<0.001). Each outcome was linearly increased with the increase of hemoglobin among subjects with polycythemia (p<0.001), and with the decrease of hemoglobin among subjects with anemia (each p<0.001, U-shaped relationship). These relationship was more profound in obese female younger than 60-year-old.

Conclusion

Not only anemia but also polycythemia were significantly associated with higher rate of MACCE including death, incident MI, ischemic stroke, and AF among the general population.

P1875Nonspecific intraventricular conduction delay is associated with future occurrence of atrial fibrillation in patients with structurally normal heart and sinus rhythm

Background

This study aimed to elucidate long-term prognosis of nonspecific intraventricular conduction delay (NIVCD) in patients with structurally normal heart.

Methods

We included 107,838 patients (age, 52.1±15.5 years; men, 46.8%) who underwent electrocardiography in outpatient clinics or medical checkup (model 1). NIVCD was defined as QRS duration ≥110 ms and incompatibility with bundle branch block. The patients with structurally normal heart and sinus rhythm were assigned to the NIVCD group and normal QRS group according to propensity score with matching variables of age, sex, hypertension, and diabetes (model 2), and additional PR interval (model 3). Baseline characteristics, electrocardiographic parameters, and clinical outcomes were compared in model 1, 2, and 3, respectively.

Results

In model 1, the frequencies of male and preexisting atrial fibrillation (AF) were significantly higher in the NIVCD group than in the normal QRS group. In model 2, sinus rate and PR interval were significantly slower and longer in the NIVCD group than in the normal QRS group. In model 3, cumulative incidence of AF was significantly higher in the NIVCD group than in the normal QRS group during follow-up of 8.8±2.9 years (Figure). NIVCD significantly increased risk of AF (hazard ratio, 2.571; 95% confidence interval, 1.074–6.156; p=0.034). NIVCD did not significantly increase risk of sick sinus syndrome, complete atrioventricular block, and heart failure.

Atrial fibrillation-free survival

Conclusions

NIVCD is associated with slow sinus rate and prolonged PR interval. NIVCD is an independent risk factor of AF in patients with structurally normal heart.

208Effect of hypertension duration and systolic blood pressure on dementia in patients with atrial fibrillation

Background

Atrial fibrillation (AF) is associated with a higher risk for cognitive impairment and dementia, with or without a history of clinical stroke. There are a paucity of data on the associations of hypertension duration and blood pressure (BP) level with risk of dementia in patients with AF.

Purpose

We examined associations of duration of hypertension and secondly, systolic blood pressure (SBP) levels with incidence of dementia among patients with AF.

Methods

We enrolled a total 196,388 patients aged ≥50 years who were newly diagnosed as AF and undergoing hypertension treatment from the Korean National Health Insurance Service database (2005–2016). Starting from AF diagnosis, participants were followed up until the date of dementia, death, or December 31, 2016. To incorporate the effect of BP level and hypertension duration changes over time on dementia incidence, we constructed time-updated multivariable Cox models in which BP levels and hypertension duration were updated at each participants' regular national health examination visits (at 0–7 years of follow-up). Similarly, age, BP medications, and health-related behaviors were included as time-varying covariates in these models.

Results

During 1,016,744 person-years of follow-up, there were 32,692 dementia events. A cubic spline curve using continuous hypertension duration measures suggested a linear association between increase of hypertension duration and dementia risk. One-year increase of hypertension duration increased the adjusted risk of dementia with a hazard ratio (HR) of 1.17 [95% confidence interval (CI) 1.13–1.22]. In patients with hypertension duration <6 years, SBP of ≥140 mmHg was significantly associated with higher dementia risk, compared to SBP of <130 mmHg (in patients with hypertension duration <3 years: adjusted HR 1.08, 95% CI 1.01–1.16; and in those with 3 ≤ hypertension duration <6 years: adjusted HR 1.13, 95% CI 1.07–1.20), whereas no significant association between SBP and dementia risk in those with hypertension duration ≥6 years.

SBP and dementia in different duration

Conclusion

In patients with AF, the increase of hypertension duration was strongly associated with increased risk of dementia. Uncontrolled SBP was also associated with higher dementia risk. But, this effect of SBP might be attenuated in patients with longer hypertension duration. These findings suggest more emphasis needed on BP control in AF patients with earlier phase of hypertension (duration <6 years).

Acknowledgement/Funding

The Korean Ministry of Education, Science and Technology (NRF-2017R1A2B3003303) and the Korean Ministry of Health & Welfare (HI16C0058, HI15C1200)

P3762The impact of type and burden of atrial fibrillation on stroke occurrence in patients with atrial fibrillation: from a prospective cohort of atrial fibrillation patients (CODE-AF Registry)

Background and purpose

Although several studies reported that stroke risk in patients with paroxysmal atrial fibrillation (AF) is similar to those with persistent or permanent AF, there is still controversy on the relationship of AF type and stroke occurrence. We investigated the effect of AF type on AF burden and stroke risk in patients with non-valvular AF.

Methods

Within the CODE-AF prospective, outpatient registry (COmparison study of Drugs for symptom control and complication prEvention of Atrial Fibrillation), we identified 8,883 patients ≥18 years of age with non-valvular AF and eligible follow-up visits. We compared AF burden and stroke risk among patients with 3 types of AF: paroxysmal (n=5,808) or persistent (n=2,806) or permanent (n=269).

Results

The median age of the overall population was 68.0 (interquartile range, 60.0–75.0); 36.0% were female. Patients with persistent and permanent AF were older and had higher CHA2DS2-VASc scores and anticoagulation rate than those with paroxysmal AF. Compared with permanent AF (5.2±16.4%), the arrhythmic burden of AF on 24hrs Holter monitoring was significantly lower in paroxysmal AF (2.1±7.2%, p<0.001) and persistent AF (2.0±7.5%, p<0.001). During median follow-up period of 1.38 years (interquartile range: 0.96–1.67), total 82 (0.92%) patients experienced ischemic stroke with incidence rates of 0.51, 1.04 and 1.69 events per 100 person-years for paroxysmal, persistent and permanent AF, respectively. Compared with paroxysmal AF, the risk of ischemic stroke was increased in persistent AF with clinical variable adjusted hazard ratio (aHR) of 1.94 (95% confidence intervals [CI], 1.23–3.07; P=0.005) and permanent AF with aHR of 2.64 (95% CI, 1.09–6.41; P=0.03).

AF type and HR of stroke occurrence Paroxysmal (n=5,808) Persistent (n=2,806) Permanent (n=269) Stoke events 39 37 6 Person years (PYs) 7673 3544 356 /100 PYs 0.51 1.04 1.69 HR (95% CI), p-value HR (95% CI), p-value HR (95% CI), p-value Unadjusted HR 1 (Reference) 2.05 (1.27–3.31), 0.003 3.32 (1.15–7.90), 0.02 Clinical variables adjusted HR 1 (Reference) 1.94 (1.23–3.07), 0.005 2.64 (1.09–6.41), 0.03 PYs: Person years; HR: Hazard ratio.

Conclusion

Persistent and permanent AF was associated with the increased risk of stroke than paroxysmal AF, after adjustment of clinical variables including age, sex, comorbidities and anticoagulation rate. These results suggest that AF type and burden might be related with the risk of ischemic stroke and should be considered in the stroke prevention of AF.

P5710Clinical applications of machine learning for prediction of incident atrial fibrillation from the general population: a nationwide cohort study

Background

To evaluate the ability of machine learning algorithms to predict incident atrial fibrillation (AF) from the general population using health examination items.

Methods

We included 483,343 subjects who received national health examinations from the Korean National Health Insurance Service-based National Sample Cohort (NHIS-NSC). We trained deep neural network model (DNN) of a deep learning system and decision tree model (DT) of a machine learning system using clinical variables and health examination items (including age, sex, body mass index, history of heart failure, hypertension or diabetes, baseline creatinine, and smoking and alcohol intake habits) to predict incident AF using a training dataset of 341,771 subjects constructed from the NHIS-NSC database. The DNN and DT were validated using an independent test dataset of 141,572 remaining subjects. C-indices of DNN and DT for prediction of incident AF were compared with that of conventional logistic regression model.

Results

During 1,874,789 person·years (mean±standard-deviation age 47.7±14.4 years, 49.6% male), 3,282 subjects with incident AF were observed. In the validation dataset, 1,139 subjects with incident AF were observed. The c-indices of the DNN and DT for incident AF prediction were 0.828 [0.819–0.836] and 0.835 [0.825–0.844], and were significantly higher (p<0.01) than conventional logistic regression model (c-index=0.789 [0.784–0.794]).

Conclusions

Application of machine learning using simple clinical variables and health examination items was helpful to predict incident AF in the general population. Prospective study is warranted to construct an individualized precision medicine.

64Risk of dementia in patients treated with non-vitamin k antagonist oral anticoagulant or warfarin for nonvalvular atrial fibrillation

Background

Evidence is accumulating that use of oral anticoagulants (OACs) decreases the risk of dementia in patients with atrial fibrillation (AF), but it is unclear if there is a difference between non-vitamin K antagonist oral anticoagulants (NOACs) and warfarin in protecting against dementia.

Purpose

To compare the risk of dementia between patients taking either NOAC or warfarin using a nationwide cohort data covering the entire Korean population.

Methods

Using the Korean national health insurance service database, 68,984 new OAC users with non-valvular AF aged ≥50 years and no prior diagnosis of dementia were identified during the period of 2013–2016 (39,687 NOAC users and 29,297 warfarin users). Starting from OAC initiation, participants were followed up until the date of dementia, death, or December 31, 2016. We compared the rates of dementia in 1:1 propensity score-matched cohorts of NOAC (n=18,925) and warfarin users (n=18,925).

Results

During the 52,259 person-years of follow-up, there were 2,750 dementia events. Use of NOAC was associated with significant lower risk of dementia [hazard ratio (HR) 0.75, 95% confidence interval (CI) 0.69–0.81], compared with warfarin. The risk reduction was prominent for vascular dementia (HR 0.60, 95% CI 0.52–0.71), whereas there was no significant difference in the risk of Alzheimer dementia (HR 0.92, 95% CI 0.83–1.02). Restricting the analyses to patients with no stroke diagnosis prior to OAC initiation (primary prevention) showed no significant difference between NOAC and warfarin in any types of dementia, but in the subgroup with prior stroke (secondary prevention), NOAC significantly reduced the risk of overall (HR 0.70, 95% CI 0.63–0.78) and vascular dementia (HR 0.59, 95% CI 0.49–0.69).

Subgroup analysis according to stroke Hx Patient N Overall dementia Alzheimer dementia Vascular dementia HR (95% CI) P for interaction HR (95% CI) P for interaction HR (95% CI) P for interaction Total 37,850 0.75 (0.69–0.81) 0.92 (0.83–1.02) 0.60 (0.52–0.71) Without prior stroke 24,773 0.90 (0.78–1.05) 0.948 0.98 (0.83–1.15) 0.235 0.85 (0.56–1.28) 0.863 With prior stroke 13,077 0.70 (0.63–0.78) 0.90 (0.79–1.03) 0.59 (0.49–0.69) CI, confidence interval; HR, hazard ratio.

KM curves of dementia incidence

Conclusion

In this propensity-weighted nationwide cohort of non-valvular AF patients, NOAC was associated with reduced risk of dementia, compared with warfarin. This association was the most pronounced for vascular dementia in patients with prior stroke.

Acknowledgement/Funding

The Korean Ministry of Education, Science and Technology (NRF-2017R1A2B3003303) and the Korean Ministry of Health & Welfare (HI16C0058, HI15C1200)

P345Catheter ablation for atrial fibrillation is associated with lower incidence of stroke, major bleeding and death: data from Korean health registries

Background

Compared with antiarrhythmic drug therapy, catheter ablation of AF reduces the number of AF episodes, prolongs the time in sinus rhythm, and improves quality of life. However, it is still unclear if catheter ablation for atrial fibrillation (AF) affects the prognosis or merely is a symptomatic treatment. Our objective was to compare long-term outcome regarding stroke, major bleeding and death in AF patients with and without ablation, and in relation to long-term exposure to anticoagulants.

Methods

We identified all 800,084 patients with a diagnosis of AF from 2006 to 2015 in the Korean national health insurance service database. During a 10-year period, 10,979 AF ablations were performed among 9,768 individuals. Propensity scores for the likelihood of AF ablation were obtained by logistic regression. Propensity score (PS) matching was used to construct two cohorts of equal size (n=9,768) with similar characteristics in 16 dimensions.

Results

Patients who had undergone catheter ablation were younger (57.2 vs. 65.6 years, P<0.001) and healthier (mean CHA2DS2-VASc scores 2.5±1.7 vs. 3.6±2.1, P<0.001) than other patients with AF. Mean follow-up was 5.5±3.1 years. After propensity score matching, in the ablated group, 472 patients suffered ischemic stroke/systemic embolism (SE) compared with 1,682 in the matched non-ablated (annual rates 2.92 vs. 1.10%, P<0.001). Major bleeding occurred in 439 and 1,219 patients in ablated and non-ablated (annual rates 2.07 vs. 1.01%, P<0.001). A total of 306 ablated and 1,439 non-ablated patients died (annual rates 2.31 vs. 0.69%, P<0.001). After multivariable adjustments, catheter ablation was associated with lower risk of ischemic stroke [hazard ratio (HR) 0.51, 95% confidence interval (CI) 0.38–0.67), lower risk of major bleeding (HR 0.65, 95% CI 0.57–0.75) and with lower mortality risk (HR 0.39, 95% CI 0.34–0.46). The reduction of stroke/SE and mortality was observed after AF ablation regardless thromboembolic risk. Major bleeding was reduced only among patients with CHA2DS2-VASc score ≥2 (HR 0.70, 95% CI 0.59–0.84).

Conclusion

We found a strong association between ablation and survival. Ablation may be associated with lower incidence of ischemic stroke and major bleeding in patients with AF. The reduction of stroke/SE and mortality was observed regardless thromboembolic risk after AF ablation. But the risk of major bleeding was reduced only in patients with high thromboembolic risk factors.

P1027The risk of dementia and catheter ablation for atrial fibrillation: a nationwide cohort study

Background

Atrial fibrillation (AF) is associated with all forms of dementia, including Alzheimer's disease. Catheter ablation of AF reduces the number of AF episodes, prolongs the time in sinus rhythm, and improves quality of life. However, it is still unclear if catheter ablation for AF improve cognitive function and prevent dementia. Our objective was to compare long-term outcome regarding dementia and type of dementia in AF patients with and without ablation, and about long-term exposure to anticoagulants.

Methods

We identified all 801,701 patients with a diagnosis of AF from 2006 to 2015 in the Korean national health insurance service database. During ten years, 10,979 AF ablations were performed among 9,768 individuals. Propensity scores for the likelihood of AF ablation were obtained by logistic regression. Propensity score (PS) matching was used to construct two cohorts of equal size (n=9,768) with similar characteristics in 16 dimensions.

Results

Patients who had undergone catheter ablation were younger (57.2 vs. 65.6 years, P<0.001) and healthier (mean CHA2DS2-VASc scores 2.5±1.7 vs. 3.6±2.1, p<0.001) than other patients with AF. Mean follow-up was 5.5±3.1 years. After propensity score matching, in the ablated group, 184 patients suffered dementia compared with 650 in the matched non-ablated (annual rates 0.42 vs. 1.08%, P<0.001). While a total of 134 ablated and 379 non-ablated patients had Alzheimer disease (annual rates 0.31 vs. 0.62%, p<0.001), 40 ablated and 191 non-ablated patients had vascular disease (annual rates 0.09 vs. 0.31%, p<0.001). After multivariable adjustments, catheter ablation was associated with lower risk of dementia (hazard ratio [HR] 0.46, 95% confidence interval [CI] 0.37–0.58), lower risk of Alzheimer disease (HR 0.61, 95% CI 0.46–0.79) and lower risk of vascular dementia (HR 0.27, 95% CI 0.19–0.38). Although the reduction of dementia and Alzheimer disease was observed after AF ablation regardless of thromboembolic risk, vascular dementia was reduced only among patients with CHA2DS2-VASc score ≥2 (HR 0.29, 95% CI 0.20–0.42).

The risk of dementia, RFCA vs. no-RFCA Type Propensity score matched ablation group vs. no ablation group adjusted HR (95% CI) P-value Overall dementia 0.46 (0.37–0.58) <0.001 Alzheimer dementia 0.61 (0.46–0.79) <0.001 Vascular dementia 0.27 (0.19–0.38) <0.001

Conclusion

Ablation may be associated with a lower incidence of dementia and both type of dementia in patients with AF. This finding appears more pronounced in patients with high thromboembolic risk factors.