Meta-analysis of the effect of radiofrequency catheter ablation on left atrial size, volumes and function in patients with atrial fibrillation

Changes in pulmonary vein size and narrowing depend on the cardiac cycle before and after pulmonary vein isolation

Accurate measurement of the pulmonary vein dimension (PVD) is important for determining stenosis and efficacy following pulmonary vein isolation (PVI). Little is known about the quantitative evaluation of the impact of the cardiac cycle on pulmonary vein (PV) morphology before and after PVI. This study aims to investigate variations in the ostial size of the PV during the cardiac cycle before and after PVI and the effect of the cardiac cycle on PV stenosis and reduction rate using cardiac computed tomography (CT). Sixty-eight patients with atrial fibrillation who underwent cardiac CT before and after PVI at our institution between 23 January 2021 and 5 February 2022 were retrospectively analyzed. The maximum and minimum PVD were measured at each segment before and after the PV. Each PV was evaluated according to the PVD reduction rate (ΔPVD), calculated as follows: (1 - post-PVD/pre-PVD) × 100 (%). The average dimension of all PVs at the end-diastolic frame was significantly reduced compared to that at the end-systolic frame before PVI. The average dimensions of the right superior and right inferior PV at the end-diastolic frame were significantly reduced compared with those at the end-systolic frame following PVI. The average reduction rate of dimension-classified stenosis of PVs, except for the left inferior PV at the end-diastolic frame, was significantly reduced compared with that at the end-systolic frame. The cardiac cycle affects PVD assessment, including PV stenosis, after PVI. PVD measurement is recommended to be unified to the end-systolic frame of the cardiac cycle to avoid underestimating PV stenosis before and after PVI, ensuring appropriate management and follow-up.

Impact of nocturnal blood pressure dipping on recurrence of atrial fibrillation after pulmonary vein isolation

Lack of the typical nocturnal blood pressure (BP) fall, i.e non-dipper, has been known as a cardiovascular risk. However, the influence of non-dipper on atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) has been unclear. We investigated the clinical impact of non-dipping as evaluated by 24-hour ambulatory BP monitoring on the long-term outcome of AF recurrence post-PVI in 76 AF patients with a history of increased BP. The PVI procedure was successful in all 76 patients (mean age, 66±9years; antihypertensive medication, 89%; non-paroxysmal AF, 24%). Twenty patients had AF recurrence during a median follow-up of 1138 days. There was no difference in BP levels between the AF recurrence and non-recurrence groups (average 24 h systolic BP:126 ± 17 vs.125 ± 14 mmHg; P = 0.84). On the other hand, the patients with non-dipper had a higher AF recurrence than those with dipper (38.9% vs.15.0%; P = 0.018). In Cox hazard analysis adjusted by age, non-paroxysmal AF and average 24-hr systolic BP level, the non-dipper was an independent predictor of AF recurrence (HR 2.78 [95%CI:1.05-7.34], P = 0.039). Non-dipper patients had a larger left atrial (LA) volume index than the dipper patients (45.9 ± 17.3 vs.38.3 ± 10.2 ml/m2, P = 0.037). Among the 58 patients who underwent high-density voltage mapping in LA, 11 patients had a low-voltage area (LVA) defined as an area with a bipolar voltage < 0.5 mV. However, there was no association of LVA with non-dipper or dipper (22.2% vs.16.1%, P = 0.555). Non-dipper is an independent predictor of AF recurrence post-PVI. Management of abnormal diurnal BP variation post-PVI may be important.

Combining catheter ablation and left atrial appendage occlusion in high-risk patients with atrial fibrillation: a propensity score-matched analysis

BACKGROUND

The safety and efficacy of a combined approach of catheter ablation (CA) and left atrial appendage occlusion (LAAO) compared to LAAO alone remain unknown.

METHODS

Patients with atrial fibrillation (AF) at increased stroke risk who underwent LAAO were divided into either combined (CA and LAAO) procedures or LAAO alone group. Propensity score matching was utilized to balance baseline characteristics. The primary endpoint of the study was a composite of death, thromboembolic events, major bleeding, heart failure (HF) rehospitalization, and major periprocedural complications.

RESULTS

A total of 707 AF patients who underwent LAAO were included. After 1:1 propensity score matching, 166 patients who underwent LAAO alone (n = 83) or the combined procedure (n = 83) were analyzed. Successful LAAO was achieved in all (100%) patients, with a low incidence of periprocedural complications in both groups (2.4% vs. 4.8%, LAAO vs. combined, p = 0.68). The incidence of peri-device leak post-LAAO was significantly higher in the combined group (25.3% vs. 43.4%, p = 0.01). After a median follow-up of 2 years, there were no significant differences in the rates of the primary composite endpoint between the two strategies (22.2% vs. 14.3%, HR: 1.24 [95% CI: 0.51-2.97], p = 0.63). However, the rate of HF rehospitalization was significantly lower in the combined group (19.6% vs. 3.6%, HR: 4.89 [95% CI: 1.50-15.97], p = 0.024).

CONCLUSIONS

Combining CA and LAAO in a "one-stop" approach is safe and brings additional benefits in relieving symptoms of heart failure, although peri-device leak was more common compared to LAAO alone.

Differences in postablation cardiac MRI scar between radiofrequency and cryoballoon ablation: A DECAAF II subanalysis

INTRODUCTION

Pulmonary vein isolation (PVI) using radiofrequency (RF) and cryoballoon (Cryo) ablation are standard approaches for rhythm control in patients with symptomatic atrial fibrillation. Both strategies create scars in the left atrium (LA). There have been few studies investigating the difference in scar formation between patients undergoing RF and Cryo using cardiac magnetic resonance (CMR) imaging.

METHODS

The current study is a subanalysis of the control arm of the Delayed-Enhancement MRI Determinant of Successful Catheter Ablation of Atrial Fibrillation study (DECAAF II). The study was a multicenter, randomized, controlled, single-blinded trial that evaluated atrial arrhythmia recurrence (AAR) between PVI alone and PVI plus CMR atrial fibrosis-guided ablation. Preablation CMR and 3- to 6-month postablation CMR were obtained to assess baseline LA fibrosis and scar formation, respectively.

RESULTS

Of the 843 patients randomized in the DECAAF II trial, we analyzed the 408 patients in the primary analysis control arm that received standard PVI. Five patients received combined RF and Cryo ablations, so they were excluded from this subanalysis. Of the 403 patients analyzed, 345 underwent RF and 58 Cryo. The average procedure duration was 146 min for RF and 103 min for Cryo (p = .001). The rate of AAR at ~15 months occurred in 151 (43.8%) patients in the RF group and 28 (48.3%) patients in the Cryo group (p = .62). On 3-month post-CMR, the RF arm had significantly more scar (8.8% vs. 6.4%, p = .001) compared to Cryo. Patients with ≥6.5% LA scar (p < .001) and ≥2.3% LA scar around the PV antra (p = .01) on 3-month post-CMR had less AAR independent of the ablation technique. Cryo caused a greater percentage of right and left pulmonary vein (PV) antral scar (p = .04, p = .02) and less non-PV antral scar (p = .009) compared to RF. On Cox regression, Cryo patients free of AAR had a greater percentage of left PV antral scar (p = .01) and less non-PV antral scar (p = .004) compared to RF free of AAR.

CONCLUSION

In this subanalysis of the control arm of the DECAAF II trial, we observed that Cryo formed a more significant percentage of PV antral scar and less non-PV antral scar compared to RF. Post ablation LA scar ≥6.5% predicted freedom from AAR, independent of ablation technique. These findings may have prognostic implications in ablation technique selection and freedom from AAR.

The first experience of a hybrid approach in the surgical treatment of atrial fibrillation

Background: Atrial fibrillation (AF) is the most common arrhythmia in clinical practice and is associated with an increased risk of death, progression of heart failure, and the development of cardiogenic thromboemboli. Despite the significant success in the management of AF in the paroxysmal form, the results of the treatment for patients with persistent forms of AF remain unsatisfactory. Though the surgical approach provides higher rates of efficiency regarding the restoration of a sinus rhythm, transmural lesions are not always attainable, as a result, the rate of AF recurrence in the long-term period remains fairly high. It is also impossible to create ablative patterns to the mitral and tricuspid valves during thoracoscopic epicardial ablation, which can cause the development of recurrent AF, perimitral and typical atrial flutter. Therefore, the development of hybrid approaches combining the advantages of catheter and thoracoscopic techniques is an urgent task of contemporary surgical and interventional arrhythmology. Aims: to estimate the immediate results of a hybrid approach in the management of patients with persistent AF. Methods: We report the first experience of a hybrid treatment of patients with persistent AF. 6 patients aged 53-64 years (1 female, 5 males) were included in the study. At the first stage, thoracoscopic epicardial bipolar ablation was performed (modified GALAXY protocol); the second stage (in 3 to 6 months after the thoracoscopic stage) included an intracardiac electrophysiological study with three-dimensional endocardial mapping followed by endocardial ablation. Results: The thoracoscopic stage of the hybrid treatment included ablation according to the box lesion scheme using a bipolar irrigation equipment. No lethal outcomes and severe, life-threatening complications were registered. The duration of the inpatient period was 510 hospital-days. The 2nd stage of the hybrid treatment was limited to intracardiac electrophysiological examination only in 2 patients. In 4 patients, epicardial radiofrequency ablation was complemented by endocardial radiofrequency exposure. In 3 of the 4 patients who underwent endocardial radiofrequency ablation, catheter ablation of the mitral and cavotricuspid isthmus was required because of the induction of perimitral and typical flutter, respectively. After the 2nd stage of the hybrid treatment, at the time of discharge all the patients maintained a stable sinus rhythm. There were no severe complications or lethal outcomes. Conclusion: a hybrid approach in the AF management is a safe and effective method of treatment, which combines the advantages of minimally invasive surgery and endocardial intervention in patients with persistent AF. The technique is safe and has acceptable short-term results.

Restoring Sinus Rhythm Reverses Cardiac Remodeling and Reduces Valvular Regurgitation in Patients With Atrial Fibrillation

BACKGROUND

Cardiac chamber remodeling in atrial fibrillation (AF) reflects the progression of cardiac rhythm and may affect functional regurgitation.

OBJECTIVES

The purpose of this study was to explore the 3-dimensional echocardiographic variables of cardiac cavity remodeling and the impact on functional regurgitation in patients with AF with/without sinus rhythm restoration at 12 months.

METHODS

A total of 117 consecutive patients hospitalized for AF were examined using serial 3-dimensional transthoracic echocardiography at admission, at 6 months, and at 12 months (337 examinations).

RESULTS

During follow-up, 47 patients with active restoration of sinus rhythm (SR) (through cardioversion and/or ablation) had a decrease in all atrial indexed volumes (Vi), end-systolic (ES) right ventricular (RV) Vi, an increase in end-diastolic (ED) left ventricular Vi, and an improvement in 4-chambers function (P < 0.05). Patients with absence/failure of restoration of SR (n = 39) had an increase in ED left atrial Vi and ED/ES RV Vi without modification of 4-chambers function, except for a decrease in left atrial emptying fraction (P < 0.05). Patients with spontaneous restoration of SR (n = 31) had no changes in Vi or function. The authors found an improvement vs baseline in severity of functional regurgitation in patients with active restoration of SR (tricuspid and mitral regurgitation) and in spontaneous restoration of SR (tricuspid regurgitation) (P < 0.05). In multivariable analysis, right atrial and/or left atrial reverse remodeling exclusively correlated with intervention (cardioversion and/or ablation) during 12-month follow-up.

CONCLUSIONS

Management of AF should focus on restoration of SR to induce anatomical (all atrial Vi, ES RV Vi) and/or functional (4 chambers) cardiac cavity reverse remodeling and reduce severity of functional regurgitation. (Thromboembolic and Bleeding Risk Stratification in Patients With Non-valvular Atrial Fibrillation [FASTRHAC]; NCT02741349).

Relationship between the time point of left atrial size change and the outcomes of radiofrequency catheter ablation

PURPOSE

The change in the left atrial anteroposterior diameter (LAD) after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) has become an independent factor in predicting the postoperative curative effect; however, whether the specific time point of this change is related to the postoperative curative effect is unclear. The purpose of this study was to explore the correlation between the specific time point of LAD change and the recurrence of AF 1 year after RFCA.

METHODS

Patients with AF who underwent RFCA in our hospital from July 2016 to May 2020 were enrolled in the study. The patients were divided into four groups according to the time point when the LAD decreased by 10% after RFCA: group A, first month after RFCA; group B, second month after RFCA; group C, third month after RFCA; group D, unchanged or changed > 3 months after RFCA.

RESULTS

In the multivariable Cox analyses, the duration of AF, LAD, and persistent AF were independent risk factors for the recurrence of AF. The recurrence rate of AF 1 year after RFCA were significantly lower in groups A (odds ratio [OR], 0.160; 95% confidence interval [CI]: 0.073-0.352; P < 0.001) and C (OR, 0.388; 95% CI: 0.156-0.963; P = 0.041) than in the control group.

CONCLUSIONS

Reduction of LAD within 3 months after operation predicts the success rate of RFCA, with reduction within 1 month after operation having a higher success rate. This indicates the necessity of treatment in patients with AF who do not experience an early reduction in the LAD after RFCA.

Current evidence on the safety and efficacy of combined atrial fibrillation ablation and left atrial appendage closure

PURPOSE OF REVIEW

Combined atrial fibrillation (AF) ablation and left atrial (LA) appendage (LAA) closure (LAAC) has been practiced for management of both the symptoms and the high stroke risk of AF. The purpose of this review is to review recent evidence regarding the combined procedure.

RECENT FINDINGS

Newly acquired long-term data of combined AF ablation and LAAC supplied satisfactory evidence on the safety and efficacy of the combined procedure. Studies also showed LA structural remodeling following combined procedure was mainly affected by sinus rhythm status post catheter ablation, not by LAAC. A cost-effectiveness study revealed that combined procedure was a cost-effective therapeutic option in symptomatic AF patients with high stroke and bleeding risk. Due to recent evidence of high incidences of LAA thrombus formation after LAA electrical isolation (LAAEI) and benefit of LAAC after LAAEI, an extended combined procedure of standard AF ablation plus LAAEI and LAAC was considered as a potential therapeutic option for persistent AF patients with high stroke risk.

SUMMARY

In conclusion, combined AF ablation and LAAC serve as a promising option for patients with symptomatic AF and high risk of stroke and/or bleeding.

The significance of pulmonary veins isolation radiofrequency time and the evolution of left atrium volume on a twelve-year observational follow-up of paroxysmal atrial fibrillation patients

Aims

Pulmonary vein isolation (PVI) is the treatment of choice of paroxysmal atrial fibrillation (PAF). However, radiofrequency delivery at extra-PV sites may be additionally required. We compared clinical and procedural characteristics of patients undergoing PVI alone versus adjunctive extra-PV substrate modification, at first procedure and repeat procedures for AF recurrence.

Methods

587 patients with PAF undergoing radiofrequency (RF) ablation were retrospectively included. Extra-PV ablation was performed in case of sustained AF despite PVI, or at re-do procedures without PV conduction recovery. Demographic, clinical and electrophysiological predictors of survival without re-intervention were analysed in patients’ groups having undergone one (G1), two (G2) or three or more procedures (G3).

Results

At baseline procedure, PV RF ablation time was shorter in G1 compared to G2/G3 whereas extra-PV RF ablation time was greater in G3 compared to G1. The proportion of patients requiring PV re-isolation decreased with repeat procedures. Smaller LA before procedure 1 (p1) or p2 was associated with PV reconnection at p2. Conversely larger LA before p1 was associated with extra-PV substrate modification at p2. Late re-do procedure timing (>1yr) was associated with increasing LA volume. Only longer PV and total RF time predicted poorer survival free from AF without re-intervention.

Conclusion

Longer PV RF time predicted requirement for re-ablation during follow-up. Smaller LA size predicted an increased probability of PV reconnection and decreased extra-PV substrate modification at p2. LA size decreased in patients undergoing early re-intervention, whereas it increased in patients undergoing re-intervention later on suggesting ongoing remodelling or progression.

Clinical Outcomes of low-voltage area-guided left atrial linear ablation for non-paroxysmal atrial fibrillation patients

Background

The therapeutic effect of low-voltage area (LVA)-guided left atrial (LA) linear ablation for non-paroxysmal atrial fibrillation (non-PAF) is uncertain. We aimed to investigate the efficacy of LA linear ablation based on the preexisting LVA and its effects on LA reverse remodeling in non-PAF patients.

Methods

We retrospectively evaluated 145 consecutive patients who underwent radiofrequency catheter ablation for drug-refractory non-PAF. CARTO-guided bipolar voltage mapping was performed in atrial fibrillation (AF). LVA was defined as sites with voltage ≤ 0.5 mV. If circumferential pulmonary vein isolation couldn’t convert AF into sinus rhythm, additional LA linear ablation was performed preferentially at sites within LVA.

Results

After a mean follow-up duration of 48 ± 33 months, 29 of 145 patients had drugs-refractory AF/LA tachycardia recurrence. Low LA emptying fraction, large LA size and high extent of LVA were associated with AF recurrence. There were 136 patients undergoing LA linear ablation. The rate of linear block at the mitral isthmus was significantly higher via LVA-guided than non-LVA-guided linear ablation. Patients undergoing LVA-guided linear ablation had larger LA size and higher extent of LVA, but the long-term AF/LA tachycardia-free survival rate was higher than the non-LVA-guided group. The LA reverse remodeling effects by resuming sinus rhythm were noted even in patients with a diseased left atrium undergoing extensive LA linear ablation.

Conclusions

LVA-guided linear ablation through targeting the arrhythmogenic LVA and reducing LA mass provides a better clinical outcome than non-LVA guided linear ablation, and outweighs the harmful effects of iatrogenic scaring in non-PAF patients.

Heart failure with preserved ejection fraction: An alternative paradigm to explain the clinical implications of atrial fibrillation

Atrial fibrillation (AF) is associated with exercise intolerance, stroke, and all-cause mortality. However, whether this can be solely attributable to the arrhythmia itself or alternative mechanisms remains controversial. Heart failure with preserved ejection (HFpEF) commonly coexists with AF and may contribute to the poor outcomes associated with AF. Indeed, several invasive hemodynamic studies have confirmed that patients with AF are at increased risk of underlying HFpEF and that the presence of HFpEF may have important prognostic implications in these patients.

Mechanistically, AF and HFpEF are closely linked. Both conditions are driven by the presence of common cardiovascular risk factors and are associated with left atrial (LA) myopathy, characterized by mechanical and electrical dysfunction. Progressive worsening of this left atrial (LA) myopathy is associated with both increased AF burden and worsening HFpEF. In addition, there is growing evidence to suggest that worsening LA myopathy is associated with poorer outcomes in both conditions and that reversal of the LA myopathy could improve outcomes. In this review article, we will present the epidemiologic and mechanistic evidence underlying the common coexistence of AF and HFpEF, discuss the importance of a progressive LA myopathy in the pathogenesis of both conditions, and review the evidence from important invasive hemodynamic studies. Finally, we will review the prognostic implications of HFpEF in patients with AF and discuss the relative merits of AF burden reduction vs HFpEF reduction in improving outcomes of patients with AF and HFpEF.

Reduction in left atrial and pulmonary vein dimensions after ablation therapy is mediated by scar

BACKGROUND

Ablative pulmonary vein isolation (PVI) decreases pulmonary vein (PV) and left atrial (LA) dimensions in atrial fibrillation (AF) patients. These changes are attributed to reverse structural remodeling following sinus rhythm restoration but evidence is lacking. We hypothesized that the downsizing is directly caused by the ablative energy and subsequent scar formation.

METHODS

We studied cardiac magnetic resonance imaging in 21 paroxysmal AF patients before and 3 months after successful PVI and in healthy sheep (n = 12) before and after PVI of the right PV only.

RESULTS

PVI decreased the PV diameter in patients and sheep by 11.0(10.3) and 9.2(11.0)%, (p < 0.001 and p = 0.020), respectively. The control left PV in sheep were unchanged. A linear correlation existed between the extent of PV scar and PVI-induced decrease in PV diameter in patients.After PVI, the LA volume decreased (103(38) vs. 92(31)ml, pre- vs. post-ablation, respectively, p = 0.006), while the right atrial (RA) volume was unchanged in patients. A decrease in active emptying fraction after ablation (26.5(10.7) vs. 21.8(10.6)%, pre- vs. post-ablation, p = 0.031) was associated with reduced contractility of the PV walls (p = 0.004). The contractility of the LA walls was unaltered (p = 0.749).

CONCLUSION

The ablation-induced PV diameter reduction was similar in patients with AF and healthy sheep without AF and was associated with PV scar extent. The volume only decreased in LA and not RA after PVI, and wall contractility decreased only in ablated sites. Therefore, the PVI-induced atrial downsizing is caused by the ablative energy and subsequent scar formation.

P wave duration ≥150 ms predicts poor left atrial function and ablation outcomes in non-paroxysmal atrial fibrillation

BACKGROUND

It remains unknown whether P wave duration (PWD) ≥ 150 ms measured after extensive radiofrequency catheter ablation (RFCA) can identify non-paroxysmal atrial fibrillation (non-PAF) patients at increased risk of atrial tachyarrhythmia recurrence. We investigated the predicting power of PWD and its association with left atrial (LA) reverse remodeling in patients with non-PAF undergoing pulmonary vein isolation with LA linear ablation.

METHODS

We retrospectively evaluated 136 patients who underwent RFCA for drug-refractory non-PAF. Electroanatomic mapping was acquired during AF. Low-voltage area (LVA) was defined as an area with bipolar voltage ≤0.5 mV. Electrocardiography and echocardiography were performed during sinus rhythm 1 day and 3 months after RFCA. PWD was measured using amplified 12‑lead electrocardiography. Prolonged PWD was defined as maximum PWD ≥ 150 ms.

RESULTS

Over a mean follow-up duration of 48 ± 35 months, 28 patients experienced atrial tachyarrhythmia recurrence. PWD was positively correlated with LVA (r = 0.527, p < 0.001) and inversely correlated with LA emptying fraction (r = -0.399, p < 0.001). PWD was shortened and LA emptying fraction (LAEF) was increased in patients without atrial tachyarrhythmia recurrence during follow-up. Atrial tachyarrhythmia-free survival was significantly more likely in patients without a prolonged PWD (83.5% vs 60.7%, p = 0.002). Multivariate analysis showed that LAEF and PWD were independent predictors of atrial tachyarrhythmia recurrence.

CONCLUSIONS

PWD ≥ 150 ms measured after RFCA can identify patients with non-PAF at increased risk of atrial tachyarrhythmia recurrence. PWD is correlated with LVA and LAEF and reflects LA reverse remodeling.

Persistence of left atrial abnormalities despite left atrial volume normalization after successful ablation of atrial fibrillation

BACKGROUND

Left atrial volume index (LAVI) of >34 mL/m2 is the cutoff value for identifying an enlarged left atrium. The definition of left atrial (LA) reverse remodeling after atrial fibrillation (AF) ablation is undetermined. We hypothesized that patients with LA dilatation who achieve normal LA volume (LAVI<34 mL/m2) after AF ablation have better long-term outcomes than those who do not. Furthermore, we investigated whether patients with a normal LA volume can also achieve normal LA function with AF ablation.

METHODS

We enrolled 140 AF patients with baseline LAVI of ≥34 mL/m2, without AF recurrence for 1 year after the initial AF ablation. We acquired conventional and speckle-tracking echocardiographic parameters within 24 hour and at 1 year after the procedure. To define the normal range of LA function, age- and sex-matched controls without a history of AF were also enrolled.

RESULTS

After restoration of sinus rhythm, LA structural and functional parameters significantly improved, and 75 patients (54%) had normal LA volume. During a median follow-up of 44 (31-61) months, 32 patients (23%) experienced a late recurrence of AF (AF recurrence >1 year). Patients who achieved normal LA volume after AF ablation had fewer late recurrences than those who did not (P < .01). However, LA abnormalities, especially LA dysfunction, persisted in AF patients even when the LA volume was normalized compared with controls.

CONCLUSION

Patients who achieved normal LA volume had better long-term outcomes of AF ablation than those who did not; however, LA abnormalities persisted even after successful ablation of AF.

The Blinding Period Following Ablation Therapy for Atrial Fibrillation: Proarrhythmic and Antiarrhythmic Pathophysiological Mechanisms

Atrial fibrillation (AF) causes heart failure, ischemic strokes, and poor quality of life. The number of patients with AF is estimated to increase to 18 million in Europe in 2050. Pharmacological therapy does not cure AF in all patients. Ablative pulmonary vein isolation is recommended for patients with drug-resistant symptomatic paroxysmal AF but is successful in only about 60%. In patients in whom ablative therapy is successful on the long term, recurrence of AF may occur in the first weeks to months after pulmonary vein ablation. The early recurrence (or delayed cure) of AF is not understood but forms the basis for the generally accepted 3-month blinding (or blanking) period after ablation therapy, which is not included in the evaluation of the eventual success rate of the procedures. The underlying pathophysiological processes responsible for early recurrence and the delayed cure are unknown. The implicit assumption of the blinding period is that the AF mechanism in this period is different from the ablation-targeted AF mechanism (ectopy from the pulmonary veins). In this review, we evaluate the temporary and long-lasting pro- and antiarrhythmic effects of each of the pathophysiological processes and interventions (necrosis, ischemia, oxidative stress, edema, inflammation, autonomic nervous activity, tissue repair, mechanical remodeling, and use of antiarrhythmic drugs) occurring in the blinding period that can modulate AF mechanisms. We propose that stretch-reducing ablation scar is a permanent antiarrhythmic mechanism that develops during the blinding period and is the reason for delayed cure.

One-stop strategy for treatment of atrial fibrillation: feasibility and safety of combining catheter ablation and left atrial appendage closure in a single procedure

BACKGROUND

Catheter ablation is effective in restoring sinus rhythm and left atrial appendage closure (LAAC) is increasingly used for stroke prevention in patients with atrial fibrillation (AF). We aimed to observe the feasibility and safety of performing AF ablation and LAAC in a single (one-stop) procedure.

METHODS

Consecutive AF patients who underwent the combined procedure of AF ablation and LAAC with WATCHMAN device between March 2017 and September 2018 were prospectively enrolled. Baseline and intra-procedural parameters were evaluated. Three-month and subsequent 1-year follow-up were performed in all and earlier-enrolled subjects, respectively.

RESULTS

A total of 178 AF patients (94 males, 68.9 ± 8.1 years) underwent the one-stop procedure with CHA2DS2-VASc score 3.3 ± 1.5 and HAS-BLED score 1.6 ± 1.0, respectively. Pulmonary vein isolation was achieved in all patients while additional linear ablation was applied if the operator deemed necessary, yielding immediate ablation success rate of 98.9% (176/178). In the subsequent LAAC, satisfactory seal (residual leak <5 mm) was achieved in all patients. One stroke and four cardiac perforations occurred peri-operatively. At 3-month follow-up, sinus rhythm and satisfactory seal were maintained in 153/178 (86.0%) and 178/178 (100%) patients, respectively. One stroke and one delayed cardiac tamponade occurred, while no device-related thrombus or device migration was observed. During the 1-year follow-up for the earlier enrolled subjects, 52/72 (72.2%) of the patients maintained sinus rhythm. There was no stroke or systemic embolism observed.

CONCLUSION

Combining catheter ablation and LAAC in a single procedure can be successfully and safely performed in non-valvular AF patients of Chinese population.

Treatment-Related Changes in Left Atrial Structure in Atrial Fibrillation: Findings From the CABANA Imaging Substudy

[Figure: see text].

A randomized ablation-based atrial fibrillation rhythm control versus rate control trial in patients with heart failure and high burden atrial fibrillation: The RAFT-AF trial rationale and design

Heart failure (HF) and atrial fibrillation (AF) are 2 cardiac conditions that are increasing in prevalence and incidence. The 2 conditions frequently coexist, and are associated with increased morbidity and mortality. Catheter ablation of AF has been successfully performed in patients with HF, with an improvement in HF and AF, when compared to amiodarone, but further data is required to compare this to rate control. OBJECTIVES: The primary objective is to determine whether AF treated by catheter ablation, with or without antiarrhythmic drugs reduces all-cause mortality and hospitalizations for HF as compared with rate control in patients with HF and a high burden AF. METHODS: This is a multi-center prospective randomized open blinded endpoint (PROBE) study. Patients with NYHA class II-III HF (HF with reduced ejection fraction (<35%) or HF with preserved ejection fraction), and high burden AF are included in the trial. Patients are randomized to either rate control or catheter ablation-based AF rhythm control in a 1:1 ratio. Patients in the rate control group receive optimal HF therapy and rate control measures to achieve a resting hazard ratio (HR) < 80 bpm and 6-minute walk HR < 110 bpm. Patients randomized to catheter ablation-based AF rhythm control group receive optimal HF therapy and one or more aggressive catheter ablation, which include PV antral ablation and LA substrate ablation with or without adjunctive antiarrhythmic drug. The primary outcome is a composite of all-cause mortality and hospitalization for heart failure defined as an admission to a health care facility. The sample size is 600. Enrolment has been completed.

The effect of left atrial remodeling after cryoballoon ablation and radiofrequency ablation for paroxysmal atrial fibrillation

Background

Cryoballoon ablation (CBA) and radiofrequency ablation (RFA) are the most common procedures used to treat refractory atrial fibrillation (AF) and are performed through pulmonary vein isolation (PVI). Studies have shown that CBA can approximately match the therapeutic effects of RFA against AF. However, few studies have investigated the difference between CBA and RFA of the effects on left atrial remodeling for paroxysmal AF.

Objective

Atrial remodeling is considered pivotal to the occurrence and development of AF, therefore we sought to assess the influence of atrial remodeling in patients with paroxysmal AF after CBA and RFA in this study.

Methods

In this nonrandomized retrospective observational study, we enrolled 328 consecutive patients who underwent CBA or RFA for refractory paroxysmal AF in May 2014 to May 2017 in our hospital. After propensity score matching, 96 patients were included in the CBA group, and 96 were included in the RFA group. Patients were asked to undergo a 12‐lead electrocardiogram, a 24‐h Holter monitor, and an echocardiogram and to provide their clinical history and symptoms at 6 months and 1, 2, and 3 years postprocedurally. Electrical remodeling of the left atrium was assessed by P wave dispersion (Pdis); structural remodeling was assessed by the left atrium diameter (LAD) and left atrial volume index (LAVI) during scheduled visits.

Results

As of January 2020, compared with baseline, at 1 year, 2 years, and 3 years after ablation, the average changes in Pdis (∆Pdis), LAD (∆LAD), and LAVI (∆LAVI) were significant in both the CBA and RFA groups. Six months after ablation, ∆Pdis, ∆LAD, and ∆LAVI were greater in the CBA group than in the RFA group. There was no significant difference between the two groups in AF/flutter recurrence, but the AF/flutter‐free survival time of CBA group may be longer than RFA group after 2 years after ablation. A higher ∆Pdis, ∆LAD, or ∆LAVI at 1 year after ablation may increase AF/flutter‐free survival.

Conclusions

Although CBA and RFA are both effective in left atrial electrical and structural reverse‐remodeling in paroxysmal AF, CBA may outperform RFA for both purposes 6 months after ablation. However, during long‐term follow‐up, there was no significant intergroup difference.

Long-standing Persistent Atrial Fibrillation Ablation: How do You Perform it?

Catheter ablation of long-standing persistent atrial fibrillation (LSPAF) presents unique challenges and the lack of large body of evidence surrounding management makes for disagreement and different approaches for treatment. Outlined is a case example that offers a comprehensive approach to ablation in patients with LSPAF that consists of risk factor management, an ablation strategy, a rigorous trigger protocol and follow-up rhythm monitoring. The case presented highlights management of this difficult population as best guided by current evidence and our experience. Ablation treatment and management strategies will continue to evolve with further randomized data and the advent of improved ablation technologies.

Role of sST2 in predicting recurrence of atrial fibrillation after radiofrequency catheter ablation

INTRODUCTION

Atrial fibrosis is associated with atrial fibrillation (AF) recurrence after ablation. This study aims to determine the relationship between soluble ST2 (sST2), a profibrotic biomarker, and AF recurrence after radiofrequency catheter ablation (RFCA).

METHODS

AF patients referred for RFCA were consecutively included from October 2017 to May 2019. Baseline characteristics were collected, and sST2 levels were determined before ablation. Left atrial substrate mapping was performed after circumferential pulmonary vein isolation under sinus rhythm, and substrate was modified in low-voltage zones. A second procedure was recommended under recurrence.

RESULTS

Two hundred fifty-eight patients (146 males, average age 61.0 ± 8.8) were included. After a medium follow-up of 13.5 months, 52 patients (20.2%) had recurrence and received a second procedure. Preoperative sST2 level in patients with recurrence was significantly higher than that in patients without (31.3 ng/mL vs 20.3 ng/mL, P < .001). In those undergoing second ablation, sST2 level in patients with new abnormalities during endocardial mapping was significantly higher than that in patients without (43.0 ng/mL vs 22.1 ng/mL, P < .001). An sST2 level over 26.9 ng/mL could predict AF recurrence with new abnormalities during endocardial mapping with a sensitivity of 100% and a specificity of 75.9%. Multiple logistic analysis showed that sST2 level was an independent predictor of AF recurrence with new abnormalities during endocardial mapping (P < .001).

CONCLUSIONS

sST2 level was associated with new abnormalities during endocardial mapping and recurrence of AF after ablation. It might have significance in choosing treatment strategies for AF.

The impact of catheter ablation of atrial fibrillation on the left atrial volume and function: study using three-dimensional echocardiography

Purpose

The exact correlation between the baseline left atrial (LA) volume (LAV) and atrial fibrillation (AF) radiofrequency catheter ablation (RFCA) outcomes and changes to the LA after AF RFCA has not yet been fully understood. We sought to evaluate the serial changes in the LAV and LA function after RFCA using 3D echocardiography.

Methods

Consecutive patients who received RFCA of paroxysmal (PAF) or persistent AF (PeAF) at our center between January 2013 and March 2016 were included. Real-time 3D apical full-volume images were acquired, and a 3D volumetric assessment was performed using an automated three-beat averaging method. The LAV index (LAVI) was calculated and the LA ejection fraction (LAEF) was calculated as [LAVmax − LAVmin]/LAVmax.

Results

Ninety-nine total patients were enrolled, and the mean age was 58.0 ± 8.2 years and 75 (74.7%) were male. There were 59 (59.6%) PAF patients and the remaining 40 (40.4%) had PeAF. AF recurred in 5 of 59 (8.5%) PAF and in 10 of 40 (25%) PeAF patients. The LAVImax increased on 1 day, decreased at 3 months, and then increased again at 1 year but was lower than that at baseline. The LAEF changes were similar to the volume changes but were more prominent in PeAF than PAF patients. The baseline 3D LAVImax was an independent predictor of AF recurrence after RFCA and the cut-off value was 44.13 ml/m².

Conclusion

In our study, even after 3 months of scar formation due to ablation, structural remodeling of the LA continued. The changes were more prominent in the non-recurrent, PeAF patients.

Electronic supplementary material

The online version of this article (10.1007/s10840-019-00696-8) contains supplementary material, which is available to authorized users.

Left Atrial Function after Atrial Fibrillation Cryoablation Concomitant to Minimally Invasive Mitral Valve Repair: A Pilot Study on Long-Term Results and Clinical Implications

Background and Objectives: Surgical atrial fibrillation (AF) ablation concomitant to minimally invasive mitral valve repair has been proven to offer improved short- and long-term sinus rhythm (SR) maintenance compared to mitral valve surgery only. The objective of the present study was to explore, by thorough echocardiographic assessment, long-term morphological and functional left atrial (LA) outcomes after this combined surgical procedure. Materials and Methods: From October 2006 to November 2015, 48 patients underwent minimally invasive mitral valve repair and concomitant surgical AF cryoablation. Results: After 3.8 ± 2.2 years, 30 (71.4%) of those completing the follow-up (n = 42, 87.5%) presented SR. During follow-up, four (9.5%) patients suffered from cerebrovascular accidents and two of these subjects had a long-standing persistent AF relapse and were in AF at the time of the event, while the other two were in SR. An echocardiographic study focused on LA characteristics was performed in 29 patients (69.0%). Atrial morphology and function (e.g., maximal LA volume indexed to body surface area and total LA emptying fraction derived from volumes) in patients with stable SR (60.6 ± 13.1 mL/mq and 25.1 ± 7.3%) were significantly better than in those with AF relapses (76.8 ± 16.2 mL/mq and 17.5 ± 7.4%; respectively, p = 0.008 and p = 0.015). At follow-up, patients who suffered from ischemic cerebral events had maximal LA volume indexed to body surface area 61 ± 17.8 mL/mq, with total LA emptying fraction derived from volumes 23.6 ± 13.7%; patients with strokes in SR showed very enlarged LA volume (>70 mL/mq). Conclusions: AF cryoablation concomitant with minimally invasive mitral valve repair provides a high rate of SR maintenance and this relates to improved long-term morphological and functional LA outcomes. Further prospective studies are needed to define the cut-off values determining an increase in the risk for thromboembolic complications in patients with restored stable SR.

Biatrial remodelling in atrial fibrillation: A three-dimensional and strain echocardiography insight

BACKGROUND

Atrial remodelling has been poorly investigated in atrial fibrillation (AF), and few studies have focused on biatrial remodelling.

AIM

To evaluate right atrial (RA) and left atrial (LA) remodelling in AF using global atrial reservoir strain and three-dimensional (3D) atrial volumes, according to rhythm outcome at mid-term follow-up.

METHODS

Two-dimensional and 3D transthoracic echocardiography (TTE) were performed within 24hours after admission (M0) and at 6-month follow-up (M6) in patients admitted for AF. RA and LA variables were assessed: body surface area-indexed maximum 3D volume (Max 3D RA Vol_i, Max 3D LA Vol_i) and minimum 3D volume (Min 3D RA Vol_i, Min 3D LA Vol_i); atrial emptying fraction (3D RAEF, 3D LAEF); atrial expansion index (3D RAEI, 3D LAEI); and global RA and LA reservoir strain.

RESULTS

Forty-eight consecutive patients were included prospectively. Three groups were identified depending on rhythm at M0 and M6: AF at M0 and sinus rhythm (SR) at M6 (AF-SR) in 25 (52.1%) patients; AF at M0 and AF at M6 (AF-AF) in 13 (27.1%) patients; and SR at M0 (spontaneous cardioversion before first TTE) and SR at M6 (SR-SR) in 10 (20.8%) patients. Between M0 and M6 in the AF-SR group, we found: significant decreases in Max 3D RA Vol_i (P=0.020), Min 3D RA Vol_i (P=0.0008), Max 3D LA Vol_i (P=0.001) and Min 3D LA Vol_i (P=0.0021); significant increases in 3D RAEF (P=0.037) and 3D RAEI (P=0.034); no significant differences in 3D LAEF and 3D LAEI; and significant increases in global RA and LA reservoir strain (both P<0.0001). There was no significant difference with regard to these variables in the AF-AF and SR-SR groups.

CONCLUSION

3D volume and strain analyses were useful in the evaluation of RA and LA reverse remodelling in successfully cardioverted patients with AF.

Determinants of postoperative left atrial structural reverse remodeling in patients undergoing combined catheter ablation of atrial fibrillation and left atrial appendage closure procedure

INTRODUCTION

Catheter ablation of atrial fibrillation (AFCA) and left atrial appendage closure (LAAC) exert opposite effects on left atrial (LA) size. We aim to observe the net impact of combined AFCA and LAAC strategy on LA size and explore those factors which might affect the postprocedure LA structural remodeling.

METHODS

A total of 53 patients, who underwent combined AFCA and Watchman LAAC in our center from March to December 2017, were enrolled. Atrial fibrillation (AF) recurrence was monitored after the procedure. Left atrial volume (LAV) and left atrial appendage volume (LAAV) were measured by Mimics based on dual-source computed tomography images.

RESULTS

At 6 months, sinus rhythm (SR) was maintained in 79.2% patients. LAV was significantly reduced (130.2 ± 36.3 mL to 107.1 ± 30.0 ml; P < .001) in SR maintenance group, but not in AF recurrence group (138.8 ± 39.3 mL to 137.9 ± 36.9 mL; P = .671). In SR group, preoperative LAAV/LAV ratio (B = -0.894; P = .015), NT-proBNP (B = 0.005; P = .019) and left ventricular ejection fraction (LVEF) (B = -0.778; P < .001) could interactively affect the extent of postoperative LA structural reverse remodeling, among which LAAV/LAV ratio could independently predict the significance of reverse remodeling (≥15% reduction in LAV) (OR, 0.56; 95% CI, 0.34-0.90; P = .018). A preoperative LAAV/LAV ratio less than 7.1% is indicative of significant LA structural reverse remodeling in this patient cohort.

CONCLUSIONS

LA structural reverse remodeling could be evidenced in patients with maintained SR following combined AFCA and LAAC. Smaller LAAV/LAV ratio, higher NT-proBNP or lower LVEF at baseline are associated with more significant LA structural reverse remodeling, while LAAV/LAV ratio can predict the significance of the process after one-stop treatment.

Atrial ectopy after pulmonary vein isolation and left heart reverse remodeling in patients with atrial fibrillation

BACKGROUND

Maintenance of sinus rhythm after pulmonary vein isolation (PVI) for atrial fibrillation (AF) is associated with left atrial (LA) and ventricular (LV) reverse remodeling, although the degree varies among individuals. We hypothesized that frequent premature atrial complex (PAC) after PVI may attenuate the left heart reverse remodeling benefited from maintenance of sinus rhythm.

METHODS

We included 82 AF patients who underwent first-time PVI and 24-h Holter recordings at 6 months after PVI. All patients had no AF recurrence before this time. The number of PAC was categorized into tertiles: <90, 90-488 and >488 PACs/day. All patients underwent two-dimensional echocardiography and serum plasma B-type natriuretic peptide (BNP) measurement before and 6 months after PVI. LA reverse remodeling was defined as ≥15% decrease in LA volume index.

RESULTS

There was no significant difference in the baseline characteristics among the PAC tertiles except for sex. Six months after PVI, LA volume index, LV mass index, and serum BNP levels were significantly decreased in lower and middle PAC tertiles (all P < .05), whereas no significant changes were observed in upper PAC tertile. Frequency of LA reverse remodeling was significantly lower in upper tertile of PAC compared with middle and lower tertiles (22.2%, 57.1%, and 59.3%, P < .001). Baseline LA volume index, changes in LV mass index, and the frequency of PAC were independently associated with LA reverse remodeling (all P < .05).

CONCLUSIONS

Frequent PAC after PVI was associated with less left heart reverse remodeling in AF patients even without AF recurrence.

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.

Stiff Left Atrial Syndrome; Prospects and Possibilities. Retrospective Analysis and Review of the Literature

OBJECTIVES

Stiff left atrial syndrome is an intriguing clinical phenomena characterized by reduced left atrial compliance, pulmonary venous hypertension and exacerbations of volume overload. We conducted a retrospective review of patients diagnosed with stiff left atrial syndrome at our center.

METHODS

All patients admitted to our hospital with volume overload and pulmonary venous hypertension who were diagnosed with stiff left atrial syndrome based on evidence by echocardiogram and right heart catheterization between July 2011 and July 2013 were included in this retrospective review.

RESULTS

Twentythree patients (mean age 73 ± 11 years, 39% male and 61% female) were diagnosed with stiff left atrial syndrome at our center. Thirty-five percent had persistent while 39% had permanent atrial fibrillation. Mean duration of atrial fibrillation was 7.6 ± 2.1 years. Forty-three percent of patients had long standing hypertension. There was no mitral regurgitation in 39% of patients while 48% had mild mitral regurgitation. On right heart catheterization, mean right atrial pressure was 12.6±4.8 mm of Hg, mean pulmonary arterial pressure was 33±7.2 mm of Hg, mean pulmonary capillary wedge pressure was 24.8± 4.2mm of Hg while peak V waves were seen at mean of 37.8± 5.3 mm of Hg. Mean left atrial volume index was 49.8±17.1 mL/m 2. After the initial diagnosis with a two year follow- up, there were no readmissions in 65% of patients who were on appropriate diuretic therapy and had regular clinical visits. Frequent readmissions were seen in 35% of patients inspite of appropriate diuretic therapy. All-cause mortality rate was 4.3% at two year follow up.

CONCLUSION

In patients with stiff left atrial syndrome, the presence of left atrial dilation, long standing atrial fibrillation and hypertension are the key factors associated with pathogenesis and clinical course. Close follow up and monitoring of volume status is essential to prevent hospital readmissions and improve long term prognosis.

Predictors of the paroxysmal atrial fibrillation recurrence following cryoballoon-based pulmonary vein isolation: Assessment of left atrial volume, left atrial volume index, galectin-3 level and neutrophil-to-lymphocyte ratio

Background

Cryoballoon-based pulmonary vein isolation (PVI) is a treatment option for atrial fibrillation (AF). Left atrial volume (LAV) and left atrial volume index (LAVi) are important parameters for long term success of PVI. Galectin-3 (Gal-3) and neutrophil to lymphocyte ratio (N/L ratio) are biomarkers to demonstrate the cardiac fibrosis and remodelling.

Methods

50 patients with symptomatic PAF despite ≥1 antiarrhythmic drug(s), who underwent PVI were enrolled. LAV, LAVi, Gal-3 and N/L ratio were calculated before ablation and after ablation at 6 and 12 months. According to AF recurrence patients were divided into two groups, recurrent AF (n = 14) and non-recurrent AF (n = 36).

Results

In both groups (recurrent and non-recurrent), initial and 12 months follow-up LAV values were 41.39 ± 18.13 ml and 53.24 ± 22.11 ml vs 48.85 ± 12.89 ml and 42.08 ± 13.85 (p = 0.037). LAVi were 20.9 ± 8.91 ml/m2 and 26.85 ± 11.28 ml/m2 vs 25.36 ± 6.21 and 21.87 ± 6.66 (p = 0.05) for recurrent and non-recurrent AF groups, respectively. In both groups PVI had no significant effect on serum Gal-3 levels and N/L ratio during 12 months follow-up. The comparison between two groups at the end of 12th month showed Gal-3 values of 6.66 ± 4.09 ng/ml and 6.02 ± 2.95 ng/ml (p = 0.516), N/L ratio values of 2.28 ± 1.07 10³/μl and 1.98 ± 0.66 10³/μl (p = 0.674).

Conclusion

LAV and LAVi are useful to predict the remodelling of the left atrium and AF recurrence after cryoballoon-based PVI. However, biomarkers such as Gal-3 and N/L ratio are not associated with AF recurrence.

Functional improvement after successful catheter ablation for long-standing persistent atrial fibrillation

Aims

Identifying patients who benefit from restored sinus rhythm (SR) would optimize the selection of candidates for ablation of long-standing persistent atrial fibrillation (LSPAF). This prospective study sought to identify the hitherto unknown factors associated with global functional improvement after successful radiofrequency catheter ablation of LSPAF.

Methods and results

In 171 LSPAF patients (84% of the total consecutive 203 patients) who were examined in SR 12 months after ablation, the individual per cent change from baseline value in maximum oxygen consumption at exercise test (VO2 max), left ventricular ejection fraction (LVEF), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and five-dimensional descriptive system (EQ-5D) of quality-of-life questionnaire were classified in quartiles by 0 (worse) to 3 (best) grades. The individual grades were summed into a composite score (SCORE, 0 … 12) reflecting global functional improvement. Significant improvement in VO2 max (3.4 ± 4.7 mL/kg/min), LVEF (7.5 ± 9.1%), NT-proBNP (-861 ± 809 pg/mL), and EQ-5D (0.7 ± 0.12) was observed (all P < 0.0001). On multivariable analysis, younger age (P = 0.001), male gender (P = 0.02), timely post-ablation left atrial appendage (LAA) outflow (P = 0.005) with improvement in outflow velocity (P = 0.0002), and withdrawal of Class I/III antiarrhythmic drugs (P < 0.05) were positively and independently correlated with the SCORE.

Conclusions

Younger male patients benefited most from catheter ablation of LSPAF. Delayed or non-improved LAA outflow and inability to discontinue Class I/III antiarrhythmic medication reduced the post-ablation functional improvement.

Acute Hemodynamic and Tissue Effects of Cryoballoon Ablation on Pulmonary Vessels: The IVUS-Cryo Study

Background

Cryoballoon‐based pulmonary vein isolation (CB‐PVI) has been widely used for the treatment of atrial fibrillation. Although generally safe and effective, the procedure may be associated with pulmonary vein (PV) stenosis and bronchial or esophageal injury. The mechanisms leading to these complications have not been studied in detail. Our aim was to examine acute effects of cryoballoon on the pulmonary vessel and right heart pressures as well as PV wall morphology.

Methods and Results

In 8 patients (5 men, mean age 55±14 years) undergoing CB‐PVI, pressure in each PV was measured by catheter located inside the PV directly before and after CB‐PVI. The right atrial, right ventricular, and pulmonary artery pressures as well as pulmonary arterial wedge capillary pressure in the pulmonary artery branch corresponding to target PV were also measured. Morphological changes in PVs were assessed using intravascular ultrasonography.

There were no significant differences in PV pressures before and after ablation. The pulmonary arterial wedge capillary pressure significantly increased during cryoapplication (left superior: 20±10 versus 29±8.5 mm Hg, P=0.004; left inferior: 24±10 versus 32±6 mm Hg, P=0.012; right superior: 25±9 versus 35±10 mm Hg, P=0.002; right inferior: 24±10 versus 37±12 mm Hg, P=0.0036). The right atrial and pulmonary artery pressures increased significantly after CB‐PVI (9±6 versus 13±8 mm Hg, P=0.004, and 20±9 versus 24±10 mm Hg, P=0.048, respectively). Intravascular ultrasonography showed acute edema and dissection‐like changes causing relative lumen narrowing in 90% of PVs.

Conclusions

CB‐PVI causes significant rise in pulmonary artery and right atrial pressures as well as PV wall damage. The clinical significance of these findings warrants further investigations.

Active Atrial Function and Atrial Scar Burden After Multiple Catheter Ablations of Persistent Atrial Fibrillation

BACKGROUND

Extensive and repeated substrate modification (SM) is frequently performed as an ablation strategy in persistent atrial fibrillation (persAF). The effect of these extended ablation strategies on atrial function has not been investigated sufficiently so far. The purpose was to assess atrial function by cardiac magnetic resonance (CMR) and its association with left atrial (LA) scar burden by electroanatomical voltage-mapping after multiple persAF ablation procedures.

METHODS

We included 16 persAF patients who had ≥2 SM procedures and a control group (CG) of 21 persAF patients without prior ablation. CMR was performed in sinus rhythm at least 4 weeks after the last cardioversion. Active left and right (RA) atrial emptying fractions (AEF) as well as peak active left atrial appendage (LAA) emptying velocities were obtained by CMR flow measurements. Furthermore, LA scar burden was quantified on electroanatomical voltage maps by the portion of points with local voltage amplitude <0.2 mV.

RESULTS

We found median LA-AEF to be lower (13 [9-22] vs 32 [26-36] %, P < 0.001) and median LA scar burden to be higher (40 [20-68] vs nine [3-18] %, P < 0.05) in the SM group compared with the CG. Furthermore, a significant correlation was found between mean LA voltage and LA-AEF (r² = 0.62, P < 0.001). No significant differences were detected with respect to median RA-AEF (41 [28-48] vs 47 [35-50] %, P = 0.43) and median peak LAA emptying velocities (30 [16-40] vs 17 [13-28] cm/s, P = 0.07).

CONCLUSIONS

Active LA function is preserved but significantly impaired and associated with ablation-related LA scar burden after multiple extensive persAF ablations.

Changes in Left Atrial Transport Function in Patients Who Maintained Sinus Rhythm After Successful Radiofrequency Catheter Ablation for Atrial Fibrillation: A 1-Year Follow-Up Multislice Computed Tomography Study

BACKGROUND

Functional remodeling of left atrium (LA) after radiofrequency catheter ablation (RFCA) for atrial fibrillation (AF) has not been fully elucidated. This study aimed to determine the impact of RFCA on LA transport function in patients who maintained sinus rhythm (SR) after AF ablation.

METHODS AND RESULTS

A total of 96 patients (paroxysmal AF [PAF] = 52) who maintained SR during 1 year after AF ablation were enrolled. Multislice computed tomography was performed to determine LA volume (LAV) and LA emptying fraction (LAEF) at pre-RFCA and 1-year post-RFCA. Creatine kinase-MB (CK-MB) and troponin-T levels were analyzed 1-day post-RFCA. At 1-year post-RFCA, mean LAV and LAEF decreased in overall patients. Based on LAEF change (ΔLAEF) cutoff of 5.0%, LAEF reduced in 41 patients (worsened group) and improved or showed no change in 55 patients (preserved group). Compared with preserved group, worsened group had a higher proportion of PAF, higher levels of CK-MB and troponin-T, and additional LA ablation. ΔLAEF was inversely correlated with CK-MB and troponin-T levels. Subgroup analysis showed that LAEF significantly decreased in PAF patients who underwent additional LA ablation. Multivariate analysis revealed that high baseline LAEF and additional LA ablation were independent predictors for worsened LAEF.

CONCLUSIONS

Although SR was maintained for 1 year after AF ablation, LAEF as well as LAV decreased. The extent of LAEF deterioration was significantly associated with the amount of iatrogenic myocardial damage. Our data indicate that extensive atrial ablation may lead to LA functional deterioration, especially in patients with PAF.

Comparisons of the underlying mechanisms of left atrial remodeling after repeat circumferential pulmonary vein isolation with or without additional left atrial linear ablation in patients with recurrent atrial fibrillation

BACKGROUND

Radiofrequency catheter ablation (RFCA) is a potentially curative treatment for atrial fibrillation (AF), however, whether or not additional left atrial (LA) linear ablation for recurrent AF adversely affects LA remodeling is unknown.

METHODS

Thirty-eight patients experiencing AF recurrence after the 1st circumferential pulmonary vein isolation (CPVI) underwent a repeat RFCA, including 20 and 18 patients receiving a repeat CPVI (group I) or CPVI plus LA linear ablation (group II), respectively. 2-D echocardiography was performed during sinus rhythm within 24h, at 1-m and 6-m after RFCA. Longitudinal strains and strain rate were measured with speckle-tracking echocardiography. The standard deviation of contraction duration was defined as LA mechanical dispersion.

RESULTS

One and two patients experienced AF recurrence after the 2nd RFCA in group I and II, respectively (P=NS). The 1st CPVI with AF recurrence did not reduce LA size significantly in two groups. After a repeat CPVI, LA diameter but not LA maximal and minimal volume was significantly reduced in group I; additional LA linear ablation significantly decreased LA diameter, maximal and minimal volume in group II. However, there was no significant difference in LA emptying function, global and segmental LA strain and strain rate among the baseline, 1-m and 6-m follow-up in two groups. RFCA did not significantly increase LA mechanical dispersion regardless of the AF ablation strategies.

CONCLUSIONS

In patients with recurrent AF, a successful repeat CPVI with or without additional LA linear ablation reduced LA size without significant deleterious effects on LA function and mechanical dispersion.

Pulmonary Hypertension due to Radiofrequency Catheter Ablation (RFCA) for Atrial Fibrillation: The Lungs, the Atrium or the Ventricle?

Atrial fibrillation is the most common heart rhythm disorder in United States, characterised by rapid and irregular beating of both the atria resulting in the similar ventricular response. While rate and rhythm control using pharmacological regimens remain the primary management strategies in these patients, radiofrequency catheter ablation (RFCA) is rapidly rising as an alternative modality of treatment. Increase in the incidence of RFCA has shed light on complications associated with this procedure. Pulmonary hypertension (PH) is one of the long-term complications that has been observed postcatheter ablation. There have been multiple mechanisms which have been proposed to explain these elevated pulmonary pressures. These include the involvement of the lungs due to pulmonary vein stenosis, pulmonary vein occlusion and, rarely, pulmonary embolism. Radiofrequency catheter ablation can also lead to scarring of the atrium which can cause left atrial diastolic dysfunction leading to elevated pulmonary pressures. Recently, it was also proposed that elevated pulmonary pressure was related to the unmasking of left ventricular diastolic dysfunction occurring after this procedure. In this article, we review all the mechanisms that are associated with the development of pulmonary hypertension in patients undergoing RCFA for atrial fibrillation and the approach to diagnosis and management of such patients.

Prognostic value of left atrial function in systemic light-chain amyloidosis: a cardiac magnetic resonance study

BACKGROUND

Cardiac involvement in systemic light-chain amyloidosis (AL) imparts an adverse impact on outcome. The left atrium (LA), by virtue of its anatomical location and muscular wall, is commonly affected by the amyloid process. Although LA infiltration by amyloid fibrils leads to a reduction in its pump function, the infiltration of the left ventricular (LV) myocardium results in diastolic dysfunction with subsequent increase in filling pressures and LA enlargement. Even though left atrial volume (LAV) is an independent prognostic marker in many cardiomyopathies, its value in amyloid heart disease remains to be determined. In addition, few data are available as to the prognostic value of LA function in systemic AL. Using cardiac magnetic resonance (CMR), the current study aims to assess the prognostic significance of the maximal LAV and total LA emptying fraction (LAEF) in patients with AL.

METHODS AND RESULTS

Fifty-four consecutive patients (age 66 ± 10 years, 59% males) with confirmed systemic AL and mean LV ejection fraction of 60 ± 12% underwent CMR. As compared with patients with no or minimal cardiac involvement (Mayo Clinic [MC] stage I), those at moderate and high risk (MC stages II and III) had significantly larger indexed maximal LAV (36 ± 15 vs. 46 ± 13 vs. 52 ± 19 mL/m(2), P = 0.03) and indexed minimal LAV (20 ± 6 vs. 34 ± 11 vs. 44 ± 17 mL/m(2), P < 0.001), lower LAEF (42 ± 9 vs. 26 ± 13 vs. 16 ± 9%, P < 0.0001) but similar LVEF. Furthermore, myocardial late gadolinium enhancement (LGE) was more frequent and significantly associated with lower LAEF. LAEF was also significantly lower in symptomatic (NHYA ≥ II, 22 ± 14%) as compared with asymptomatic patients (NYHA class I, 33 ± 13%, P = 0.006). Two-year survival rate was lower in patients with LAEF ≤ 16% as compared with those with LAEF > 16% (37 ± 11 vs. 94 ± 4%, P = 0.001). In multivariate analysis, lower LAEF remained independently associated with a higher risk of 2-year mortality (HR = 1.08 per 1% decrease, 95% CI: 1.02-1.15, P = 0.003).

CONCLUSION

In patients with systemic AL, LAEF as assessed by CMR is associated with NYHA functional class, MC stage, myocardial LGE and 2-year mortality.

Cardiovascular Imaging in the Electrophysiology Laboratory

In recent years, rapid technological advances have allowed the development of new electrophysiological procedures that would not have been possible without the parallel development of imaging techniques used to plan and guide these procedures and monitor their outcomes. Ablation of atrial fibrillation is among the interventions with the greatest need for imaging support. Echocardiography allows the appropriate selection of patients and the detection of thrombi that would contraindicate the intervention; cardiac magnetic resonance imaging and computed tomography are also essential in planning this procedure, by allowing a detailed anatomical study of the pulmonary veins. In addition, in cardiac resynchronization therapy, echocardiography plays a central role in both patient selection and, later, in device adjustment and in assessing the effectiveness of the technique. More recently, ablation of ventricular tachycardias has been established as a treatment option; this would not be possible without planning using an imaging study such as cardiac magnetic resonance imaging of myocardial scarring.

Stiff Left Atrial Syndrome: A Complication Undergoing Radiofrequency Catheter Ablation for Atrial Fibrillation

Radiofrequency catheter ablation for atrial fibrillation is an effective approach for treating atrial fibrillation. Its complications have attracted much attention, of which the stiff left atrial syndrome is a recently discovered complication that has not been completely understood. This study aims to investigate the concept, pathologic basis, clinical characteristics, predictors, and treatment protocols of the stiff left atrial syndrome after radiofrequency ablation for atrial fibrillation.

Pre-Procedural Serum Atrial Natriuretic Peptide Levels Predict Left Atrial Reverse Remodeling After Catheter Ablation in Patients With Atrial Fibrillation

OBJECTIVES

This study aimed to investigate the role of atrial natriuretic peptide (ANP) levels to predict left atrial (LA) reverse remodeling in atrial fibrillation (AF) patients.

BACKGROUND

Although LA reverse remodeling after radiofrequency catheter ablation (RFCA) for AF was reported to be associated with favorable outcomes and improvement of LA and left ventricular function, the predictor has not been extensively evaluated.

METHODS

This study included 104 consecutive patients who underwent RFCA for AF. All patients underwent multidetector computed tomography examination and laboratory tests, including measurement of ANP, plasma B-type natriuretic peptide (BNP), and high-sensitivity C-reactive protein (hs-CRP) levels before and 6 months after RFCA. The study population was divided according to the extent of the decrease in the LA volume index at follow-up; responders were defined as patients who exhibited a ≥15% decrease in the LA volume index.

RESULTS

At follow-up, 49 patients (47%) were classified as responders. Pre-procedural serum ANP and BNP levels were significantly higher in the responders than in the nonresponders (both p < 0.01). In the responders, a significant decrease was observed in the log ANP, log BNP, and log hs-CRP levels from baseline to follow-up (all p < 0.01). Multivariate linear regression analysis revealed that log ANP levels before RFCA and maintenance of sinus rhythm during follow-up were independent predictors of LA reverse remodeling (both p < 0.01).

CONCLUSIONS

In this study, 47% of the patients exhibited LA reverse remodeling after RFCA for AF, with a concomitant improvement in serum ANP, BNP, and hs-CRP levels. The pre-procedural ANP level and maintenance of sinus rhythm were independently associated with LA reverse remodeling.

Atrial fibrillation ablation by single ring isolation versus wide antral isolation: Effects on left atrial size and function

BACKGROUND

Pulmonary vein isolation (PVI) by single ring isolation (SRI) has been demonstrated to reduce recurrence of atrial fibrillation (AF) compared to the standard technique of wide antral isolation (WAI). In this study, we examine the differential effect of these techniques on left atrial size and function.

METHODS

We examined left atrial (LA) size (LA maximum and LA minimum volumes) and function (LA emptying fraction and LA expansion index) over a period of 6 months following PVI as measured by transthoracic echocardiography in 187 patients that were enrolled in a randomised controlled trial of SRI vs WAI.

RESULTS

Compared to pre-ablation, at 6 months post-PVI, there was a small decrease in the LA maximum volume in the WAI group (67.3 vs 62.7 mL, p=0.02). The LA size did not change significantly over 6 months in the SRI group. Patients who underwent SRI had a small reduction in the LA expansion index at 6 months post-PVI compared to baseline (80.6 vs 66.6%, p=0.02). LA function did not change significantly over 6 months in the WAI group. However, at 6 months, there was no difference in any measure of LA size or function between the SRI and WAI groups.

CONCLUSIONS

SRI, whilst previously demonstrated to be more effective than WAI in preventing AF recurrence, is associated with minimal adverse effects on left atrial function at medium term follow-up despite the isolation of a larger region of LA myocardium.

Combined catheter ablation for atrial fibrillation and Watchman® left atrial appendage occlusion procedures: Five-year experience

Background

Patients with atrial fibrillation (AF) may benefit from undergoing concomitant interventions of left atrial catheter ablation and device occlusion of the left atrial appendage (LAA) as a two-pronged strategy for rhythm control and stroke prevention. We report on the outcome of combined procedures in a single center case series over a 5-year timeframe.

Methods

Ninety-eight patients with non-valvular AF and a mean CHA₂DS₂-VASc score 2.6±1.0 underwent either first time, or redo pulmonary vein isolation (PVI) procedures, followed by successful implant of a Watchman® device.

Results

All procedures were generally uncomplicated with a mean case time of 213±40 min. Complete LAA occlusion was achieved at initial implant in 92 (94%) patients. Satisfactory LAA occlusion was achieved in 100% of patients at 12 months, with a complete LAA occlusion rate of 86%. All patients discontinued oral anticoagulation. Persistent late peri-device leaks were more frequently associated with device angulation or shoulder protrusion, and were associated with a significantly lower achieved device compression of 12±3% vs. 15±5% (p<0.01) than complete occlusion. One ischemic stroke was recorded over a mean follow-up time of 802±439 days. Twelve months׳ freedom from detectable AF was achieved in 77% of patients.

Conclusions

Combined procedures of catheter ablation for AF and Watchman® LAA implant appear to be feasible and safe, with excellent rates of LAA occlusion achieved and an observed stroke rate of 0.5% per year during mid-term follow-up. Incomplete occlusion was associated with lower achieved device compression and was more frequently associated with suboptimal device position.