Impact of atrial remodeling on the outcome of radiofrequency catheter ablation of paroxysmal atrial fibrillation

Decreased estimated glomerular filtration rate predicts long-term recurrence after catheter ablation of atrial fibrillation in mild to moderate renal insufficiency

BACKGROUND

Catheter ablation is an established therapy for atrial fibrillation (AF), but recurrence after ablation remains a great challenge. Additionally, little is known about the effect of renal function on the efficiency of AF ablation. This study aimed to evaluate the predictors of the prognosis of catheter ablation for AF, especially the effect of renal function.

METHODS

A total of 306 drug-refractory symptomatic patients with AF who underwent first-time catheter ablation were enrolled in the present study. Individuals underwent circumferential pulmonary vein isolation for paroxysmal AF and stepwise ablation for persistent AF.

RESULTS

The follow-up time was 27.2 ± 19.5 months, 202 patients (66.01%) were free of atrial tachyarrhythmia (non-recurrence group), and the other 104 patients experienced recurrence (recurrence group). The recurrence group had a larger left atrial diameter (LAD) and left atrial volume (LAV), a higher LAV index (LAVI) (both, p < 0.01), and a lower estimated glomerular filtration rate (eGFR) (53.5 ± 14.4 vs. 65.5 ± 13.3 ml/min/1.732, p < 0.001) and creatinine clearance rate (CCr) (85.2 ± 26.1 vs. 101.5 ± 29.4 ml/min, p < 0.05). Multivariate logistic regression indicated both eGFR (p = 0.002) and LAVI (p < 0.001) as independent associated factors for long-term recurrence after single catheter ablation; multivariate Cox proportional hazard regression with backward feature selection identified both eGFR (HR: 0.93, 95% CI: 0.91-0.95, p < 0.001) and LAVI (HR: 1.32, 95% CI: 1.25-1.40, p < 0.001) as independent prognostic factors for recurrence when adjusting other clinical variables.

CONCLUSIONS

Decreased eGFR and elevated LAVI may facilitate the long-term recurrence of atrial tachyarrhythmia after catheter ablation for AF.

Echocardiography-derived total atrial conduction time (PA-TDI duration): risk stratification and guidance in atrial fibrillation management

Atrial fibrillation (AF) is a major cause of cardiovascular morbidity and mortality. To early detect and to avoid AF-related complications, several cardiac imaging modalities and approaches aim to quantify the severity of the underlying atrial cardiomyopathy (i.e., the extent of atrial remodeling). However, most established cardiac imaging modalities just incorporate single components of atrial remodeling and do not reflect the complete multifactorial process, which may contribute to their limited predictive value. Echocardiography-derived PA-TDI duration is a sophisticated echocardiographic parameter to assess total atrial conduction time and directly reflects both electrical and structural changes to the atria. Therefore, PA-TDI duration provides a more comprehensive quantification of the extent of atrial remodeling than other imaging modalities. In this article we review the role of PA-TDI duration as a marker of atrial remodeling and summarize the available data on PA-TDI duration to identify patients at risk for AF, as well as to guide AF management. Moreover, we discuss how to assess PA-TDI duration and provide recommendations on the implementation of PA-TDI duration into routine clinical care.

Total atrial conduction time as a possible predictor of atrial fibrillation recurrence after catheter ablation for paroxysmal atrial fibrillation: relationship between electrical atrial remodeling and structural atrial remodeling time courses

PURPOSE

Recently, the estimated total atrial conduction time measured using tissue Doppler imaging (PA-TDI duration) has been reported as a more accurate predictor of atrial fibrillation (AF) recurrence after catheter ablation than left atrial volume index (LAVI). The PA-TDI duration is considered to reflect electrical and structural remodeling in the right atrium (RA) and left atrium (LA). We sought to investigate the association between AF recurrence and PA-TDI duration after AF ablation.

METHODS

We studied 209 patients who underwent radiofrequency ablation for paroxysmal AF and 75 patients who underwent second ablation for AF recurrence. We assessed the duration from the onset of the P wave on the surface electrocardiogram to the atrial electrogram in distal coronary sinus (CS) (PA-CSd duration) indicating electrical remodeling of the atrium, the PA-CS proximal duration (PA-CSp duration) representing electrical remodeling of RA, and the conduction time in CS (proximal to distal) (CSp-CSd duration) reflecting electrical remodeling of LA. We also measured LAVI as a marker of structural remodeling of LA.

RESULTS

The PA-TDI duration had a positive correlation with PA-CSd duration. In the patients with AF recurrence, PA-TDI duration, PA-CSd duration, and CSp-CSd duration in the second ablation were significantly longer than those in the first (p < 0.01, respectively), whereas there was no significant difference in LAVI and PA-CSp duration between the first and second ablation sessions.

CONCLUSION

A prolonged PA-TDI duration after AF ablation may indicate advanced electrical remodeling of LA, and may predict AF recurrence after ablation in patients with paroxysmal AF.

Right atrial conduction time for predicting coexistent typical atrial flutter in patients with paroxysmal atrial fibrillation

INTRODUCTION

Screening of coexistent typical atrial flutter (AFL) in patients with atrial fibrillation (AF) is sometimes challenging. This study investigated whether a prolonged right atrial conduction time (RACT) estimated by tissue Doppler imaging (TDI) predicts patients with concomitant AFL and AF.

METHODS AND RESULTS

We retrospectively analyzed 398 patients (mean age: 61.6 years, 73.4% men) undergoing catheter ablation of paroxysmal AF. The patients were classified into two groups according to whether they had evidence of AFL (N = 122, 30.7%) determined by a clinical observation (N = 68), induction during procedures (N = 33), or AFL recurrence after procedures (N = 21) or not (N = 276, 69.3%). The preoperative RACT, defined as a longer duration between the onset of the P-wave and peak A'-wave on the right atrial lateral wall or septal wall, and total atrial conduction time (TACT), defined as the same time duration on the left atrial lateral wall, were evaluated in all patients. Patients with evidence of AFL had a significantly longer RACT than those without AFL (p < .001). A multiple logistic regression and receiver operator characteristics curve analysis revealed the ratio of the RACT and TACT (RACT/TACT) was the independent and most superior accurate cofounder for predicting evidence of AFL (area under the curve: 0.867). When adding a discriminator of an RACT/TACT ≧ 93% into the conventional screening, 98.4% of the patients with evidence of AFL were estimated to be treated during the initial procedures.

CONCLUSION

The estimated RACT/TACT using the TDI may be useful for predicting patients with concomitant AFL in patients with AF.

Immunopathogenesis and biomarkers of recurrent atrial fibrillation following ablation therapy in patients with preexisting atrial fibrillation

INTRODUCTION

Recurrent atrial fibrillation (RAF) following ablation therapy occurs in about 50% of patients. The pathogenesis of RAF is unknown, but is believed to be driven by atrial remodeling in the setting of background inflammation. Structural, electrophysiological and mechanical remodeling has been associated with atrial fibrillation (AF). Inflammation and fibrotic remodeling are the major factors perpetuating AF, as mediators released from the atrial tissues and cardiomyocytes due to mechanical and surgical injury could initiate the inflammatory process. In this article, we have critically reviewed the key mediators that may serve as potential biomarkers to predict RAF. Areas covered: Damage associated molecular patterns, heat shock proteins, inflammatory cytokines, non-inflammatory markers, markers of inflammatory cell activity, and markers of collagen deposition and metabolism are evaluated as potential biomarkers with molecular treatment options in RAF. Expert commentary: Establishing biomarkers to predict RAF could be useful in reducing morbidity and mortality. Investigations into the role of DAMPs participating in a sterile immune response may provide greater insight into the pathogenesis of RAF. Markers evaluating immune cell activity, collagen deposition, and levels of heat shock proteins show the greatest promise as potential biomarkers to predict RAF and develop novel therapies.

Echocardiographic assessment in patients with atrial fibrillation (AF) and normal systolic left ventricular function before and after catheter ablation: If AF begets AF, does pulmonary vein isolation terminate the vicious circle?

BACKGROUND

Radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) can be curative. There are conflicting data on whether AF associated atrial and ventricular structural remodeling reverses after ablation. The aim of this study was to evaluate the hemodynamic effect of AF ablation in patients with preserved left ventricular ejection fraction (LVEF).

METHODS

Forty three AF patients were studied (aged 56 ± 11 years; 29 male, 23% persistent AF, LVEF ≥ 50%) in whom RFCA was performed. Echocardiographic evaluation of atrial and ventricular diameters, volumes and strain imaging by two-dimensional speckle tracking were performed before and at least 6 months after RFCA. Nine patients had AF during baseline examination.

RESULTS

A significant decrease in the left (LA) and right (RA) atrial volume and an increase in the LA strain were observed 15 ± 7 months after RFCA. In the subgroup with baseline sinus rhythm, the increment in LA strain was only borderline significant. An increase in RA, right ventricular (RV) and Biatrial strain was noticed (p < 0.05). LVEF and global longitudinal strain of the left ventricle (LV), however, did not improve substantially.

CONCLUSIONS

Radiofrequency catheter ablation of AF in patients with preserved LV systolic function results in significant improvement in RA and RV function with a substantial reduction in LA and RA size. No deleterious impact of AF ablation on LA function was revealed.

Impact of a prolonged interatrial conduction time for predicting the recurrence of atrial fibrillation after circumferential pulmonary vein isolation of persistent atrial fibrillation

There are some cases that are difficult to cure with only circumferential pulmonary vein isolation (CPVI) of persistent atrial fibrillation (PerAF). Recently, prolonged interatrial conduction times (IACTs), which seem to be associated with progressive remodeled atria, have been reported as a predictor of new-onset AF. This study aimed to investigate the prognostic value of a prolonged IACT for predicting AF recurrences after CPVI of PerAF. One hundred thirteen patients who underwent CPVI without an empirical substrate modification of PerAF were retrospectively analyzed. The IACT was defined as the interval from the earliest P-wave onset on the ECG to the latest activation in the coronary sinus and was measured after achieving the CPVI and conversion to sinus rhythm. During a mean 22.7-month follow-up after the initial procedure, 56 patients (50%) had AF recurrences. Patients with AF recurrence had a longer IACT than those without AF recurrence (p < 0.001). The best discriminative cut-off value for the IACT was 123 ms (sensitivity 53%, specificity 85%). In a Cox multivariate analysis, a prolonged IACT of ≥ 123 ms was the only independent predictor (hazard ratio: 2.38; 95% confidence interval: 1.36-4.16, p = 0.002) of being associated with the incidence of an AF recurrence. Even after multiple CPVI procedures, patients with an IACT ≥ 123 ms had a higher AF recurrence rate than those with an IACT < 123 ms (p = 0.002). In conclusion, a prolonged IACT of ≥ 123 ms may be a useful marker for predicting AF recurrences after both initial and multiple CPVI procedures for PerAF.

Fibrinolytic Deficit and Platelet Activation in Atrial Fibrillation and Their Postablation Modulation

This study aims to examine the effects of atrial fibrillation (AF) on the expression of the cellular mediators plasminogen activator inhibitor 1 (PAI-1) and CD40 ligand (CD40-L). Additionally, the effect of catheter ablation on the levels of the aforementioned biomarkers was also examined. In this prospective study, plasma samples were collected from patients with AF at baseline prior to ablation and at 1 and 3 months postablation. There was a statistically significant increase in CD40-L at baseline in patients with AF compared to control ( P = .0034). There was a statistically significant decrease in CD40-L levels postablation at both 1 month ( P < .0001) and 3 months ( P < .0001) compared to baseline. Baseline levels of PAI-1 were elevated compared to the control group (mean 19.55 ± 2.17 ng/mL vs 4.85 ± 0.41 ng/mL) and a statistically significant decrease in circulating PAI-1 levels 1 month postablation ( P = .05) was noted compared to preablation levels. These data suggest that inflammation plays an important role in the pathogenesis of AF and that these cellular mediators are modulated by catheter ablation.

Comparison of the Efficacy of Empiric Thoracic Vein Isolation for the Treatment of Paroxysmal and Persistent Atrial Fibrillation in Patients Without Structural Heart Disease

INTRODUCTION

The guidelines suggest that an adjuvant substrate modification in addition to pulmonary vein isolation (PVI) may be needed for persistent atrial fibrillation (PerAF) assuming that catheter ablation is less successful for PerAF than paroxysmal AF (PAF). To revisit the above assumption, we compared the outcome of the same catheter ablation strategy between PAF and PerAF.

METHODS AND RESULTS

Two hundred and thirty-three consecutive patients (mean age 60 ± 10 years, 53 PerAF and 8 long-lasting PerAF) without structural heart disease underwent catheter ablation of AF by the same strategy using an empiric thoracic vein isolation (a wide circumferential PVI plus empiric superior vena cava isolation) as a major part of the strategy without any adjuvant substrate modification. The duration of AF in the patients with PerAF was 6 ± 4 months. During 25 ± 10 months of follow-up after single procedures, 71 (30%) patients had atrial tachyarrhythmia recurrences without antiarrhythmic drugs. A Kaplan-Meier analysis of the recurrence-free survival rate after a single procedure and after repeat procedures revealed no significant difference between the patients with PAF and those with PerAF (log-rank, P = 0.38 and P = 0.27, respectively). A Cox regression multivariate analysis of the variables including the age, gender, PerAF, body mass index, left ventricular ejection fraction, and left atrial volume index demonstrated that none of the variables were an independent predictor of an atrial tachyarrhythmia recurrence after a single ablation procedure.

CONCLUSION

In patients without underlying heart disease, the procedural outcome of an empiric thoracic vein isolation is comparable for PAF and PerAF.

Investigation of the atrial conduction time measured by tissue Doppler imaging at the left atrial appendage and the actual electrical conduction time: consideration of left atrial remodeling in atrial fibrillation patients

PURPOSE

The atrial conduction time measured by echocardiography using tissue Doppler imaging (TDI) has been reported as a predictive factor of left atrial (LA) remodeling. We investigated the P wave to LA appendage (LAA) conduction time defined by transthoracic echocardiography using TDI (P-LAA TDI), and directly compared the actual LA electrical conduction time determined by the electrophysiological data. Additionally, we confirmed the clinical utility of the P-LAA TDI by examining the relationship to the electroanatomical LA remodeling data.

METHODS

Sixty-three AF patients (22 paroxysmal AF, 41 persistent AF) underwent ablation and electroanatomical LA mapping. The P-LAA TDI was measured after the ablation and was compared with the electrophysiological data during sinus rhythm, including the actual electrical conduction time.

RESULTS

A strong linear correlation (r = 0.776, p < 0.001, y = 1.28x + 49) was observed between the P-LAA TDI (161 ± 24 ms) and electrophysiological P-LAA time (87 ± 15 ms). The P-LAA TDI was also strongly correlated with the LA volume (173 ± 52 ml, r = 0.632, p < 0.001) and LA conduction velocity index (1.07 ± 0.19 mm/ms, r = -0.735, p < 0.001), but less to the focal anterior-LVA region surface area (2.2 [0.4-5.0] cm², r = 0.380, p = 0.002). Additionally, a stepwise multiple linear regression demonstrated that both the LA volume and LA conduction velocity index were strongly associated with the value of the P-LAA TDI (p < 0.001).

CONCLUSIONS

The P-LAA TDI was useful for estimating the actual electrophysiological conduction time and represented both electrical and anatomical LA remodeling.

Atrial Fibrillation-Mediated Upregulation of miR-30d Regulates Myocardial Electrical Remodeling of the G-Protein-Gated K(+) Channel, IK.ACh

BACKGROUND

Atrial fibrillation (AF) begets AF in part due to atrial remodeling, the molecular mechanisms of which have not been completely elucidated. This study was conducted to identify microRNA(s) responsible for electrical remodeling in AF.

METHODS AND RESULTS

The expression profiles of 1205 microRNAs, in cardiomyocytes from patients with persistent AF and from age-, gender-, and cardiac function-matched control patients with normal sinus rhythm, were examined by use of a microRNA microarray platform. Thirty-nine microRNAs differentially expressed in AF patients' atria were identified, including miR-30d, as a candidate responsible for ion channel remodeling by in silico analysis. MiR-30d was significantly upregulated in cardiomyocytes from AF patients, whereas the mRNA and protein levels ofCACNA1C/Cav1.2 andKCNJ3/Kir3.1, postulated targets of miR-30d, were markedly reduced.KCNJ3/Kir3.1 expression was downregulated by transfection of the miR-30 precursor, concomitant with a reduction of the acetylcholine-sensitive inward-rectifier K(+)current (IK.ACh).KCNJ3/Kir3.1 (but notCACNA1C/Cav1.2) expression was enhanced by the knockdown of miR-30d. The Ca(2+)ionophore, A23187, induced a dose-dependent upregulation of miR-30d, followed by the suppression ofKCNJ3mRNA expression. Blockade of protein kinase C signaling blunted the [Ca(2+)]i-dependent downregulation of Kir3.1 via miR-30d.

CONCLUSIONS

The downward remodeling ofIK.AChis attributed, at least in part, to deranged Ca(2+)handling, leading to the upregulation of miR-30d in human AF, revealing a novel post-transcriptional regulation ofIK.ACh. (Circ J 2016; 80: 1346-1355).

Impact of Catheter Ablation for Paroxysmal Atrial Fibrillation in Patients With Sick Sinus Syndrome - Important Role of Non-Pulmonary Vein Foci

BACKGROUND

The clinical efficacy of catheter ablation (CA) for paroxysmal atrial fibrillation (PAF) in patients with sick sinus syndrome (SSS) and the mechanism and predictors of recurrence are not yet completely elucidated.

METHODS AND RESULTS

Of 963 consecutive patients who underwent PAF ablation during the study period, a total of 108 patients with SSS (SSS group) and 108 matched controls without SSS (non-SSS group) were followed up. During the follow-up period (mean, 32.8±17.5 months), the SSS group had significantly higher AF recurrence rate since the last procedure than the non-SSS group (26.9% vs. 12.0%; P=0.02). The SSS group had significantly higher prevalence of non-pulmonary vein (non-PV) foci than the non-SSS group (25.9% vs. 13.9%; P=0.027). On multivariate analysis congestive heart failure (HR, 13.7; 95% CI: 1.57-119; P=0.02) and non-PV foci (HR, 5.75; 95% CI: 1.69-19.6; P=0.005) were independent predictors of recurrence following CA in the SSS group. In the SSS group, 88 patients had bradycardia-tachycardia syndrome without prior permanent pacemaker implantation. Of these, 6 required pacemaker implantation because of AF and sinus pause recurrence.

CONCLUSIONS

Patients with SSS are at higher risk of AF recurrence after CA. Non-PV foci are associated with AF recurrence following PAF with SSS.

Impact of an Empiric Isolation of the Superior Vena Cava in Addition to Circumferential Pulmonary Vein Isolation on the Outcome of Paroxysmal Atrial Fibrillation Ablation

The safety and efficacy of an empiric superior vena cava isolation (SVCI) in addition to circumferential pulmonary vein isolation (CPVI) in patients with paroxysmal atrial fibrillation (PAF) have not been clarified. A total of 186 consecutive patients who underwent catheter ablation of PAF were included. All patients underwent a CPVI. Patients in the first half underwent an additional SVCI only if SVC-triggered AF or rapid SVC activity was observed during the procedure (n = 93, as-needed SVCI, group I), and those in the second half underwent an empirical SVCI after the CPVI (n = 93, empiric SVCI, group II). The CPVI was successfully performed in all patients. An SVCI was performed in 8 of 93 patients (9%) in group I and 81 of the 93 patients (87%) in group II. In the remaining 12 patients in group II, an SVCI was not performed because of the lack of SVC potentials. During a mean follow-up of 27 ± 12 months, the atrial tachyarrhythmia recurrence rate after a single ablation procedure in the patients in group II was lower than that in group I (44% vs 23%, p = 0.035). A Cox regression multivariate analysis demonstrated that an empiric SVCI was an independent predictor of an atrial tachyarrhythmia recurrence after a single ablation procedure (odds ratio: 0.57, 95% confidence interval 0.31 to 0.999; p = 0.049). Neither sinus node injury nor any injury to the phrenic nerve was observed. In conclusion, an empiric SVCI in addition to the CPVI improved the outcome of AF ablation in patients with PAF without any additional adverse effects.

Predictive value of various Doppler-derived parameters of atrial conduction time for successful atrial fibrillation ablation

Various Doppler-derived parameters of left atrial electrical remodeling have been demonstrated to predict recurrence of atrial fibrillation (AF) after AF ablation. The aim of this study was to compare three Doppler-derived measures of atrial conduction time in patients undergoing AF ablation, and to investigate their predictive value for successful procedure. In 32 prospectively enrolled patients undergoing the first AF ablation, atrial conduction time was estimated by measuring the time delay between the onset of P-wave on the surface ECG to the peak of the a′-wave on the pulsed-wave Doppler and color-coded tissue Doppler imaging of the left atrial lateral wall, and to the peak of the A-wave on the pulsed-wave Doppler of the mitral inflow. There was a significant difference in the baseline atrial conduction time measured by different echocardiographic techniques. Most (88%) patients had normal or only mildly dilated left atrium. At 6 months, 12 patients (38%) had recurrent AF/atrial tachycardia. The duration of history of AF was the only predictor of AF/atrial tachycardia recurrence following the first AF ablation (P=0.024; OR 1.023, CI 1.003–1.044). A combination of normal left atrial volume and history of paroxysmal AF of ≤48 months was associated with the best outcome. Predictive value of the Doppler derived parameters of atrial conduction time may be reduced in the early stages of left atrial remodeling. Future studies may determine which echocardiographic parameter correlates best with the extent of left atrial remodeling and is most predictive of successful AF ablation.

Topographic variability of the left atrium and pulmonary veins assessed by 3D-CT predicts the recurrence of atrial fibrillation after catheter ablation

BACKGROUND

Catheter ablation (CA) is an established therapy for atrial fibrillation (AF). However, the assessment of anatomical information and predictors of AF recurrence remain unclear. We investigated the relationship between anatomical information on the left atrium (LA) and pulmonary veins (PVs) from three-dimensional computed tomography images and the recurrence of AF after CA.

METHODS

Sixty-seven consecutive AF patients (mean age: 62±10 years, median AF history: 42 (12; 60) months, mean LA size: 41±7 mm, paroxysmal: 56%) underwent CA and were followed for 19±10 months. The segmented surface areas (antral, posterior, septal, and lateral) and dimensions (between the anterior and posterior walls, the right inferior PV and mitral annulus [MA], the right superior PV and MA, the left superior PV and MA, and the mitral isthmus) of the LA were evaluated three dimensionally using the NavX system. The cross-sectional areas of the PVs were also evaluated.

RESULTS

After the follow-up period, 49 patients (73%) remained free from AF. A multivariate analysis showed that the diameter of the mitral isthmus and cross-sectional area of the right upper PV were associated with AF recurrence (odds ratio: 1.070, CI: 1.02-1.12, p=0.001; odds ratio: 0.41, CI: 0.21-0.77, p=0.006).

CONCLUSION

Enlargement of the mitral isthmus and a smaller right superior PV cross-sectional area were associated with AF recurrence.

QTc Interval Prolongation Predicts Arrhythmia Recurrence After Catheter Ablation of Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy

BACKGROUND

In hypertrophic cardiomyopathy (HCM) patients complicated with atrial fibrillation (AF), catheter ablation has been recommended as a treatment option. Meanwhile, prolongation of QTc interval has been linked to an increased AF incidence in the general population and to poor outcomes in HCM patients. However, whether QTc prolongation predicts arrhythmia recurrence after AF ablation in the HCM population remains unknown.

METHODS AND RESULTS

Thirty-nine HCM patients undergoing primary AF ablation were enrolled. The ablation strategy included bilateral pulmonary vein isolation (PVI) for paroxysmal AF (n=27) and PVI plus left atrial roof, mitral isthmus and tricuspid isthmus linear ablations for persistent AF (n=12). Pre-procedural QTc was corrected by using the Bazett's formula. At a 14.8-month follow up, 23 patients experienced atrial tachyarrhythmia recurrence. Recurrent patients had longer QTc than non-recurrent patients (461.0±28.8 ms vs. 434.3±18.2 ms, P=0.002). QTc and left atrial diameter (LAD) were independent predictors of recurrence. The cut-off value of QTc 448 ms predicted arrhythmia recurrence with a sensitivity of 73.9% and a specificity of 81.2%. A combination of LAD and QTc (global chi-squared=13.209) was better than LAD alone (global chi-squared=6.888) or QTc alone (global chi-squared=8.977) in predicting arrhythmia recurrence after AF ablation in HCM patients.

CONCLUSIONS

QTc prolongation is an independent predictor of arrhythmia recurrence in HCM patients undergoing AF ablation, and might be useful for identifying those patients likely to have a better outcome following the procedure.

Catheter ablation of atrial fibrillation in patients with severely impaired left ventricular systolic function

Little is known about the outcome of catheter ablation of atrial fibrillation (AF) in patients with heart failure (HF) and a severely reduced left ventricular ejection fraction (LVEF). We aimed to clarify the effectiveness of catheter ablation of AF in patients with a severely low LVEF. This retrospective study included 18 consecutive patients with HF and an LVEF of ≤ 35 % who underwent catheter ablation of AF. We investigated the clinical parameters, echocardiographic parameters and the incidence of hospitalizations for HF. During a median follow-up of 21 months (IQR, 13-40) after the final procedure (9 with repeat procedures), 11 patients (61 %) maintained sinus rhythm (SR) (6 with amiodarone). The LVEF and NYHA class significantly improved at 6 months after the CA in 12 patients (67 %) who were in SR or had recurrent paroxysmal AF (from 25.8 ± 6.3 to 37.0 ± 11.7 %, P = 0.02, and from 2.3 ± 0.5 to 1.5 ± 0.7, P < 0.01, respectively) but not in patients who experienced recurrent persistent AF. The patients with SR or recurrent paroxysmal AF had significantly fewer hospitalizations for HF than those with recurrent persistent AF after the AF ablation (log-rank test; P < 0.01). Catheter ablation of AF improved the clinical status in patients with an LVEF of ≤ 35 %. A repeat ablation procedure and amiodarone were often necessary to obtain a favorable outcome.

Left atrial appendage flow velocity and time from P-wave onset to tissue Doppler-derived A' predict atrial fibrillation recurrence after radiofrequency catheter ablation

BACKGROUND

Atrial fibrillation (AF) is associated with atrial remodeling. We investigate the abilities of preprocedural echocardiographic parameters reflecting atrial remodeling to predict AF recurrence after radiofrequency catheter ablation (RFCA) for paroxysmal AF (PAF).

METHODS

Preprocedural echocardiographic parameters were measured during sinus rhythm in 105 patients with PAF undergoing RFCA. Electrical remodeling was assessed by the time from the onset of the P-wave to the peak A'-wave on the tissue Doppler imaging (PA-TDI), functional remodeling was assessed by the left atrial appendage flow velocity (LAAFV), and structural remodeling was assessed by the left atrial volume index (LAVI). PA-TDI, LAAFV, and LAVI values were divided into tertiles, and their abilities to predict AF recurrence were assessed using Cox regression analysis.

RESULTS

AF recurrence occurred in 39/105 (37.1%) patients. After adjustment for confounders, the rate of AF recurrence was significantly higher in the highest tertile of PA-TDI compared with the lowest tertile (≥151.3 msec vs. <131.0 msec; hazard ratio [HR]: 2.477, 95% confidence interval [CI]: 1.031-5.950; P = 0.042), and in the lowest tertile of LAAFV compared with the highest tertile (<48.5 cm/sec vs. ≥64.9 cm/sec; HR: 2.680, 95% CI: 1.136-6.318; P = 0.024). The risk of AF recurrence was also higher in the highest tertile of LAVI (≥34.2 mL/m(2) ) compared with the lowest tertile, but this difference was not significant (HR: 2.146, 95% CI: 0.834-5.523; P = 0.113).

CONCLUSIONS

LAAFV (reflecting functional remodeling) and PA-TDI (reflecting electrical remodeling) are independent predictors of AF recurrence after RFCA for PAF.