Outcomes in Patients Requiring Cardioversion Following Catheter Ablation of Atrial Fibrillation

Outcomes of Cardioversion Post AF Ablation.   Introduction: Early recurrence of atrial tachyarrhythmias is commonly noted after catheter ablation of atrial fibrillation (AF). The long-term outcomes of patients who require cardioversion for persistent AF after AF ablation is not known. This study reports the outcomes of patients who underwent cardioversion for persistent AF or atrial flutter following an AF ablation procedure.
Methods: The patient population comprised 55 patients (mean age 58 ± 10 years, 35% paroxysmal) who underwent catheter ablation of AF and subsequently required electrical cardioversion for persistent AF (45 patients) or atrial flutter (10 patients). Cardioversion was defined as early (within 90 days of the ablation procedure) or late (between 90 and 180 days following ablation).
Results: The mean follow-up duration was 15 ± 8 months. Forty-six of the 55 patients (84%) patients experienced recurrence during follow-up. The average time to recurrence after cardioversion was 37 days. Of the 55 patients, 8 (15%) patients had a complete success, 11 (20%) patients had a partial success and 36 patients (65%) had a failed outcome. Seven of the 43 patients (16%) who underwent early cardioversion had a complete success as opposed to one of 12 patients (8%) who underwent late cardioversion (P = 0.49).
Conclusions: This study shows that >80% of patients who undergo cardioversion for persistent AF or atrial flutter after AF ablation have recurrence. The timing of cardioversion did not affect the outcome. These findings allow clinicians to provide realistic expectations to patients regarding the long-term outcome and/or requirement for a second ablation procedure. (J Cardiovasc Electrophysiol, Vol. 21, pp. 27–32, January 2010)     

Does Left Atrial Volume and Pulmonary Venous Anatomy Predict the Outcome of Catheter Ablation of Atrial Fibrillation?

Introduction: Preprocedural factors may be helpful in selecting patients with atrial fibrillation (AF) for treatment with catheter ablation and in making an assumption regarding their prognosis. The aims of this study were to investigate whether left atrial (LA) volume and pulmonary venous (PV) anatomy, evaluated by computed tomography (CT) prior to ablation, will predict AF recurrence following catheter ablation.
Methods and Results: We included 146 patients (mean age 57 ± 11 years, 83% male) with symptomatic AF (55% paroxysmal, 18% persistent, 27% long-standing persistent). All patients underwent CT scanning prior to catheter ablation to evaluate LA volume and PV anatomy. Circumferential PV isolation was performed guided by Cartomerge electroanatomical mapping. The outcome was defined as complete success, improvement, or failure.
After a mean follow-up of 19 ±7 months, complete success was achieved in 59 patients (40%), and 38 patients (26%) demonstrated improvement. LA volume was found to be an independent predictor of AF recurrence with an adjusted OR of 1.14 for every 10-mL increase in volume (95% CI 1.00–1.29, P = 0.047). PV variations were equally distributed among the different outcomes of the ablation procedure, and therefore univariate analysis did not identify PV anatomy as a predictor of outcome.
Conclusion: LA volume is an independent predictor of AF recurrence after catheter ablation. Additionally, PV anatomy did not have any effect on the outcome. These findings suggest that an assessment of LA volume may be incorporated into the preprocedural evaluation of patients being considered for AF ablation.     

Left atrial contractility is preserved after successful circumferential pulmonary vein ablation in patients with atrial fibrillation

Introduction: Circumferential pulmonary vein ablation (CPVA) for atrial fibrillation (AF) consists of creating extensive lesions in the left atrium (LA). The aim of the study was to evaluate changes in LA contractility after ablation and their relationship with procedure outcome.
Methods and Results: A series of 90 consecutive patients underwent cardiac magnetic resonance imaging (MRI) before and 4–6 months after CPVA. Only patients in sinus rhythm during both imaging acquisitions were included in the study to measure LA end-diastolic (LAmax) and LA end-systolic (LAmin) volumes. Fifty-five patients were finally analyzed (41 men, 52 ± 11 years, 74% paroxysmal AF). During a mean follow-up of 12 ± 7 months and after 1.2 ± 0.3 ablation procedures, 38 patients (69%) were arrhythmia-free (group I), and the remaining 17 patients had recurrences (group II). There was a significant decrease in mean LAmax volume in both groups, whereas mean LAmin volume only decreased in group I. Mean LA ejection fraction (EF) was preserved after CPVA in group I (40 ± 11% vs 38 ± 10%; P = 0.27) but decreased in patients with arrhythmia recurrences (37 ± 10% vs 27 ± 10%; P < 0.001). In fact, LA EF remained stable or increased in 68% of patients without arrhythmia recurrences.
Conclusions: LAmax volume reduction following CPVA occurs regardless of the clinical efficacy of the procedure, whereas mean LAmin volume only decreased in patients without recurrences. LA EF was preserved or even increased in most patients with successful CPVA.     

Does Electrogram Guided Substrate Ablation Add to the Success of Pulmonary Vein Isolation in Patients with Paroxysmal Atrial Fibrillation? A Prospective,Randomized Study

Introduction: Pulmonary vein isolation (PVI) is an established treatment for paroxysmal atrial fibrillation (AF). The ablation of complex fractionated atrial electrograms (CFAE) has emerged as a novel treatment approach. We sought to evaluate the additional effect of CFAE ablation to PVI in paroxysmal AF.
Methods and Results: Ninety-eight patients with paroxysmal AF (57 ± 10 years, 74 male) were randomized to the PVI (n = 48) or PVI + CFAE group (n = 50). After PVI, CFAE ablation was performed in patients with inducible AF in the PVI + CFAE group. The primary endpoint was combined objective (7-day Holter ECG) and subjective (symptoms) freedom of atrial tachyarrhythmia 3 months after ablation. Long-term follow-up (19 ± 8 months) was available in 94 of 98 patients. CFAE ablation was performed in 30 of 50 patients of the PVI + CFAE group. After 3 months, 36 of 48 patients (75%) in the PVI group and 38 of 50 patients (76%) in the PVI + CFAE group were in stable sinus rhythm (P = NS). During long-term follow-up (19 ± 8 months), 34 of 46 patients (74%) in the PVI group and 40 of 48 patients (83%) in the PVI + CFAE group were in sinus rhythm (P = 0.08). In a subgroup analysis, a significantly better long-term outcome was achieved if inducible AF after PVI had been treated by additional CFAE ablation as compared with PVI only (sinus rhythm in 25/28 patients; 89% vs 22/30 patients 73%; P = 0.003).
Conclusion: In the intention-to-treat analysis, additional CFAE ablation did not improve the success rate of PVI in patients with paroxysmal AF. However, during long-term follow-up, patients with still inducible AF after PVI seemed to profit from additional CFAE ablation.     

Early recurrences after atrial fibrillation ablation: prognostic value and effect of early reablation

Introduction: Early arrhythmia recurrences are common within the first month after atrial fibrillation (AF) ablation. The long-term consequences of these early recurrences (ER) are controversial. We investigated whether ER were predictive of late recurrences and the impact of early reablation on clinical outcome.
Methods: Three hundred two consecutive patients with paroxysmal or persistent AF were studied. Arrhythmia recurrence was defined as documented episode of AF or atrial tachycardia. Of 151 patients with ER, a subset of 61 patients had reablation within the first month following the index ablation (early reablation). In the remaining 90 patients, a repeat procedure was only performed for later arrhythmia recurrences occurring beyond 1 month. Patients were followed with clinical interview and ambulatory 24 hours monitoring.
Results: Patients with and without early reablation had similar baseline characteristics including echocardiographic parameters and type of AF. During a mean follow-up of 11 ± 11 months, 82 patients (91%) without early reablation experienced late clinical recurrences. In contrast, patients with early reablation had lower rate of clinical recurrences (51% vs 91%, P < 0.0001) and fewer additional procedures (36% vs 91%, P < 0.0001). However, the total number of procedures over the entire follow-up was greater in those patients with early reablation (2.5 ± 0.7 vs 2.2 ± 0.6, P = 0.02).
Conclusion: An overwhelming majority of patients with recurrences within the first month after ablation have late recurrences. An early reablation reduces the incidence of further recurrences. However, the overall number of procedures is higher in the medium-term follow-up. The optimal timing for the second procedure remains to be defined.     

The efficacy of inducibility and circumferential ablation with pulmonary vein isolation in patients with paroxysmal atrial fibrillation

Introduction: Some conflicting results of the efficacy of the inducibility test used in the catheter ablation of atrial fibrillation (AF) have been reported. The aim of this study was to investigate the inducibility and efficacy of circumferential ablation with pulmonary vein isolation (PVI) in patients with paroxysmal AF and its relationship to the atrial substrate.
Methods and Results: This study consisted of 88 patients with paroxysmal AF who underwent catheter ablation. Electroanatomic mapping using a NavX system was performed and the biatrial voltage was obtained during sinus rhythm. After successful circumferential ablation with PVI, an inducibility test was performed to determine the requirement for creating left atrial (LA) ablation line. After procedure, patients with inducible AF had a higher recurrence rate than did those with noninducibility of AF (55% vs 18%, P = 0.02). The patients with inducible AF after the PVI had a lower biatrial voltage than did those with negative inducibility. The patients with inducible AF after the final procedure who had a recurrence had a lower LA voltage (1.3 ± 0.4 vs 1.8 ± 0.4 mV, P = 0.02) and longer LA total activation time (99 ± 18 vs 88 ± 13 msec, P = 0.02) than did those with noninducible AF and no recurrence. None of the patients had occurrence of LA flutter during the follow-up.
Conclusion: After a single procedure of circumferential ablation with PVI and noninducibility, 82% patients did not have recurrence of AF. The inducibility of AF was related to the recurrence of AF. The atrial substrate affected the outcome of the inducibility.     

The Impact of Left Atrial Size on Long-Term Outcome of Catheter Ablation of Chronic Atrial Fibrillation

Background: The left atrial (LA) size is an important predictor of atrial fibrillation (AF) procedural termination and the long-term outcome. We sought to evaluate the long-term outcome in regard to the LA size and procedural termination.
Methods: Eighty-seven consecutive chronic AF patients (72 males, 53 ± 10 years) underwent 3D mapping (NavX) and ablation. A stepwise approach including circumferential pulmonary vein (PV) isolation, linear ablation, and continuous complex-fractionated electrogram (CFE) ablation (targeting fractionation intervals of < 50 ms). Electrical cardioversion was applied to those without any procedural termination. The freedom from AF was defined as the maintenance of sinus rhythm without the use of any class I or III antiarrhythmic drugs after the blanking period.
Results: Among the 87 patients, all received a circumferential PV isolation, 93% a linear ablation, and 59% a continuous CFE ablation. Those with AF procedural termination (n = 30) had a better long-term outcome when compared with those without termination during a follow-up of 21 ± 12 months. Moreover, a Kaplan-Meier analysis showed that in those with an LA diameter of less than 45 mm (n = 49), the freedom from AF rate was higher when procedural termination was achieved (P = 0.004). On the contrary, the outcome was comparable in those with an LA diameter of ≥ 45 mm (n = 38), whether AF procedural termination occurred or not (P = 0.658).
Conclusions: AF procedural termination was related to the long-term success during chronic AF ablation, especially in those with an LA diameter of less than 45 mm. The favorable effect of termination decreased when the LA diameter was ≥ 45 mm.     

Efficacy of catheter ablation of atrial fibrillation in patients with hypertrophic obstructive cardiomyopathy.

BACKGROUND: Although pulmonary vein (PV) antrum isolation is effective in curing atrial fibrillation (AF) in a variety of heart diseases, results in patients with hypertrophic obstructive cardiomyopathy (HOCM) have not been reported. OBJECTIVES: The purpose of this study was to report the results and outcome of PV antrum isolation in patients with AF and HOCM. METHODS: Data from patients with AF and HOCM who underwent PV antrum isolation between February 2002 and May 2004 were analyzed retrospectively. An intracardiac echocardiographic-guided ablation technique with an 8-mm-tip catheter was used in all patients. Patients were followed in the outpatient clinic at 3, 6, and 12 months after ablation. RESULTS: Twenty-seven patients with AF and HOCM (mean age 55 +/- 10 years) underwent PV antrum isolation. Mean AF duration was 5.4 +/- 3.6 years. AF was paroxysmal in 14 (52%), persistent in 9 (33%), and permanent in 4 (15%). During a mean follow-up of 341 +/- 237 days, 13 patients (48%) had AF recurrence. Of these patients, five maintained sinus rhythm (SR) with antiarrhythmic drugs, one patient remained in persistent AF, and seven patients underwent a second PV antrum isolation. After the second PV antrum isolation, five patients remained in SR, giving a final success rate of 70% (19/27). Two patients had recurrence after second PV antrum isolation; one maintained SR with antiarrhythmic drugs and one remained in persistent AF. CONCLUSION: Compared with previously reported results in patients with lone AF, AF recurrence after the first PV antrum isolation is higher in patients with HOCM. However, after repeated ablation procedures, long-term cure can be achieved in a sizable number of patients. PV antrum isolation is a feasible therapeutic option in patients with AF and HOCM.     

Incidence and predictors of very late recurrence of atrial fibrillation after ablation

Introduction: Radiofrequency catheter ablation can effectively treat patients with refractory atrial fibrillation (AF). Very late AF recurrence (≥12 months post-ablation) is uncommon and may represent a unique patient cohort.
Methods and Results: A nested case-control study was performed in the cohort who underwent AF ablation at the University of Pennsylvania to characterize patients who develop very late AF recurrence after ablation. The procedure consisted of isolation of pulmonary veins (PVs) demonstrating triggers and elimination of non-PV triggers initiating AF. Twenty-seven (7.9%) patients with very late recurrence were compared to 219 patients without recurrence and ≥12 months of follow-up. The mean age was 54.6 ± 11.3 years and 79% were men. Very late recurrence patients more likely weighed >200 lbs (70% vs 55%, P = 0.01); during initial ablation had fewer PVs isolated (2.8 ± 1.1 vs 3.3 ± 1.0, P = 0.03); and were less likely to have right inferior PV isolation (37% vs 61%, P = 0.02), less likely to have isolation of all PVs (30% vs 56%, P = 0.01), and more likely to have non-PV triggers (30% vs 11% OR 3.4(95% CI, 1.3–8.7), P = 0.01). PV reconnectivity and new triggers were found in the majority of patients with very late recurrence of AF who underwent repeat ablation.
Conclusion: Very late recurrence of AF more likely occurred in patients >200 lbs who demonstrated non-PV triggers and did not undergo right inferior PV isolation. The majority of patients undergoing repeat ablation for very late recurrence demonstrated PV reconnectivity and new non-PV and PV triggers not observed during the initial ablation.     

Computed tomography-fluoroscopy image integration-guided catheter ablation of atrial fibrillation

Introduction: This study examines the feasibility of atrial fibrillation (AF) ablation using registered three-dimensional computed tomography (CT) images of the left atrium with fluoroscopy.
Methods and Results: A total of 50 consecutive patients with symptomatic AF refractory to medical therapy (32 paroxysmal, 18 persistent, age 55 ± 10 years) were randomized to undergo a catheter-based AF ablation procedure with or without the CT-fluoroscopy guidance system. All patients underwent preprocedural contrast-enhanced CT imaging and segmentation of the left atrium. For the CT-fluoroscopy group, circumferential lesions encompassing the pulmonary vein (PV) antrum and linear lesions along the roof of the left atrium between the superior PVs and the mitral isthmus were created on the CT image, which was registered with real-time fluoroscopy. The registered images were then used to navigate the ablation catheters to the sites of planned ablation. After the ablation sites were completed, any remaining PV potentials were isolated with electrophysiological guidance. In the control patients, the same technique was performed without using the CT-fluoro guidance system. CT scans were accurately registered to fluoroscopic images with minimal manual correction. Operators could navigate catheters on the registered images to preplanned, extraostial sites for ablation. CT-fluoroscopy guidance decreased procedure duration and fluoro times (P < 0.05). At a mean follow-up of 9 ± 2 months, 21 patients (84%) in the CT-fluoro guidance group and 16 patients (64%) in the control group have had no recurrence of AF.
Conclusion: CT-fluoroscopic-guided left atrial ablation is feasible and allows appropriate catheter manipulation in the left atrium.     

Long-term safety and efficacy of circumferential ablation with pulmonary vein isolation

Background: Each of the two main approaches to catheter ablation of atrial fibrillation (AF, segmental and circumferential) is associated with moderate long-term efficacy.
Objective: To report the long-term outcomes of a modified technique that combines circumferential ablation with pulmonary vein (PV) isolation, determined by a circular mapping catheter and to determine the relationship between complete PV isolation and long-term efficacy.
Methods: The patient population was composed of 64 consecutive patients (47 men [73%]; age 59 ± 11 years) with AF who underwent catheter ablation. AF was paroxysmal in 29 (45%) and nonparoxysmal in 35 (55%). Each patient was followed for a minimum of 12 months.
Results: After a mean follow-up of 13 ± 1 months, the long-term single-procedure success rate was 45% (n = 29) with an additional 4% (n = 3) of patients demonstrating improvement. With repeat procedures in 19 patients, the overall long-term success rate was 62% (n = 40) with 9% (n = 6) demonstrating improvement. All the patients who underwent repeat ablations had recovered PV conduction. Incomplete PV isolation was the only independent predictor of failure. A major complication occurred in four (6%) patients, including three patients with vascular complications and one with cardiac tamponade.
Conclusion: Our results suggest that the long-term single-procedure efficacy of circumferential ablation with PV isolation in a cohort of patients with predominantly nonparoxysmal AF approaches 50%. Repeat procedures involving re-isolation of the PVs result in a significant improvement in outcomes. Complete electrical isolation of the PVs has a significant impact on the long-term efficacy of the procedure.     

New insights into long-term follow-up of atrial fibrillation ablation: full disclosure by an implantable pacemaker device

Introduction : Long-term outcome of radiofrequency ablation (RFA) for atrial fibrillation (AF) is difficult to assess. This study sought to evaluate various aspects of very long-term follow-up (FU) by the properties of an implantable device.
Methods : Fourteen patients with an implanted pacemaker device (Medtronic AT500) were selected for RFA, due to drug-refractory and highly symptomatic AF despite antibradycardic pacing.
Results : With a mean FU of 41.4 ± 15.1 months, we could achieve continuous monitoring for more than 400,000 hours after RFA. Based on symptomatic episodes, simulated 24-hour, 48-hour, or 7-day Holter, 57% to 71% of the patients were classified as RFA responders. With permanent FU provided by the implanted device, 43% of the patients exhibited a positive treatment effect and only 21% had no tachyarrhythmic episode at all in long-term FU. With a mean of 1.7 ± 0.7 RFA per subject, atrial tachyarrhythmia burden (ATB) was significantly reduced from a median of 3.6 to 0.3 hours per day (P < 0.001). Two out of 14 patients developed AF recurrences after a tachyarrhythmia-free period of more than 12 months.
Conclusion : Continuous monitoring provided by an implantable device is able to detect significantly more AF episodes than routine FU. ATB is decreased significantly by (repeated) RFA over a very long-term FU. AF may reoccur very late after long-lasting (>1 year) episode-free intervals. A subgroup of patients with drug-aggravated bradycardia in brady-tachy syndrome might be considered for PV isolation rather than pacemaker implantation.     

Efficacy of Additional Ablation of Complex Fractionated Atrial Electrograms for Catheter Ablation of Nonparoxysmal Atrial Fibrillation

Background: The efficacy of ablation of complex fractionated atrial electrograms (CFEs) in the single ablation procedure for nonparoxysmal atrial fibrillation (AF) patients is not well demonstrated. The aim of this study was to compare the ablation strategies of pulmonary vein isolation (PVI) plus linear ablation with and without additional ablation of CFEs in these patients.
Methods: Consecutive 60 patients (49 ± 11 years old, 50 male, 10 female) with nonparoxysmal AF underwent catheter ablation guided by a NavX mapping system. A stepwise approach included a circumferential PVI and left atrial (LA) linear ablation followed by either the additional ablation of continuous CFEs in the LA/coronary sinus (the first 30 patients) or not (the second 30 patients), detected by an automatic algorithm.
Results: There was no difference in the baseline characteristics between the two groups. Complete PVI eliminated some continuous CFEs and altered the distribution of CFEs. Following PVI and linear ablation, the remaining continuous CFEs were identified in 7.9 ± 10% mapping sites of the LA and CS, and were ablated successfully with a procedural AF termination rate of 53%. With a follow-up of 19 ± 11 months, a Kaplan–Meier analysis showed that the patients with additional ablation of the CFEs had a higher rate of sinus rhythm maintenance. Multivariate analysis showed the single procedure success could be predicted by the procedural AF termination and the additional ablation of continuous CFEs in the LA/CS.
Conclusions: Ablation of continuous CFEs after PVI and LA linear ablation had a better long-term efficacy based on the results of single-ablation procedure.     

Long-term outcome following successful pulmonary vein isolation: pattern and prediction of very late recurrence

Background:  Despite encouraging results of pulmonary vein isolation (PVI) ablation for atrial fibrillation (AF), it is unclear whether there is genuine cure or there is an important attrition rate. We sought to determine the long-term outcome of the initial responders who experienced a prolonged AF-free complete response.
Methods:  From a series of 350 consecutive patients who underwent PVI for AF, 264 patients (75%) (males 71%, age 57 ± 12 years, paroxysmal AF 87%) who demonstrated ≥1 year AF-free follow-up on no antiarrhythmic drugs were followed for 1–5 years.
Results:  During 28 ± 12 months follow-up, 23 of 264 (8.7%) patients had recurrence of AF. The actuarial recurrence at 2 years postablation was 5.8% and increased to 25.5% at 5 years. Compared with long-term responders, more patients with late recurrence had hypertension (HR = 2.18, P = 0.009) and hyperlipidemia (HR = 4.01, P = 0.0005). Among 18 patients with recurrent AF necessitating repeat PVI, 15 (83%) required re-isolation of > 1 PV and 28 of 45 (58%) PVs showed reconnection. All PVs were re-isolated and five (28%) patients had additional linear ablation. All 15 patients became AF-free again.
Conclusions:  Although most patients following PVI remain AF-free, some patients develop "late" recurrence of AF. The "late" recurrence patients are more likely to have hypertension and hyperlipidemia. Most late recurrences are associated with PV reconnections. Our observations emphasize the importance of continued long-term vigilance for AF recurrence, and also raise concerns regarding the need for long-term anticoagulation therapy.     

Evaluation of an individualized strategy of cavotricuspid isthmus ablation as an adjunct to atrial fibrillation ablation

Objectives: To evaluate supplementary cavotricuspid isthmus (CTI) ablation as an adjunct to atrial fibrillation (AF) ablation in selected patients.
Background: It is unclear whether routine CTI ablation is beneficial in all patients undergoing AF ablation.
Methods and Results: In patients undergoing AF ablation, additional CTI block was created only for those with typical atrial flutter (Afl) before or during the ablation. Out of 188 consecutive patients (108 male, 56 ± 9 years), 75 underwent CTI ablation (Group CTI+) and left atrial (LA) ablation (circular mapping-guided extensive pulmonary vein isolation in all and linear LA ablation when required), while 113 underwent LA ablation alone (Group CTI−). Group CTI+ patients had smaller LA and less frequently persistent/permanent AF and linear LA ablation. Over a follow-up of 30 ± 10 months, complications (4% vs 5%, P = NS), typical Afl occurrence (1.3% and 2.6%, P = NS) and AF recurrence (25% and 28%, P = NS) were similar. Atypical Afl was more common in Group CTI− (4 vs 14%, P = 0.026). Eighty-two percent and 79% of patients in Groups CTI+ and CTI−, respectively, remained arrhythmia free in stable sinus rhythm without antiarrhythmic drug treatment (P = NS).
Conclusions: Avoiding supplementary CTI ablation in AF ablation patients without evidence of typical flutter does not result in a higher incidence of typical Afl. Despite more persistent/permanent AF and larger LA in patients without evidence of typical flutter, a strategy of selective supplementary ablation resulted in similar and low AF recurrence rates in the group without CTI ablation compared with the group with CTI ablation.     

Body mass index, obstructive sleep apnea, and outcomes of catheter ablation of atrial fibrillation

Background: Obesity and obstructive sleep apnea (OSA) are associated with atrial fibrillation (AF). The effects of a large body mass index (BMI) and OSA on the results of radiofrequency catheter ablation (RFA) of AF are unclear.
Objective: To evaluate the effect of BMI and OSA on the efficacy of RFA for AF.
Methods: RFA was performed in 324 consecutive patients (mean age = 57 ± 11 years) with paroxysmal (234) or chronic (90) AF. OSA was diagnosed by polysomnography in 32 of 324 patients (10%) prior to ablation. Among the 324 patients, 18% had a normal BMI (<25 kg/m²), 39% were overweight (BMI ≥ 25 kg/m² and <30 kg/m²), and 43% were obese (≥30 kg/m²). RFA was performed to eliminate complex fractionated atrial electrograms (CFAE) in the pulmonary vein antrum and left atrium.
Results: At 7 ± 4 months after a single ablation procedure, 63% of patients without OSA and 41% with OSA were free from recurrent AF without antiarrhythmic drug therapy (P = 0.02). Multivariate analysis including variables of age, gender, type and duration of AF, OSA, BMI, left atrial size, ejection fraction, and hypertension demonstrated that OSA was the strongest predictor of recurrent AF (OR = 3.04, 95% CI: 1.11–8.32, P = 0.03). There was no association between BMI and freedom from recurrent AF. A serious complication occurred in 3 of 324 patients, with no relationship to BMI.
Conclusions: OSA is a predictor of recurrent AF after RFA independent of its association with BMI and left atrial size. Obesity does not appear to affect outcomes after radiofrequency catheter ablation of AF.     

The effects of statins and renin-angiotensin system blockers on atrial fibrillation recurrence following antral pulmonary vein isolation

Introduction: Ablation has emerged as a major treatment option for atrial fibrillation (AF). However, this procedure is limited by a significant rate of AF recurrence. We aimed to examine the effects of statins, angiotensin-converting enzyme inhibitors (ACE-I), and angiotensin receptor blockers (ARB) on the recurrence rate of AF following ablation.
Methods: We conducted a retrospective study of 177 consecutive patients (mean age = 56 ± 11 yrs, 69% males) who underwent ablation for paroxysmal (n = 132) or persistent AF (n = 45). Patients were treated with ACE-I (n = 31) or ARB (n = 18) or statins (n = 50) prior to ablation and for the duration of follow-up.
Results: After a mean follow-up of 13.8 ± 8.6 months, 72% of patients were free of AF. For patients taking statins, 33 of 50 (60%) were free of AF. In patients treated with ACE-I, 17 of 31 (55%) were free from AF, while in the group of patients treated with ARB, 17 of 18 (94%) were free from AF. Using Cox regression analysis to correct for baseline variables, treatment with statins did not decrease the recurrence rate (HR = 1.10 [95% CI: 0.55–2.27] p = 0.79); nor did treatment with renin angiotensin system (RAS) blockers (HR 0.94 [95% CI: 0.46–1.93] p = 0.87). However, subgroup analysis showed that treatment with ARB was associated with a trend towards lower AF recurrence [HR 0.17, (95% CI: 0.02–1.34) p = 0.09].
Conclusions: Even though statins and RAS blockers possess anti-inflammatory properties, they did not decrease the recurrence of AF following ablation. However, the subset of patients taking ARB exhibited a trend towards lower AF recurrence. Larger, randomized studies are needed to address this observation.     

Characteristics and outcome in patients receiving multiple (more than two) catheter ablation procedures for paroxysmal atrial fibrillation

Background: The features of multiple catheter ablation procedures for paroxysmal atrial fibrillation (AF) are unknown. We aimed to investigate the electrophysiologic characteristics and the clinical outcomes in the patients with AF who received more than two ablation procedures.
Methods: The study consisted of 15 consecutive patients (age 48 ± 14 years, 10 males) who had undergone three to five (3.3 ± 0.6) catheter ablation procedures for recurrent paroxysmal AF.
Results: Ten patients had pulmonary vein (PV)-AF and one had AF originating from both PVs and the superior vena cava (SVC) in the first ablation procedure. All of them exhibited PV reconnection during the recurrent episodes. Four of the 15 patients had AF originating from non-PV foci (three from the SVC, one from the crista terminalis) in the first procedure, and two had AF recurrences due to recovered conduction from the SVC. In all patients with PV-AF recurrences, repeated PV isolation procedures could effectively eliminate the AF. The incidence of the need for additional LA linear ablation lesions was higher comparing between the first procedure and in the following ablation procedures (18% vs. 71%, P = 0.02). During a follow-up of 1.7 ± 1.1 years, 73% of the patients remained in sinus rhythm without any antiarrhythmic drugs after the final procedure.
Conclusions: Recovered PV connection was the major cause of the AF recurrences despite undergoing multiple catheter ablation procedures. It is advisable to inspect all PVs during the AF recurrence. Repeated PV isolation plus left atrial linear ablations could effectively eliminate the AF with satisfactory outcomes.     

Is Empirical Four Pulmonary Vein Isolation Necessary for Focally Triggered Paroxysmal Atrial Fibrillation? Comparison of Selective Pulmonary Vein Isolation Versus Empirical Four Pulmonary Vein Isolation

Background: We questioned whether the empirical four pulmonary vein (PV) isolation (EmPVI) was necessary in patients with paroxysmal atrial fibrillation (PAF) triggered from clearly and reproducibly defined arrhythmogenic PVs.
Methods: We compared the selective or ipsilateral isolation of the PVs triggering AF (SePVI: n = 42) and EmPVI (n = 35) in 77 patients (males 80.5%, mean age 53.0 ± 13.4 years) with PAF who underwent radiofrequency catheter ablation (RFCA). Arrhythmogenic PVs were identified by the immediate recurrence of AF three consecutive times after cardioverting AF.
Results: (1) The duration of the RF energy deliveries (P < 0.01) and total procedure time (P < 0.01) were shorter for the SePVI than the EmPVI. (2) During a mean follow-up of 38.6 ± 23.1 months, the AF recurrence rate was 38.1% in the SePVI group and 25.7% in the EmPVI group (P = NS). (3) A redo-ablation was performed in 25 patients, and 81.0% of the recurrent arrhythmogenic foci were found at a previously ablated PV or ipsilateral PV. (4) In 15.4% of the SePVI and 20.0% of the EmPVI procedures, AF recurred after 32.5 ± 15.2 months of the redo-ablation. Subsequently, the AF-free rate for each group was 88.1% (37/42) in the SePVI group and 91.4% (32/35) in the EmPVI group (P = NS).
Conclusions: In patients with clearly documented arrhythmogenic PVs, the SePVI of the PV triggering the AF or an ipsilateral PV had a comparable long-term success rate and shorter RF energy delivery and procedure times than the EmPVI.     

Correlation of Left Atrial Diameter by Echocardiography and Left Atrial Volume by Computed Tomography

Introduction: For patients undergoing catheter ablation of atrial fibrillation (AF), left atrial size is a predictor of recurrence of AF during follow-up. For this reason, major clinical trials have used a left atrial diameter (LAD) of more than 5.0 or 5.5 cm, assessed by echocardiography, as an exclusion criterion for patients deemed candidates for ablation of AF. However, whether LAD accurately reflects true left atrial size has not been systematically investigated. Therefore, the purpose of this study was to test the hypothesis that LAD, measured by echocardiography, accurately correlates to left atrial volume measured by computed tomography (CT).
Methods and Results: We included 50 patients (mean age 56 ± 12 years, five female) with symptomatic AF (40% paroxysmal, 60% persistent), referred for catheter ablation. In each patient, transthoracic echocardiography was performed. Additionally, all patients underwent CT using a 64-slice CT scanner. Left atrial volume was calculated by manually tracing left atrial area on each CT cross-sectional image. Patients had a mean LAD measured by echocardiography of 4.5 ± 0.7 cm, ranging from 2.9 to 5.7 cm. Left atrial volume measured by CT ranged from 67 mL to 270 mL with a mean value of 146 ± 49 mL. A poor correlation was noted between LAD and left atrial volume, r = 0.49 (P < 0.001).
Conclusion: LAD measured by echocardiography correlates poorly with left atrial volume measured by CT in patients with AF. As a result, selecting patients with AF for treatment with catheter ablation should not be based on an echocardiographic-derived LAD alone.