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.

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

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

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.

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.

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

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

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.

Atrial fibrillation burden and the risks of ischemic stroke and intracranial hemorrhage: comparisons of catheter ablation, medical therapy, and non-atrial fibrillation population

Background

Although atrial fibrillation (AF) burden was known to be related to the risk of ischemic stroke (IS), clinical evidence regarding intracranial hemorrhage (ICH) or comparison of the patients after AF catheter ablation (AFCA) and the non-AF population are limited.

Objective

We explored the risks of IS and ICH after AFCA or medical therapy (Med) in the AF population and the matched non-AF population.

Methods

We compared 1,629 with AFCA (Yonsei AF cohort), 3,258 with Med (Korean National Health Insurance Sharing Service [KNHISS] database), and 3,258 non-AF population (KNHISS database) after 1:2:2 propensity-score match in terms of clinical characteristics and medications (57±12 years old, 22.1% female). IS and ICH were determined by ICD code, brain imaging, and hospital admission in Med and non-AF groups. All AFCA patients underwent regular rhythm follow-up, and the medications including antithrombotic therapies were evaluated for 52±23 months.

Results

1. Among AFCA group, the annualized IS rate was significantly higher in the patients with sustaining recurrence of AF/atrial tachycardia (AT) after the last ablation procedure than those remaining in sinus rhythm (SR) (0.87% vs. 0.24%, p=0.017; HR 4.87 [1.36–17.49], p=0.015; log rank p=0.003).

2. The annualized ICH rate was 0% in SR group and 0.06% in sustaining recurrent AF/AT group after AFCA (p=0.361, log rank p=0.545).

3. The annualized IS rate was significantly higher in Med group (1.09%) than in AFCA group (0.30%, p<0.001, log rank p<0.001) or non-AF group (0.34%, p<0.001, log rank p<0.001). There was no significant difference in annualized IS rate between AFCA and non-AF groups (p=0.673, log rank p=0.874)

4. The annualized ICH rates were 0.17% in Med group, 0.06% AFCA group (p=0.023, log rank p=0.042 vs. Med; p=0.172, log rank p=0.193 vs. non-AF), and 0.12% in non-AF group (p=0.226, log rank p=0.241 vs. Med), respectively.

Conclusion

Post-procedural AF burden influence the risk of IS. AFCA significantly reduces the risks of both IS and ICH to the extent of non-AF population compared to Med group.

Funding Acknowledgement

Type of funding source: None

Efficacy and safety of dronedarone vs placebo in patients with atrial fibrillation or atrial flutter across a spectrum of renal function: post hoc analyses of the EURIDIS-ADONIS trials

Background/Introduction

The use of antiarrhythmic drugs in patients with chronic kidney disease (CKD) is complex because impaired renal clearance can cause increased drug levels, and risk of intolerance or adverse events. Since CKD commonly co-occurs with atrial fibrillation/atrial flutter (AF/AFL), it is important to establish efficacy and safety for such drugs when used in AF/AFL patients with CKD.

Purpose

To evaluate the efficacy and safety of dronedarone in patients with AF or AFL across different levels of renal function.

Methods

This post hoc analysis evaluated pooled data from two multicentre, double-blind, randomised (2:1) trials of rhythm control with dronedarone 400 mg twice daily vs placebo. Primary endpoint was time to first recurrence of AF or AFL. Renal function (estimated glomerular filtration rate [eGFR]) was assessed with the CKD-Epidemiology Collaboration equation. Patients were grouped by eGFR strata. Log-rank testing and Cox regression were used to compare time to events between treatment groups.

Results

Most (85%) patients had mild or mild-to-moderate decrease in eGFR (Table 1). Median time to first AF recurrence was significantly longer in the dronedarone vs placebo group for all eGFR subgroups except the 30–44 mL/min group (Figure 1), where the trend was consistent; however, the small population size may have precluded meaningful analyses in this subgroup. Serious adverse events, deaths, and treatment discontinuations did not differ notably between each group irrespective of eGFR strata.

Conclusions

This analysis confirms the efficacy and safety of dronedarone in patients with AF across a wide spectrum of renal function.

Figure 1

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Sanofi

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

Mechanisms of long-term recurrence three years after catheter ablation of atrial fibrillation

Background

AF is a progressive disease, and the mechanism underlying long-term recurrence after AFCA is unclear.

Purpose

This study explored the potential mechanisms of long-term recurrence (LTR) of atrial fibrillation (AF) 3-years after AF catheter ablation (AFCA).

Methods

Among 2,209 consecutive patients who underwent AFCA, 1,325 (59±11 years, 72.5% male) who underwent regular rhythm follow-ups for >3-years were enrolled. Among them, 659 patients remained in sinus rhythm (SR), 327 recurred after 3–12 months (short-term recurrence; STR), 235 after 1–3 years (mid-term recurrence; MTR), and 104 after 3-years (long-term recurrence; LTR). Two hundred eighteen recurrent patients underwent repeat procedures: 112, 80, and 26 in the STR, MTR, and LTR groups, respectively.

Results

The pre-ablation left atrial (LA) dimensions were larger in the STR (p<0.001) and MTR groups (p<0.001), but not in the LTR group compared to the SR group. Low LA voltages were independently associated with an LTR (adjusted HR 0.57 [0.36–0.92], p=0.022). Upon the redo-mapping, the number of reconnected pulmonary veins (PVs) was 2.0 (IQR 0–3), 1.5 (IQR 0–3), and 1.0 (IQR 0–2) in the STR, MTR, and LTR groups, respectively (p=0.030). Post-ablation extra-PV triggers were more commonly found in the LTR than STR or MTR groups (LTR 40.9% to STR 19.2%, p=0.014) during the second procedure.

Conclusions

The LTR group had a similar baseline LA size and significantly lower LA voltage than the SR group. In the repeat procedures, the LTR group had fewer reconnected PVs, but extra-PV triggers were more common than in the STR and MTR groups.

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Ministry of Health and Welfare, Ministry of Science, ICT & Future Planning (MSIP).

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

Electrocardiographic characteristics of 5-year atrial tachy-arrhythmia free patients after catheter ablation for atrial fibrillation

Background

Predictors are not well known for long-lasting sinus rhythm after atrial fibrillation catheter ablation (AFCA).

Purpose

We investigated the pre-procedural clinical factors associated with the patients with 5-year long-term atrial fibrillation (AF) free after AFCA.

Methods

Among 2,085 patients who underwent de novo AFCA, 934 patients (58±11 years, 73.1% male, 66.0% paroxysmal AF), who underwent guidelines-based rhythm follow-up longer than 5-years, were included in this study. We compared 340 patients who never showed AF recurrence for 5-years and 594 patients with AF/ atrial tachycardia (AT) recurrence at least a single episode. Cut-off values of pericardial fat volume and electrocardiogram (ECG) parameters were obtained by Youden index.

Results

1. The patients with AF-free for 5-years (AF-Free-5yrs) had higher proportion of paroxysmal AF (p<0.001), lower body mass index (p=0.020), and lower proportion of pre-existing congestive heart failure (p=0.035), and smaller LA size (p<0.001) than those who experienced recurrence. 2. The patients with AF-Free-5yrs showed lower pericardial fat volume (105.9±47.5 vs. 121.2±53.cm3, p<0.001) and shorter PR interval (181.5±29.6 vs. 190.5±33.1ms, p<0.001) and P wave duration in lead II (PWDII, 121.1±18.0 vs. 129.4±18.8ms, p<0.001) rather than those of counter-part. 3. Multivariate regression analysis revealed that paroxysmal AF at the procedure, lower pericardial fat volume (OR 0.995, 95% CI [0.991–0.998], p=0.004), short PR interval (OR 0.994, 95% CI [0.988–1.000], p=0.038), and PWDII (OR 0.986, 95% CI [0.978–0.995], p=0.002) were independently associated with the AF-Free-5yrs. 3. Among the patients with persistent AF, PWDII was significantly shorter in AF-Free-5yrs group. (123.7±22.6 vs. 133.5±19.5, p<0.001), and PWDII <127.1ms was independently associated with AF-Free-5yrs (OR 3.114, 95% CI [1.819–5.331], p<0.001).

Conclusions

Pericardial fat volume (<113.7cm3) and PR interval (<196 ms) in pre-procedural ECG was independently associated with an excellent 5-year rhythm outcome after AFCA, and PWDII (<127.1 ms) predicted super-responders especially after persistent AF ablation.

Funding Acknowledgement

Type of funding source: None

Electrical posterior box isolation in persistent atrial fibrillation changed to paroxysmal atrial fibrillation: a multi-center, prospective, randomized study

Background

Persistent atrial fibrillation (PeAF) can change to paroxysmal AF (PAF) after antiarrhythmic drug medication and cardioversion.

Purpose

We investigated whether electrical posterior box isolation (POBI) may improve rhythm outcome of catheter ablation in those patient group.

Methods

We prospectively randomized 114 patients with PeAF to PAF (male 75%, 59.8±9.9 years old) to circumferential pulmonary vein isolation (CPVI) alone group (n=57) and additional POBI group (n=57). The primary end-point was AF recurrence after a single procedure, and the secondary end-point was a recurrence pattern, cardioversion rate, and the response to antiarrhythmic drugs (AADs).

Results

After a mean follow-up of 22.5±9.4 months, the clinical recurrence rate did not significantly differ between the two groups (29.8% vs. 28.1%, p=0.836; log rank p=0.815) The recurrence rate for atrial tachycardias (17.6% vs. 43.8%, p=0.141) was higher in POBI group, but the cardioversion rates (13.5% vs. 8.5%, p=0.434) were not significantly different between two groups. At the final follow-up, sinus rhythm was maintained without antiarrhythmic drug in 52.6% in CPVI group and 59.7% of POBI group (p=0.452). No significant difference was found in the major complication rates between the two groups (5.3% vs. 1.8%, p=0.618), but the total ablation time was significantly longer in the POBI group (4397±842 sec vs. 5337±1517 sec, p<0.001).

Conclusion

In patients with persistent AF converted to paroxysmal AF by AAD, the addition of POBI to CPVI did not improve the rhythm outcome of catheter ablation nor influence overall safety.

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

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

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)

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.