Reverse Atrial Remodeling Following Pulmonary Vein Isolation: The Importance of the Body Mass Index EDUARDO ARANA-RUEDA, M.D., PH.D., ALONSO PEDROTE, M.D., PH.D., ´ LORENA GARC´IA-RIESCO, M.D., ALVARO ARCE-LEON, M.D., ´ ´ FEDERICO GOMEZ-PULIDO, M.D., JUAN-MANUEL DURAN-GUERRERO, M.D., ´ ´ AGUST´IN FERNANDEZ-CISNAL, M.D., MANUEL FRUTOS-LOPEZ, M.D., ´ and JUAN-ANTONIO SANCHEZ-BROTONS, M.D. From the Arrhythmia Unit, Department of Cardiology, Hospital Universitario Virgen del Roc´ıo, Seville, Spain

Background: Pulmonary vein isolation (PVI) causes a reduction in left atrium size that is attributable to reverse atrial remodeling (RAR). The objective of this study was to identify predictors of RAR and determine its association with other parameters of improvement in cardiac function. Methods: It is a prospective study with 74 patients (52 ± 9 years old, 81% male), and 51% of patients had paroxysmal atrial fibrillation. Patients were serially assessed with transthoracic echocardiography; plasma N-terminal B-type natriuretic peptide (NT-proBNP); and high-sensitivity C-reactive protein levels at baseline and 3, 6, and 12 months following the PVI. RAR was defined as a reduction in the left atrial volume index (LAV-index) >10% from baseline at the end of follow-up. A multivariate analysis was conducted to identify predictors of RAR. Results: The LAV-index decreased significantly during follow-up in the entire population (P = 0.0005). RAR (experienced by 63.5% of the patients) was more frequent (76% vs. 42%; P = 0.004) and pronounced (reduction 16.65 ± 14% vs. 8 ± 14%; P = 0.015) in patients with a successful ablation (46 of 74 patients, 62.2%). Only patients with RAR showed significant improvement in NT-proBNP levels (P = 0.0001), systolic function (P = 0.035), and diastolic function (P = 0.005). Multivariable analysis revealed that a successful ablation (odds ratio [OR] = 4.6; 95% confidence interval [CI] 1.46–14.68; P = 0.009), LAV-index (OR = 1.15; 95% CI 1.03–1.2; P = 0.021), and patient’s body mass index (OR = 0.84; 95% CI 0.74–0.96; P = 0.012) were independent predictors of RAR. Conclusions: Successful PVI ablation is the main predictor of RAR that is associated with other parameters of improvement in cardiac function. The patient’s body mass index may have a negative effect on RAR. (PACE 2015; 38:216–224) ablation, atrial fibrillation, electrophysiology – clinical, echocardiography

Introduction Catheter ablation has been established as an effective treatment for patients with symptomatic atrial fibrillation (AF) refractory to antiarrhythmic drugs.1 Despite technical improvements, the rate of relapse following ablation remains high.1–3 A characteristic of AF is its selfgeneration/perpetuation within the context of an atrial substrate that is morphologically and functionally altered by different diseases or by age.4 Left atrium (LA) enlargement, a marker for atrial structural remodeling, is a predictor of the occurrence of new episodes of AF and of Address for reprints: Eduardo Arana-Rueda, M.D., PH.D., Unidad de arritmias, Servicio de Cardiolog´ıa, Hospital Virgen del Roc´ıo, Avda Manuel Siurot, s/n 41013 Seville, Spain. Fax: 34-955012330; e-mail: [email protected] Received June 9, 2014; revised October 24, 2014; accepted November 2, 2014. doi: 10.1111/pace.12560

catheter ablation failure.5 Different studies have described an association between AF ablation and a reduction in LA size that is attributed to reverse atrial remodeling (RAR). RAR may have an impact on the long-term maintenance of the sinus rhythm (SR).6–10 The objective of this study was to identify the predictors of RAR. We also described the changes in cardiac structure and function associated with RAR, as observed in echography and lab tests. Methods Study Population and Design This was a prospective observational study. All patients referred to our center for AF ablation from June 2009 to February 2011 were consecutively enrolled in the study. Patients were considered eligible if they presented with symptomatic AF that was refractory to at least one antiarrhythmic agent. In the case of paroxysmal AF (duration 50 mm in the parasternal long-axis view by transthoracic echocardiography (TTE), patients with a cardiac prosthesis, patients with a contraindication for anticoagulation therapy, and patients who had previously undergone an AF ablation procedure. Ablation Procedure The ablation procedure has been previously described.11 All patients provided informed consent. Antiarrhythmic drugs were stopped >5 half-lives (amiodarone >1 month) before the ablation. Patients receiving anticoagulation therapy continued treatment until the procedure was performed. All patients underwent a chest computed tomography (CT) scan to visualize pulmonary vein anatomy and a transesophageal echocardiography to rule out the presence of thrombi in the LA. Following a double transseptal puncture, a 10-pole circular catheter (Lasso, Biosense Webster Inc., Diamond Bar, CA, USA) was introduced into the LA and sequentially situated in each pulmonary vein along with an irrigated ablation catheter with a 3.5-mm tip (Navistar Thermocool, Biosense Webster Inc.). During the procedure, sodium heparin was administered to maintain an activation clotting time between 250 and 350 seconds, and deep sedation was induced with propofol and fentanyl administered intravenously. A three-dimensional reconstruction of the LA, which was produced with the CARTO System (Biosense Webster Inc.), was merged with the image obtained from the CT scan. Ablation was conducted incorporating both ipsilateral pulmonary veins and the intervein carina. Radiofrequency was applied with a power of 35 W and a maximum temperature of 45°C. The ablation endpoint was a bidirectional block of all pulmonary veins represented by a disappearance of spikes in the circular catheter and the absence of atrial capture from inside each pulmonary vein. Biochemical Assays and Echocardiography On the day of the intervention, highsensitivity C-reactive protein (HsCRP) and Nterminal B-type natriuretic peptide (NT-proBNP) levels were measured in all patients before the procedure. Given the complexity of measuring atrial function in patients with persistent AF, and because previous studies have shown no differences between basal measurements and measurements

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took 24 hours after the ablation,7 basal TTE was performed in all patients (with paroxysmal and persistent AF) the day after the ablation, when the SR had been restored in all of the patients. Standard parameters were obtained according to the recommendations of the European Association of Echocardiography and the American Society of Echocardiography.12 A 3.5-MHz transducer with a depth of 16 cm in the parasternal and apical positions (standard views in the parasternal longaxis and apical two- and four-chamber views) was used. Images were stored in a cine loop in the device. The measurement of the anteroposterior LA was obtained from the parasternal long axis at the end of systole. The measurements of the LA short and long axis were taken in the apical two- and four-chamber views. The LA telesystolic volume (LAV) was defined as the higher volume recorded in ventricular telesystole. The LAV was obtained by the biplane area-length method using the mean value of three consecutive heartbeats. To standardize measures, the LAV was indexed by body surface (LAV-index). The left ventricle ejection fraction (LVEF) was measured with Simpson’s method. A Doppler test and an atrial tissue Doppler were conducted to measure the mitral filling flow following the recommendations for the assessment of diastolic function described by Nagueh et al.13 Measurements were taken by a single operator. The intraobserver variability for the LAV was estimated in a sample of 10 patients; the agreement among measurements was 96%, with a median variation of 2.6 ± 2.2 mL/m2 . Due to the limitations of the technique itself, we defined RAR at the end of follow-up as a reduction in the LAV-index ࣙ10% and an absolute value of ࣙ5 mL. Lower values were not considered significant. Follow-up Patients were discharged on the day after the ablation treated with dicoumarol and taking the antiarrhythmic medication they had been taking before the procedure for a 3-month blanking period. To assess the success of the procedure, patients were asked to record all symptomatic episodes they experienced. Follow-up was conducted during a specialized visit 3, 6, and 12 months after the ablation. This visit involved a clinical evaluation, lab tests, surface ECG, TTE, and 24-hour Holter. In case of symptoms suggesting relapse that were not recorded by these methods, an event recorder was used for 10 days (SpiderFlash-t, SorinCRM-SAS, Clamart, France). We defined a successful ablation as the absence of AF/atrial tachycardia after the blanking period in patients who had undergone a single procedure

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Table I. Basal Characteristics of Patients According to the Presence or Absence of RAR during the Follow-Up Period

Age (years) Male, n (%) BMI OSA, n (%) HTA, n (%) DM, n (%) Structural heart disease, n (%) Paroxysmal AF, n (%) AF history (years) CHADS2 , Mn (P25 -p75 ) NT-proBNP (pg/mL), Mn (P25 -p75 ) hsCRP (mg/L), Mn (P25 -p75 ) LVEF (%) Diastolic dysfunction, n (%) A wave (cm/s) LA long-axis (mm) LAV index (mL/m2 ) Procedure time (minute) LA excluded area (%)

Basal

RAR Present 47 (63.5)

RAR Absent 27 (36.5)

P

52 ± 9 60 (81) 29.42 ± 5.3 8 (10.8) 38 (51) 5 (6.7) 13 (17.5) 44 (59.5) 3.1 ± 2.2 1 (0–1) 294.8 (200–398) 2 (0.9–3.8) 60.7 ± 5 36 (49) 51.6 ± 14 40 ± 4.3 40.7 ± 9.5 140 ± 34 27 ± 5

52 ± 9.3 38 (81) 28.3 ± 4.4 6 (12) 22 (46.8) 2 (4.3) 7 (15) 24 (51) 3 ± 2.16 1 (0–1) 127 (75–350) 1.5 (0.8–4) 59 ± 5.3 24 (51) 51.4 ± 14,5 40.2 ± 4.8 43 ± 10 136 ± 33 27 ± 5

53 ± 9 22 (81.5) 31.3 ± 6.3 2 (7.4) 16 (59.3) 3 (11) 6 (22) 20 (74) 3.2 ± 2.4 1 (0–1) 146 (57–260) 2 (1.2–3.6) 61.6 ± 4.6 12 (44) 52 ± 14 39.8 ± 5 37 ± 7.8 144 ± 43 26.4 ± 5

0.54 0.94 0.021 0.47 0.3 0.26 0.42 0.052 0.75 0.8 0.56 0.5 0.95 0.58 0.49 0.66 0.01 0.99 0.61

AF = atrial fibrillation; BMI = body mass index; DM = diabetes mellitus; hsCRP = high-sensitivity C-reactive protein; HTA = hypertension; LA = left atrium; LAV-index = indexed volume of left atrium; LVEF = left ventricular ejection fraction; NT-proBNP = N-terminal B-type natriuretic peptide; OSA = obstructive sleep apnea; RAR = reverse atrial remodeling.

and were not taking antiarrhythmic drugs; any recorded episode ࣙ30 seconds was considered significant. In the event of a relapse following the blanking period that was judged to require treatment, the same antiarrhythmic medication previously taken by the patient was prescribed again or a second ablation was performed. Statistical Analysis Continuous variables are presented as the mean and standard deviation or as the median and 25th and 75th percentiles for normally and nonnormally distributed variables, respectively. Categorical variables were presented as frequencies. An analysis of variance was used to detect differences among various LAV-index samples, and the Bonferroni post hoc correction was used for paired sample t-tests. Continuous variables were compared with Student’s t-test, and categorical variables were compared with the χ 2 test. To identify independent predictors of RAR, a multivariate logistical regression test including variables with P < 0.1 in the univariate analysis was conducted. P < 0.05 was considered statistically significant. The analysis was conducted with SPSS v18.0 (IBM Corp., Armonk, NY, USA).

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Results During the recruitment period, 98 patients underwent pulmonary vein isolation (PVI). Of these, 13 patients had undergone a previous procedure, seven patients had undergone a different technique, and four patients did not finish the 12-month follow-up. Therefore, a total of 74 patients were included in the final analysis. The clinical characteristics of the patients are summarized in Table I. Most (81%) of the patients were male, and the mean age of the patients was 52 ± 9 years. Forty-four (59.5%) patients experienced paroxysmal AF; the AF was persistent in 30 patients (40.5%). The mean duration of the procedure was 140 ± 34 minutes. The radiofrequency time was 50 ± 8 minutes and the fluoroscopy time was 21 ± 12 minutes. The isolation of all four pulmonary veins was achieved in 92% of the patients. One patient suffered a femoral pseudoaneurysm and one patient suffered an inguinal hematoma; both were treated with local compression. At the end of the follow-up period, 46 patients (62.2%) had not experienced any relapse (Fig. 1). A second procedure was conducted in six patients (8%), four of whom had left atrial tachycardia

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Figure 1. Survival curve of AF/AT for patients who underwent a single ablation procedure. AF = atrial fibrillation; AT = atrial tachycardia.

and two of whom experienced AF relapse. The reconnection of pulmonary veins was observed in all cases. No macroreentrant tachycardias were documented, and no major complications occurred. In all cases a discrete closing of gaps was done, minimizing atrial aggression. Changes in LA and Cardiac Function during Follow-Up At the end of the follow-up period, the patients experienced a mean reduction of 13.4 ± 14.8% in the LAV index (from 40.7 ± 9.5 mL/m2 to 35.5 ± 7.5 mL/m2 ; P = 0.0001) that occurred within the first 3 months of follow-up (Fig. 2). In the patients with paroxysmal AF, the rate of atrial reduction was lower (8.6 ± 13% vs. 20.4 ± 14%; P = 0.01) and occurred sooner than in the patients with persistent AF (within the first 3 months vs. 6 months of follow-up; P < 0.05; Fig. 2). A greater reduction in the LAV index was noted in the patients who experienced a successful ablation than in the patients who experienced arrhythmia relapse (16.65 ± 14% vs. 8 ± 14%; P = 0.015). RAR was noted in 47 of 74 (63.5%) patients. The patients with RAR also experienced significant improvements in LVEF (59 ± 5.3% to 63.2 ± 3.5%; P = 0.035), in the E/´e ratio (11.5 ± 3.8 to 9 ± 2.8; P = 0.005), in diastolic function (51% to 30%; P = 0.03), and in NT-proBNP levels (127 p25–75 75–350 pg/mL to 47 p25–75 24–109 pg/mL; P = 0.001; Table II and Fig. 3). Predictors of RAR RAR was present in 35 of the 46 (76%) patients who experienced successful ablation and in 12 of the 28 (42%) patients who experienced

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arrhythmia relapse (P = 0.004). The patients with persistent AF tended to experience RAR more frequent than the patients with paroxysmal AF (23 of 30 (76.6%) patients vs. 24 of 40 (54.5%); P = 0.052). The patients who experienced RAR had a lower body mass index (BMI; 28.3 ± 4.4 vs. 31.3 ± 6.3; P = 0.021) and a higher basal LAV index (43 ± 10 mL/m2 vs. 37 ± 7.8 mL/m2 ; P = 0.01; Table III). However, the patients did not have any other significantly different basal variables (clinical variables, variables assessed by tests, or variables associated with the procedure). In the multivariate analysis conducted to detect predictors of RAR, ablation success (odds ratio [OR] = 4.6; 95% confidence interval [CI] 1.45–14.6; P = 0.004), the LAV-index (OR = 1.15; 95% CI 1.03–1.2; P = 0.021), and the patient’s BMI (OR = 0.84; 95% CI 0.74–0.96; P = 0.012) were independent predictors of RAR (Table III). Discussion This prospective study evaluates the factors associated with RAR following ablation, using a definition of RAR that fits the limitations of the technique used. The main findings are the following: (1) PVI ablation success is the main factor associated with RAR; (2) RAR is associated with other parameters of improvement in atrial and ventricular function; (3) RAR is directly associated with atrial size; and (4) the probability of RAR decreases by 16% with every unit increase in BMI. LAV Reduction and PVI Ablation Success Sustained AF causes electric, contractile, and structural remodeling of the heart, which, in turn, contributes to the maintenance/perpetuation of AF. Atrial fibrosis and atrial enlargement are the main markers of structural remodeling.4,5 Various studies have assessed the effects of ablation on LA structure and function.6,9,14 Despite the heterogeneity in follow-up periods (from 3 months to 12 months) and the use of different imaging techniques in these studies, it is currently accepted that AF ablation results in a 10–20% reduction in atrial size.1,10 Our study confirms this finding, as we observed a mean reduction of 13.4% in the LAV-index in the entire sample during the first 3 months following ablation. The reduction rate was higher in those patients who experienced successful procedures, and RAR was clearly associated with the maintenance of the SR. Although these data agree with the majority of published studies,10 certain studies have found no association between success in ablation and atrial reduction.1,15,16 These differences depend on multiple factors, including the studied

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Figure 2. Box plot of the evolution of the LAV index during the follow-up period. (A) All patients. (B) Patients with paroxysmal AF. (C) Patients with persistent AF. The entire population had a reduction in the LAV index during the first months following ablation. A greater reduction was noted in the patients with persistent atrial fibrillation. AF = atrial fibrillation; LAV index = left atrial volume indexed by body surface. Table II. TTE and Lab Variables at Baseline and at 12 Months According to the Presence or Absence of RAR RAR Present

LVEF (%) LA long-axis (mm) LAV-index (mL/m2 ) LVDD (mm) E/e´ Diastolic dysfunction, n (%) hsCRP (mg/L), Mn (P25 -p75 ) NT-proBNP (pg/m), Mn (P25 -p75 )

RAR Absent

Baseline

12 Months

P

Baseline

12 Months

P

59 ± 5.3 40.2 ± 5 43 ± 10 47.4 ± 4.9 11.5 ± 3.8 24 (51) 1.5 (0.8–4) 127 (75–350)

63.2 ± 3.5 37.2 ± 3.8 33 ± 6.8 46.2 ± 4.2 9 ± 2.8 14 (30) 1.1 (0.7–3.1) 47 (24–109)

0.035 0.0001 0.0001 0.33 0.005 0.03 0.09 0.0001

61 ± 4.6 39.8 ± 5 37 ± 7.8 47.3 ± 5.5 10.8 ± 3.2 12 (44) 2 (1.2–3.6) 146 (57–260)

62.2 ± 4.4 40 ± 3.7 37.3 ± 7.6 49 ± 4 10.5 ± 4.4 10 (42) 1.7 (1–3.2) 99 (47–140)

0.26 0.7 0.5 0.67 0.6 0.7 0.31 0.56

hsCRP = high-sensitivity C-reactive protein; LA = left atrial; LAV-index = indexed left atrial volume; LVDD = left ventricular diastolic diameter; LVEF = left ventricular ejection fraction; NT-proBNP = N-terminal B-type natriuretic peptide; RAR = reverse atrial remodeling; TTE = transthoracic echocardiography.

population, the imaging technique, the definition of success, and the extent of ablation.6,14,17 We used a restrictive definition of RAR, thereby ruling out minor changes that can be attributed to the technique used, and we conducted uniform PVI with a mean atrial exclusion of 27 ± 5%. Although we did not measure the scar volume created in both groups, which could have an impact on atrial reduction, our data suggest that the maintenance of the SR influences RAR. Studies with continuous monitoring have shown a >90% reduction in AF burden in a major proportion of the population undergoing PVI11 ; this could explain the reduction in LA size observed in the overall population.10 RAR and other Cardiac Function Markers The occurrence of RAR is associated with a significant improvement in TTE parameters (LVEF, E/´e ratio, and diastolic function) and

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in lab test parameters (NT-proBNP levels). This relationship suggests that RAR is part of a more complex series of changes in cardiac structure and function that occurs secondary to SR maintenance and in addition to a reduction in the LAV index. In a series of patients with AF without cardiopathy followed-up with TTE, Reant et al.7 demonstrated the association between the success of the procedure and a reduction in LA size and improved systolic and diastolic function parameters. Tops et al.18 reported that LA size decreased with an improvement in the atrial function measured with strain. Solheim et al.19 reported that atrial size and NT-proBNP levels both decreased following a successful ablation, with NT-proBNP levels acting as markers of success during the follow-up period. These data indicate that the maintenance of the SR following PVI, despite the potentially negative effect of lesions caused by ablation, will result in an improvement

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Figure 3. Box plot of the LAV index, LVEF, NT-proBNP, and E/e´ index before and 12 months after PVI, according to the presence or absence of RAR. Only patients with RAR demonstrated significant reduction in LAV index and improvement in LVEF, NT-proBNP levels, and E/e´ index. LAV index = left atrial volume indexed by body surface; LVEF = left ventricular ejection fraction; NT-proBNP = N-terminal B-type natriuretic peptide; PVI = pulmonary vein isolation; RAR = reverse atrial remodeling.

in atrial function, more efficient left ventricle filling, and an improvement in ventricular mechanics.1,7,10,18,19 Therefore, RAR is the result of these interacting events on the atrial structure.18 RAR Predictors: The Importance of BMI Few studies have investigated the factors associated with RAR following PVI ablation, and have diverse study designs. A lower degree of basal atrial fibrosis estimated with cardiac magnetic resonance imaging,20 LA strain and basal LAV-index18 and Lone AF15 have been associated with RAR following PVI. Despite the heterogeneity of these studies, a direct relationship between atrial size and RAR is usually observed,15,16,18 as

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was observed in this study. Even though a larger LA is associated with more extensive remodeling and worse AF ablation outcomes,1,5,21 we showed that the maintenance of the SR causes patients with a higher LAV index to also have a higher probability of RAR. This study establishes for the first time a relationship between patient’s BMI and the occurrence of RAR. More specifically, we found that the probability of RAR decreases by 16% with each unit increase in BMI. The association between obesity and AF is widely known1,22 Epidemiological studies have associated BMI with the incidence of AF, with each BMI unit increasing the risk of AF by 4–5%.22,23 Patients with a

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Table III. Univariate and Multivariate Analysis of Basal RAR Predictors Univariate Analysis

Variable Age Male BMI HTA OSA DM Structural heart disease AF type (parox/persistent) NT-proBNP hsCRP LVEF Diastolic dysfunction LA long axis LAV-index Ablation success Procedure time Excluded area

Multivariate Analysis

Hazard Ratio (95% CI)

P

0.98 (0.93–10.3) 0.96 (0.28–3.2) 0.89 (0.8–0.98) 1.6 (0.6–4.3) 0.54 (0.1–2.9) 2.8 (0.4–18) 1.6 (0.48–5.4) 0.36 (0.13–1.1) 1 (0.99–1.01) 0.94 (0.81–1.1) 0.94 (0.9–1.1) 0.76 (0.3–1.9) 1.02 (0.9–1.14) 1.08 (1.01–1.15) 4.24 (1.5–11.6) 1 (0.98–1.02) 1 (0.9–1.1)

0.54 0.94 0.02 0.3 0.48 0.26 0.43 0.052 0.84 0.45 0.95 0.58 0.65 0.01 0.004 0.99 0.61

Hazard Ratio P (95% CI)

P

0.84 (0.74–0.96)

0.012

0.9 (0.26–3.27)

0.89

1.15 (1.03–1.2) 4.6 (1.46–14.68)

0.021 0.009

AF = atrial fibrillation; BMI = body mass index; CI = confidence interval; DM = diabetes mellitus; hsCRP = high-sensitivity C reactive protein; HTA = hypertension; LA = left atrium; LAV-index = indexed volume of left atrium; LVEF = left ventricular ejection fraction; NT-proBNP = N-terminal B-type natriuretic peptide; OSA = obstructive sleep apnea.

BMI >25 have been found to have a relapse rate 31% higher than that of patients with a normal BMI.24 This association is partly due to the conditions associated with being overweight (hypertension, sleep apnea, heart failure)22,25 and partly due to a direct involvement of BMI in the presentation and persistence of AF.26 In the general population, obesity appears to be the most important risk factor for LA enlargement.27,28 In an experimental study with sheep, Abed et al.29 showed that an increase in BMI is associated with more extensive electrical and structural remodeling, resulting in an increase in atrial size, more extensive diastolic dysfunction, and an increase in inflammation and histological markers associated with the atrial substrate that promotes AF. Recently, Abed et al.30 demonstrated that aggressive interventions to mitigate risk factors, including undergoing an intensive reduction in BMI, resulted in a reduction in the AF burden, thus establishing a direct relationship between modifiable risk factors and the presence of AF. The benefits of weight reduction are attributed to a reduction in LA pressure secondary to a reduction in atrial volume and ventricular thickness.26,30 These findings support our results; therefore, even if the SR can be maintained following AF ablation,

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a high BMI may have a negative and direct impact on atrial structure and function, leading to less extensive RAR. Limitations This study has limitations. The sample consists of a small number of patients from a single center; therefore, the results of this study cannot be extrapolated to the overall population and are not comparable to results from multicenter studies. Patients with a significantly enlarged LA (>50 mm) were excluded because, in clinical practice, these patients are not considered ideal for PVI; therefore, our data are not relevant to this population. Using cardiac magnetic resonance imaging to evaluate LAV is more accurate than TTE and it can also determine LA scar; however, this technique was not as accessible for such an exhaustive monitoring of LAV and function. The definition of RAR that we used is empirical; even though it fits the limitations of the technique used, we cannot rule out the possibility that lower degrees of LA reduction may result from RAR. Since undergoing a redo involves new lesions in the atrium, it may be a limitation when assessing atrial remodeling in these patients. Monitoring of patients after ablation included

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intermittent 24-hour Holter and event monitoring guided by symptoms. It is recognized that this method might underestimate the identification of recurrences, especially if those are asymptomatic. A very restrictive definition of ablation success was used. Major reductions in AF burden could have positive consequences for atrial structure11 ; however, relevant data to confirm this hypothesis have yet to be obtained.

Conclusions Successful PVI ablation promotes RAR that is associated with other parameters of improvement in cardiac function. The patient’s BMI has a negative effect on RAR, even in arrhythmiafree patients; more specifically, the risk of RAR decreases by 16% with every unit increase in BMI.

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Reverse atrial remodeling following pulmonary vein isolation: the importance of the body mass index.

Pulmonary vein isolation (PVI) causes a reduction in left atrium size that is attributable to reverse atrial remodeling (RAR). The objective of this s...
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