Ablation Versus Amiodarone for Treatment of Persistent Atrial Fibrillation in Patients With Congestive Heart Failure and an Implanted Device: Results From the AATAC Multicenter Randomized Trial.

BACKGROUND: Whether catheter ablation (CA) is superior to amiodarone (AMIO) for the treatment of persistent atrial fibrillation (AF) in patients with heart failure is unknown. METHODS AND RESULTS: This was an open-label, randomized, parallel-group, multicenter study. Patients with persistent AF, dual-chamber implantable cardioverter defibrillator or cardiac resynchronization therapy defibrillator, New York Heart Association II to III, and left ventricular ejection fraction <40% within the past 6 months were randomly assigned (1:1 ratio) to undergo CA for AF (group 1, n=102) or receive AMIO (group 2, n=101). Recurrence of AF was the primary end point. All-cause mortality and unplanned hospitalization were the secondary end points. Patients were followed up for a minimum of 24 months. At the end of follow-up, 71 (70%; 95% confidence interval, 60%-78%) patients in group 1 were recurrence free after an average of 1.4±0.6 procedures in comparison with 34 (34%; 95% confidence interval, 25%-44%) in group 2 (log-rank P<0.001). The success rate of CA in the different centers after a single procedure ranged from 29% to 61%. After adjusting for covariates in the multivariable model, AMIO therapy was found to be significantly more likely to fail (hazard ratio, 2.5; 95% confidence interval, 1.5-4.3; P<0.001) than CA. Over the 2-year follow-up, the unplanned hospitalization rate was (32 [31%] in group 1 and 58 [57%] in group 2; P<0.001), showing 45% relative risk reduction (relative risk, 0.55; 95% confidence interval, 0.39-0.76). A significantly lower mortality was observed in CA (8 [8%] versus AMIO (18 [18%]; P=0.037). CONCLUSIONS: This multicenter randomized study shows that CA of AF is superior to AMIO in achieving freedom from AF at long-term follow-up and reducing unplanned hospitalization and mortality in patients with heart failure and persistent AF. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00729911.

Management of Periprocedural and Early Pericardial Effusions With Tamponade Following Ablation of Atrial Fibrillation With Uninterrupted Factor Xa Inhibitors: A Case Series.

INTRODUCTION: Because of the absence of a dedicated reversal agent, the outcome of pericardial effusion (PE) following procedures performed with uninterrupted apixaban or rivaroxaban is unknown. We report the characteristics of PEs presenting with tamponade in patients undergoing AF ablation with uninterrupted factor Xa inhibition (FXaI) to understand their management and prognosis. METHODS AND RESULTS: We performed a multicenter cross-sectional survey in 10 centers across the United States. Patient data were obtained by chart review. In all patients the procedure was performed with uninterrupted FXaI. A total of 16 PEs requiring intervention were reported from 5 centers. Two patients were on apixaban 5 mg BD, the remaining on rivaroxaban 20 mg OD. Eleven PEs occurred in the periprocedural setting, and 5 PEs occurred from 1 to 28 days after the procedure. Pericardiocentesis and drainage were performed in all cases. Protamine and 4-factor prothrombin complex concentrate (4F-PCC) were given in all periprocedural cases. Two patients required surgery: in one case coagulation of the pericardial blood prevented effective drainage, and in the other bleeding was secondary to a steam pop-induced atrial tear. None of the postprocedural cases required FXaI reversal and the dose of rivaroxaban was temporarily reduced. No fatal outcomes or thromboembolic events were reported. CONCLUSION: Pericardiocentesis and drainage with FXaI reversal proved effective in the management of acute PEs with tamponade occurring periprocedurally in patients undergoing AF ablation with uninterrupted FXaI. Early postprocedural effusions can be treated with pericardiocentesis without the need of a reversal agent.

Periprocedural stroke and bleeding complications in patients undergoing catheter ablation of atrial fibrillation with different anticoagulation management: results from the Role of Coumadin in Preventing Thromboembolism in Atrial Fibrillation (AF) Patients Undergoing Catheter Ablation (COMPARE) randomized trial.

BACKGROUND: Periprocedural thromboembolic and hemorrhagic events are worrisome complications of catheter ablation for atrial fibrillation (AF). The periprocedural anticoagulation management could play a role in the incidence of these complications. Although ablation procedures performed without warfarin discontinuation seem to be associated with lower thromboembolic risk, no randomized study exists. METHODS AND RESULTS: This was a prospective, open-label, randomized, parallel-group, multicenter study assessing the role of continuous warfarin therapy in preventing periprocedural thromboembolic and hemorrhagic events after radiofrequency catheter ablation. Patients with CHADS2 score ≥1 were included. Patients were randomly assigned in a 1:1 ratio to the off-warfarin or on-warfarin arm. The incidence of thromboembolic events in the 48 hours after ablation was the primary end point of the study. The study enrolled 1584 patients: 790 assigned to discontinue warfarin (group 1) and 794 assigned to continuous warfarin (group 2). No statistical difference in baseline characteristics was observed. There were 39 thromboembolic events (3.7% strokes [n=29] and 1.3% transient ischemic attacks [n=10]) in group 1: two events (0.87%) in patients with paroxysmal AF, 4 (2.3%) in patients with persistent AF, and 33 (8.5%) in patients with long-standing persistent AF. Only 2 strokes (0.25%) in patients with long-standing persistent AF were observed in group 2 (P<0.001). Warfarin discontinuation emerged as a strong predictor of periprocedural thromboembolism (odds ratio, 13; 95% confidence interval, 3.1-55.6; P<0.001). CONCLUSION: This is the first randomized study showing that performing catheter ablation of AF without warfarin discontinuation reduces the occurrence of periprocedural stroke and minor bleeding complications compared with bridging with low-molecular-weight heparin. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01006876.

Pulmonary Vein Isolation to Reduce Future Risk of Atrial Fibrillation in Patients Undergoing Typical Flutter Ablation: Results from a Randomized Pilot Study (REDUCE AF).

BACKGROUND: This study examined incidence of AF following cavotricuspid isthmus (CTI) ablation alone or CTI plus prophylactic pulmonary vein isolation (PVI) in patients presenting with isolated atrial flutter (AFL) with no history of AF. METHODS AND RESULTS: We enrolled 216 patients with isolated typical atrial flutter and randomized them to CTI alone (group 1, n = 108, 61.2 ± 9.7 year, 75% male) or CTI+PVI ablation (group 2, n = 108, 62.4 ± 9.3 year, 73% male). Insertible loop recorder (ILR) was implanted in 21 and 19 patients from groups 1 and 2, respectively. Remaining patients were monitored with event recorders, ECG, 7-day Holter. Follow-up period was for 18 ± 6 months. Compared to group 1, group 2 had significantly longer procedural duration (75.9 ± 33 min vs. 161 ± 48 min [P < 0.001]) and fluoroscopy time (15.9 ± 12.3 min vs. 56.4+21 min [P < 0.001]). At the end of follow-up, 65 (60.2%) in group 1 and 77 (71.3%) in group 2 were arrhythmia free off-AAD (log-rank P = 0.044). A subgroup analysis was performed with 55 year age cut-off. In the <55 age group the CTI only population had similar success as in CTI+PVI, (21 of 24 [83.3%] vs. 19 of 22 [86.4%], respectively, log-rank P = 0.74). In the ≥55 group, having CTI+PVI showed significantly higher success compared to CTI only; 45 of 84 (53.6%) were AF/AT free in CTI only group versus 58 of 86 (67.4%) with CTI+PVI (log-rank P = 0.029). CONCLUSION: Prophylactic PVI reduced new-onset AF in patients with lone atrial flutter.

Catheter ablation of asymptomatic longstanding persistent atrial fibrillation: impact on quality of life, exercise performance, arrhythmia perception, and arrhythmia-free survival.

BACKGROUND: Impact of catheter ablation on exercise performance, quality of life (QoL) and symptom perception in asymptomatic longstanding persistent AF (LSP-AF) patients has not been reported yet. METHODS AND RESULTS: Sixty-one consecutive patients (mean age 62 ±13 years, 71% males) with asymptomatic LSP-AF undergoing first catheter ablation were enrolled. Extended pulmonary vein antrum isolation plus ablation of complex fractionated atrial electrograms and nonpulmonary vein triggers was performed in all. QoL survey was taken at baseline and 12-months postablation, using Short Form-36 (SF-36). Information on arrhythmia perception was obtained using a standard questionnaire and corroborating symptoms with documented evidence of arrhythmia. Exercise tests were performed on 38 patients at baseline and 5 months after procedure. Recurrence was assessed using event recorder, cardiology evaluation, electrocardiogram, and 7-day holter monitoring. After 20 ± 5 months follow-up, 36 (57%) patients remained recurrence-free off-AAD. Of the 25 patients experiencing recurrence, 21 (84%) were symptomatic. Compared to baseline, follow-up SF-36 scores improved significantly in many measures. For patients with successful ablation, physical component summary (PCS) and mental component summary (MCS) demonstrated substantial improvement ( MCS: 64.2 ± 22.3 to 70.1 ± 18.6 [P = 0.041]; PCS: 62.6 ± 18.4 to 70.0 ± 14.4 [P = 0.032]). Postablation exercise study in recurrence-free patients showed significant reduction in resting and peak heart rate (75 ± 11 vs. 90 ± 17 and 132 ± 20 vs. 154.5 ± 36, respectively, P < 0.001), increase in peak oxygen pulse (13.4 ± 3 vs. 18.9 ± 16 mL/beat, Δ5.5 ± 15, P = 0.001), peak VO2 /kg (19.7 ± 5 to 23.4 ± 13 mL/kg/min [Δ 3.7 ± 10, P = 0.043]), and corresponding MET (5.6 ± 1 to 6.7 ± 4 [Δ1.1 ± 3, P = 0.03]). No improvement was observed in patients with failed procedures. CONCLUSION: Successful ablation improves exercise performance and QoL in asymptomatic LSP-AF patients.

Long-term outcome of catheter ablation in atrial fibrillation patients with coexistent metabolic syndrome and obstructive sleep apnea: impact of repeat procedures versus lifestyle changes.

INTRODUCTION: Metabolic syndrome (MS) and obstructive sleep apnea (OSA) are well-known independent risk factors for atrial fibrillation (AF) recurrence. This study evaluated ablation outcome in AF patients with coexistent MS and OSA and influence of lifestyle modifications (LSM) on arrhythmia recurrence. METHODS AND RESULTS: We included 1,257 AF patients undergoing first catheter ablation (30% paroxysmal AF). Patients having MS + OSA were classified into Group 1 (n = 126; 64 ± 8 years; 76% male). Group 2 (n = 1,131; 62 ± 11 years; 72% male) included those with either MS (n = 431) or OSA (n = 112; no CPAP users) or neither of these comorbidities (n = 588). Patients experiencing recurrence after first procedure were divided into 2 subgroups; those having sporadic events (frequency < 2 months) remained on previously ineffective antiarrhythmic drugs (AAD) and aggressive LSM, while those with persistent arrhythmia (incessant or ≥2 months) underwent repeat ablation. After 34 ± 8 months of first procedure, 66 (52%) in Group 1 and 386 (34%) in Group 2 had recurrence (P < 0.001). Recurrence rate in only-MS, only-OSA, and without MS/OSA groups were 40%, 38%, and 29%, respectively. Patients with MS + OSA experienced substantially higher recurrence compared to those with lone MS or OSA (52% vs. 40% vs. 38%; P = 0.036). Of the 452 patients having recurrence, 250 underwent redo-ablation and 194 remained on AAD and LSM. At 20 ± 6 months, 76% of the redo group remained arrhythmia-free off AAD whereas 74% of the LSM group were free from recurrence (P = 0.71), 33% of which were off AAD. CONCLUSIONS: MS and OSA have additive negative effect on arrhythmia recurrence following single procedure. Repeat ablation or compliant LSM increase freedom from recurrent AF.

Atrioesophageal Fistula Rates Before and After Adoption of Active Esophageal Cooling During Atrial Fibrillation Ablation.

BACKGROUND: Active esophageal cooling reduces the incidence of endoscopically identified severe esophageal lesions during radiofrequency (RF) catheter ablation of the left atrium for the treatment of atrial fibrillation. A formal analysis of the atrioesophageal fistula (AEF) rate with active esophageal cooling has not previously been performed. OBJECTIVES: The authors aimed to compare AEF rates before and after the adoption of active esophageal cooling. METHODS: This institutional review board (IRB)-approved study was a prospective analysis of retrospective data, designed before collecting and analyzing the real-world data. The number of AEFs occurring in equivalent time frames before and after adoption of cooling using a dedicated esophageal cooling device (ensoETM, Attune Medical) were quantified across 25 prespecified hospital systems. AEF rates were then compared using generalized estimating equations robust to cluster correlation. RESULTS: A total of 14,224 patients received active esophageal cooling during RF ablation across the 25 hospital systems, which included a total of 30 separate hospitals. In the time frames before adoption of active cooling, a total of 10,962 patients received primarily luminal esophageal temperature (LET) monitoring during their RF ablations. In the preadoption cohort, a total of 16 AEFs occurred, for an AEF rate of 0.146%, in line with other published estimates for procedures using LET monitoring. In the postadoption cohort, no AEFs were found in the prespecified sites, yielding an AEF rate of 0% (P < 0.0001). CONCLUSIONS: Adoption of active esophageal cooling during RF ablation of the left atrium for the treatment of atrial fibrillation was associated with a significant reduction in AEF rate.

Healthcare utilization and expenditures in patients with atrial fibrillation treated with catheter ablation.

AIM: The aim was to estimate the impact of catheter ablation on short- and long-term healthcare utilization and expenditures among atrial fibrillation (AF) patients in general and Medicare populations. METHODS: Data were analyzed from The MarketScan(®) Databases. MarketScan data contain deidentified patient-level records from employer-sponsored and public health insurance plans. Multivariable regression models for utilization and expenditures were built for all patients, with subanalyses performed for patients ≥65 years. Results were compared to preablation figures and reported for 5 time groups, based on duration of available postablation follow-up: 6-12 months; 12-18 months; 18-24 months; 24-30 months; and 30-36 months. RESULTS: A total of 3,194 patients were identified who had undergone catheter ablation for treatment of AF, had continuous enrollment in the database 6 months prior to first ablation, and had at least 1-year follow-up postablation. Compared to the 6 months prior to ablation, there were significant reductions in the number of outpatient appointments, inpatient days, and emergency room visits in the total study population and in the subset ≥65 years. There was a statistically significant (P < 0.01) decrease in total healthcare expenditures across 4 of the 5 6-month time periods, with annual savings ranging from $3,300 to $9,200. For patients ≥65 years, annual savings ranged from $3,200 to $9,200. Drug utilization also significantly declined (P < 0.01), with average annual medication savings ranging from $670 to $890, and from $740 to $880 for patients ≥65 years. CONCLUSION: Catheter ablation for AF reduced healthcare utilization and expenditures up to 3 years postablation. This reduction was consistent, significant, and had implications for general and Medicare populations.

Early-stage COVID-19 pandemic observations on pulmonary embolism using nationwide multi-institutional data harvesting.

We introduce a multi-institutional data harvesting (MIDH) method for longitudinal observation of medical imaging utilization and reporting. By tracking both large-scale utilization and clinical imaging results data, the MIDH approach is targeted at measuring surrogates for important disease-related observational quantities over time. To quantitatively investigate its clinical applicability, we performed a retrospective multi-institutional study encompassing 13 healthcare systems throughout the United States before and after the 2020 COVID-19 pandemic. Using repurposed software infrastructure of a commercial AI-based image analysis service, we harvested data on medical imaging service requests and radiology reports for 40,037 computed tomography pulmonary angiograms (CTPA) to evaluate for pulmonary embolism (PE). Specifically, we compared two 70-day observational periods, namely (i) a pre-pandemic control period from 11/25/2019 through 2/2/2020, and (ii) a period during the early COVID-19 pandemic from 3/8/2020 through 5/16/2020. Natural language processing (NLP) on final radiology reports served as the ground truth for identifying positive PE cases, where we found an NLP accuracy of 98% for classifying radiology reports as positive or negative for PE based on a manual review of 2,400 radiology reports. Fewer CTPA exams were performed during the early COVID-19 pandemic than during the pre-pandemic period (9806 vs. 12,106). However, the PE positivity rate was significantly higher (11.6 vs. 9.9%, p < 10-4) with an excess of 92 PE cases during the early COVID-19 outbreak, i.e., ~1.3 daily PE cases more than statistically expected. Our results suggest that MIDH can contribute value as an exploratory tool, aiming at a better understanding of pandemic-related effects on healthcare.

Periprocedural stroke and management of major bleeding complications in patients undergoing catheter ablation of atrial fibrillation: the impact of periprocedural therapeutic international normalized ratio.

BACKGROUND: Catheter ablation of atrial fibrillation is associated with the potential risk of periprocedural stroke, which can range between 1% and 5%. We developed a prospective database to evaluate the prevalence of stroke over time and to assess whether the periprocedural anticoagulation strategy and use of open irrigation ablation catheter have resulted in a reduction of this complication. METHODS AND RESULTS: We collected data from 9 centers performing the same ablation procedure with the same anticoagulation protocol. We divided the patients into 3 groups: ablation with an 8-mm catheter off warfarin (group 1), ablation with an open irrigated catheter off warfarin (group 2), and ablation with an open irrigated catheter on warfarin (group 3). Outcome data on stroke/transient ischemic attack and bleeding complications during and early after the procedures were collected. Of 6454 consecutive patients in the study, 2488 were in group 1, 1348 were in group 2, and 2618 were in group 3. Periprocedural stroke/transient ischemic attack occurred in 27 patients (1.1%) in group 1 and 12 patients (0.9%) in group 2. Despite a higher prevalence of nonparoxysmal atrial fibrillation and more patients with CHADS2 (congestive heart failure, hypertension, age >75 years, diabetes mellitus, and prior stroke or transient ischemic attack) score >2, no stroke/transient ischemic attack was reported in group 3. Complications among groups 1, 2, and 3, including major bleeding (10 [0.4%], 11 [0.8%], and 10 [0.4%], respectively; P>0.05) and pericardial effusion (11 [0.4%], 11 [0.8%], and 12 [0.5%]; P>0.05), were equally distributed. CONCLUSIONS: The combination of an open irrigation ablation catheter and periprocedural therapeutic anticoagulation with warfarin may reduce the risk of periprocedural stroke without increasing the risk of pericardial effusion or other bleeding complications.

Left atrial appendage: an underrecognized trigger site of atrial fibrillation.

BACKGROUND: Together with pulmonary veins, many extrapulmonary vein areas may be the source of initiation and maintenance of atrial fibrillation. The left atrial appendage (LAA) is an underestimated site of initiation of atrial fibrillation. Here, we report the prevalence of triggers from the LAA and the best strategy for successful ablation. METHODS AND RESULTS: Nine hundred eighty-seven consecutive patients (29% paroxysmal, 71% nonparoxysmal) undergoing redo catheter ablation for atrial fibrillation were enrolled. Two hundred sixty-six patients (27%) showed firing from the LAA and became the study population. In 86 of 987 patients (8.7%; 5 paroxysmal, 81 nonparoxysmal), the LAA was found to be the only source of arrhythmia with no pulmonary veins or other extrapulmonary vein site reconnection. Ablation was performed either with focal lesion (n=56; group 2) or to achieve LAA isolation by placement of the circular catheter at the ostium of the LAA guided by intracardiac echocardiography (167 patients; group 3). In the remaining patients, LAA firing was not ablated (n=43; group 1). At the 12+/-3-month follow-up, 32 patients (74%) in group 1 had recurrence compared with 38 (68%) in group 2 and 25 (15%) in group 3 (P<0.001). CONCLUSIONS: The LAA appears to be responsible for arrhythmias in 27% of patients presenting for repeat procedures. Isolation of the LAA could achieve freedom from atrial fibrillation in patients presenting for a repeat procedure when arrhythmias initiating from this structure are demonstrated.

Pulmonary-vein isolation for atrial fibrillation in patients with heart failure.

BACKGROUND: Pulmonary-vein isolation is increasingly being used to treat atrial fibrillation in patients with heart failure. METHODS: In this prospective, multicenter clinical trial, we randomly assigned patients with symptomatic, drug-resistant atrial fibrillation, an ejection fraction of 40% or less, and New York Heart Association class II or III heart failure to undergo either pulmonary-vein isolation or atrioventricular-node ablation with biventricular pacing. All patients completed the Minnesota Living with Heart Failure questionnaire (scores range from 0 to 105, with a higher score indicating a worse quality of life) and underwent echocardiography and a 6-minute walk test (the composite primary end point). Over a 6-month period, patients were monitored for both symptomatic and asymptomatic episodes of atrial fibrillation. RESULTS: In all, 41 patients underwent pulmonary-vein isolation, and 40 underwent atrioventricular-node ablation with biventricular pacing; none were lost to follow-up at 6 months. The composite primary end point favored the group that underwent pulmonary-vein isolation, with an improved questionnaire score at 6 months (60, vs. 82 in the group that underwent atrioventricular-node ablation with biventricular pacing; P<0.001), a longer 6-minute-walk distance (340 m vs. 297 m, P<0.001), and a higher ejection fraction (35% vs. 28%, P<0.001). In the group that underwent pulmonary-vein isolation, 88% of patients receiving antiarrhythmic drugs and 71% of those not receiving such drugs were free of atrial fibrillation at 6 months. In the group that underwent pulmonary-vein isolation, pulmonary-vein stenosis developed in two patients, pericardial effusion in one, and pulmonary edema in another; in the group that underwent atrioventricular-node ablation with biventricular pacing, lead dislodgment was found in one patient and pneumothorax in another. CONCLUSIONS: Pulmonary-vein isolation was superior to atrioventricular-node ablation with biventricular pacing in patients with heart failure who had drug-refractory atrial fibrillation. (ClinicalTrials.gov number, NCT00599976.)

Atrial fibrillation ablation in patients with therapeutic international normalized ratio: comparison of strategies of anticoagulation management in the periprocedural period.

BACKGROUND: The best approach to management of anticoagulation before and after atrial fibrillation ablation is not known. METHODS AND RESULTS: We compared outcomes in consecutive patients undergoing pulmonary vein antrum isolation for persistent atrial fibrillation. Early in our practice, warfarin was stopped 3 days before ablation, and a transesophageal echocardiogram was performed to rule out clot. Enoxaparin, initially 1 mg/kg twice daily (group 1) and then 0.5 mg/kg twice daily (group 2), was used to "bridge" patients after ablation. Subsequently, warfarin was continued to maintain the international normalized ratio between 2 and 3.5 (group 3). Minor bleeding was defined as hematoma that did not require intervention. Major bleeding was defined as either cardiac tamponade, hematoma that required intervention, or bleeding that required blood transfusion. Pulmonary vein ablation was performed in 355 patients (group 1=105, group 2=100, and group 3=150). More patients had spontaneous echocardiographic contrast in groups 1 and 2. One patient in group 1 had an ischemic stroke compared with 2 patients in group 2 and no patients in group 3. In group 1, 23 patients had minor bleeding, 9 had major bleeding, and 1 had pericardial effusion but no tamponade. In group 2, 19 patients had minor bleeding, and 2 patients developed symptomatic pericardial effusion with need for pericardiocentesis 1 week after discharge. In group 3, 8 patients developed minor bleeding, and 1 patient developed pericardial effusion with no tamponade. CONCLUSIONS: Continuation of warfarin throughout pulmonary vein ablation without administration of enoxaparin is safe and efficacious. This strategy can be an alternative to bridging with enoxaparin or heparin in the periprocedural period.

Efficacy, safety, and outcome of atrial fibrillation ablation in septuagenarians.

AIMS: Catheter ablation is an effective treatment for atrial fibrillation (AF). The outcome of AF ablation in septuagenarians is not clear. Our aim was to evaluate success rate, outcome, and complication rate of AF ablation in septuagenarians. METHODS AND RESULTS: We collected data from 174 consecutive patients over 75 years of age who underwent AF ablation from 2001 to 2006. AF was paroxysmal in 55%. High-risk CHADS score (>or=2) was present in 65% of the population. Over a mean follow-up of 20 +/- 14 months, 127 (73%) maintained sinus rhythm (SR) with a single procedure, whereas 47 patients had recurrence of AF. Twenty of them had a second ablation, successful in 16 (80%). Major acute complications included one CVA and one hemothorax (2/194 [1.0%]). During the follow-up, three patients had a CVA within the first 6 weeks after ablation. Warfarin was discontinued in 138 out 143 patients (96%) who maintained SR without AADs with no embolic event occurring over a mean follow-up of 16 +/- 12 months. CONCLUSION: AF ablation is a safe and effective treatment for AF in septuagenarians.

Pulmonary vein calcification by EBCT in patients with drug refractory nonvalular atrial fibrillation.

INTRODUCTION: Pulmonary veins in patients with atrial fibrillation (AF) have been shown to be highly arrhythmogenic. Calcification in these veins may play an adjunctive role in the pathogenesis of AF. METHODS AND RESULTS: A case control study was performed in patients with drug refractory nonvalvular AF whose preablation computed tomography chest scans demonstrated pulmonary vein (PV) calcification. Eight out of 48 patients with PV calcification were compared to 50 patients without AF who underwent electron beam computed tomography coronary artery calcium scores. These patients were matched for age, gender, coronary artery calcium scores, and the presence of PV calcification. The mean age of the combined group was 57 +/- 9 years and 60% were men. The mean total PV calcium score was significantly higher at 199 +/- 112 in patients with AF compared to 106 +/- 52 in controls (p = 0.018). Men had significantly higher total PV calcium score than women in both groups. CONCLUSION: Total PV calcium score was significantly higher in patients with atrial fibrillation. Increased PV calcification may play an adjunctive role in the pathogenesis in initiating and maintaining AF.

Intracardiac echo-guided image integration: optimizing strategies for registration.

INTRODUCTION: Image integration is being used in ablation procedures. However, the success of this approach is dependent on the accuracy of the image integration process. This study aims to evaluate the in vivo accuracy and reliability of the integrated image. METHODS AND RESULTS: One hundred twenty-four patients undergoing radiofrequency (RF) ablation catheter ablation for atrial fibrillation (AF) were recruited for this study from three different centers. Cardiac computerized tomography (CT) was performed in all patients and a 3D image of the left atrium (LA) and pulmonary veins (PVs) was extracted for registration after segmentation using a software program (CartoMerge, Biosense Webster, Inc.). Different landmarks were selected for registration and compared. Surface registration was then done and the impact on integration and the landmarks was evaluated. The best landmark registration was achieved when the posterior points on the pulmonary veins were selected (5.6 +/- 3.2). Landmarks taken on the anterior wall, left atrial appendage (LAA) or the coronary sinus (CS) resulted in a larger registration error (9.1 +/- 2.5). The mean error for surface registration was 2.17 +/- 1.65. However, surface registration resulted in shifting of the initially registered landmark points leading to a larger error (from 5.6 +/- 3.2 to 9.2 +/- 2.1; 95% CI 4.2-3.05). CONCLUSION: Posterior wall landmarks at the PV-LA junction are the most accurate landmarks for image integration in respect to the target ablation area. The concurrent use of the present surface registration algorithm may result in shifting of the initial landmarks with loss of their initial correlation with the area of interest.