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.

Changes in Cardiovascular Health Status and Risk of Sudden Cardiac Death in Older Adults

PURPOSE

Cardiovascular health (CVH) status is associated with several cardiovascular outcomes; however, correlations between changes in CVH status and risk of sudden cardiac death (SCD) are unknown. We aimed to evaluate associations between changes in CVH status and risk of SCD and all-cause death in older adults.

MATERIALS AND METHODS

We used data from the Korea National Health Insurance Service-Senior cohort database (2005-2012). Six metrics from the American Heart Association (smoking, body mass index, physical activity, blood pressure, total cholesterol, and fasting blood glucose) were used to calculate CVH scores. Changes in CVH status between two health checkups were categorized as low to low, low to high, high to low, and high to high.

RESULTS

We included 105200 patients whose CVH status for an initial and follow-up health checkup (2-year interval) was available. During a median of 5.2 years of follow-up after a second health checkup, 688 SCDs occurred. Compared to patients with a persistent low CVH status, those with a consistently high CVH status had a reduced risk of SCD [adjusted hazard ratio (HR), 0.69; 95% confidence interval (CI), 0.56-0.86] and all-cause death (adjusted HR, 0.74; 95% CI, 0.69-0.78). The risk of all-cause death followed similar trends. However, an inconsistent linear relationship was observed for changes in CVH status and the risk of SCD, but not of all-cause death.

CONCLUSION

Maintaining a high CVH status was associated with future risks of SCD and all-cause death among an older adult population.

Percutaneous Left Atrial Appendage Occlusion Yields Favorable Neurological Outcomes in Patients with Non-Valvular Atrial Fibrillation

BACKGROUND AND OBJECTIVES

Prior studies have shown that stroke patients treated with percutaneous left atrial appendage occlusion (LAAO) for non-valvular atrial fibrillation (NVAF) experience better outcomes than similar patients treated with warfarin. We investigated the impact of percutaneous left atrial appendage closure on post-stroke neurological outcomes in NVAF patients, compared with non-vitamin K antagonist oral anticoagulant (NOAC) therapy.

METHODS

Medical records for 1,427 patients in multiple registries and for 1,792 consecutive patients at 6 Korean hospitals were reviewed with respect to LAAO or NOAC treatment. Stroke severity in patients who experienced ischemic stroke or transient ischemic attack after either treatment was assessed with modified Rankin Scale (mRS) scoring at hospital discharge and at 3 and 12 months post-stroke.

RESULTS

mRS scores were significantly lower in LAAO patients at 3 (p<0.01) and 12 months (p<0.01) post-stroke, despite no significant differences in scores before the ischemic cerebrovascular event (p=0.22). The occurrences of disabling ischemic stroke in the LAAO and NOAC groups were 36.7% and 44.2% at discharge (p=0.47), 23.3% and 44.2% at 3 months post-stroke (p=0.04), and 13.3% and 43.0% at 12 months post-stroke (p=0.01), respectively. Recovery rates for disabling ischemic stroke at discharge to 12 months post-stroke were significantly higher for LAAO patients (50.0%) than for NOAC patients (5.6%) (p<0.01).

CONCLUSIONS

Percutaneous LAAO was associated with more favorable neurological outcomes after ischemic cerebrovascular event than NOAC treatment.

Efficacy and Safety of Outpatient Clinic-based Elective External Electrical Cardioversion in Patients with Atrial Fibrillation

BACKGROUND AND OBJECTIVES

Little is known about the outcomes of outpatient clinic-based elective external cardioversion (OPC-ECV) for persistent atrial fibrillation (PeAF). We investigated the acute, short-term, and long-term elective external cardioversion (ECV) outcomes.

METHODS

We included 1,718 patients who underwent OPC-ECV (74% male, 61.1±11.0 years old, 90.9% long-standing PeAF, 9.1% after atrial fibrillation [AF] ablation) after excluding patients with atrial tachycardia or inappropriate antiarrhythmic drug medication, and in-patient ECV. Biphasic shocks were delivered sequentially until successful cardioversion was achieved (70-100-150-200-250 J). If ECV failed at 150 J, we administered intravenous amiodarone 150 mg and delivered 200 J.

RESULTS

ECV failed in 11.4%, and the complication rate was 0.47%. Within 3 months, AF recurred in 55.5% (44.7% as sustaining AF, 10.8% as paroxysmal AF), and the AF duration was independently associated (odds ratio [OR], 1.01 [1.00-1.02]; p=0.006), but amiodarone was independently protective (OR, 0.46 [0.27-0.76]; p=0.002, Log rank p<0.001) against an early recurrence. Regarding the long-term recurrence, pre-ECV heart failure was protective against an AF recurrence (hazard ratio, 0.63 [0.41-0.96], p=0.033) over 32 (9-66) months of follow-up. ECV energy (p<0.001) and early recurrence rate within 3 months (p=0.007, Log rank p=0.006) were significantly lower in post-ablation patients than in those with long-standing persistent AF.

CONCLUSIONS

The success rate of OPC-ECV was 88.6%, and the complication rate was low. However, AF recurred in 55.5% within 3 months. Amiodarone was protective against short-term AF recurrences, and long-term AF recurrences were less in patients with baseline heart failure.

Social Inequalities of Oral Anticoagulation after the Introduction of Non-Vitamin K Antagonists in Patients with Atrial Fibrillation

Background and Objectives

Nationwide social inequalities of oral anticoagulation (OAC) usage after the introduction of non-vitamin K antagonist oral anticoagulants (NOACs) have not been well identified in patients with atrial fibrillation (AF). This study assessed overall rate and social inequalities of OAC usage after the introduction of NOAC in Korea.

Methods

Between January 2002 and December 2016, we identified 888,540 patients with AF in the Korea National Health Insurance system database. The change of OAC rate in different medical systems after the introduction of NOAC were evaluated.

Results

In all population, overall OAC use increased from 13.2% to 23.4% (p for trend <0.001), and NOAC use increased from 0% to 14.6% (p for trend <0.001). Compared with pre-reimbursement (0.48%), the annual increase of OAC use was significantly higher after partial (1.16%, p<0.001), and full reimbursement of OAC (3.72%, p<0.001). Full reimbursement of NOAC (adjusted odds ratio, 2.10; 95% confidence interval, 2.04–2.15) was independently associated with higher OAC use. However, the difference of overall OAC usage between tertiary referral hospitals and nursing or public health centers increased from 17.9% in 2010 to 36.8% in 2016. Moreover, usage rate of NOAC was significantly different among different medical systems from 37.2% at the tertiary referral hospital and 5.5% at nursing or public health centers.

Conclusions

Introduction of NOACs in routine practice for stroke prevention in AF was associated with improved rates of overall OAC use. However, significant practice-level variations in OAC and NOAC use remain producing social inequalities of OAC despite full reimbursement.

Permanent Pacemaker Implantations after Catheter Ablation in Patients with Atrial Fibrillation Associated with Underlying Sinus Node Dysfunction

BACKGROUND AND OBJECTIVES

The objective of this study was to evaluate the long-term clinical outcomes and the incidence of permanent pacemaker implantation after catheter ablation in patients with of atrial fibrillation (AF) and sinus node dysfunction (SND).

METHODS

Among 3,068 total consecutive patients who underwent AF catheter ablation (AFCA), this study included 222 (9.5%; men 53.2%, 63.7±9.2 years of age, 81.5% paroxysmal AF) with underlying SND and a regular rhythm follow-up. We analyzed the rhythm outcomes, changes in the mean heart rate or heart rate variability, and permanent pacemaker implantation rate.

RESULTS

During 47.5±28.8 months of follow-up, 25 (11.3%) patients received pacemaker implantations due to symptomatic SND. More than half (56.0%, 14/25) underwent a pacemaker implantation within 3 months of the AFCA, and the annual pacemaker implantation rate was 2.0% afterwards. Both the early (68.0% vs. 31.0%, p<0.001) and clinical AF recurrence (68.0% vs. 32.5%, p=0.001) rates and continuous antiarrhythmic drug use after 3 months (44.0% vs. 24.4%, p=0.036) were significantly higher in patients requiring pacemaker implantations than those that did not. An anterior linear ablation (odds ratio [OR], 9.37 [3.03-28.9]; p<0.001) and the E/Em (OR, 1.15 [1.02-1.28]; p=0.018) were independently associated with permanent pacemaker implantations after AFCA in patients with AF and SND.

CONCLUSIONS

After AFCA in patients with AF and SND, 1 of 9 patients needed a pacemaker implantation and half needed implantations within 3 months. The AF recurrence rate was significantly higher in those who required pacemaker implantations after the AFCA.

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.

Association of Newly Developed Right Bundle Branch Block with Graft Rejection Following Heart Transplantation

PURPOSE

We aimed to examine associations between right bundle branch block (RBBB) following heart transplantation (HT) and graft rejection.

MATERIALS AND METHODS

We investigated 51 patients who underwent endomyocardial biopsies, electrocardiogram, right-side cardiac catheterization, and echocardiography at 1 month and 1 year after HT. We classified patients into four groups according to the development of RBBB, based on electrocardiogram at 1 month and 1 year: 1) sustained RBBB, 2) disappeared RBBB, 3) newly developed RBBB, and 4) sustained non-RBBB. The RBBB was defined as an RSR' pattern in V1 with a QRS duration ≥100 ms on electrocardiogram.

RESULTS

The newly developed RBBB group (n=13, 25.5%) had a higher rate of new onset graft rejection (from grade 0 to grade ≥1R, 30.8% vs. 10.0% vs. 21.4%, p=0.042) at 1 year, compared with sustained RBBB (n=10, 19.6%) and sustained non-RBBB group (n=28, 54.9%). In contrast, the incidence of resolved graft rejection (from grade ≥1R to grade 0) was higher in the sustained RBBB group than the newly developed RBBB and sustained non-RBBB groups (70.0% vs. 7.7% vs. 25.0%, p=0.042). Left atrial volume index was significantly higher in the newly developed RBBB group than the sustained RBBB and sustained non-RBBB groups (60.6±25.9 mL/m² vs. 36.0±11.0 mL/m² vs. 38.4±18.1 mL/m², p=0.003).

CONCLUSION

Close monitoring for new development of RBBB at 1 year after HT, which was associated with a higher incidence of new onset graft rejection, may be helpful to identify high risk patients for graft rejection.

Unilateral versus Bilateral Groin Puncture for Atrial Fibrillation Ablation: Multi-Center Prospective Randomized Study

PURPOSE

Catheter ablation for atrial fibrillation (AF) requires heavy anticoagulation and uncomfortable post-procedural hemostasis. We compared patient satisfaction with and the safety of unilateral groin (UG) puncture-single trans-septal (ST) ablation with conventional bilateral groin (BG) puncture-double trans-septal (DT) ablation in paroxysmal AF patients.

MATERIALS AND METHODS

We enrolled 222 patients with paroxysmal AF (59.4±10.7 years old) who were randomized in a 2:1 manner into UG-ST ablation (n=148) and BG-DT ablation (n=74) groups. If circumferential pulmonary vein isolation could not be achieved after three attempts of touch-up ablation in the UG-ST group, the patient was crossed over to BG-DT by performing a left groin puncture.

RESULTS

Ten patients in the UG-ST group (6.8%) required crossover to the BG-DT approach. There were no significant differences in procedure time (p=0.144) and major complications rate (p>0.999) between the UG-ST and BG-DT groups. Access site pain (p=0.014), back pain (p=0.023), and total pain (p=0.015) scores were significantly lower for the UG-ST than BG-DT group as assessed by the Visual Analog Scale. Over 20.2±8.7 months of follow up, there was no difference in AF recurrence free-survival rates between the two groups (Log rank, p=0.984).

CONCLUSION

UG-ST AF ablation is feasible and safe, and was found to significantly reduce post-procedural hemostasis-related discomfort, compared to the conventional DT approach, in patients with paroxysmal AF.

Catheter Ablation of Long-standing Persistent Atrial Fibrillation: a Reckless Challenge or a Way to Real Cure?

Long-standing persistent atrial fibrillation (L-PeAF) is a category in which rhythm control is attempted while atrial fibrillation (AF) is maintained for more than 1 year. Because AF is a progressive disease and L-PeAF accompanies significant electrical and structural remodeling of atria, it is difficult to restore and maintain sinus rhythm in patients with L-PeAF. Nonetheless, the rhythm outcome is being increasingly improved by the development of sophisticated mapping devices, highly efficient catheters, and evidence-based ablation strategies, and the rational choice of patient selection criteria. This review discusses the evolution of the rhythm control outcome of L-PeAF and its future direction of development.

Left Ventricular End-Systolic Volume Can Predict 1-Year Hierarchical Clinical Composite End Point in Patients with Cardiac Resynchronization Therapy

PURPOSE

This study aimed to elucidate which echocardiographic criteria at three time points, for cardiac resynchronization therapy (CRT) response, are accurate in discriminating the hierarchical clinical composite end point (HCCEP).

MATERIALS AND METHODS

We included 120 patients (age, 66.1±12.6 years; men, 54.2%) who underwent CRT implantation for heart failure (HF). Echocardiography was performed before and at 3, 6, and 12 months after CRT implantation. The 1-year HCCEP included all-cause mortality, hospitalization for HF, and New York Heart Association functional class for 12 months. CRT response criteria were decrease in left ventricular (LV) end-systolic volume (LVESV) >15%, decrease in LV end-diastolic volume >15%, absolute increase in LV ejection fraction (LVEF) ≥5%, relative increase in LVEF ≥15%, and decrease in mitral regurgitation ≥1 grade. Temporal changes in CRT response rates, accuracy of CRT response criteria at each time and cutoff value for the discrimination of improvement in HCCEP, and agreements with improvement in HCCEP were analyzed.

RESULTS

HCCEP improvement rates were 65.8% in total group. In nonischemic group, CRT response rates according to all echocardiographic criteria significantly increased with time. In ischemic group, CRT response rate did not significantly change with time. In total group, ΔLVESV at 6 months (ΔLVESV6) had the most significant accuracy for the discrimination of HCCEP (area under the curve=0.781). The optimal cutoff value of ΔLVESV6 was 13.5% (sensitivity=0.719, specificity=0.719). ΔLVESV6 had fair agreement with HCCEP (κ=0.391, p<0.001).

CONCLUSION

ΔLVESV6 is the most useful echocardiographic CRT response criterion for the prediction of 1-year HCCEP.

The Role of Serotonin in Ventricular Repolarization in Pregnant Mice

PURPOSE

The mechanisms underlying repolarization abnormalities during pregnancy are not fully understood. Although maternal serotonin (5-hydroxytryptamine, 5-HT) production is an important determinant for normal fetal development in mice, its role in mothers remains unclear. We evaluated the role of serotonin in ventricular repolarization in mice hearts via 5Htr3 receptor (Htr3a) and investigated the mechanism of QT-prolongation during pregnancy.

MATERIALS AND METHODS

We measured current amplitudes and the expression levels of voltage-gated K⁺ (Kv) channels in freshly-isolated left ventricular myocytes from wild-type non-pregnant (WT-NP), late-pregnant (WT-LP), and non-pregnant Htr3a homozygous knockout mice (Htr3a(-/-)-NP).

RESULTS

During pregnancy, serotonin and tryptophan hydroxylase 1, a rate-limiting enzyme for the synthesis of serotonin, were markedly increased in hearts and serum. Serotonin increased Kv current densities concomitant with the shortening of the QT interval in WT-NP mice, but not in WT-LP and Htr3a(-/-)-NP mice. Ondansetron, an Htr3 antagonist, decreased Kv currents in WT-LP mice, but not in WT-NP mice. Kv4.3 directly interacted with Htr3a, and this binding was facilitated by serotonin. Serotonin increased the trafficking of Kv4.3 channels to the cellular membrane in WT-NP.

CONCLUSION

Serotonin increases repolarizing currents by augmenting Kv currents. Elevated serotonin levels during pregnancy counterbalance pregnancy-related QT prolongation by facilitating Htr3-mediated Kv currents.

CHA₂DS₂-VASc Score in the Prediction of Ischemic Stroke in Patients after Radiofrequency Catheter Ablation of Typical Atrial Flutter

PURPOSE

Despite undergoing successful catheter ablation of typical atrial flutter (AFL), patients remain at increased risk for ischemic stroke. However, data on risk prediction tools for the development of stroke after AFL ablation are lacking. This study investigates whether CHA₂DS₂-VASc score is useful for predicting ischemic stroke after successful ablation of typical AFL.

MATERIALS AND METHODS

A total of 293 patients (236 men, mean age 56.1±13.5 years) who underwent successful radiofrequency catheter ablation for typical AFL were included in this study. The clinical end point was occurrence of ischemic stroke during follow-up after AFL ablation.

RESULTS

During the follow-up period (60.8±45.9 months), ischemic stroke occurred in 18 (6%) patients at a median of 34 months (interquartile range, 13-65 months). CHA₂DS₂-VASc score [hazard ratio 2.104; 95% confidence interval (CI), 1.624-2.726; p<0.001] was an independent predictor for the occurrence of stroke after AFL ablation. The area under the receiver operating characteristic curve for CHA₂DS₂-VASc score was 0.798 (95% CI, 0.691-0.904). The CHA₂DS₂-VASc score could be used to stratify patients into two groups with different incidences of ischemic stroke (1.6% vs. 14.4%, p<0.001) at a cutoff value of 2.

CONCLUSION

CHA₂DS₂-VASc score is useful in a prediction model for the risk of stroke after catheter ablation of typical AFL.

Effect of Non-vitamin K Antagonist Oral Anticoagulants in Atrial Fibrillation Patients with Newly Diagnosed Cancer

BACKGROUND AND OBJECTIVES

There are limited data on the use of non-vitamin K antagonist oral anticoagulants (NOACs) in atrial fibrillation (AF) patients with cancer. We aimed to assess the efficacy and safety of NOACs in AF patients with cancer in this study.

METHODS

In 2,568 consecutive non-valvular AF patients with newly diagnosed cancer, we analyzed ischemic stroke/systemic embolism (SE), major bleeding, and all-cause death. Based on propensity score matching, 388 matched pairs were included in the NOAC and warfarin groups.

RESULTS

Patient baseline characteristics were comparable between the matched groups. During median follow-up of 1.8 years, the NOAC group had significantly lower incidences of ischemic stroke/SE (p<0.001), major bleeding (p<0.001), and all-cause death (p<0.001) than the warfarin group. Moreover, the incidence of major bleeding was significantly lower in the NOAC group than in the warfarin group with optimal international normalized ratio control (p=0.03). Especially, within 1 year after cancer diagnosis, the incidences of all clinical events were significantly lower in the NOAC group than in the warfarin group.

CONCLUSIONS

In AF patients with newly diagnosed cancer, NOACs showed lower incidences of ischemic stroke/SE, major bleeding, and all-cause death than warfarin, especially within 1 year after cancer diagnosis.

Simultaneous Closure of a Left Atrial Appendage through an Atrial Septal Defect and the Atrial Septal Defect

Left atrial appendage (LAA) occlusion can be employed as an alternative treatment to oral anticoagulation in patients with atrial fibrillation to prevent embolic events. Atrial septal defect (ASD) may be related with right heart dysfunction and allow paradoxical embolism to occur. However, occlusion of both LAA through atrial access with ostium secundum ASD and ASD in the same setting is unusual. Therefore, we report a case in which a LAA and an ASD was sequentially occluded.