Impact of biomarkers of inflammation and extracellular matrix turnover on the outcome of atrial fibrillation ablation: importance of matrix metalloproteinase-2 as a predictor of atrial fibrillation recurrence

MMP‐2 Predicts the Outcome of AF Ablation. Introduction: Although catheter ablation can effectively eliminate atrial fibrillation (AF), the progression of atrial remodeling increases the risk of recurrence. AF is associated with inflammation and subsequent myocardial fibrosis. We therefore examined the possibility of determining the postablation prognosis of patients with AF using biomarkers of inflammation and collagen turnover. Methods and Results: Subjects were 50 patients who underwent catheter ablation for drug‐resistant AF. High‐sensitivity CRP (hs‐CRP), interleukin (IL)‐6, carboxyl‐terminal telopeptide of collagen type I (ICTP), metalloproteinase (MMP)‐2, tissue inhibitor of MMP‐2 (TIMP‐2), atrial natriuretic peptide (ANP), and brain natriuretic peptide (BNP) were measured before and 2.2 ± 0.8 months after ablation. During the follow‐up period of 14.0 (4.7–20.9) months, AF recurred in 21 of the 50 patients. Recurrence was associated with an MMP‐2 elevation (860.3 ± 120.8 ng/mL vs 687.0 ± 122.5 ng/mL [in patients without recurrence]), ICTP elevation (3.2 ± 1.1 ng/mL vs 2.7 ± 0.6 ng/mL), BNP elevation, greater body mass index, nonparoxysmal AF, and hypertension (P < 0.05 for all). Serum MMP‐2 and nonparoxysmal AF were shown by multivariate analysis to be independent predictors for postablation AF recurrence. Overall, hs‐CRP, IL‐6, ANP, and BNP levels decreased, and MMP‐2, TIMP‐2, and ICTP levels increased 2 months after ablation. Conclusions: Our finding that markers of collagen turnover were elevated in patients who experienced AF recurrence after ablation indicate that these markers might be a useful guide to identify a subgroup of AF patients who require extensive ablation strategies. A 2‐month postablation elevation in collagen turnover markers suggests that the wound healing process persists for that long after ablation. (J Cardiovasc Electrophysiol, Vol. 22, pp. 987‐993, September 2011)     

The Impact of Catheter Ablation on the Dynamic Function of the Left Atrium in Patients with Atrial Fibrillation: Insights from Four‐Dimensional Computed Tomographic Images

Functional Evaluation of the LA by Dynamic CT. Introduction: Elucidating the functional properties and remodeling process of the entire left atrium (LA) is important not only for offering the mechanistic insight into atrial fibrillation (AF) but also for assessing the effectiveness of catheter ablation. Methods: We included 65 patients with paroxysmal AF and 29 controls. Baseline multidetector computed tomography (MDCT) was acquired in all subjects and a follow‐up MDCT was available in 48 patients after pulmonary vein and LA ablation. The 3‐dimensional images at atrial end‐diastole (ED) and end‐systole (ES) were analyzed. Results: The LA volume (ED: 61.11 ± 15.94 vs 54.12 ± 8.94 mL/m², P = 0.03; ES: 45.29 ± 17.64 vs 33.38 ± 7.78 mL/m², P < 0.001) was increased, and ejection fraction (EF) (26.93 ± 13.40 vs 38.09 ± 11.62%, P < 0.001) decreased in AF patients as compared to controls. After ablation, the ES LA volume (44.73 ± 14.93 vs 38.04 ± 11.51 mL/m², P = 0.04) decreased and the LA EF (25.04 ± 13.13 vs 30.82 ± 7.85%, P = 0.03) increased in patients without any AF recurrence. The wall motion (WM) analysis of the 18 segments of LA revealed increased motional magnitudes of entire LA except for the anterior roof. In contrast, the volume, EF, and WM of LA remained similar in patients with recurrence. Conclusion: Dilated LA with global hypokinesia was noted in AF patients. Improved LA transport function was demonstrated in patients without any recurrence after ablation. However, the anatomic and functional reverse remodeling was not significant in patients with AF recurrence. (J Cardiovasc Electrophysiol, Vol. 21, pp. 270–277, March 2010)     

Long‐Term Outcome of Catheter Ablation in Patients with Atrial Fibrillation Originating from Nonpulmonary Vein Ectopy

Long‐Term Outcome of NPV AF Ablation . Introduction: Data regarding the long‐term outcome of catheter ablation in patients with nonpulmonary vein (NPV) ectopy initiating atrial fibrillation (AF) are limited. We aimed to evaluate the long‐term result of patients with AF who had NPV triggers and underwent catheter ablation. Methods and Results: The study included 660 consecutive patients (age 54 ± 11 years old, 477 males) who had undergone catheter ablation for AF. Group 1 consisted of 132 patients with AF initiating from the NPV, and group 2 consisted of 528 patients with AF initiating from pulmonary vein (PV) triggers only. Patients from Group 1 were younger than those from Group 2 (51 ± 12 years old vs 54 ± 11 years old, P = 0.001) and were more likely to be females (34.4% vs 25.8%, P = 0.049). The incidences of nonparoxysmal AF (36.4% vs 16.3%, P < 0.001) and right atrial (RA) enlargement (31.3% vs 19%, P = 0.004) were higher, and the biatrial substrates were worse in Group 1 than those in Group 2 (left atrial voltage 1.5 ± 0.7 mV vs 1.9 ± 0.7 mV, P < 0.001, RA voltage 1.6 ± 0.5 mV vs 1.8 ± 0.6 mV, P = 0.014). During a follow‐up period of 46 ± 23 months, there was a higher AF recurrence rate in Group 1 than in Group 2 (57.6% vs 38.8%, P < 0.001). The independent predictors of AF recurrence were NPV trigger (P < 0.001, HR 2, 95% CI 1.4–2.85), nonparoxysmal AF (P = 0.021, HR 1.55, 95% CI 1.07–2.24), larger left atrial diameter (P = 0.002, HR 1.04, 95% CI 1.02–1.07) and worse left atrial substrate (P = 0.028, HR 1.3, 95% CI 1.03–1.64). Conclusion: Compared to AF originating from the PV alone, AF originating from the NPV ectopy showed a worse outcome. (J Cardiovasc Electrophysiol, Vol. 24, pp. 250‐258, March 2013)     

Long-term outcome of catheter ablation in patients with atrial fibrillation originating from the superior vena cava

Long‐Term Outcome of SVC AF Ablation. Introduction: Data of the long‐term clinical outcome after superior vena cava (SVC) isolation are limited. We aimed to evaluate the long‐term outcome in patients with atrial fibrillation (AF) who had triggers originating from the SVC and received catheter ablation of AF. Methods and Results: The study consisted of 68 patients (age 56 ± 12 years old, 32 males) who underwent the ablation procedure for drug‐refractory, symptomatic paroxysmal AF originating from the SVC since 1999. Group 1 consisted of 37 patients with AF initiated from the SVC only, and group 2 consisted of 31 patients with both SVC and pulmonary vein (PV) triggers. During a follow‐up period of 88 ± 50 months, the AF recurrence rate was 35.3% after a single procedure. The freedom‐from‐AF rates were 85.3% at 1 year and 73.3% at 5 years. In the baseline study, group 2 had larger left atrium (38 ± 4 mm vs 36 ± 5 mm, P = 0.04), left ventricle (50 ± 5 mm vs 46 ± 5 mm, P = 0.003), and PV diameters. Kaplan–Meier survival analysis showed a higher AF recurrence rate in group 2 compared to that in group 1 (P = 0.012). The independent predictor of an AF recurrence was a larger SVC diameter (P = 0.02, HR 1.4, 95% CI 1.1–1.8). Conclusion: Among the patients with paroxysmal AF originating from the SVC, 73% remained free of AF for 5 years after a single catheter ablation procedure. Superior vena cava isolation without PV isolation is an acceptable therapeutic strategy in those patients with AF originating from the SVC only. The SVC diameter was an independent predictor of AF recurrence. (J Cardiovasc Electrophysiol, Vol. 23, pp. 955‐961, September 2012)     

The Impact of Age on the Electroanatomical Characteristics and Outcome of Catheter Ablation in Patients with Atrial Fibrillation

Age and Atrial Fibrillation. Background: Previous studies have indicated that atrial fibrillation (AF) in patients over the age of 60 at diagnosis is a risk factor for a substantial increase in cardiovascular events. However, information about the impact of age on the atrial substrate and clinical outcome after catheter ablation of AF is limited. Methods: This study included 350 patients (53 ± 12 years, 254 males) who underwent circumferential pulmonary vein isolation (CPVI) of AF, guided by a NavX mapping system. The subjects were divided into three groups according to their age, as follows: Group I: age ≤50 (n = 141), Group II: age = 51–64 (n = 149) and Group III: age ≥65 years old (n = 60). The mean voltage and total activation time of the individual atria were obtained by using a NavX mapping system before ablation. Several parameters, including the gender, AF duration, and left atrial (LA) diameter were analyzed. Results: The younger age group had a significantly smaller LA diameter (Group I vs Group II vs Group III, 36.89 ± 7.11 vs 39.16 ± 5.65 vs 40.77 ± 4.95 mm, P = 0.002) and higher LA bipolar voltage (2.09 ± 0.83 vs 1.73 ± 0.73 vs 1.86 ± 0.67 mV, respectively, P = 0.024), compared with the older AF patients. The LA bipolar voltage exhibited a significant reduction when the patients became older, however, that did not occur in the right atrium. The incidence of an AF recurrence was higher in the older age group than in the younger age groups. A subgroup of patients with lone AF was analyzed and age was found to be an independent predictor of the AF recurrence after receiving the first CPVI in the multivariable model (P < 0.05). Conclusions: Age has a significant impact on the LA substrate properties and outcome of the catheter ablation of AF. (J Cardiovasc Electrophysiol, Vol. 21, pp. 966‐972, September 2010)     

Preprocedural predictors of atrial fibrillation recurrence following pulmonary vein antrum isolation in patients with paroxysmal atrial fibrillation: long-term follow-up results

Predictors of Recurrence after AF Ablation. Introduction: The objective of this study was to identify the simple preprocedural parameters of atrial fibrillation (AF) recurrence following single ablation procedure in patients with paroxysmal AF during long‐term follow‐up period. Methods and Results: Consecutive 474 patients (61 ± 10 years; 364 males, left atrial (LA) diameter 37.6 ± 5.1 mm) with drug‐refractory paroxysmal AF who underwent AF ablation were analyzed. Pulmonary vein antrum isolation (PVAI), cavotricuspid isthmus line creation with bidirectional conduction block, and elimination of all non‐PV triggers of AF were performed in all patients. With a mean follow‐up of 30 ± 13 months after single procedure, 318 patients (67.1%) were in sinus rhythm without any antiarrhythmic drugs. Multivariate analysis using Cox's proportional hazards model, including the age, gender, duration of AF, body mass index, LA size, left ventricular ejection fraction, and presence of hypertension and structural heart disease as variables, demonstrated that LA size was an independent predictor of AF recurrences after PVAI with a 7.2% increase in the probability for every 1 mm increase in LA diameter (P = 0.0007). When the patients were categorized into 3 groups according to the LA diameter, the patients with moderate (40–50 mm) and severe dilatation (>50 mm) had a 1.30‐fold (P = 0.0131) and 2.14‐fold (P = 0.0057) increase, respectively, in the probability of recurrent AF as compared with the patients with normal LA diameter (≤40 mm). Conclusion : In the long‐term follow‐up period, LA size was the best preprocedural predictor of AF recurrence following single ablation procedure in the patients with paroxysmal AF, even in the patients with a relatively small LA. (J Cardiovasc Electrophysiol, Vol. 22, pp. 621‐625, June 2011)     

Effect of Therapeutic INR on Activated Clotting Times,Heparin Dosage,and Bleeding Risk During Ablation of Atrial Fibrillation

Effect of INR on Anticoagulation During Ablation of Atrial Fibrillation . Background: Ablation of atrial fibrillation (AF) with international normalized ratio (INR) ≥ 2.0 is safe and may reduce thromboembolic complications. Heparin is administered during the procedure, but the effect of elevated INR on heparin requirements and target activation clotting times (ACT) ≥ 350 seconds during ablation is unknown. Objectives: To study the effect of INR on intraprocedural anticoagulation during ablation of AF. Methods: We retrospectively studied 427 consecutive patients over an 18‐month period when we were transitioning to continuation of warfarin for AF ablation. Baseline INR, procedural ACT measurements, heparin doses and major complications were analyzed according to Group 1 with INR < 2.0 (n = 246) and Group 2 with INR ≥ 2.0 (n = 181). Results: In Group 1, the mean INR was lower (1.3 ± 0.3 s vs 2.4 ± 0.3; P < 0.001), and the mean heparin dose was greater (106.82 ± 40.01 vs 77.03 ± 18.5 U/kg; P < 0.001). A single heparin bolus achieved ACT ≥ 350 seconds throughout the procedure in 51 patients (20.7%) in Group 1 compared to 108 patients (59.7%) in Group 2 (P < 0.01). Mean ACT values were higher in Group 2. Symptomatic pericardial effusions were similar (2.4% in Group 1 and 2.2% in Group 2). There were 3 thromboembolic cerebrovascular events in Group 1 and none in Group 2. Femoral hematomas occurred more frequently in Group 1 (8.1%) than in Group 2 (3.3%) (P = 0.007). Conclusions: AF ablation with INR ≥ 2.0 provides a consistent anticoagulant milieu during the procedure, with lower heparin requirements that are important to anticipate. (J Cardiovasc Electrophysiol, Vol. 22, pp. 248‐254, March 2011)     

Outcomes of Ablation of Paroxysmal Atrial Fibrillation in Patients on Chronic Hemodialysis

AF Ablation in HD Patients . Introduction: It is not common for patients on chronic hemodialysis (HD) to undergo catheter ablation of atrial fibrillation (AF). We aimed to show the outcomes of AF ablation in the HD patients. Methods and Results: Thirty HD patients who underwent pulmonary vein (PV) isolation for drug refractory paroxysmal AF were retrospectively studied, and their AF recurrence free rate and frequency of periprocedural complications were compared to 60 age‐ and gender‐matched control patients not requiring HD. A nonirrigated ablation catheter was used in both patient groups. During a mean follow‐up period of 821 ± 218 days, 16 (54%) of the HD patients remained free from AF recurrence without any antiarrhythmic agents versus 47 (78%) of the control patients with an initial ablation (P = 0.013). A second ablation procedure was performed in 12 patients with an AF recurrence, and consequently 20 (67%) of the HD patients were in sinus rhythm compared to 53 (88%) of the controls during a follow‐up duration of 747 ± 221 after the last ablation (P = 0.012). Bleeding from the venipuncture site requiring a prolonged hospital stay was identified in 2 HD patients and 1 control subject, while no life‐threatening complications were observed in either patient group. Conclusion: Although the success rate of the PV isolation in HD patients was far from satisfactory, it may be considered as one of the therapeutic options for them. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1289‐1294, December 2012)     

Left atrial deformation imaging with ultrasound based two-dimensional speckle-tracking predicts the rate of recurrence of paroxysmal and persistent atrial fibrillation after successful ablation procedures

Predict AF. Objective: Since predictors of recurrence of atrial fibrillation (AF) after ablation procedures are poorly defined, this prospective study was conducted to assess the value of left atrial (LA) deformation imaging with two‐dimensional speckle‐tracking (2D‐ST) to predict AF recurrences after successful ablation procedures. Methods and results: One hundred and three consecutive patients (age 58.1 ± 16.6 years, 72.8% male) with AF (76 paroxysmal, 27 persistent) and 30 matched controls underwent transthoracic echocardiography and 2D‐ST‐LA‐deformation analysis with assessment of LA‐radial and LA‐longitudinal strain (Sr, Sl), and velocities derived from the apical 4‐ and 2‐chamber views (4CV, 2CV). AF recurrence was assessed during 6 months of follow‐up. For determination of AF‐related LA changes, AF patients were compared to controls and patients with AF recurrences after ablation procedures (n = 30, 29.1%) were compared with patients who maintained sinus rhythm (n = 73, 70.9%). Atrial deformation capabilities were significantly reduced (P < 0.0005) in patients with AF (4CVSl 17.8 ± 13.5%; 4CVSr 22.3 ± 14.9%; 4CV‐velocities 2.53 ± 0.97 seconds) when compared with controls (4CVSl 31.3 ± 12.4%; 4CVSr 30.3 ± 9.1%; 4CV‐velocities 3.48 ± 1.01 cm/s). Independent predictors for AF recurrence after ablation procedures were 2CV‐LA‐global‐strain (Sr, P = 0.03; Sl, P = 0.003), 4CV‐LA‐gobal‐strain (Sr, P = 0.03; Sl, P = 0.02), and regional LA‐septal wall‐Sl (P = 0.008). LA‐global‐strain parameters were superior to regional LA function analysis for the prediction of AF recurrences, with cutoff values (cov), hazard ratios (HR), positive and negative predictive values (PPV, NPV) were: 4CVSl cov, 10.79% (HR 27.8, P < 0.0005; PPV 78.8%, NPV 93.9%), 4CVSr cov, ?16.65% (HR 24.8, P < 0.0005; PPV 69.4%, NPV 96.6%), 2CVSl cov, 12.31% (HR 22.7, P < 0.0005; PPV 75.8%, NPV 95.3%), and 2CVSr cov, ?14.9% (HR 12.9, P < 0.0005; PPV 64.3%, NPV 93.2%). Conclusion: Compared with controls, AF itself seems to decrease LA deformation capabilities. The assessment of global LA strain with 2D‐ST identifies patients with high risk for AF recurrence after ablation procedures. This imaging technique may help to improve therapeutic guiding for patients with AF. (J Cardiovasc Electrophysiol, Vol. 23 p. 247‐255, March 2012.)     

A novel finding of the atrial substrate properties and long-term results of catheter ablation in chronic atrial fibrillation patients with left atrial spontaneous echo contrast

Atrial Substrate Properties in Chronic AF Patients with LASEC. Background: The atrial substrate in chronic atrial fibrillation (AF) patients with a left atrial spontaneous echo contrast (LASEC) has not been previously reported. The aim of this study was to investigate the atrial substrate properties and long‐term follow‐up results in the patients who received catheter ablation of chronic AF. Methods: Of 36 consecutive patients with chronic AF who received a stepwise ablation approach, 18 patients with an LASEC (group I) were compared with 18 age‐gender‐left atrial volume matched patients without an LASEC (group II). The atrial substrate properties including the weighted peak‐to‐peak voltage, total activation time during sinus rhythm (SR), dominant frequency (DF), and complex fractionated electrograms (CFEs) during AF in the bi‐atria were evaluated. Result: The left atrial weighted bipolar peak‐to‐peak voltage (1.0 ± 0.6 vs 1.6 ± 0.7 mV, P = 0.04), total activation time (119 ± 20 vs 103 ± 13 ms, P < 0.001) and DF (7.3 ± 1.3 vs 6.6 ± 0.7 Hz, P < 0.001) differed between group I and group II, respectively. Those parameters did not differ in the right atrium. The bi‐atrial CFEs (left atrium: 89 ± 24 vs 92 ± 25, P = 0.8; right atrium: 92 ± 25 vs 102 ± 3, P = 0.9) did not differ between group I and group II, respectively. After a mean follow‐up of 30 ± 13 month, there were significant differences in the antiarrhythmic drugs (1.1 ± 0.3 vs 0.7 ± 0.5, P = 0.02) needed after ablation, and recurrence as persistent AF (92% vs 50%, P = 0.03) between group I and group II, respectively. After multiple procedures, there were more group II patients that remained in SR, when compared with group I (78% vs 44%, P = 0.04). Conclusion: There was a poorer atrial substrate, lesser SR maintenance after catheter ablation and need for more antiarrhythmic drugs in the chronic AF patients with an LASEC when compared with those without an LASEC. (J Cardiovasc Electrophysiol, Vol. pp. 1‐8)     

Clinical Significance of Early Recurrences of Atrial Tachycardia After Atrial Fibrillation Ablation

Early Recurrence After AF Ablation. Background: Atrial tachycardia (AT) commonly recurs within 3 months after radiofrequency catheter ablation for atrial fibrillation (AF). However, it remains unclear whether early recurrence of atrial tachycardia (ERAT) predicts late recurrence of AF or AT. Methods: Of 352 consecutive patients who underwent circumferential pulmonary vein isolation with or without linear ablation(s) for AF, 56 patients (15.9%) with ERAT were identified by retrospective analysis. ERAT was defined as early relapse of AT within a 3‐month blanking period after ablation. Results: During 21.7 ± 12.5 months, the rate of late recurrence was higher in patients with ERAT (41.1%) compared with those without ERAT (11.8%, P < 0.001). In a multivariable model, positive inducibility of AF or AT immediately after ablation (65.2% vs 36.4%, P = 0.046; odd ratio, 3.9; 95% confidence interval, 1.0–14.6) and the number of patients who underwent cavotricuspid isthmus (CTI) ablation (73.9% vs 42.4%, P = 0.042; odd ratio, 4.5; 95% confidence interval, 1.1–19.5) were significantly related to late recurrence in the ERAT group. The duration of ablation (174.3 ± 62.3 vs 114.7 ± 39.5 minutes, P = 0.046) and the procedure time (329.3 ± 83.4 vs 279.2 ± 79.7 minutes, P = 0.027) were significantly longer in patients with late recurrence than in those without late recurrence following ERAT. Conclusions: The late recurrence rate is higher in the patients with ERAT compared with those without ERAT following AF ablation, and is more often noted in the patients who underwent CTI ablation and had a prolonged procedure time. Furthermore, inducibility of AF or AT immediately after ablation independently predicts late recurrence in patients with ERAT. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1331‐1337, December 2010)     

Triggering Pulmonary Veins: A Paradoxical Predictor for Atrial Fibrillation Recurrence After PV Isolation

Triggering Pulmonary Veins and Recurrence After Ablation . Purpose: To identify procedural parameters predicting recurrence of atrial fibrillation (AF) after a first circumferential pulmonary vein isolation (CPVI). Methods: One hundred seventy‐one patients undergoing CARTO‐guided CPVI for recurrent AF with a left atrial (LA) diameter <45 mm were studied. Follow‐up (symptoms and 7‐day Holter) was performed at 1 and 3 months and every 3 months thereafter. Clinical and procedural characteristics between successful patients and patients undergoing repeat ablation were compared. In addition, procedural parameters of the first procedure were compared with parameters during repeat ablation. Results: After first CPVI, 80% of patients were free of AF without antiarrhythmic drugs after a follow‐up (FU) of 28 ± 11 months (N = 136). Thirty‐five patients (20%) had recurrence of AF of which 25 underwent repeat ablation (N = 25). Clinical characteristics did not differ between the successful and repeat group. A triggering vein during the index procedure was significantly more observed in the repeat group (56% vs 11%, P < 0.001). At repeat ablation, 2.6 ± 1.2 veins per patient were reconnected. Whereas there was no preferential reconnecting PV, all PVs triggering at index were reconnected (100%). Conclusions: (1) In patients with symptomatic recurrent AF, the presence of a triggering pulmonary vein during ablation is a paradoxical predictor for AF recurrence after PV isolation. (2) The consistent finding of reconnection of the triggering PV at repeat ablation, suggests that, in these patients, the triggering PV is the culprit vein and that reconnection invariably results in clinical AF recurrence. (3) The present study advocates a strategy of even more stringent PV isolation in case of a triggering PV. (J Cardiovasc Electrophysiol, Vol. 21, pp. 381–388, April 2010)     

Impact of adenosine-provoked acute dormant pulmonary vein conduction on recurrence of atrial fibrillation

Impact of ATP Reconduction on AF Recurrence. Introduction: Adenosine can be associated with acute recovery of conduction to the pulmonary veins (PVs) immediately after isolation. The objective of this study was to evaluate whether the response to adenosine predicts atrial fibrillation (AF) recurrence after a single ablation procedure in patients with paroxysmal AF. Methods and Results: A total of 109 consecutive patients (61 ± 10 years; 91 males) with drug‐refractory paroxysmal AF who underwent AF ablation were analyzed. After PV antrum isolation (PVAI), dormant PV conduction was evaluated by an administration of adenosine in all patients. No acute reconnections were provoked by the adenosine in 70 (64.2%) patients (Group‐1), but they were provoked in at least one side of the ipsilateral PVs in 39 (35.8%) patients (Group‐2). All adenosine‐provoked dormant conductions were successfully eliminated by additional ablation applications. By 12 months after the initial procedure, 72 (66.1%) patients were free of AF recurrences without any antiarrhythmic drugs. A Cox regression multivariate analysis of the variables including the adenosine‐provoked reconductions, age, gender, duration of AF, presence of hypertension or structural heart disease, left atrial size, left ventricular ejection fraction, and body mass index demonstrated that adenosine‐provoked reconductions were an independent predictor of AF recurrence after a single ablation procedure (hazard ratio: 1.387; 95% confidence interval: 1.018–1.889, P = 0.038). At the repeat session for recurrent AF, conduction recovery was observed similarly in both groups (P = 0.27). Conclusion: Even after the elimination of any adenosine‐provoked dormant PV conduction, the appearance of acute adenosine‐provoked reconduction after the PVAI was an independent predictor of AF recurrence after a single AF ablation procedure. (J Cardiovasc Electrophysiol, Vol. 23 p. 256‐260, March 2012.)     

Catheter ablation of atrial fibrillation in octogenarians: safety and outcomes

AF Ablation in Octogenarians. Introduction: Radiofrequency catheter ablation (RFCA) is an effective treatment for atrial fibrillation (AF), although studies evaluating the role of RFCA have largely excluded elderly patients. We report the safety and outcomes of RFCA of AF in octogenarians. Methods and Results: From 2008 to 2011, out of 2,754 consecutive patients undergoing RFCA of AF, 103 (3.7%) had ≥80 years (age 85 ± 3 years, 4 with >90 years). Pulmonary vein (PV) antrum isolation was performed in paroxysmal AF. In nonparoxysmal AF, ablation was extended to the entire left atrial posterior wall and to complex fractionated electrograms. Non‐PV triggers were disclosed by isoproterenol challenge at the end of the procedure and targeted for ablation. Octogenarians presented a high rate of non‐PV triggers (84% vs 69%, P = 0.001), especially in patients with paroxysmal AF (62% vs 19%, P < 0.001); non‐PV triggers were most commonly mapped in the coronary sinus (54%), left atrial appendage (32%), interatrial septum and superior vena cava (14%). After a mean follow‐up of 18 ± 6 months, 71 (69%) octogenarians remained free from AF recurrence off antiarrhythmic drugs after a single procedure (vs 71% in patients <80 years, P = 0.65). The success rate reached 87% after 2 procedures. Total periprocedural complication rates also did not differ between the 2 age groups. Conclusions: RFCA of AF is safe and effective in octogenarians. A high rate of non‐PV triggers is present in these patients, and targeting multiple structures other than the pulmonary veins is often necessary to achieve long‐term success. (J Cardiovasc Electrophysiol, Vol. 23, pp. 687‐693, July 2012)     

Is Selective Ipsilateral PV Isolation Sufficient for Focally Triggered Paroxysmal Atrial Fibrillation? Comparison of Selective Ipsilateral Pulmonary Vein Isolation versus Bilateral Pulmonary Vein Isolation

Is SIPVI Sufficient for Focally Triggered Paroxysmal Atrial Fibrillation? Introduction: Selective ipsilateral pulmonary vein isolation (SIPVI) has shown comparable efficacy in focal triggered atrial fibrillation (AF) versus isolation of all pulmonary veins (PVs), yet the sufficiency for such an ablation strategy to all patients is unclear. This study sought to identify a subgroup of patients for SIPVI and a subgroup of patients for bilateral PV isolation (BiPVI) with long‐term success by comparing the clinical efficacy of SIPVI and BiPVI on PV‐triggered AF. Methods and Results: One hundred and forty‐two patients (106 males; mean age 51 ± 13 years) with focal PV triggered paroxysmal AF (PAF) were studied. Seventy patients underwent SIPVI and 72 patients underwent BiPVI. After the first ablation, 44 patients (44/70) in the SIPVI group and 54 patients (54/72) in the BiPVI group were free of AF without antiarrhythmic drugs, after a follow‐up period of 36 ± 12 months (log‐rank test P = 0.1594). In patients younger than 50 years of age with a left atrium (LA) diameter <40 mm, SIPVI had a high success rate (15/18, 83%) of freedom from AF. However, for patients aged ≥50 years with an LA diameter ≥40 mm, 10 of the 12 patients in the SIPVI group and only 5 of the 15 patients in the BiPVI group had a recurrence of AF (log‐rank test P = 0.0173). Conclusions: For focally triggered PAF, in patients aged <50 years with an LA diameter <40 mm, SIPVI of triggering PV had a high success rate of freedom from AF. However, in patients aged ≥50 years with an LA diameter ≥40 mm, BiPVI achieved a higher success rate. (J Cardiovasc Electrophysiol, Vol. 23, pp. 130‐136, February 2012)     

The impact of age on ablation outcomes in AF-mediated cardiomyopathy

Introduction

The absence of ventricular scar in patients with atrial fibrillation (AF) and systolic heart failure (HF) predicts left ventricular (LV) recovery following AF ablation. It is unknown whether age impacts the degree of LV recovery, reverse remodeling, or AF recurrence following catheter ablation (CA) among this population.

Objectives

To evaluate the impact of age on LV recovery and AF recurrence in a population with AF and systolic HF without fibrosis (termed AF-mediated cardiomyopathy) following CA.

Methods

Consecutive patients undergoing CA between 2013 and 2021 with LV ejection fraction (LVEF) < 45% and absence of cardiac magnetic resonance imaging (CMR) detected LV myocardial fibrosis were stratified by age (<65 vs. ≥65 years). Following CA, participants underwent remote rhythm monitoring for 12 months with repeat CMR for HF surveillance.

Results

The study population consisted of 70 patients (10% female, mean LVEF 33 ± 9%), stratified into younger (age < 65 years, 63%) and older (age ≥ 65 years, 37%) cohorts. Baseline comorbidities, LVEF (34 ± 9 vs. 33 ± 8 ≥65 years, p = .686), atrial and ventricular dimensions (left atrial volume index: 55 ± 21 vs. 56 ± 14 mL/m² age ≥ 65, p = .834; indexed left ventricular end-diastolic volume: 108 ± 40 vs. 104 ± 28 mL/m² age ≥ 65, p = .681), pharmacotherapy and ablation strategy (pulmonary vein isolation in all; posterior wall isolation in 27% vs. 19% age ≥ 65, p = .448; cavotricuspid isthmus in 9% vs. 11.5% age ≥ 65) were comparable (all p > .05) albeit a higher CHADS₂VASc score in the older cohort (2.7 ± 0.9 vs. 1.6 ± 0.6 age < 65, p < .001).   Freedom from AF was comparable (hazard ratio: 0.65, 95% confidence interval: 0.38–1.48, LogRank p = .283) as was AF burden [0% (interquartile range, IQR: 0.0–2.1) vs. age ≥ 65: [0% (IQR 0.0–1.7), p = .516], irrespective of age. There was a significant improvement in LV systolic function in both groups (ΔLVEF + 21 ± 14% vs. +21 ± 12% age ≥ 65, p = .913), with LV recovery in the vast majority (73% vs. 69%, respectively, p = .759) at 13 (IQR: 12–16) months. This was accompanied by comparable improvements in functional status (New York Heart Association class p = .851; 6-min walk distance 50 ± 61 vs. 93 ± 134 m in age ≥ 65, p = .066), biomarkers (ΔN-terminal-pro brain natriuretic peptide −139 ± 246 vs. −168 ± 181 age ≥ 65,p = .629) and HF symptoms (Short Form-36 survey Δphysical component summary p = .483/Δmental component summary, p = .841).

Conclusion

In patients undergoing CA for AF with systolic HF in the absence of ventricular scar, comparable improvements in ventricular function, symptoms, and freedom from AF are achieved irrespective of age.     

Effect of telmisartan on paroxysmal atrial fibrillation recurrence in hypertensive patients with normal or increased left atrial size

Background:

Hypertension is the most prevalent and potentially modifiable risk factor for atrial fibrillation (AF). In a previous secondary prevention study, the authors observed that the angiotensin II receptor blocker telmisartan was more effective than the calcium channel blocker amlodipine in preventing AF relapse in hypertensive patients with normal atrial size.

Hypothesis:

Telmisartan may be more effective than amlodipine in preventing AF recurrence in hypertensive patients with paroxysmal AF and normal or increased left atrial dimension (LAD).

Methods:

The authors assigned 378 mild hypertensive outpatients in sinus rhythm, but with ≥2 episodes of AF in the previous 6 months, to 1 of 2 groups. Group 1 comprised patients with LAD <40 mm in females and <45 mm in males. Group 2 comprised patients with LAD >40 mm and <45 mm in females and >45 mm and <50 mm in males. In both groups, patients were randomly treated with telmisartan or amlodipine for 1 year.

Results:

Systolic and diastolic blood pressure were similarly reduced by telmisartan and amlodipine in both groups. The AF recurrence rate was significantly lower in the telmisartan‐treated patients than in the amlodipine‐treated patients in both group 1 (12 vs 39, P < 0.01) and group 2 (40 vs 59, P < 0.05). Under telmisartan, the AF recurrence rate was significantly lower in group 1 than in group 2 (12.9% vs 42.1%, P < 0.05). Time to a first AF relapse was significantly longer with telmisartan than with amlodipine in both group 1 (176 ± 94 days vs 74 ± 61 days, P < 0.05) and group 2 (119 ± 65 days vs 38 ± 35 days, P < 0.05).

Conclusions:

Telmisartan was more effective than amlodipine in preventing AF recurrences in hypertensive patients with paroxysmal AF. Clin. Cardiol. 2012 DOI: 10.1002/clc.21994 The authors have no funding, financial relationships, or conflicts of interest to disclose.     

Impact of Radiofrequency Characteristics on Acute Pulmonary Vein Reconnection and Clinical Outcome After PVAC Ablation

Impact of Radiofrequency Characteristics . Objective: The objective was to study the impact of radiofrequency (RF) characteristics on acute pulmonary vein reconnection (PVR) and outcome after PVAC ablation. PVI with additional ablation of PVR (PVI + PVR) was compared to PVI‐only. Methods: In 40 consecutive patients, after PVAC‐guided PVI, adenosine and a 1‐hour waiting time were used to unmask and ablate acute PVR (PVI + PVR group). RF‐characteristics and 1‐year AF freedom were compared post hoc to 40 clinically matched patients undergoing PVI only (PVI‐only group). Custom‐made software was used to assess RF characteristics of the PVAC applications needed to obtain baseline PVI. Results: There was no difference in clinical characteristics or baseline RF‐profile between both groups. Acute PVR was observed and ablated in 38 of 160 veins (24%). AF‐freedom after PVI + PVR was higher than PVI (85% vs 65%, P < 0.05). Within the PVI group, comparing patients with and without AF‐recurrence, the percentage of PVAC applications with high T° (>48°) but low power (<3W) was higher (28 ± 18% vs 11 ± 11%, P < 0.0001). Within the PVI + PVR group, when comparing PVs with and without PVR, the percentage of low power/high T° PVAC applications was also higher (27 ± 13% vs 13 ± 15%, P < 0.0001). Conclusions: (1) After PVAC ablation, 24% of PVs exhibit acute reconnection. Additional ablation of reconnection improves clinical outcome. (2) Acute reconnection as well as clinical recurrence of AF are characterized by PVAC ablation with a considerable number of applications with high temperature but low power. (3) If PV isolation is obtained with low power applications, a consistent use of both adenosine and waiting time is required. (J Cardiovasc Electrophysiol, Vol. 24, pp. 290‐296, March 2013)     

Complex electrograms within the coronary sinus: time- and frequency-domain characteristics, effects of antral pulmonary vein isolation, and relationship to clinical outcome in patients with paroxysmal and persistent atrial fibrillation

Background: The mechanistic and clinical significance of complex fractionated atrial electrograms (CFAE) in the coronary sinus (CS) has been unclear. Methods and Results: Antral pulmonary vein isolation (APVI) was performed in 77 patients with paroxysmal (32) or persistent AF (45). CS electrograms recorded for 60 seconds before and after APVI were analyzed in the time‐ and frequency‐domains. Dominant frequency (DF), complexity index (CI: change in polarity of depolarization), and fractionation index (FI: change in direction of depolarization slope) were determined. Before APVI, there was no difference in DF, CI, or FI between paroxysmal and persistent AF. APVI resulted in a significant decrease in DF, CI, and FI in all patients. Baseline CI (43 ± 13/s vs 54 ± 14/s, P = 0.03) and FI (64 ± 23/s vs 87 ± 30/s, P = 0.02) were lower in patients with paroxysmal AF who had AF terminated by ablation than who did not. At 10 ± 2 months, 69% of patients with paroxysmal AF and 49% of patients with persistent AF were free from AF after single ablation. Baseline CI was higher among patients with paroxysmal AF who had AF after APVI (56 ± 20/s vs 44 ± 10/s, P = 0.03). In patients with persistent AF, there was a larger decrease in DF after APVI among patients who remained free from AF (13 ± 11% vs 7 ± 9%, P < 0.05). Conclusions: Complexity of CS electrograms may reflect drivers of AF that perpetuate paroxysmal AF after APVI. In persistent AF, the extent to which APVI decreases DF in the CS correlates with efficacy, suggesting that DF identifies patients who may require additional ablation beyond APVI.     

Predictors of recurrence in patients undergoing cryoballoon ablation for treatment of atrial fibrillation: the independent role of sleep-disordered breathing

Predictors of AF Recurrence After Cryoballoon PVI. Introduction: In patients with atrial fibrillation (AF) undergoing pulmonary vein isolation, cryoballoon technique (cryoPVI) has been adopted in many centers. This study aimed to evaluate predictors of AF recurrence including impact of sleep‐disordered breathing (SDB). Methods and Results: In 82 patients consecutively assigned to cryoPVI cardiorespiratory screening for SDB, assessment of medical history, ECG, echocardiography, standard laboratory measurement, and blood gas analysis were performed prior to intervention. After a 3‐month blanking period, a 7‐day Holter ECG was performed at 3, 6 and then every 6 months to determine AF recurrence. Seventy‐five patients (69 paroxysmal AF, 6 persistent AF, 22 female, age 60 ± 9 years) completed at least 6‐month follow‐up. Median follow‐up of 12 months (interquartile range 6–18 months) confirmed maintenance of sinus rhythm in 69.4% of these patients. Stepwise forward regression model revealed moderate to severe SDB (cut‐off apnea‐hypopnea‐index (AHI) ≥ 15 per hour; Hazard Ratio (HR) 2.95, P = 0.04), early recurrence of AF (HR 8.74, P < 0.001), persistent AF (HR 7.16, P < 0.001), preprocedural class III‐antiarrhythmic drug treatment (HR 3.63, P = 0.02), but not SDB per se (AHI ≥ 5 per hour) as independent predictors for AF recurrence. Conclusion: Moderate to severe SDB is a treatable condition that independently predicts AF recurrence in patients undergoing cryoPVI. Screening for SDB and adequate treatment may improve long‐term success of cryoPVI. (J Cardiovasc Electrophysiol, Vol. 23, pp. 18‐25, January 2012)