Assessment of atrioventricular junction ablation and DDDR mode-switching pacemaker versus pharmacological treatment in patients with severely symptomatic paroxysmal atrial fibrillation: a randomized controlled study

Single-center experience of efficacy and safety of atrioventricular node ablation after left bundle branch area pacing for the management of atrial fibrillation

BACKGROUND

Atrioventricular node ablation (AVNA) with permanent pacing is an effective treatment of symptomatic atrial fibrillation (AF). Left bundle branch area pacing (LBBAP) prevents cardiac dyssynchrony associated with right ventricular pacing and could prevent worsening of heart failure (HF).

METHODS

In this retrospective monocentric study, all patients who received AVNA procedure with LBBAP were consecutively included. AVNA procedure data, electrical and echocardiographic parameters at 6 months, and clinical outcomes at 1 year were studied and compared to a matched cohort of patients who received AVNA procedure with conventional pacing between 2010 and 2023.

RESULTS

Seventy-five AVNA procedures associated with LBBAP were studied. AVNA in this context was feasible, with a success rate of 98.7% at first ablation, and safe without any complications. There was no threshold rise at follow-up. At 1 year, 6 (8%) patients were hospitalized for HF and 2 (2.7%) were deceased. Patients had a significant improvement in NYHA class and left ventricular ejection fraction (LVEF) (P ≤ 0.0001). When compared to a matched cohort of patients with AVNA and conventional pacing, AVNA data and pacing complications rates were similar. Patients with LBBAP had a better improvement of LVEF (+5.27 ± 9.62% vs. -0.48 ± 14%, P = 0.01), and a lower 1-year rate of composite outcome of hospitalization for HF or death (HR 0.39, 95% CI: 0.16-0.95, P = 0.037), significant on survival analysis (log-rank P-value = 0.03).

CONCLUSION

AVNA with LBBAP in patients with symptomatic AF is feasible, safe, and efficient. Hospitalization for HF or death rate was significantly lower and LVEF improvement was greater.

Outcomes of Atrioventricular Node Ablation and Pacing in Patients with Heart Failure and Atrial Fibrillation: From Cardiac Resynchronization Therapy to His Bundle Pacing

Objective: To review the relevant literature on the use of atrioventricular node ablation and pacing in patients with heart failure and atrial fibrillation. Methods: APubMed/MEDLINE and SCOPUS search was performed in order to assess the clinical outcomes of atrioventricular node ablation and pacemaker implantation, as well as the complications that may occur. Results: Several clinical trials, observational analyses and meta-analyses have shown that the "pace and ablate" strategy not only improves symptoms but also can enhance cardiac performance in patients with heart failure and atrial fibrillation. Although this procedure is effective and safe, some complications may occur including worsening of heart failure, permanent fibrillation, arrhythmias and sudden death. Regarding pacemaker implantation, cardiac resynchronization therapy is shown to be the optimal choice compared to right ventricle apical pacing. His bundle pacing is a promising alternative to cardiac resynchronization therapy and has shown beneficial effects, while left bundle branch pacing is an innovative modality. Conclusions: Atrioventricular node ablation and pacemaker implantation is shown to have beneficial effects on clinical outcomes of patients with atrial fibrillation ± heart failure who do not respond or are intolerant to medical treatment. Cardiac resynchronization therapy is the treatment of choice and His bundle pacing seems to be an effective alternative way of pacing in these patients.

An aggressive solution for patients with heart failure and atrial fibrillation: nodal ablation and cardiac resynchronization therapy

Heart failure and atrial fibrillation are two diseases that often coexist and contribute to worsening the prognosis and quality of life of patients. Managing this situation is still a challenge today. The ablation of the atrioventricular node associated with cardiac resynchronization therapy (CRT) fits into this context as a definitive but effective solution. Indeed, long-term positive results have been demonstrated in patients with atrial fibrillation ineligible for ablation and refractory to medical therapy in terms of symptom reduction and, more recently, also mortality. Furthermore, the role of this strategy in obtaining adequate biventricular pacing in patients who may benefit from CRT but are ineligible due to the presence of atrial fibrillation is being highlighted.

Transcatheter ablation of the atrioventricular junction in refractory atrial fibrillation: A clinicopathological study

BACKGROUND

Catheter ablation of the specialized atrioventricular junction (AVJ) with a right-side approach is an effective therapy for refractory atrial fibrillation with fast ventricular rate. Our aim is to assess the efficacy of the procedure in a single center experience and investigate the histologic findings of AVJ after catheter ablation.

METHODS

A) Analysis of AVJ ablation efficacy in a consecutive series of patients with refractory atrial fibrillation; B) Histopathologic study of the conduction system by serial section technique and clinical-electrophysiologic correlation in four patients who underwent AVJ ablation.

RESULTS

A) Right-sided AVJ ablation was successful in all 87 consecutive patients (mean procedural time 19.2±17.9 min). Energy applications ranged from 1 to 27 (mean 5.8±5.1) with eight patients (9%) requiring > 15 applications. B) Fibrotic disruption of atrioventricular (AV) node and/or His bundle interruption was found in three cases with previous AVJ ablation. In the case requiring a left side approach, the compact AV node and common His bundle appeared undamaged whereas extensive fibrosis of the summit of the ventricular septum, branching His bundle and proximal bundle branches was found. Noteworthy, a continuity between the septal and anterior tricuspid valve leaflets was present.

CONCLUSION

Our data confirm that the ideal site for ablation of the specialized AVJ is the AV node. In selected cases with unsuccessful AV node ablation, a shift towards the His bundle is needed. A continuity between the septal and anterior leaflets of the tricuspid valve may protect the His bundle as to require multiple shocks and prolong the procedure.

Long-term experience of atrioventricular node ablation in patients with refractory atrial arrhythmias

Atrial fibrillation and other atrial tachyarrhythmias are increasing with age and concomitant morbidity. First options in symptomatic patients are drug treatment and catheter ablation. Nevertheless, a considerable number of patients suffer from refractory atrial tachyarrhythmias despite treatment. Atrioventricular node ablation (AVNA) may be helpful in many of these patients. Therefore, we investigated AVNA patients with a long-term follow-up. We enrolled 82 patients with a follow-up longer than 1 year receiving AVNA for drug- and ablation-resistant atrial tachyarrhythmias (AA) in a retrospective manner. Mean follow-up duration was 48 ± 24 months. 50% of the patients initially received AVNA to optimize biventricular pacing in cardiac resynchronization therapy, the other 50% because of refractory symptomatic tachyarrhythmias. Persistent AV block was achieved in every patient. Symptom relief and patient satisfaction were high during follow-up. Due to system upgrades there were 63% of patients with a biventricular system during follow-up. In these patients, left-ventricular ejection fraction (LV-EF) increased by 7% (42-49%) after ablation. AVNA is effective in increasing biventricular pacing as well as for symptom relief in patients with refractory atrial tachyarrhythmias. AVNA should be considered as a valuable option in patients with refractory atrial tachyarrhythmias lacking other treatment options.

Atrioventricular junction ablation in patients with atrial fibrillation treated with cardiac resynchronization therapy: positive impact on ventricular arrhythmias, implantable cardioverter-defibrillator therapies and hospitalizations

AIMS

We sought to determine whether atrioventricular junction ablation (AVJA) in patients with cardiac resynchronization therapy (CRT) implantable cardioverter-defibrillator (ICD) and with permanent atrial fibrillation (AF) has a positive impact on ICD shocks and hospitalizations compared with rate-slowing drugs.

METHODS AND RESULTS

This is a pooled analysis of data from 179 international centres participating in two randomized trials and one prospective observational research. The co-primary endpoints were all-cause ICD shocks and all-cause hospitalizations. Out of 3358 CRT-ICD patients (2720 male, 66.6 years), 2694 (80%) were in sinus rhythm (SR) and 664 (20%) had permanent AF-262 (8%) treated with AVJA (AF + AVJA) and 402 (12%) treated with rate-slowing drugs (AF + Drugs). Median follow-up was 18 months. The mean (95% confidence intervals) annual rate of all-cause ICD shocks per 100 patient years was 8.0 (5.3-11.9) in AF + AVJA, 43.6 (37.7-50.4) in AF + Drugs, and 34.4 (32.5-36.5) in SR patients, resulting in incidence rate ratio (IRR) reductions of 0.18 (0.10-0.32) for AF + AVJA vs. AF + Drugs (P < 0.001) and 0.48 (0.35-0.66) for AF + AVJA vs. SR (P < 0.001). These reductions were driven by significant reductions in both appropriate ICD shocks [IRR 0.23 (0.13-0.40), P < 0.001, vs. AF + Drugs] and inappropriate ICD shocks [IRR 0.09 (0.04-0.21), P < 0.001, vs. AF + Drugs]. Annual rate of all-cause hospitalizations was significantly lower in AF + AVJA vs. AF + Drugs [IRR 0.57 (0.41-0.79), P < 0.001] and SR [IRR 0.85 (073-0.98), P = 0.027].

CONCLUSION

In AF patients treated with CRT, AVJA results in a lower incidence and burden of all-cause, appropriate and inappropriate ICD shocks, as well as to fewer all-cause and heart failure hospitalizations.

CLINICAL TRIAL REGISTRATION

NCT00147290, NCT00617175, NCT01007474.

The effects of rhythm control strategies versus rate control strategies for atrial fibrillation and atrial flutter: A systematic review with meta-analysis and Trial Sequential Analysis

Background

Atrial fibrillation and atrial flutter may be managed by either a rhythm control strategy or a rate control strategy but the evidence on the clinical effects of these two intervention strategies is unclear. Our objective was to assess the beneficial and harmful effects of rhythm control strategies versus rate control strategies for atrial fibrillation and atrial flutter.

Methods

We searched CENTRAL, MEDLINE, Embase, LILACS, Web of Science, BIOSIS, Google Scholar, clinicaltrials.gov, TRIP, EU-CTR, Chi-CTR, and ICTRP for eligible trials comparing any rhythm control strategy with any rate control strategy in patients with atrial fibrillation or atrial flutter published before November 2016. Our primary outcomes were all-cause mortality, serious adverse events, and quality of life. Our secondary outcomes were stroke and ejection fraction. We performed both random-effects and fixed-effect meta-analysis and chose the most conservative result as our primary result. We used Trial Sequential Analysis (TSA) to control for random errors. Statistical heterogeneity was assessed by visual inspection of forest plots and by calculating inconsistency (I²) for traditional meta-analyses and diversity (D²) for TSA. Sensitivity analyses and subgroup analyses were conducted to explore the reasons for substantial statistical heterogeneity. We assessed the risk of publication bias in meta-analyses consisting of 10 trials or more with tests for funnel plot asymmetry. We used GRADE to assess the quality of the body of evidence.

Results

25 randomized clinical trials (n = 9354 participants) were included, all of which were at high risk of bias. Meta-analysis showed that rhythm control strategies versus rate control strategies significantly increased the risk of a serious adverse event (risk ratio (RR), 1.10; 95% confidence interval (CI), 1.02 to 1.18; P = 0.02; I² = 12% (95% CI 0.00 to 0.32); 21 trials), but TSA did not confirm this result (TSA-adjusted CI 0.99 to 1.22). The increased risk of a serious adverse event did not seem to be caused by any single component of the composite outcome. Meta-analysis showed that rhythm control strategies versus rate control strategies were associated with better SF-36 physical component score (mean difference (MD), 6.93 points; 95% CI, 2.25 to 11.61; P = 0.004; I² = 95% (95% CI 0.94 to 0.96); 8 trials) and ejection fraction (MD, 4.20%; 95% CI, 0.54 to 7.87; P = 0.02; I² = 79% (95% CI 0.69 to 0.85); 7 trials), but TSA did not confirm these results. Both meta-analysis and TSA showed no significant differences on all-cause mortality, SF-36 mental component score, Minnesota Living with Heart Failure Questionnaire, and stroke.

Conclusions

Rhythm control strategies compared with rate control strategies seem to significantly increase the risk of a serious adverse event in patients with atrial fibrillation. Based on current evidence, it seems that most patients with atrial fibrillation should be treated with a rate control strategy unless there are specific reasons (e.g., patients with unbearable symptoms due to atrial fibrillation or patients who are hemodynamically unstable due to atrial fibrillation) justifying a rhythm control strategy. More randomized trials at low risk of bias and low risk of random errors are needed.

Trial registration

PROSPERO CRD42016051433

Benefits of Permanent His Bundle Pacing Combined With Atrioventricular Node Ablation in Atrial Fibrillation Patients With Heart Failure With Both Preserved and Reduced Left Ventricular Ejection Fraction

BACKGROUND

Clinical benefits from His bundle pacing (HBP) in heart failure patients with preserved and reduced left ventricular ejection fraction are still inconclusive. This study evaluated clinical outcomes of permanent HBP in atrial fibrillation patients with narrow QRS who underwent atrioventricular node ablation for heart failure symptoms despite rate control by medication.

METHODS AND RESULTS

The study enrolled 52 consecutive heart failure patients who underwent attempted atrioventricular node ablation and HBP for symptomatic atrial fibrillation. Echocardiographic left ventricular ejection fraction and left ventricular end-diastolic dimension, New York Heart Association classification and use of diuretics for heart failure were assessed during follow-up visits after permanent HBP. Of 52 patients, 42 patients (80.8%) received permanent HBP and atrioventricular node ablation with a median 20-month follow-up. There was no significant change between native and paced QRS duration (107.1±25.8 versus 105.3±23.9 milliseconds, P=0.07). Left ventricular end-diastolic dimension decreased from the baseline (P<0.001), and left ventricular ejection fraction increased from baseline (P<0.001) in patients with a greater improvement in heart failure with reduced ejection fraction patients (N=20) than in heart failure with preserved ejection fraction patients (N=22). New York Heart Association classification improved from a baseline 2.9±0.6 to 1.4±0.4 after HBP in heart failure with reduced ejection fraction patients and from a baseline 2.7±0.6 to 1.4±0.5 after HBP in heart failure with preserved ejection fraction patients. After 1 year of HBP, the numbers of patients who used diuretics for heart failure decreased significantly (P<0.001) when compared to the baseline diuretics use.

CONCLUSIONS

Permanent HBP post-atrioventricular node ablation significantly improved echocardiographic measurements and New York Heart Association classification and reduced diuretics use for heart failure management in atrial fibrillation patients with narrow QRS who suffered from heart failure with preserved or reduced ejection fraction.

Ventricular pacing - Electromechanical consequences and valvular function

Although great strides have been made in the areas of ventricular pacing, it is still appreciated that dyssynchrony can be malignant, and that appropriately placed pacing leads may ameliorate mechanical dyssynchrony. However, the unknowns at present include: 1. The mechanisms by which ventricular pacing itself can induce dyssynchrony; 2. Whether or not various pacing locations can decrease the deleterious effects caused by ventricular pacing; 3. The impact of novel methods of pacing, such as atrioventricular septal, lead-less, and far-field surface stimulation; 4. The utility of ECG and echocardiography in predicting response to therapy and/or development of dyssynchrony in the setting of cardiac resynchronization therapy (CRT) lead placement; 5. The impact of ventricular pacing-induced dyssynchrony on valvular function, and how lead position correlates to potential improvement. This review examines the existing literature to put these issues into context, to provide a basis for understanding how electrical, mechanical, and functional aspects of the heart can be distorted with ventricular pacing. We highlight the central role of the mitral valve and its function as it relates to pacing strategies, especially in the setting of CRT. We also provide future directions for improved pacing modalities via alternative pacing sites and speculate over mechanisms on how lead position may affect the critical function of the mitral valve and thus overall efficacy of CRT.

Impact of Tricuspid Regurgitation on the Success of Atrioventricular Node Ablation for Rate Control in Patients With Atrial Fibrillation: The Node Blast Study

Atrioventricular node (AVN) ablation is an effective treatment for symptomatic patients with atrial arrhythmias who are refractory to rhythm and rate control strategies where optimal ventricular rate control is desired. There are limited data on the predictors of failure of AVN ablation. Our objective was to identify the predictors of failure of AVN ablation. This is an observational single-center study of consecutive patients who underwent AVN ablation in a large academic center. Baseline characteristics, procedural variables, and outcomes of AVN ablation were collected. AVN "ablation failure" was defined as resumption of AVN conduction resulting in recurrence of either rapid ventricular response or suboptimal biventricular pacing. A total of 247 patients drug refractory AF who underwent AVN ablation at our center with a mean age of 71 ± 12 years with 46% being males were included. Ablation failure was seen in 11 (4.5%) patients. There were no statistical differences between patients with "ablation failure" versus "ablation success" in any of the baseline clinical variables. Patients with moderate-to-severe tricuspid regurgitation (TR) were much more likely to have ablation failure than those with ablation success (8 [73%] vs 65 [27%]; p = 0.003). All 11 patients with ablation failure had a successful redo procedure, 9 with right and 2 with the left sided approach. On multivariate analysis, presence of moderate-to-severe TR was found to be the only predictor of failure of AVN ablation (odds ratio 9.1, confidence interval 1.99 to 42.22, p = 0.004). In conclusion, moderate-to-severe TR is a strong and independent predictor of failure of AVN ablation.

Atrioventricular Junction Ablation In Atrial Fibrillation: Choosing The Right Patient And Pacing Device

Atrial fibrillation (AF) is the most common cardiac arrhythmia and despite advancements in rhythm control through direct catheter ablation, maintaining sinus rhythm is not possible in a large proportion of AF patients, who therefore are subject to a rate control strategy only. Nonetheless, in some of these patients pharmacological rate control may be ineffective, often leaving the patient highly symptomatic and at risk of developing tachycardia-induced cardiomyopathy and heart failure (HF). Catheter ablation of the atrioventricular junction (AVJ) with subsequent permanent pacemaker implantation provides definite rate control and represents an attractive therapeutic option when pharmacological rate control is not achieved. In patients with reduced ventricular function, cardiac resynchronization therapy (CRT) should be considered over right ventricular apical (RVA) pacing in order to avoid the deleterious effects associated with a high amount of chronic RVA pacing. Another group of patients that may also benefit from AVJ ablation are HF patients with concomitant AF receiving CRT. In this patient cohort AVJ ablation ensures near 100% biventricular pacing, thus allowing optimization of the therapeutic effects of CRT.

Comparison of different approaches to atrioventricular junction ablation and pacemaker implantation in patients with atrial fibrillation

BACKGROUND

To compare the feasibility and efficiency of atrioventricular junction (AVJ) ablation and device implantation in patients with drug-refractory atrial fibrillation using three different approaches.

METHODS

Sixty-nine patients (57% male; age 72 ± 10; ejection fraction 45 ± 15%) undergoing device implantation and AVJ ablation were retrospectively studied at a tertiary referral center. In 20 patients (29%) AVJ ablation was performed via the femoral vein immediately following device implantation (group 1), whereas 33 patients (48%) underwent a staged procedure with AVJ ablation via the femoral vein >3 weeks after device implantation (group 2). In a third group of 16 patients (23%), AVJ ablation was performed during device implantation through the pocket using the same axillary vein access site (group 3). The main outcome measures were: procedure time, fluoroscopy time, laboratory occupancy time, and success rate.

RESULTS

There was a significant difference in procedure time (118 ± 45 minutes. in group 1, 133 ± 32 minutes in group 2, and 87 ± 26 minutes in group 3, P < 0.001) and the laboratory occupancy time (175 ± 48 minutes in group 1, 200 ± 32 minutes in group 2, and 121 ± 27 minutes in group 3, P < 0.001). There was no difference in fluoroscopy time (group 1: 20 ± 15 minutes, group 2: 27 ± 22 minutes, and group 3: 24 ± 9 minutes P = 0.4). The procedure was successfully completed in all patients, but cross-over to a femoral approach was required in one patient in group 3.

CONCLUSION

The alternative approach of AVJ ablation during permanent pacemaker implantation from the same axillary vein access site is feasible and more efficient compared to the femoral approach.

Two-Year Follow-up in Atrial Fibrillation Patients Referred for Catheter Ablation of the Atrioventricular Node

INTRODUCTION

At the present time there is still concern regarding the long-term deleterious effects of right ventricular apical pacing in patients referred for auriculoventricular node ablation (AVNA). Furthermore, scarce information is available regarding differences in the follow up according to the baseline cardiopathy and predictors associated with a worse outcome.

METHODS

104 consecutives patients referred for AVNA were retrospectively analyzed. Patients included were seen in the outpatient clinic at 6, 12 and 24 months post ablation (mean follow-up 24 ± 2 months). An echocardiogram two years after the procedure was obtained in 68 patients. Three categories were done according to the change in the left ventricular function (LVEF) (increase, decrease or absence of change, defined as less than 10% variation in either LVEF).

RESULTS

After two years of follow up there was a decrease in the rate of hospital admission (from 0.9 admission/year to 0.35, p<0.001), an increase in the functional status in at least one NYHA class in 58 patients, and an increase in the global LVEF (from 48.9% to 54,1%; p<0.001). Valvular replacement and LVEF less than 50% were independently associated with a decrease in the LVEF. Regarding safety issues, one patient who presented a polymorphic ventricular tachycardia (Torsade de pointes) 60 minutes after the ablation.

CONCLUSIONS

AVNA results in a decrease in hospital admission rates and an improvement in functional status. Baseline LVEF < 50% and mitral valvulopathy were multivariate predictor of LVEF decline, hence, it is our belief that, in this particular population, the "ablate and pace" strategy is not the most suitable option, and or maybe a biventricular pacemaker should be implanted or an AF ablation reconsidered." Finally, although it is a safe procedure and rate of complications were low, there is a potential risk of fatal complications.

Atrial fibrillation in the elderly

Atrial fibrillation (AF) is the most common arrhythmia in older adults with a prevalence of 9 % in adults aged 80 years or older. AF patients have a five times greater risk of developing stroke than the general population. Using anticoagulants for stroke prevention in the elderly becomes a challenge because both stroke and bleeding complications increase with age. CHA₂DS₂-VASc and HAS-BLED scores are currently used as stroke and bleeding risk evaluations. When the HAS-BLED score is 3 or higher, caution and efforts to correct reversible risk factors are advised. Regardless of the HAS-BLED score, warfarin or novel oral anticoagulants are a IIa recommendation for CHA₂DS₂-VASc of 1, except for a score of 1 for females, and a IA recommendation for the score of 2 or higher. Aspirin is no longer recommended for AF thromboprophylaxis. In an elderly patient, lenient rate control is preferred over rhythm control owing to fewer adverse drugs effects and hospitalizations. When rhythm control is needed, dronedarone is a new antiarrhythmic drug that can be considered in patients who have paroxysmal AF and no history of heart failure. Although less efficacious than amiodarone, dronedarone has a fewer thyroid, neurologic, dermatologic, and ocular side effects than amiodarone.

Ventricular rate control of atrial fibrillation in heart failure

In the last few years, there has been a major shift in the treatment of atrial fibrillation (AF) in the setting of hear failure (HF), from rhythm to ventricular rate control in most patients with both conditions. In this article, the authors focus on ventricular rate control and discuss the indications; the optimal ventricular rate-control target, including detailed results of the Rate Control Efficacy in Permanent Atrial Fibrillation: a Comparison Between Lenient versus Strict Rate Control II (RACE II) study; and the pharmacologic and nonpharmacologic options to control the ventricular rate during AF in the setting of HF.

Current Evidence and Recommendations for Rate Control in Atrial Fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia encountered in clinical practice, which is associated with substantial risk of stroke and thromboembolism. As an arrhythmia that is particularly common in the elderly, it is an important contributor towards morbidity and mortality. Ventricular rate control has been a preferred and therapeutically convenient treatment strategy for the management of AF. Recent research in the field of rhythm control has led to the advent of newer antiarrhythmic drugs and catheter ablation techniques as newer therapeutic options. Currently available antiarrhythmic drugs still remain limited by their suboptimal efficacy and significant adverse effects. Catheter ablation as a newer modality to achieve sinus rhythm (SR) continues to evolve, but data on long-term outcomes on its efficacy and mortality outcomes are not yet available. Despite these current developments, rate control continues to be the front-line treatment strategy, especially in older and minimally symptomatic patients who might not tolerate the antiarrhythmic drug treatment. This review article discusses the current evidence and recommendations for ventricular rate control in the management of AF. We also highlight the considerations for rhythm control strategy in the management of patients of AF.

Current role of atrioventricular junction (AVJ) ablation

Atrioventricular junction ablation with permanent pacemaker insertion is a highly effective treatment approach in patients with atrial fibrillation that is resistant to other treatment modalities, especially in the elderly or those with severe comorbidities. This effect likely reflects reversal of rapid ventricular rates and regularizing ventricular rates. There is increasing evidence that cardiac resynchronization therapy devices may be beneficial in selected populations after atrioventricular node ablation. The limitations of this approach include continued need for anticoagulation and lifelong pacemaker therapy.

Cardiac resynchronization therapy after atrioventricular junction ablation for symptomatic atrial fibrillation: a meta-analysis

AIMS

Atrioventricular junction (AVJ) ablation with permanent pacing improves symptoms in selected patients with atrial fibrillation (AF). The optimal pacing modality after AVJ ablation remains unclear. We performed a meta-analysis of randomized controlled trials to examine whether cardiac resynchronization therapy (CRT) is superior to right ventricular (RV) pacing in this patient population.

METHODS AND RESULTS

We searched the MEDLINE and EMBASE databases for studies evaluating the effect of CRT vs. RV pacing after AVJ ablation for AF. Pooled risk ratios (RRs) and mean differences with 95% confidence intervals (CIs) were calculated for categorical and continuous outcomes, respectively, using a random effects model. Five trials involving 686 patients (413 in CRT and 273 in RV pacing group) were included in the analysis. On the basis of the pooled estimate across the studies, CRT resulted in a non-significant reduction in mortality (RR = 0.75, 95% CI 0.43-1.30; P= 0.30) and a significant reduction in hospitalizations for heart failure (RR = 0.38, 95% CI = 0.17-0.85; P= 0.02) compared with RV pacing. Cardiac resynchronization therapy did not improve 6 min walk distance (mean difference 15.7, 95% CI -7.2 to 38.5 m; P= 0.18) and Minnesota Living with Heart Failure quality-of-life score (mean difference -3.0, 95% CI -8.6 to 2.6; P= 0.30) compared with RV pacing. The change in left ventricular ejection fraction between baseline and 6 months favoured CRT (mean change 2.0%, 95% CI 1.5-2.4%; P< 0.001).

CONCLUSION

Cardiac resynchronization therapy may be superior to RV pacing in patients undergoing AVJ ablation for AF. Further studies, adequately powered to detect clinical outcomes, are required.

The downside of right ventricular apical pacing

The right ventricular (RV) apex has been the standard pacing site since the development of implantable pacemaker technology. Although RV pacing was initially only utilized for the treatment of severe bradyarrhythmias usually due to complete heart block, today the indications for and implantation of RV pacing devices is dramatically larger. Recently, the adverse effects of chronic RV apical pacing have been described including an increased risk of heart failure and death. This review details the detrimental effects of RV apical pacing and their shared hemodynamic pathophysiology. In particular, the role of RV apical pacing induced ventricular dyssynchrony is highlighted with a specific focus on differential outcome based upon QRS morphology at implant.

Adverse effects of permanent atrial fibrillation on heart failure in patients with preserved left ventricular function and chronic right apical pacing for complete heart block

BACKGROUND

The impact of atrial fibrillation (AF) on heart failure (HF) was evaluated in patients with preserved left ventricular (LV) function and long-term right ventricular (RV) pacing for complete heart block.

METHODS

Clinical, echocardiographic, and laboratory parameters of HF were assessed in 35 patients with established AF who had undergone ablation of the atrioventricular node and pacemaker implantation (Group A) and 31 patients who received dual-chamber pacing for spontaneous complete heart block (Group B).

RESULTS

During a follow-up period of 12.7 ± 7.5 years, New York Heart Association (NYHA) functional class increased from 1.3 ± 0.5 to 2.1 ± 0.6 (p < 0.0001) in Group A, and from 1.3 ± 0.4 to 1.6 ± 0.7 (p < 0.01) in Group B. Left ventricular ejection fraction (LVEF) decreased from 59.7 ± 5.1 to 53.0 ± 8.2 (p < 0.0001) in Group A, but remained stable (58.6 ± 4.2 vs. 56.9 ± 7.0 %, p = 0,21) in Group B. At the end of follow-up, markers of LV function were moderately depressed in Group A compared with those in Group B: NYHA class 2.1 ± 0.6 versus 1.6 ± 0.7, p = 0.001; LVEF 53.0 ± 8.2 versus 56.9 ± 7.0 %, p < 0.05; LV diastolic diameter 53.6 ± 5.8 mm versus 50.7 ± 4.9 mm, p < 0.05; N-terminal pro-brain natriuretic peptide (NT-proBNP) 1116.8 ± 883.9 versus 622.9 ± 1059.4 pg/ml, p < 0.05. Progression of paroxysmal AF to permanent AF during follow-up was common, while new onset of AF was rare. Permanent AF was an independent predictor of declining LVEF >10 %, increasing NYHA class ≥1, and NT-proBNP levels >1,000 pg/ml.

CONCLUSIONS

Permanent AF was associated with adverse effects on LV function and symptoms of HF in patients with long-term RV pacing for complete heart block, and appears to play an important role in the development of HF in this specific patient cohort.

Non-pharmacologic management of atrial fibrillation

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice today. Contemporary medical treatment options include atrioventricular nodal blocking agents to control heart rates during AF, antiarrhythmic drugs aimed at maintaining normal sinus rhythm, and anticoagulation therapies to reduce stroke risk. Invasive treatment of AF has emerged because of the toxicities and lack of long-term efficacy of available antiarrhythmic medications along with the lack of improvement in symptoms for rate-controlled patients. The investigators review the evolution of the current catheter-delivered AF procedures, starting with surgical maze up to and including left atrial appendage occlusion devices. Individual catheter ablation targets, anatomic and electrophysiologic, are discussed, with a particular focus on the use of an incremental ablation target strategy dependent on the type of AF being treated. In conclusion, the history of invasive AF therapy provides a basic understanding of contemporary ablation strategies and a backdrop for the cutting-edge rhythm and stroke prevention therapies of today.

Cardiac resynchronization therapy in patients undergoing atrioventricular junction ablation for permanent atrial fibrillation: a randomized trial

AIMS

On the basis of the current knowledge, cardiac resynchronization therapy (CRT) cannot be recommended as a first-line treatment for patients with severely symptomatic permanent atrial fibrillation undergoing atrioventricular (AV) junction ablation. We examined whether CRT was superior to conventional right ventricular (RV) pacing in reducing heart failure (HF) events.

METHODS AND RESULTS

In this prospective, multi-centre study, we randomly assigned 186 patients, in whom AV junction ablation and CRT device implantation had been successfully performed, to receive optimized echo-guided CRT (97 patients) or RV apical pacing (89 patients). The data were analysed according to the intention-to-treat principle. During a median follow-up of 20 months (interquartile range 11-24), the primary composite endpoint of death from HF, hospitalization due to HF, or worsening HF occurred in 11 (11%) patients in the CRT group and 23 (26%) patients in the RV group [CRT vs. RV group: sub-hazard ratio (SHR) 0.37 ( 95% CI 0.18-0.73), P = 0.005]. In the CRT group, compared with the RV group, fewer patients had worsening HF [SHR 0.27 (95% CI 0.12-0.58), P = 0.001] and hospitalizations for HF [SHR 0.20 (95% CI 0.06-0.72), P = 0.013]. Total mortality was similar in both groups [hazard ratio (HR) 1.57 (95% CI 0.58-4.27), P = 0.372]. The beneficial effects of CRT were consistent in patients who had ejection fraction ≤35%, New York Heart Association Class ≥III and QRS width ≥120 and in those who did not. At multi-variable Cox regression, only CRT mode remained an independent predictor of absence of clinical failure during the follow-up [HR = 0.23 (95% CI 0.08-0.66), P = 0.007].

CONCLUSIONS

In patients undergoing 'Ablate and Pace' therapy for severely symptomatic permanent atrial fibrillation, CRT is superior to RV apical pacing in reducing the clinical manifestations of HF. (ClinicalTrials.gov number: NCT00111527).

Atrioventricular nodal ablation versus antiarrhythmic drugs after permanent pacemaker implantation for bradycardia-tachycardia syndrome

Patients often require antiarrhythmic drugs to control tachycardia after permanent pacemaker implantation (PMI) for bradycardia-tachycardia syndrome. We compared atrioventricular nodal ablation (AVNA) to antiarrhythmic drugs after PMI for bradycardia-tachycardia syndrome. Twenty-eight symptomatic patients with bradycardia-tachycardia syndrome, all of which had a long pause after termination of paroxysmal atrial fibrillation, underwent PMI with RV lead placement at the mid-septum site. Among these patients, 14 underwent PMI and AVNA (AVNA group). The remaining 14 patients underwent PMI only, and continued to take anti-arrhythmic drugs (drug group). We compared cardiac function (cardio-thoracic ratio on chest X-ray, left atrial diameter, left ventricular end-diastolic dimension, and left ventricular-ejection fraction by echocardiography), exercise tolerance (6-min walking distance), symptoms, and the number of antiarrhythmic drugs just before and 6 months after PMI. Baseline characteristics were similar between the two groups, except for the number of antiarrhythmic drugs. Six months after PMI, cardiac function, exercise tolerance, and symptoms did not differ significantly between the two groups. Compared to the drug group (p < 0.01), the number of antiarrhythmic drugs was significantly smaller in the AVNA group 6 months after PMI. Patients who underwent AVNA concurrently with PMI with RV lead placement at the mid-septum site for bradycardia-tachycardia syndrome were able to reduce the intake of drugs and improve their tachycardia-related symptoms while maintaining cardiac function and exercise tolerance.

Predictors of stroke risk in native Chinese with nonrheumatic atrial fibrillation: retrospective investigation of hospitalized patients

BACKGROUND

Data on stroke risk factor profiles and atrial fibrillation (AF) for the Chinese population are sparse. This study identified risk factors for stroke among native Chinese with nonrheumatic AF.

METHODS

In this retrospective investigation, patients diagnosed with nonrheumatic AF were identified from 18 hospitals in representative areas of the country, from January 2000 to April 2002, based on the medical records. All parameters relevant to AF were compared between AF patients with stroke and those without. The independent risk factors for stroke were assessed with a logistic regression analysis.

RESULTS

Patients numbering 3,425 with AF were included, among whom 827 subjects were discharged on account of stroke. The prevalence of stroke in nonrheumatic AF patients was 24.15%. AF patients with stroke were significantly older than controls (73.31 +/- 9.18 versus 68.22 +/- 12.29 y, p < 0.001) and more likely to have a history of hypertension (71.0 versus 51.6%, p < 0.001) and diabetes (17.9 versus 11.1%, p = 0.001).Both, systolic and diastolic blood pressure, are significantly higher in patients with stroke. Of all the parameters of echocardiography, there was strong evidence that left atrial (LA) thrombi significantly increased risk of stroke. Patients with persistent AF were more likely to have stroke than paroxysmal AF patients, while lone AF is less in patients with stroke than in those without. The rate of anticoagulation treatment is only 9.27%, but there were no significant differences between the 2 groups. In multivariate analysis, age > or = 75 y (odds ratio [OR] 1.76; 95% confidence interval [CI] 1.08-2.98), history of hypertension (OR 1.52; 95% CI 1.28-1.80), diabetes (OR 1.39; 95% CI 1.11-1.76), high systolic blood pressure (OR 1.71; 95% CI 1.21-2.28), LA thrombi (OR 2.77; 95% CI 1.25-6.13) were independent predictors for stroke.

CONCLUSIONS

The prevalence of stroke in hospitalized nonrheumatic AF patients was high. The population-specific risk factors for stroke were age > or = 75 y, diabetes, history of hypertension, high systolic blood pressure and LA thrombi by transesophageal echocardiography (TEE). These merit further evaluation.

The effects of right ventricular apical pacing on ventricular function and dyssynchrony implications for therapy

Cardiac pacing is the only effective treatment for patients with sick sinus syndrome and atrioventricular conduction disorders. In cardiac pacing, the endocardial pacing lead is typically positioned at the right ventricular (RV) apex. At the same time, there is increasing indirect evidence, derived from large pacing mode selection trials and observational studies, that conventional RV apical pacing may have detrimental effects on cardiac structure and left ventricular function, which are associated with the development of heart failure. These detrimental effects may be related to the abnormal electrical and mechanical activation pattern of the ventricles (or ventricular dyssynchrony) caused by RV apical pacing. Still, it remains uncertain if the deterioration of left ventricular function as noted in a proportion of patients receiving RV apical pacing is directly related to acutely induced left ventricular dyssynchrony. The upgrade from RV pacing to cardiac resynchronization therapy may partially reverse the deleterious effects of RV pacing. It has even been suggested that selected patients with a conventional pacemaker indication should receive cardiac resynchronization therapy to avoid the deleterious effects. This review will provide a contemporary overview of the available evidence on the detrimental effects of RV apical pacing. Furthermore, the available alternatives for patients with a standard pacemaker indication will be discussed. In particular, the role of cardiac resynchronization therapy and alternative RV pacing sites in these patients will be reviewed.

Electrophysiological characteristics associated with symptoms in pacemaker patients with paroxysmal atrial fibrillation

PURPOSE

The purpose of this study is to identify the electrophysiological factors affecting symptoms in paroxysmal atrial fibrillation (PAF) using patients with paroxysmal atrial fibrillation and pacemakers with advanced atrial fibrillation (AF) diagnostics.

METHODS

Seventy-nine patients (age 71.0 +/- 8.2, 54.4% male) with symptomatic PAF and AF burden of 1% to 50% with DDDRP pacemakers implanted were assessed for 6 months. Patients recorded symptom onset and duration and these were correlated with device-derived electrophysiological data.

RESULTS

Of 2,638 AF episodes, 333 were symptomatic and 2,305 asymptomatic, with 194 non-atrial tachyarrhythmia symptomatic episodes giving a sensitivity of 12.6% and a positive predictive value of 63.2% for specific AF symptoms. Symptomatic AF episodes were 3.8 times more common diurnally than nocturnally (p < 0.001). Diurnally, symptomatic AF was significantly associated with a shorter AF cycle length (CL; p = 0.04), faster ventricular rate (p = 0.004), shorter PR interval (p < 0.001), faster preceding heart rate (p = 0.001) and increased early recurrence of AF (p < 0.04). Nocturnally, a significantly longer AF CL (p = 0.04) and PR interval (p < 0.001) prior to AF onset predicted symptomatic AF.

CONCLUSIONS

Symptoms in PAF are predicted by changes in AF episode duration, ventricular rate during AF, preceding sinus heart rate, AV nodal conduction and AF cycle length but not ventricular irregularity. Excess diurnal sympathetic tone and excess nocturnal vagal tone predispose to symptomatic PAF. These findings may have relevance for therapies for symptom control of PAF.

Usefulness of echo-guided cardiac resynchronization pacing in patients undergoing "ablate and pace" therapy for permanent atrial fibrillation and effects of heart rate regularization and left ventricular resynchronization

An acute comparative study of right ventricular (RV) pacing and echocardiographically guided cardiac resynchronization pacing (CRP) was performed in patients who underwent "ablate and pace" therapy for permanent atrial fibrillation. It was hypothesized that optimized CRP guided by tissue Doppler echocardiography would exert an additive beneficial hemodynamic effect to that of rate regularization achieved through atrioventricular junction ablation. An acute intrapatient comparison of echocardiographic parameters was performed between baseline preablation values and RV pacing and CRP (performed <24 hours after ablation) in 50 patients. Optimized CRP configuration was defined as the modality of pacing corresponding to that of the shortest intra-left ventricular (LV) delay among simultaneous biventricular pacing, sequential biventricular pacing, and single-chamber pacing. The intra-LV delay was defined as the difference between the longest and the shortest activation time in the six basal segments of the left ventricle. Compared with preablation measures, the ejection fraction increased by 10.8% during RV pacing (19% in patients with intra-LV delays <47.5 ms and 3% in those with intra-LV delays >47.5 ms). Compared with RV pacing, CRP caused a 9.2% increase in the ejection fraction, a 6.8% decrease in LV systolic diameter, and a 17.3% decrease in mitral regurgitation area; LV dyssynchrony was reduced from 52 +/- 27 to 21 +/- 12 ms. Similar results were observed in patients with and without depressed systolic function and in patients with and without left bundle branch block. In conclusion, rate regularization achieved through atrioventricular junction ablation and RV pacing provides a favorable hemodynamic effect that is inversely related to the level of LV dyssynchrony. Minimizing LV dyssynchrony by means of optimized CRP yields an additional important benefit.

Long-term survival in patients undergoing cardiac resynchronization therapy: the importance of performing atrio-ventricular junction ablation in patients with permanent atrial fibrillation

AIMS

To investigate the effects of cardiac resynchronization therapy (CRT) on survival in heart failure (HF) patients with permanent atrial fibrillation (AF) and the role of atrio-ventricular junction (AVJ) ablation in these patients.

METHODS AND RESULTS

Data from 1285 consecutive patients implanted with CRT devices are presented: 1042 patients were in sinus rhythm (SR) and 243 (19%) in AF. Rate control in AF was achieved by either ablating the AVJ in 118 patients (AVJ-abl) or prescribing negative chronotropic drugs (AF-Drugs). Compared with SR, patients with AF were significantly older, more likely to be non-ischaemic, with higher ejection fraction, shorter QRS duration, and less often received ICD back-up. During a median follow-up of 34 months, 170/1042 patients in SR and 39/243 in AF died (mortality: 8.4 and 8.9 per 100 person-year, respectively). Adjusted hazard ratios were similar for all-cause and cardiac mortality [0.9 (0.57-1.42), P = 0.64 and 1.00 (0.60-1.66) P = 0.99, respectively]. Among AF patients, only 11/118 AVJ-abl patients died vs. 28/125 AF-Drugs patients (mortality: 4.3 and 15.2 per 100 person-year, respectively, P < 0.001). Adjusted hazard ratios of AVJ-abl vs. AF-Drugs was 0.26 [95% confidence interval (CI) 0.09-0.73, P = 0.010] for all-cause mortality, 0.31 (95% CI 0.10-0.99, P = 0.048) for cardiac mortality, and 0.15 (95% CI 0.03-0.70, P = 0.016) for HF mortality.

CONCLUSION

Patients with HF and AF treated with CRT have similar mortality compared with patients in SR. In AF, AVJ ablation in addition to CRT significantly improves overall survival compared with CRT alone, primarily by reducing HF death.

Who, when and how to rate control for atrial fibrillation

PURPOSE OF REVIEW

The aim of this review is to provide a perspective on rate control in atrial fibrillation, in the era after the large randomized trials comparing rate and rhythm control. This review emphasizes the indications for rate control, the optimal heart rate and the different treatment modalities.

RECENT FINDINGS

Large studies have shown that rate control is not inferior to rhythm control with regard to cardiovascular morbidity and mortality. Rate control may now be instituted earlier during the course of the disease, even as first-choice therapy in some patients, particularly those with hypertension and underlying heart diseases, and those who are not (severely) symptomatic. The goals of rate-control therapy are to reduce symptoms, improve quality of life, minimize the development of heart failure, and prevent thromboembolic complications. An important negative aspect of rate-control therapy is the side effects of drugs. The optimal heart rate during atrial fibrillation has not yet been carefully investigated. Several approaches to control rate during atrial fibrillation are available, including pharmacological rate control and atrioventricular nodal ablation with pacemaker implantation.

SUMMARY

Understanding the indications for rate control, treatment goals and options will gain the largest benefit for the individual patient with atrial fibrillation.

Diagnostic approach and treatment strategy in tachycardia-induced cardiomyopathy

BACKGROUND

Due to the absence of differential guidelines for heart failure with tachyarrhythmia, it is difficult to diagnose tachycardia-induced cardiomyopathy (TIC) at the initial visit. Furthermore, clinical outcomes of rate versus rhythm control in TIC are unclear.

HYPOTHESIS

Because the etiology of TIC is different from dynamic cardiomyoplasty (DCMP), differential parameters may be present.

METHODS

We assessed 21 patients with TIC (15 men; mean age, 50+/-14 years) and 21 control patients with idiopathic DCMP. We assessed clinical courses, echocardiographic parameters, as well as outcomes by treatment.

RESULTS

In the TIC group, the related tachyarrhythmias were atrial fibrillation (n=12), atrial flutter (n=5), atrial tachycardia (n=3) and paroxysmal supraventricular tachycardia (n=1). After treatment, all patients became asymptomatic and the ejection fraction (EF) improvement (DeltaEF>or=15%) was observed in all patients (left ventricular ejection fraction [LVEF], 30+/-11%initial versus 58+/-6%last). In the idiopathic DCMP group, no patient showed EF improvement (EF increase

CONCLUSIONS

In patients presented as heart failure with tachyarrhythmia, initial echocardiographic parameters, especially LV end-diastolic dimension, help to differentiate TIC from idiopathic DCMP. Rate control was as effective as rhythm control for EF improvement and prognosis.

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Key Words

• dynamic cardiomyoplasty
• tachycardia‐induced cardiomyopathy
• echocardiography
• left ventricle end‐diastolic dimension
• clinical outcomes
• rate control
• rhythm control

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MESH Headings

• Adult
• Aged
• Cardiomyopathies/diagnosis
• Cardiomyopathies/etiology
• Cardiomyopathies/physiopathology
• Cardiomyopathies/therapy
• Diagnosis, Differential
• Echocardiography
• Female
• Humans
• Male
• Middle Aged
• Stroke Volume
• Tachycardia/complications
• Tachycardia/therapy
• Ventricular Function, Left

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Affiliation(s)

Young‐Hoon Jeong Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
Kee‐Joon Choi Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
Jong‐Min Song Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
Eui‐Seock Hwang Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
Kyoung‐Min Park Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
Gi‐Byoung Nam Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
Jae‐Joong Kim Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
You‐Ho Kim Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea

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Quality of life in atrial fibrillation: measurement tools and impact of interventions

Quality of life (QoL) is of central importance in atrial fibrillation as both a treatment goal and an endpoint in the evaluation of new therapies. QoL appears to be impaired in the majority of patients with AF. A number of interventions for AF have been shown to improve QoL, including pharmacologic and nonpharmacologic rate control, antiarrhythmic drugs, and nonpharmacologic rhythm control strategies. This paper will review the rationale, design, strengths, and limitations of the questionnaires most commonly used to assess QoL in AF studies, and present QoL outcomes from major studies of AF interventions.

Preserved left ventricular ejection fraction following atrioventricular junction ablation and pacing for atrial fibrillation

INTRODUCTION

Right ventricular apical (RVA) pacing creates ventricular dyssynchrony and may compromise left ventricular ejection fraction (LVEF). The impact of RVA pacing in patients who have undergone atrioventricular junction (AVJ) ablation for atrial fibrillation (AF) is unclear. We sought to determine whether RVA pacing after AVJ ablation for patients with AF compromises LVEF in the short- or long-term.

METHODS/RESULTS

We studied 286 patients with AF who underwent AVJ ablation and RVA pacing at our institution between 1990 and 2002. Patients were stratified into a short-term follow-up group (LVEF reassessed by echocardiography within a year after AVJ ablation, n = 134) and a long-term group (LVEF reassessed after a year, n = 152). Among all 286 patients (mean follow-up 20 months), we observed no change in mean LVEF after AVJ ablation and RVA pacing (48% before vs. 48% after, P = 0.42). Short-term follow-up patients had a statistically significant improvement in mean LVEF (46% before vs. 49% after, P = 0.03), whereas there was no statistically significant change in mean LVEF in long-term follow-up patients (49% before vs. 48% after, P = 0.37). Only 9% of short-term patients, 15% of long-term patients, and 1% of patients with baseline LVEF <or= 40% experienced >or=10% absolute decrease in LVEF. Baseline LVEF > 40% was a multivariate predictor of LVEF decline.

CONCLUSIONS

RVA pacing after AVJ ablation does not compromise LVEF in the short- or long-term for the vast majority of patients. Better predictors are needed to help us select patients for biventricular pacing after AVJ ablation.

Atrioventricular junction ablation combined with either right ventricular pacing or cardiac resynchronization therapy for atrial fibrillation: The need for large-scale randomized trials

BACKGROUND

Nonrandomized studies suggest that atrioventricular (AV) junction ablation and pacemaker implantation may improve quality of life, ejection fraction, and exercise tolerance in patients with symptomatic drug-refractory atrial fibrillation.

OBJECTIVE

The purpose of this study was to determine whether recent randomized trials support the use of AV junction ablation in combination with conventional right ventricular pacemaker therapy or cardiac resynchronization therapy (CRT) in atrial fibrillation.

METHODS

Meta-analysis of randomized trials comparing AV junction ablation vs drugs or CRT vs right ventricular pacing for atrial fibrillation.

RESULTS

Six randomized trials with 323 patients compared AV junction ablation vs pharmacologic therapy. The majority of these trials did not individually report a statistically significant improvement in survival, stroke, hospitalization, functional class, atrial fibrillation-associated symptoms, left ventricular ejection fraction, exercise capacity, healthcare costs, or quality of life. Overall, all-cause mortality was 3.5% for AV junction ablation patients and 3.3% for controls (relative risk 1.18, 99% confidence interval 0.26-5.22). Three randomized trials with 347 patients compared CRT vs right ventricular pacing in atrial fibrillation. These trials did not individually report a statistically significant improvement in survival, stroke, hospitalization, exercise capacity, or healthcare costs. CRT was associated with a statistically significant improvement in ejection fraction in two of the three trials. Overall, CRT was associated with a trend toward reduced all-cause mortality relative to controls (relative risk 0.51, 99% confidence interval 0.22-1.16). All-cause mortality was 7.1% for CRT patients and 14% for controls.

CONCLUSION

Limited randomized trial data have been published regarding AV junction ablation in combination with conventional pacemaker therapy or CRT for atrial fibrillation. Large-scale randomized trials are needed to assess the efficacy of these therapies.

Overview of Management of Atrial Fibrillation in Symptomatic Elderly Patients: Pharmacologic Therapy Versus AV Node Ablation

Atrial fibrillation is an abnormal heart rhythm affecting the upper chambers of the heart in which uncoordinated electrical depolarizations lead to ineffective contractions. Approximately five million patients in the US have atrial fibrillation, and this number is expected to double to 10 million over the next 30 years. Advancing age is a major risk factor for the development of atrial fibrillation; new cases of atrial fibrillation are diagnosed in men over age 80 at the rate of 2% per year. Although several drugs are available for management of atrial fibrillation, the efficacy of these drugs may be limited in elderly patients. In this review, we provide an overview of management of atrial fibrillation, with special emphasis on pharmacologic therapy versus arteriovenous (AV) node ablation in symptomatic elderly patients.