Catheter Ablation of Atrial Fibrillation in Patients With Valvular Heart Disease: Long-Term Follow-Up Results

Practical approach for atrial cardiomyopathy characterization in patients with atrial fibrillation

Atrial fibrillation (AF) causes progressive structural and electrical changes in the atria that can be summarized within the general concept of atrial remodeling. In parallel, other clinical characteristics and comorbidities may also affect atrial tissue properties and make the atria susceptible to AF initiation and its long-term persistence. Overall, pathological atrial changes lead to atrial cardiomyopathy with important implications for rhythm control. Although there is general agreement on the role of the atrial substrate for successful rhythm control in AF, the current classification oversimplifies clinical management. The classification uses temporal criteria and does not establish a well-defined strategy to characterize the individual-specific degree of atrial cardiomyopathy. Better characterization of atrial cardiomyopathy may improve the decision-making process on the most appropriate therapeutic option. We review current scientific evidence and propose a practical characterization of the atrial substrate based on 3 evaluation steps starting with a clinical evaluation (step 1), then assess outpatient complementary data (step 2), and finally include information from advanced diagnostic tools (step 3). The information from each of the steps or a combination thereof can be used to classify AF patients in 4 stages of atrial cardiomyopathy, which we also use to estimate the success on effective rhythm control.

Creation and Validation of an Algorithm for Predicting the Recurrence of Atrial Fibrillation Following Pulmonary Vein Isolation by Utilizing Real-World Data and Ensemble Modeling Techniques

Introduction Catheter ablation (CA) of atrial fibrillation (AF) represents a mainstay in the treatment of this increasingly prevalent arrhythmia. Prospective clinical trials investigating the efficacy of CA may poorly represent real-world patient populations. However, many real-world clinical datasets possess missing data, which may impede their applicability in research. Thus, we sought to use ensemble modeling to address missing data and develop a model to estimate the probability of AF recurrence following CA. Methods We retrospectively analyzed clinical variables in 476 patients who underwent an initial CA of AF. Univariate and multivariate logistic regression was performed to determine those variables predictive of AF recurrence. A multivariate logistic model was created to estimate the probability of AF recurrence after CA. Missing data were addressed using ensemble modeling, and variable selection was performed using the aggregate of multiple models. Results After analysis, six variables remained in the model: AF during the post-procedural blanking period, coexistence of atrial flutter, end-stage renal disease, reduced left ventricular ejection fraction, prior failure of anti-arrhythmic drugs, and valvular heart disease. Predictive modeling was performed using these variables for 1000 randomly partitioned datasets (80% training, 20% testing) and 1000 random imputations for each partitioned dataset. The model predicted AF recurrence with an accuracy of 74.34 ± 3.99% (recall: 54.03 ± 8.15%; precision: 89.30 ± 4.21%; F1 score: 81.08 ± 3.65%).  Conclusion We successfully identified six clinical variables that, when modeled, predicted AF recurrence following CA with a high degree of classification accuracy. Application of this model to patients undergoing CA of AF may help identify those at risk of post-procedural AF recurrence.

Catheter Ablation for Atrial Fibrillation in Structural Heart Disease: A Review

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. Patients with structural heart disease (SHD) are at an increased risk of developing this arrhythmia and are particularly susceptible to the deleterious hemodynamic effects it carries. In the last two decades, catheter ablation (CA) has emerged as a valuable strategy for rhythm control and is currently part of the standard care for symptomatic relief in patients with AF. Growing evidence suggests that CA of AF may have potential benefits that extend beyond symptoms. In this review, we summarize the current knowledge of this intervention on SHD patients.

Combined atrial fibrillation ablation and balloon mitral commissurotomy in patients with rheumatic mitral stenosis

INTRODUCTION

Ablation of atrial fibrillation (AF) is usually not considered in patients with rheumatic mitral stenosis (RMS). We analyzed the results of a combined procedure of AF ablation and percutaneous balloon mitral commissurotomy (PBMC).

METHODS

We prospectively included 22 patients with severe RMS to undergo a combined PBMC + AF ablation procedure. Noninvasive mapping of the atria was also performed. A historical sample of propensity-scored matched patients who underwent PBMC alone was used as controls. The primary endpoint was freedom from AF/AT at 1-year. Multivariate analysis evaluated sinus rhythm (SR) predictors.

RESULTS

Successful pulmonary vein isolation and electrocardiographic imaging-based drivers ablation was performed in 20 patients following PBMC. At 1-year, 75% of the patients in the combined group were in SR compared to 40% in the propensity-score matched group (p = 0.004). The composite of AF recurrence, need for mitral surgery and all-cause mortality was also more frequent in the control group (65% vs. 30%; p = 0.005). Catheter ablation (odds ratio [OR] 1.58; 95% confidence interval [CI] [1.17-17.37]; p = 0.04) and AF type (OR 1.46; 95% CI [1.05-82.64]; p < 0.001) were the only independent predictors of SR at 1-year. Noninvasive mapping in the combined group showed that the number of simultaneous rotors (OR 2.10; 95% CI [1.41-10.2]; p = 0.04) was the only independent predictor of AF.

CONCLUSION

A combined procedure of AF ablation and PBMC significantly increased the proportion of patients in sinus rhythm at 1-year. Noninvasive mapping may help to improve AF characterization and guide personalized AF treatment.

The Right Atrial Area as a New Factor to Predict Successful Pulmonary Vein Isolation: an Emergent Predictor Variable

Up to now, few factors have been identified to predict successful pulmonary vein isolation, none of which with high predictive values. The objective of our study was to compare different predictive factors of atrial fibrillation recurrence after pulmonary vein isolation,including new parameters of the right atrium (area and index volume). We retrospectively analysed data from 66 patients and included echocardiogram parameters performed within 18 months prior to the ablation procedure. We excluded patients with left ventricular dysfunction (defined as a left ventricular ejection fraction < 50%); previous diagnostic of cardiomyopathy; severe valvular heart disease; severe pulmonary hypertension; or those with poor image quality in the echocardiogram. We considered atrial fibrillation recurrence to be the presence of atrial fibrillation of 30 seconds or longer demonstrated by a standard electrocardiogram or in a 24-hour Holter electrocardiogram within a year after the ablation procedure. We found that the right atrium area (odds ratio = 1.52; 95% confidence interval 0.95–2.43, P = 0.08) and a previous pulmonary vein isolation procedure (odds ratio = 0.21; 95% confidence interval 0.04–1.01, P = 0.05) were nearly statistically significant predictors of successful atrial fibrillation ablation at one year. Although our study was limited because of a low number of patients and because it is a retrospective analysis, we found that a higher right atrial area may be related to the late recurrence of atrial fibrillation. This tendency may be useful in predicting patient outcomes.

Safety of Catheter Ablation for Atrial Fibrillation in Patients with Mechanical Prosthetic Valves

BACKGROUND

Catheter ablation (CA) for Atrial Fibrillation (AF) is increasingly utilized in the recent years, with promising results. We aimed to investigate the nationwide trends in utilization and procedural complications of CA for AF in patients with mechanical prosthetic valves (MPVs).

METHODS AND RESULTS

We drew data from the US National Inpatient Sample (NIS) database to identify cases of AF ablations in patients with MPVs, between 2003-2015. Sociodemographic and clinical data were collected, and incidence of procedural complications, mortality, and length of stay were analyzed. We compared the outcomes to a propensity matched cohort of patients without MPVs. The study included a weighted total of 1898 CA for AF cases in patients with MPVs. The median age of the study population was 67 (61-75) years and 53% were males. Despite the increasing age and significant uptrend in the prevalence of individual comorbidities and Deyo - Charlson Comorbidity Index (CCI) over the years, the risk of peri-procedural complications and mortality in the study group didn't change between the early (2003-2008) and late (2009-2015) study years. The peri-procedural complication rate (8.4% vs 10.4%, p=0.33) and in-hospital mortality (0.2% vs. 0.2%, p=0.9) did not differ significantly between patients with MPVs and 1901 matched patients without MPVs. Length of stay was higher among patients with prior MPVs compared to the controls (4.0±0.2 vs. 3.3±0.2 days, p=0.011).

CONCLUSION

This nationwide analysis shows that AF ablation in patients with mechanical valve prostheses bares similar risk of periprocedural complications and mortality as in patients without prosthetic valves. This article is protected by copyright. All rights reserved.

Complications Associated With Catheter Ablation in Patients With Atrial Fibrillation: A Report From the JROAD-DPC Study

Background Aging is one of the major concerns and determinants of the indications for catheter ablation (CA) for atrial fibrillation. This study aimed to assess the safety of CA in older patients with atrial fibrillation undergoing CA. Methods and Results The JROAD-DPC (Japanese Registry of All Cardiac and Vascular Diseases-Diagnosis Procedure Combination) is a nationwide claims database using data from the Japanese Diagnosis Procedure Combination/Per Diem Payment System. Among 6 632 484 records found between April 2012 and March 2018 from 1058 hospitals, 135 299 patients with atrial fibrillation (aged 65±10 years, 38 952 women) who underwent CA in 456 hospitals were studied and divided into the following age groups: <60, 60 to 64, 65 to 69, 70 to 74, 75 to 79, 80 to 84, and ≥85 years. The overall in-hospital complication rate was 3.4% (cardiac tamponade 1.2%), and in-hospital mortality was 0.04%. Older patients had a higher prevalence of women, lower body mass index, and a higher burden of comorbidities such as hypertension, and all of those characteristics were predictors for complications in multivariate analysis. A multivariate adjusted odds ratio revealed that increased age was independently and significantly associated with overall complications (60-64 years, 1.19; 65-69 years, 1.29; 70-74 years, 1.57; 75-79 years, 1.63; 80-84 years, 1.90; and ≥85 years, 2.86; the reference was <60 years). Conclusions The nationwide JROAD-DPC database demonstrated that the frequency of complications following CA in patients with atrial fibrillation increased according to age.

Comparison between cryoballoon ablation and radiofrequency catheter ablation for atrial fibrillation in patients on hemodialysis

Background

Difficulties are often encountered while controlling atrial fibrillation (AF), especially in hemodialysis (HD) patients. Previous data revealed that cryoballoon ablation (CBA) for treating paroxysmal atrial fibrillation (PAF) was not inferior to radiofrequency ablation (RFA); however, HD patients were excluded in this prior trial. Thus, the efficacy of CBA for HD patients is still unknown.

Methods

This retrospective study analyzed HD patients who underwent catheter ablation (CA) for AF from August 2011 to June 2019. Patients who received CBA (CBA group) and those who received RFA (RFA group) were compared. The primary endpoint was defined as freedom from a composite outcome (a documented recurrence of any atrial tachyarrhythmia or a prescription of antiarrhythmic drugs) at one year after CA.

Results

The RFA and CBA groups were composed of 21 and 23 patients, respectively. Freedom from a composite outcome was 58.4% in the RFA group and 68.2% in the CBA group (Log-rank: p = 0.571).

Conclusion

Our results suggest that patients on HD with AF who were treated with CBA tended to have better outcomes than patients treated with RFA. Therefore, CBA could be a suitable ablation method for HD patients.

Presence of a left common pulmonary vein and pulmonary vein anatomical characteristics as predictors of outcome following cryoballoon ablation for paroxysmal atrial fibrillation

PURPOSE

Pulmonary vein (PV) isolation using cryoballoon ablation (CBA) is a common therapy for patients with drug-refractory paroxysmal atrial fibrillation (PAF). However, initial CBA is successful in only 70-80% of patients. The role of an atypical left common PV (LCPV) and PV anatomical indices on CBA outcomes remains unclear.

METHODS

We followed 80 patients (age 60.7 ± 9.7, 31 % women) with PAF undergoing CBA for 1-year post-procedure for the development of recurrent atrial arrhythmias (AA). Recurrence was assessed by documented AA on EKG or any form of long-term cardiac rhythm monitoring. The presence of an LCPV and individual PV diameters were evaluated using cardiac CT. Based on the maximum and minimum PV ostial diameters, the eccentricity index (EI), ovality index (OI), and PV ostial area (PVA) were calculated for all the veins. A multivariable Cox-proportional hazard model assessed whether the presence of an LCPV or PV anatomic indices (EI, OI, and PVA) predicted recurrence of AA following CBA.

RESULTS

After 1-year follow-up, 19 (23.7%) participants developed recurrence of AA. On multivariable regression, the presence of an LCPV did not predict the recurrence of AA (p = 0.38). Among the PV anatomical indices, on univariate analysis, only the area of the left inferior PV showed a trend towards predicting recurrence, though this result was not significant on multivariate analysis (p = 0.09).

CONCLUSIONS

In patients with PAF, neither the presence of an LCPV nor individual PV anatomical indices predicted recurrence of AA following CBA.

Clinical implication of adenosine test at repeat atrial fibrillation ablation procedure: the importance of detecting dormant thoracic vein conduction

BACKGROUND

Pulmonary vein reconnection after electrical isolation is commonly observed in the context of atrial fibrillation ablation and is associated with recurrent atrial tachyarrhythmias. Adenosine test was been performed to identify acute dormant conduction immediately after pulmonary vein isolation at index procedure. However, the utility of adenosine test at repeat procedure has not been reported.

METHODS AND RESULTS

We report 5 paroxysmal atrial fibrillation cases without any structural heart disease in which dormant thoracic vein conduction was associated with recurrent atrial tachyarrhythmias. All patients had undergone circumferential ipsilateral pulmonary vein isolation at the index procedure. Superior vena cava isolation was performed if superior vena cava-triggered atrial fibrillation was identified. At the index procedure, adenosine test did not provoke venous reconduction. At the repeat procedure, adenosine provoked clinical arrhythmia in 4 out of 5 cases after transient reconnection between culprit thoracic vein and atrium despite absence of reconnection at the start of the procedure. After the elimination of the dormant conduction gaps, all patients were free from recurrent arrhythmia.

CONCLUSIONS

Adenosine provokes dormant thoracic vein conduction associated with the late recurrence of atrial tachyarrhythmias after previous thoracic vein isolation. Thus, adenosine provocation test can specifically help identify and target the cause of recurrent atrial arrhythmia.

Predictors of Recurrence After Radiofrequency Ablation of Persistent Atrial Fibrillation

Radiofrequency catheter ablation that targets the pulmonary veins is well established as a mainstay for drug-refractory, paroxysmal atrial fibrillation (AF). However, in patients with persistent AF, the ideal approach remains elusive. Further, despite the various additional ablation strategies that have been investigated in patients with persistent AF, the rate of recurrent atrial tachyarrhythmias after ablation remains relatively high. In this review, the predictors of recurrent atrial tachyarrhythmias after catheter ablation of persistent AF will be discussed.

Ablation of atrial tachycardia occurring after catheter ablation of atrial fibrillation in patients with corrected rheumatic valve disease

OBJECTIVE

The purpose of this study is to investigate the mechanism and the effectiveness of ablation of atrial tachycardia (AT) recurring after atrial fibrillation (AF) ablation in patients with rheumatic valvular disease (RVD) and mitral valve prosthesis.

METHODS

Twenty-eight consecutive patients with RVD and mitral valve prosthesis and a 1:2 matched control group (n = 56) without RVD underwent reablation for recurrent AT after catheter ablation of long-standing persistent AF.

RESULTS

Macro- or localized reentrant ATs were identified in 47 (87 %) of 54 ATs from RVD group and in 65 (78.3 %) of 83 ATs from control. There were more average ATs per patient in the RVD group than in the control (1.9 ± 0.6 vs.1.5 ± 0.6, P = 0.002). The proportion of patients having ≥2 ATs was significantly higher in the RVD group than in the control (78.6 vs.41.1 %, P = 0.001). In the RVD group, ATs were successfully ablated in 44 (81.5 %) of 54 ATs and terminated in 18 (64.3 %) of 28 patients. In the control, ATs were successfully ablated in 72 (86.7 %) of 83 ATs and terminated in 45 (80.4 %) of 56 patients, P = 0.54 and 0.10, respectively. After a mean follow-up of 13 months, 16 patients (57.1 %) from the RVD group and 45 patients (80.4 %) from the control were free of further recurrence, P = 0.02.

CONCLUSIONS

Macro- or localized reentries were the predominant type of recurrent AT after long-standing persistent AF ablation in both the RVD and the control groups. Compared with patients without RVD, patients with RVD had more average number of ATs and had higher probability of further recurrence despite the similar acute effectiveness of reablation.

Impact of adenosine-provoked acute dormant pulmonary vein conduction on recurrence of atrial fibrillation

INTRODUCTION

Adenosine can be associated with acute recovery of conduction to the pulmonary veins (PVs) immediately after isolation. The objective of this study was to evaluate whether the response to adenosine predicts atrial fibrillation (AF) recurrence after a single ablation procedure in patients with paroxysmal AF.

METHODS AND RESULTS

A total of 109 consecutive patients (61 ± 10 years; 91 males) with drug-refractory paroxysmal AF who underwent AF ablation were analyzed. After PV antrum isolation (PVAI), dormant PV conduction was evaluated by an administration of adenosine in all patients. No acute reconnections were provoked by the adenosine in 70 (64.2%) patients (Group-1), but they were provoked in at least one side of the ipsilateral PVs in 39 (35.8%) patients (Group-2). All adenosine-provoked dormant conductions were successfully eliminated by additional ablation applications. By 12 months after the initial procedure, 72 (66.1%) patients were free of AF recurrences without any antiarrhythmic drugs. A Cox regression multivariate analysis of the variables including the adenosine-provoked reconductions, age, gender, duration of AF, presence of hypertension or structural heart disease, left atrial size, left ventricular ejection fraction, and body mass index demonstrated that adenosine-provoked reconductions were an independent predictor of AF recurrence after a single ablation procedure (hazard ratio: 1.387; 95% confidence interval: 1.018-1.889, P = 0.038). At the repeat session for recurrent AF, conduction recovery was observed similarly in both groups (P = 0.27).

CONCLUSION

Even after the elimination of any adenosine-provoked dormant PV conduction, the appearance of acute adenosine-provoked reconduction after the PVAI was an independent predictor of AF recurrence after a single AF ablation procedure.

Prevalence, electrophysiological properties, and clinical implications of dissociated pulmonary vein activity following pulmonary vein antrum isolation

The objective of this study was to investigate the prevalence, electrophysiologic properties, and clinical implications of dissociated pulmonary vein (PV) activity after PV antrum isolation (PVAI) in patients with paroxysmal atrial fibrillation (AF). One hundred seventy-three consecutive patients (61 ±10 years old, 141 men) with drug-refractory paroxysmal AF who underwent AF ablation were analyzed. After identification of arrhythmogenic foci, PVAI was performed in all patients. Of the total 346 isolated ipsilateral PVs, 97 (28.0%) were silent, 35 (10.1%) demonstrated isolated ectopic beats, 209 (60.4%) demonstrated a regular ectopic rhythm, and 5 (1.4%) demonstrated fibrillatory activity. The culprit thoracic vein was identified in 77 patients (44.5%). After isolation of ipsilateral PVs, venous activity was observed in 68 (79.1%) and 178 (68.5%) PVs among the 86 PVs with AF triggers and 260 PVs without AF triggers, respectively (p = 0.06). There was no significant difference in the incidence of acute PV reconnections exposed by adenosine triphosphate between the 97 silent ipsilateral PVs and 209 ipsilateral PVs with dissociated PV activity after the PVAI (20.6% vs 19.1%, p = 0.78). After a mean follow-up of 48.7 ± 7.9 months there was no significant difference in rates of freedom from atrial tachyarrhythmias after a single procedure between patients with and those without dissociated activity (62.1% vs 63.3%, p = 0.74, log-rank test). In conclusion, although dissociated PV activity appearing after PV isolation is an important electrophysiologic finding to prove bidirectional conduction block between the left atrium and the PV during the procedure, the clinical implications might be limited.