Salwa Beheiry

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.)

Pulmonary Vein Stenosis After Radiofrequency Ablation of Atrial Fibrillation Functional Characterization, Evolution, and Influence of the Ablation Strategy

Background—Pulmonary vein (PV) stenosis is a complication of ablation for atrial fibrillation. The impact of different ablation strategies on the incidence of PV stenosis and its functional characterization has not been described. Methods and Results—PV isolation was performed in 608 patients. An electroanatomic approach was used in 71 and circular mapping in 537 (distal isolation, 25; ostial isolation based on PV angiography, 102; guided by intracardiac echocardiography, 140; with energy delivery based on visualization of microbubbles, 270). Severe (≥70%) narrowing was detected in 21 patients (3.4%), and moderate (50% to 69%) and mild (<50%) narrowing occurred in 27 (4.4%) and 47 (7.7%), respectively. Severe stenosis occurred in 15.5%, 20%, 2.9%, 1.4%, and 0%, respectively. Development of symptoms was correlated with involvement of >1 PV with severe narrowing (P =0.01), whereas all patients with mild and moderate narrowing were asymptomatic. In the latter group, lung perfusion (V/Q) scans were normal in all but 4 patients. All patients with severe stenosis had abnormal perfusion scans. Conclusions—V/Q scans are useful to assess the functional significance of PV stenosis. Mild and moderate degrees of PV narrowing are not associated with development of symptoms and seem to have no or minimal detrimental effect on pulmonary flow. The incidence of severe PV stenosis seems to be declining with better imaging techniques to ensure ostial isolation and to guide power titration. Mild narrowing 3 months after ablation does not preclude future development of severe stenosis and should be assessed with repeat imaging studies.

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.

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. Conclusion— 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.

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.

Ventricular tachycardias arising from the aortic sinus of valsalva: an under-recognized variant of left outflow tract ventricular tachycardia.

OBJECTIVES To describe a normal heart left bundle branch block, inferior axis ventricular tachycardia (VT), that could not be ablated from the right or left ventricular outflow tracts. BACKGROUND Whether these VTs are epicardial and can be identified by a specific electrocardiographic pattern is unclear. METHODS Twelve patients with normal heart left bundle branch block, inferior axis VT and previously failed ablation were included in this study. Together with mapping in the right and left ventricular outflow tracts, we obtained percutaneous epicardial mapping in the first five patients and performed aortic sinus of Valsalva mapping in all patients. RESULTS No adequate pace mapping was observed in the right and left ventricular outflow tracts. Earliest ventricular activation was noted in the epicardium and the aortic cusps. All patients were successfully ablated from the aortic sinuses of Valsalva (95% CI 0% to 18%). The electrocardiographic pattern associated with this VT was left bundle branch block, inferior axis and early precordial transition with Rs or R in V2 or V3. Ventricular tachycardia from the left sinus had rS pattern in lead I, and VT from the noncoronary sinus had a notched R wave in lead I. None of the patients had complications and all remained arrhythmia-free at a mean follow-up of 8 +/- 2.6 months. CONCLUSIONS Normal heart VT with left bundle branch block, inferior axis and early precordial transition can be ablated in the majority of patients from either the left or the noncoronary aortic sinus of Valsalva.

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.

Impact of type of atrial fibrillation and repeat catheter ablation on long-term freedom from atrial fibrillation: Results from a multicenter study

BACKGROUND/OBJECTIVE The purpose of this prospective multicenter study was to compare results of catheter ablation in patients with paroxysmal atrial fibrillation (PAF) and those with nonparoxysmal atrial fibrillation (NPAF). The impact and the role of repeat catheter ablation were assessed in patients with recurrence. METHODS/RESULTS One thousand four hundred four patients underwent catheter ablation for atrial fibrillation (AF) performed by 12 operators at four institutions using a single technique guided by intracardiac echocardiography. Of these patients, 728 had PAF and 676 had NPAF. Among the NPAF patients, 293 had persistent AF and 383 had long-standing persistent AF. Patients with NPAF had a higher incidence of hypertension and/or structural heart disease (64.8% vs 48.5%, P = .003) and a lower mean left ventricular ejection fraction (53.3% +/- 8.7% vs 55.7 +/- 6.5%, P <.001). All patients underwent antral isolation of all four pulmonary veins and the superior vena cava. At mean follow-up of 57 +/- 17 months, 565 of 728 patients with PAF and 454 of 676 patients with NPAF (77.6% vs 67.2%, P <.001) had freedom from AF after a single ablation procedure. For arrhythmia recurrences, 74.2% (121/163) patients with PAF and 74.8% (166/222) with NPAF underwent repeat ablation, after which 92.4% patients with PAF and 84.0% patients with NPAF remained free from AF. CONCLUSION Pulmonary vein antrum isolation guided by intracardiac echocardiography results in significant freedom from AF, even when performed by multiple operators in different centers. At least moderate efficacy can be achieved in patients with NPAF, although the success rate is lower than in patients with PAF. Considerably higher success can be achieved in both groups with repeat ablation.

Percutaneous Pericardial Instrumentation for Endo-Epicardial Mapping of Previously Failed Ablations

Background—The epicardial location of an arrhythmia could be responsible for unsuccessful endocardial catheter ablation. Methods and Results—In 48 patients referred after prior unsuccessful endocardial ablation, we considered percutaneous, subxiphoid instrumentation of the pericardial space for mapping and ablation. Thirty patients had ventricular tachycardia (VT), 6 patients had a right- and 4 had a left-sided accessory pathway (AP), 4 patients had inappropriate sinus tachycardia, and 4 patients had atrial arrhythmias. Of the 30 VTs, 24 (6 with ischemic cardiomyopathy, 3 with idiopathic cardiomyopathy, and 15 with normal hearts) appeared to originate from the epicardium. Seventeen (71%) of these 24 VTs were successfully ablated with epicardial lesions. The other 7 VTs had early epicardial sites that were inaccessible, predominantly because of interference from the left atrial appendage. Six of these were successfully ablated from the left coronary cusp. In 5 of the 10 patients with an AP, the earliest activation was recorded epicardially. Three of these were right atrial appendage–to–right ventricle APs, and epicardial ablation was successful. No significant complications were observed. Conclusions—Failure of endocardial ablation could reflect the presence of an epicardial arrhythmia substrate. Epicardial instrumentation and ablation appeared feasible and safe and provided an alternative strategy for the treatment of patients with a variety of arrhythmias. This was particularly true for VT, including patients without structural heart disease.

Endo-epicardial homogenization of the scar versus limited substrate ablation for the treatment of electrical storms in patients with ischemic cardiomyopathy.

OBJECTIVES This study investigated the impact on recurrences of 2 different substrate approaches for the treatment of these arrhythmias. BACKGROUND Catheter ablation of electrical storms (ES) for ventricular arrhythmias (VAs) has shown moderate long-term efficacy in patients with ischemic cardiomyopathy. METHODS Ninety-two consecutive patients (81% male, age 62 ± 13 years) with ischemic cardiomyopathy and ES underwent catheter ablation. Patients were treated either by confining the radiofrequency lesions to the endocardial surface with limited substrate ablation (Group 1, n = 49) or underwent endocardial and epicardial ablation of abnormal potentials within the scar (homogenization of the scar, Group 2, n = 43). Epicardial access was obtained in all Group 2 patients, whereas epicardial ablation was performed in 33% (14) of these patients. RESULTS Mean ejection fraction was 27 ± 5. During a mean follow-up of 25 ± 10 months, the VAs recurrence rate of any ventricular tachycardia (VTs) was 47% (23 of 49 patients) in Group 1 and 19% (8 of 43 patients) in Group 2 (log-rank p = 0.006). One patient in Group 1 and 1 patient in Group 2 died at follow-up for noncardiac reasons. CONCLUSIONS Our study demonstrates that ablation using endo-epicardial homogenization of the scar significantly increases freedom from VAs in ischemic cardiomyopathy patients.