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.