Outcome of tailored therapy in rheumatic heart disease with persistent atrial fibrillation (RHD-AF)

INTRODUCTION

Rheumatic heart disease with persistent atrial fibrillation (RHD-AF) is associated with increased morbidity. However, there is no standardized approach for the maintenance of sinus rhythm (SR) in them. We aimed to determine the utility of a stepwise approach to achieve SR in RHD-AF.

METHODS

Consecutive patients with RHD-AF from July 2021 to August 2023 formed the study cohort. The stepwise approach included pharmacological rhythm control and/or electrical cardioversion (Central illustration). In patients with recurrence, additional options included AF ablation or pace and ablate strategy with conduction system pacing or biventricular pacing. Clinical improvement, NT-proBNP, 6-Minute Walk Test (6MWT), heart failure (HF) hospitalizations, and thromboembolic complications were documented during follow-up.

RESULTS

Eighty-three patients with RHD-AF (mean age 56.13 ± 9.51 years, women 72.28%) were included. Utilizing this approach, 43 (51.81%) achieved and maintained SR during the study period of 11.04 ± 7.14 months. These patients had improved functional class, lower NT-proBNP, better distance covered for 6MWT, and reduced HF hospitalizations. The duration of AF was shorter in patients who achieved SR, compared to those who remained in AF (3.15 ± 1.29 vs 6.93 ± 5.23, p = 0.041). Thirty-five percent (29) maintained SR after a single cardioversion over the study period. Only one underwent AF ablation. Of the 24 who underwent pace and ablate strategy, atrial lead was implanted in 22 (hybrid approach), and 50% of these achieved and maintained SR. Among these 24, none had HF hospitalizations, but patients who maintained SR had further improvement in clinical and functional parameters.

CONCLUSIONS

RHD-AF patients who could achieve SR with a stepwise approach, had better clinical outcomes and lower HF hospitalizations.

The 40th Anniversary of Percutaneous Balloon Valvuloplasty for Mitral Stenosis: Current Status

Percutaneous balloon mitral valvuloplasty (PBMV), once the most complex of percutaneous cardiac procedures and essentially the first adult structural heart intervention, set the stage for a host of new technologies. Randomized studies comparing PBMV to surgery were the first to provide a high-level evidence base in structural heart. The devices used have changed little in 40 years, but the advent of improved imaging and the expertise gained in interventional cardiology has provided some additional procedural safety. However, with the decline in rheumatic heart disease, PBMV is being performed in fewer patients in industrialized nations; in turn, these patients have more comorbidities, less favorable anatomy, and thus a higher rate of procedure-related complications. There remain relatively few experienced operators, and the procedure is distinct enough from the rest of the structural heart intervention world that it has its own steep learning curve. This article reviews the use of PBMV in a variety of clinical settings, the influence of anatomic and physiologic factors on outcomes, the changes in the guidelines, and alternative approaches. PBMV remains the procedure of choice in patients with mitral stenosis with ideal anatomy and a useful tool in patients with less than ideal anatomy who are poor surgical candidates. In the 40 years since its first performance, PBMV has revolutionized the care of mitral stenosis patients in developing countries and remains an important option for suitable patients in industrialized nations.

Comparison of the Efficacy and Safety Endpoints of Five Therapies for Atrial Fibrillation: A Network Meta-Analysis

Introduction

Atrial fibrillation (AF) is a prevalent arrhythmia that occurs in 2–4% of adults and poses a threat to human health. Thus, comparison of the efficacy and safety of therapies for AF is warranted. Here, we used network analysis to compare efficacy (arrhythmia recurrence and re-hospitalization) and safety (ischemic cerebral vascular events, all-cause mortality, and cardiovascular mortality) endpoints among five major therapies for AF.

Methods

The PubMed, Cochrane, and Embase databases were searched, and relevant literature was retrieved. Only studies that made comparisons among the therapies of interest and involved patients with AF were included. Pairwise comparisons and frequentist method (SUCRA plot) analyses were conducted.

Results

In total, 62 studies were included in the pooled analysis. In pairwise comparisons, atrioventricular nodal ablation plus permanent pacemaker (AVN + PPM) was associated with a significantly higher risk of atrial arrhythmia recurrence than surgical ablation [odds ratio (OR): 23.82, 95% confidence interval (CI): 1.97–287.59, fixed-effect model; 3.82, 95% CI: 1.01–559.74, random-effects model]. Furthermore, radiofrequency ablation was associated with a significantly lower risk of cardiovascular mortality than medication in pairwise comparison (OR: 0.49, 95% CI: 0.29–0.83, fixed-effect model; OR: 0.49, 95% CI: 0.27–0.9, random-effects model). Frequentist analysis indicated that AVN + PPM had the best performance in reducing the risk of safety and efficacy endpoints.

Conclusion

Non-pharmaceutical therapies showed superior performance to traditional drug therapy in lowering the risk of safety and efficiency endpoint events. AVN + PPM performed best in reducing the risk of safety and efficacy endpoints.

Comparison of catheter and surgical ablation of atrial fibrillation: A systemic review and meta-analysis of randomized trials

OBJECTIVE

To compare both the beneficial and adverse effects of catheter ablation (CA) and surgical ablation (SA) on patients with atrial fibrillation (AF).

METHODS

We searched MEDLINE and 4 additional databases for randomized controlled trials that compared CA with SA. Following data extraction, we conducted a meta-analysis to estimate the efficacy and safety of CA relative to SA. The primary end point of this study was the absence of AF during a 12-month follow-up period without the use of antiarrhythmic drugs.

RESULTS

Seven trials comparing SA with CA met the inclusion criteria for efficacy outcome assessments. Following the meta-analysis, we obtained a summary odds ratio (OR) of achieving success 1 year after CA relative to SA was 0.37:1 (95% confidence interval [CI], 0.20-0.69). The result was robust in the subgroup analysis. CA was associated with a greater incidence of femoral vascular complications (OR, 5.81; 95% CI, 1.03-32.71), but a lower incidence of pneumothorax (OR, 0.09; 95% CI, 0.01-0.74) than SA. Statistically significant differences in the other safety outcomes were not observed between CA and SA.

CONCLUSIONS

SA confers a moderate advantage over CA in 1-year efficacy outcomes and may be safely performed by experienced surgeons.

Electrogram dispersion-guided driver ablation adjunctive to high-quality pulmonary vein isolation in atrial fibrillation of varying durations

OBJECTIVE

To investigate the role of driver mechanism and the effect of electrogram dispersion-guided driver mapping and ablation in atrial fibrillation (AF) at different stages of progression.

METHODS

A total of 256 consecutive patients with AF who had undergone pulmonary vein isolation (PVI) plus driver ablation or conventional ablation were divided into three groups: paroxysmal atrial fibrillation (PAF; group A, n = 51); persistent atrial fibrillation (PsAF; group B, n = 38); and long standing-persistent atrial fibrillation (LS-PsAF; group C, n = 39). PVI was performed with the guidance of the ablation index. The electrogram dispersion was analyzed for driver mapping.

RESULTS

The most prominent driver regions were at roof (28.0%), posterior wall (17.6%), and bottom (21.3%). From patients with PAF to those with PsAF and LS-PsAF: the complexity of extra-pulmonary vein (PV) drivers including distribution, mean number, and area of dispersion region increased (P < .001). Patients who underwent driver ablation vs conventional ablation had higher procedural AF termination rate (76.6% vs 28.1%; P < .001). With AF progression, the termination rate gradually decreased from group A to group C, and the role of PVI in AF termination was also gradually weakened from group A to group C (39.6%, 7.4%, and 4.3%; P < .001) in patients with driver ablation. At the end of the follow-up, the rate of sinus rhythm maintenance was higher in patients with driver ablation than those with conventional ablation (89.1% vs 70.3%; P < .001).

CONCLUSION

The formation of extra-PV drivers provides an important mechanism for AF maintenance with their complexity increasing with AF progression. Electrogram dispersion-guided driver ablation appears to be an efficient adjunctive approach to PVI for AF treatment.

Dispersion-guided ablation in conjunction with circumferential pulmonary vein isolation is superior to stepwise ablation approach for persistent atrial fibrillation

BACKGROUND

Due to the lack of optimal ablation strategy, the success rate of persistent atrial fibrillation (AF) is still low. We hypothesize that a strategy that targeting pulmonary triggers and dispersion areas in atria improves prognosis of persistent AF.

METHODS

We prospectively enrolled 142 persistent AF patients admitted for catheter ablation. These patients were randomly assigned in a 1:1 ratio to ablation with circumferential pulmonary vein isolation (CPVI) + ablation of electrogram dispersion areas (71 patients, group A) or stepwise ablation strategy (71 patients, group B).

RESULTS

Procedural time and fluoroscopy time did not differ between group A and group B (204.6 ± 26.9 min vs 207.8 ± 26.3 min and 7.3 ± 1.3 min vs 7.1 ± 1.3 min, respectively, P > 0.05), however, radiofrequency delivery time in group A was significantly shorter than that in group B (70 ± 7.2 min vs 83.2 ± 9.1 min, P < 0.001). In total, 265 electrogram dispersion areas were identified in 67 patients, and the most prominent areas were roof, bottom, and inferoposterior wall. The rates of acute AF endpoint (including AF termination and AFCL elongation >30 ms) and termination in group A were significantly higher than that in group B (97.2% vs. 71.8% and 70.4% vs. 15.5%, respectively, P < 0.001). During a follow-up period of 204 ± 67 days, both AF-free and AF/AT-free survival in group A were significantly higher than that in group B (P = 0.012 and P = 0.014, respectively).

CONCLUSION

Dispersion-guided ablation in conjunction with CPVI is efficient, personalized, and accurate for persistent AF.

Eplerenone Prevents Atrial Fibrosis via the TGF-β Signaling Pathway

OBJECTIVES

Eplerenone (EPL), an antagonist of the mineralocorticoid receptor, is beneficial for atrial fibrillation and atrial fibrosis. However, the underlying mechanism remains less well known. We aimed to investigate the effect of EPL on atrial fibrosis using a mouse with selective atrial fibrosis and to explore the underlying mechanisms.

METHODS

EPL-treated MHC-TGFcys33ser transgenic mice that have selective atrial fibrosis (Tx+EPL mice), as well as control mice, were used for in vivo studies including histological analyses, Western blotting, and qRT-PCR studies. TGF-β1-stimulated atrial fibroblasts were treated with EPL or vehicle for the in vitro studies including Western blotting and qRT-PCR studies. In addition, Smad7 siRNA was used to knock down Smad7.

RESULTS

EPL inhibited atrial fibrosis in the Tx mice. In addition, EPL suppressed the expression of fibrosis-related molecules induced by TGF-β1 in vivo and in vitro. This occurred in concert with a downregulation of Smad7 protein expression and an upregulation of p-Smad2/3 protein expression. In addition, knockdown of Smad7 by siRNA abolished the protective roles of EPL.

CONCLUSIONS

EPL inhibited atrial fibrosis in Tx mice. The underlying mechanism may involve increased protein expression of Smad7, which enhances the inhibitory feedback regulation of TGF-β1/Smad signaling.

Very early recurrence predicts long-term outcome in patients after atrial fibrillation catheter ablation: a prospective study

Background

Long-term recurrence (LR) is a tendency that re-occurs within 3 months after catheter ablation for atrial fibrillation (AF). Whether very early recurrence (VER) within 7 days of post ablation is a prognostic factor of LR or not is unclear. For this reason, present study sought to examine the relationship between VER and LR.

Methods

In this prospective analysis 378 consecutive patients underwent an initial catheter ablation for paroxysmal or persistent AF. The association between VER and LR was analyzed by univariate and multivariate Cox regression, as well as time-dependent receiver operator characteristic (ROC) analysis.

Results

After a mean follow-up of 14.71 ± 8.58 months, 81 (65.90%) patients with VER experienced LR and were associated with lower event of free survival from LR (Log rank test, P < 0.001). Multivariate Cox regression analysis revealed that VER (HR = 7.02, 95% CI = 4.78–10.31; P < 0.001), left atrial enlargement (HR = 2.92, 95% CI = 1.88–4.54; P < 0.001), tendency in advanced age (HR = 1.50, 95% CI = 0.99–2.28; P = 0.054), and tendency in male (HR = 0.71, 95% CI = 0.50–1.01; P = 0.060) were independent predictors of LR. According to time-dependent ROC analysis, it was found that VER was more sensitive than common risk factors in predicting LR (0.74 vs 0.66, P < 0.001) and combination model further improved the C statistic for predicting LR (0.82 vs 0.66, P < 0.001).

Conclusions

After a single procedure of catheter ablation, patients with VER were strongly associated with LR and combination of VER and common risk factors could further improve prediction of patients who were at high risk for LR.

A clinical study on the electrophysiological characteristics of patients without recurrence after ablation of persistent atrial fibrillation

BACKGROUND

The electrophysiological characteristics of patients without recurrence after ablation of persistent atrial fibrillation (AF) have not been systematically determined. This study compared the electrophysiological characteristics in patients with and without recurrence of AF after persistent AF ablation.

METHODS

Forty-five patients without recurrence of AF after persistent AF ablation were enrolled to assess electrophysiological characteristics including pulmonary vein (PV) reconnection, the mitral isthmus (MI) line and the roof line reconduction. Ninety-five patients with recurrence of AF after ablation were used as the control group.

RESULTS

Among patients without recurrence, recovery of PV conduction was observed in 37 of 45 (82.2%) patients: 3/45 (6.7%) reconnection in 4 veins, 7/45 (15.6%) in 3 veins, 11/45 (24.4%) in 2 veins, and 16/45 (35.6%) in 1 vein. No significant differences were seen in the proportion of patients with PV reconnection compared to patients with recurrence (p>0.05). Among patients without recurrence, the MI line reconduction was observed in 3/45 (6.7%) patients; the roof line conduction was observed in 5/45 (11.1%) patients. In comparison, patients with clinical recurrence of AF had recovery of the MI line conduction in 27/95 (28.4%) and recovery of the roof line conduction in 26/95 (27.4%). Significant differences were seen between these two groups (6.7% vs 28.4%, p=0.004; 11.1% vs 27.4%, p=0.031).

CONCLUSION

Although a high incidence of PV reconnection was similarly observed in patients with and without recurrence of AF, a lower incidence of lines reconduction was observed in patients without recurrence of AF.

Concomitant atrial fibrillation surgery for people undergoing cardiac surgery

BACKGROUND

People with atrial fibrillation (AF) often undergo cardiac surgery for other underlying reasons and are frequently offered concomitant AF surgery to reduce the frequency of short- and long-term AF and improve short- and long-term outcomes.

OBJECTIVES

To assess the effects of concomitant AF surgery among people with AF who are undergoing cardiac surgery on short-term and long-term (12 months or greater) health-related outcomes, health-related quality of life, and costs.

SEARCH METHODS

Starting from the year when the first "maze" AF surgery was reported (1987), we searched the Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library (March 2016), MEDLINE Ovid (March 2016), Embase Ovid (March 2016), Web of Science (March 2016), the Database of Abstracts of Reviews of Effects (DARE, April 2015), and Health Technology Assessment Database (HTA, March 2016). We searched trial registers in April 2016. We used no language restrictions.

SELECTION CRITERIA

We included randomised controlled trials evaluating the effect of any concomitant AF surgery compared with no AF surgery among adults with preoperative AF, regardless of symptoms, who were undergoing cardiac surgery for another indication.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data. We evaluated the risk of bias using the Cochrane 'Risk of bias' tool. We included outcome data on all-cause and cardiovascular-specific mortality, freedom from atrial fibrillation, flutter, or tachycardia off antiarrhythmic medications, as measured by patient electrocardiographic monitoring greater than three months after the procedure, procedural safety, 30-day rehospitalisation, need for post-discharge direct current cardioversion, health-related quality of life, and direct costs. We calculated risk ratios (RR) for dichotomous data with 95% confidence intervals (CI) using a fixed-effect model when heterogeneity was low (I² ≤ 50%) and random-effects model when heterogeneity was high (I² > 50%). We evaluated the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework to create a 'Summary of findings' table.

MAIN RESULTS

We found 34 reports of 22 trials (1899 participants) with five additional ongoing studies and three studies awaiting classification. All included studies were assessed as having high risk of bias across at least one domain. The effect of concomitant AF surgery on all-cause mortality was uncertain when compared with no concomitant AF surgery (7.0% versus 6.6%, RR 1.14, 95% CI 0.81 to 1.59, I² = 0%, 20 trials, 1829 participants, low-quality evidence), but the intervention increased freedom from atrial fibrillation, atrial flutter, or atrial tachycardia off antiarrhythmic medications > three months (51.0% versus 24.1%, RR 2.04, 95% CI 1.63 to 2.55, I² = 0%, eight trials, 649 participants, moderate-quality evidence). The effect of concomitant AF surgery on 30-day mortality was uncertain (2.3% versus 3.1%, RR 1.25 95% CI 0.71 to 2.20, I² = 0%, 18 trials, 1566 participants, low-quality evidence), but the intervention increased the risk of permanent pacemaker implantation (6.0% versus 4.1%, RR 1.69, 95% CI 1.12 to 2.54, I² = 0%, 18 trials, 1726 participants, moderate-quality evidence). Investigator-defined adverse events, including but limited to, need for surgical re-exploration or mediastinitis, were not routinely reported but were not different between the two groups (other adverse events: 24.8% versus 23.6%, RR 1.07, 95% CI 0.85 to 1.34, I² = 45%, nine trials, 858 participants), but the quality of this evidence was very low.

AUTHORS' CONCLUSIONS

For patients with AF undergoing cardiac surgery, there is moderate-quality evidence that concomitant AF surgery approximately doubles the risk of freedom from atrial fibrillation, atrial flutter, or atrial tachycardia off anti-arrhythmic drugs while increasing the risk of permanent pacemaker implantation. The effects on mortality are uncertain. Future, high-quality and adequately powered trials will likely affect the confidence on the effect estimates of AF surgery on clinical outcomes.

Renal function after repeat catheter ablation for long-standing persistent atrial fibrillation : Low CHA2DS2-VASc score and sinus rhythm predict improved renal function

BACKGROUND

Renal impairment and atrial fibrillation (AF) often coexist. Catheter ablation is an effective way to reduce the burden of AF and improve symptoms; however, little is known about the relationship between renal function and AF and its role in the progression of AF for patients undergoing repeat catheter ablation.

METHODS

In all, 171 patients with long-standing persistent AF ablation were enrolled in the study. The patients were divided into two groups according to their delta estimated glomerular filtration rate (eGFR) values, which was defined as the eGFR before the repeat procedure minus the eGFR before the initial procedure. Patients with decreasing eGFR (delta eGFR < 0) were categorized as group I, while individuals with no change or increasing eGFR (delta eGFR≥ 0) were categorized as group II. eGFR was estimated at baseline and at the 12-month and 24-month follow-up visits.

RESULTS

After a mean follow-up of 31.4 ± 13.2 months, group I had a significantly higher arrhythmia recurrence rate than group II (71.2 vs. 49.2 %, p < 0.001). On multivariable analyses, eGFR changes after the repeat procedure were associated with arrhythmia recurrence, hypertrophic cardiomyopathy, and CHA2DS2-VASc score. Patients with arrhythmia recurrence and those with a CHA2DS2-VASc score of ≥ 3 were more likely to show an eGFR decline at follow-up.

CONCLUSION

Patients with long-standing persistent AF, with a failed initial ablation procedure and undergoing a repeat ablation procedure, appear to have a higher risk of arrhythmia recurrence. During the follow-up period, patients without arrhythmia recurrence and those with a CHA2DS2-VASc score of < 3 show improved renal function.

Repeat Catheter Ablation of Long-standing Persistent Atrial Fibrillation in Patients with a Total Atrial Fibrillation Duration of More Than 2 Years: Effects of the CHA2DS2-VASc Score and Estimated Glomerular Filtration Rate on the Outcomes

Objective Little is known about the outcome of repeat catheter ablation of long-standing persistent atrial fibrillation (AF) in patients with a total AF duration of more than 2 years. The main objective of this study was to explore the results and factors affecting the clinical success rate of these repeat procedures. Methods We enrolled 99 patients with a total AF duration of more than 2 years and recurrent atrial arrhythmias after the initial catheter ablation of long-standing persistent AF. The enrolled patients were divided into two groups named the AF-recurrence group (50 patients) and the atrial tachycardia (AT)-recurrence group (49 patients) and all underwent a strict follow-up. The quality of life (QOL) and AF-related symptom classification were assessed at baseline and at 24 months post re-ablation. Results After a mean follow-up of 31 months, 30 (30.3%) patients were free from arrhythmia recurrence, and the success rate in the AT-recurrence group was higher than that in the AF-recurrence group (32.7% vs. 28.0%, p=0.614). A Cox regression analysis revealed a CHA2DS2-VASc score ≥3 to be a predictor of recurrence. AF recurrent patients with an abnormal renal function were more prone to undergo a failed procedure. However, an abnormal renal function had no effect on the outcome of the repeat procedure for patients with AT recurrence. At the 24-month follow-up, patients maintaining sinus rhythm (SR) had a significantly improved QOL and AF-related symptoms. Conclusion The success rate of repeat procedures for long-standing persistent AF and a total AF duration of more than 2 years is poor for patients with a CHA2DS2-VASc score ≥3. An impaired renal function has an unfavorable effect on the outcome for patients with AF recurrence. For patients maintaining SR, both the QOL and AF symptomatology improve significantly.

TGF-β1 and TIMP-4 regulate atrial fibrosis in atrial fibrillation secondary to rheumatic heart disease

To investigate the involvement of transforming growth factor-β1 (TGF-β1) and tissue inhibitor of metalloproteinase 4 (TIMP-4) in influencing the severity of atrial fibrosis in rheumatic heart disease (RHD) patients with atrial fibrillation (AF). The degree of myocardial fibrosis was evaluated using Masson staining. The expression levels of TGF-β1, TIMP-4, matrix metalloproteinase-2 (MMP-2), type I collagen, and type III collagen were estimated by Western blot analysis. Additionally, TGF-β1 and TIMP-4 mRNA levels were quantified by qRT-PCR. The effect of TGF-β1 stimulation on TIMP-4 expression was assessed by in vitro stimulation of freshly isolated human atrial fibroblasts with recombinant human TGF-β1, followed by Western blot analysis to detect changes in TIMP-4 levels. Masson stain revealed that the left atrial diameter and collagen volume fraction were obviously increased in AF patients, compared to sinus rhythm (SR) controls (both P < 0.05). Western blot analysis showed significantly elevated levels of the AF markers MMP-2, type I collagen, and type III collagen in the AF group, in comparison to the SR controls (all P < 0.05). In the AF group, TGF-β1 expression was relatively higher, while TIMP-4 expression was apparently lower than the SR group (all P < 0.05). TIMP-4 expression level showed a negative association with TGF-β1 expression level (r = -0.98, P < 0.01) and TGF-β1 stimulation of atrial fibroblasts led to a sharp decrease in TIMP-4 protein level. Increased TGF-β1 expression and decreased TIMP-4 expression correlated with atrial fibrosis and ECM changes in the atria of RHD patients with AF. Notably, TGF-β1 suppressed TIMP-4 expression, suggesting that selective TGF-β1 inhibitors may be useful therapeutic agents.

Effect of pulmonary vein isolation on atrial fibrillation recurrence after ablation of paroxysmal supraventricular tachycardia in patients with high dispersion of atrial refractoriness

PURPOSE

This study aimed to assess pulmonary vein isolation (PVI) efficacy on atrial fibrillation (AF) recurrence and to determine a predictive dispersion of atrial refractoriness (dERP) value for performing PVI in paroxysmal supraventricular tachycardia (PSVT) patients.

METHODS

Of 67 PSVT patients with past AF episodes who underwent accessory pathway (AP) or slow pathway of atrioventricular node ablation, 63 (4 lost to follow-up or death) were assigned into two groups (A and B; 29 and 34 patients, respectively) based on whether they underwent or not subsequent PVI, and all were followed-up up to 3 years. Atrial effective refractory period (AERP) and dERP were measured during the ablation procedure.

RESULTS

In receiver operating characteristic (ROC) curve analysis, dERP = 74.5 ms effectively predicted AF recurrence in PSVT patients (p = 0.003). Difference in AF recurrence rate between groups did not reach statistical significance (17.2%, 5/29 vs. 29.4%, 10/34, p = 0.203). AF recurrence rate was lower in patients with dERP >74.5 ms who underwent AP or slow-pathway ablation with vs. without PVI (18.2%, 2/11 vs. 77.8%, 7/9, p = 0.012).

CONCLUSIONS

PVI addition after successful AP or slow pathway of atrioventricular node ablation significantly reduced AF recurrence in PSVT patients with high atrial vulnerability (dERP >74.5 ms).

Optimal rhythm-control strategy for recurrent atrial tachycardia after catheter ablation of persistent atrial fibrillation: a randomized clinical trial

AIM

Although catheter ablation (CA) has replaced antiarrhythmic drugs (AAD) as first-line treatment in selected patients with atrial fibrillation (AF), optimal treatment of recurrent atrial tachycardia (AT) after AF ablation remains unclear. This parallel randomized controlled study compared CA vs. AAD for recurrent AT after persistent AF ablation.

METHODS AND RESULTS

Two-hundred and one patients (aged 59.1 ± 10.9 years, 68.7% male) with recurrent AT after persistent AF ablation were enrolled and randomized to either CA (n = 101) or AAD (n = 100) treatment. Primary endpoint was freedom from recurrent atrial tachyarrhythmia (ATa, including AT and AF) at 24-month follow-up. Composite secondary endpoints comprised procedural complications, long-term morbidity and improvement in quality of life (QoL). On an intention-to-treat basis, the CA group had a higher rate of freedom from recurrent ATa (56.4 vs. 34.0%; P = 0.001). Adjusted Cox regression analysis showed a significant treatment effect with a hazard ratio of 0.538 (95% CI: 0.355-0.816) in favour of CA. There was a higher proportion of periprocedural complications in the CA group (7.9 vs. 0; P = 0.012), and of long-term adverse events in the AAD group (10.9 vs. 24.0%; P = 0.014). Quality of life was significantly higher for CA.

CONCLUSIONS

This study demonstrates superiority of CA over AAD for recurrent AT after persistent AF ablation with regard to SR maintenance, long-term safety and QoL improvement. However, CA use might be limited by a higher risk for periprocedural complications.

Comparison of catheter ablation and surgical ablation in patients with long-standing persistent atrial fibrillation and rheumatic heart disease: a four-year follow-up study

BACKGROUND

In our previous prospective and randomized study, we have demonstrated that the concomitant surgical ablation using saline-irrigated cooled tip radiofrequency ablation (SICTRA) system is more effective than subsequent circumferential pulmonary vein isolation (CPVI) combined with substrate modification in treating patients with long-standing persistent atrial fibrillation (LS-AF) and rheumatic heart disease (RHD) undergoing cardiac surgery during middle-term follow-up. Whether this strategy also decreases longer-term arrhythmia recurrence is unknown. This study describes the 4-year efficacy of SICTRA for these patients. Furthermore, we seek to compare the electrophysiological characteristics for recurrent atrial tachyarrhythmia (ATa) at the session of catheter ablation between two groups.

METHODS

Long-term follow-up was performed in 95 patients who underwent the catheter ablation strategy (n=47, Group A) or SICTRA (n=48, Group B) combined with valvular surgery for symptomatic LS-AF patients with RHD.

RESULTS

After one procedure, Group B had a significantly higher freedom from ATa compared with Group A (29/48 vs 15/47, P=0.005) after a mean follow-up of 54 months (range 48 to 63 months). Catheter-based mapping and ablation of recurrent ATa showed larger amounts of macro-reentrant atrial tachycardias (ATs) in Group B and higher incidence of pulmonary vein (PV) recovery in Group A. After multiple catheter ablations for recurrent ATa, sinus rhythm (SR) could be maintained equally between two groups.

CONCLUSIONS

Single procedure success seems to be higher with SICTRA but repeated catheter ablation potentially results in comparable outcomes in treating patients with LS-AF and RHD during long-term follow-up. More macro-reentrant ATs and more PV recoveries are identified to be responsible for ATa in SICTRA and catheter ablation group, respectively.

Association of angiotensin-converting enzyme gene I/D and CYP11B2 gene -344T/C polymorphisms with lone atrial fibrillation and its recurrence after catheter ablation

The renin-angiotensin-aldosterone system (RAAS) plays a key role in atrial structural and electrical remodeling. The aim of this study was to investigate the potential associations of angiotensin-converting enzyme (ACE) gene insertion/ deletion (I/D) and aldosterone synthase (CYP11B2) gene −344T/C polymorphisms with the risk and recurrence of lone atrial fibrillation (AF). One hundred and ninety-three patients who underwent successful catheter ablation for lone AF were recruited. Two hundred and ninety-seven sinus rhythm subjects without a history of arrhythmia served as controls. The subjects were genotyped for ACE gene I/D and CYP11B2 gene −344T/C polymorphisms. Results showed that the ACE gene DD genotype and D allele were associated with a greater prevalence of lone AF (both P<0.01). In addition, the ACE gene DD genotype had a significantly larger left atrial dimension (LAD; 41.6±5.7 mm vs. 39.6±5.2 mm; P=0.043) and higher risk of AF recurrence [44.7% vs. 23.2%; odds ratio (OR), 2.68; 95% confidence interval (CI), 1.28–5.61; P=0.008] compared with the II+ID genotype in lone AF patients. After adjustment for a variety of risk factors, the ACE gene DD genotype had a 1.97-fold increased risk for lone AF (OR, 1.97; 95% CI, 1.15–3.37; P= 0.013) and 2.35-fold increased risk for AF recurrence (RR, 2.35; 95% CI, 1.10–5.04; P=0.028) compared with the ACE gene II+ID genotype. However, no correlation between the CYP11B2 gene −344T/C polymorphism and lone AF or its recurrence was observed in this cohort. In conclusion, the ACE gene DD genotype was associated with an increased incidence of lone AF and its recurrence following ablation, which was partly mediated by LAD.

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.

Effect of electrical stimulus parameters on the development and propagation of action potentials in short excitable fibres

Intracellular action potentials (IAPs) produced by short fibres in response to their electrical stimulation were analysed. IAPs were calculated on the basis of the Hodgkin-Huxley (1952) model by the method described by Joyner et al. (1978). Principal differences were found in processes of activation of short (semilength L less than 5 lambda) and long fibres under near-threshold stimulation. The shorter the fibre, the lower was the threshold value (Ithr). Dependence of the latency on the stimulus strength (Ist) was substantially non-linear and was affected by the fibre length. Both fibre length and stimulus strength influenced the IAP amplitude, the instantaneous propagation velocity (IPV) and the site of the first origin of the IAP (and, consequently, excitability of the short fibre membrane). With L less than or equal to 2 lambda and Ithr less than or equal to Ist less than or equal to 1.1Ithr, IPV could reach either very high values (so that all the fibre membrane fired practically simultaneously) or even negative values. The latter corresponded to the first origin of the propagated IAP, not at the site of stimulation but at the fibre termination or at a midpoint. The characters of all the above dependencies were unchanged irrespective of the manner of approaching threshold (variation of stimulus duration or its strength). Reasons for differences in processes of activation of short and long fibres are discussed in terms of electrical load and latency. Applications of the results to explain an increased jitter, velocity recovery function and velocity-diameter relationship are also discussed.