P94 LOWER RATE OF MAJOR BLEEDING IN HIGH–RISK PATIENTS UNDERGOING LEFT ATRIAL APPENDAGE OCCLUSION: A PROPENSITY MATCHED COMPARISON WITH DIRECT ORAL ANTICOAGULATION

Background

Stroke prophylaxis in very high risk (CHA2DS2–VASc ≥ 5) patients with atrial fibrillation (AF) is one of the major challenges faced by physicians. Specifically, initiating direct oral anticoagulants (DOACs) in these patients poses a therapeutic conundrum due to the concomitant high risk of bleeding. Left atrial appendage occlusion (LAAO) might be a potential alternative for thromboembolic (TE) prevention; however, there are no studies comparing these two strategies in very high–risk patients.

Objective

To evaluate the efficacy of LAAO versus DOACs in AF patients at very high TE risk.

Methods

Data were extracted from two prospective databases including 1053 Watchman and 1328 DOAC patients. Watchman patients with a CHA2DS2–VASc ≥ 5 accounted for 26.3% (n = 277). In order to attenuate the imbalance in covariates, a 1:1 propensity score matching technique was used (co–variates: age, sex, CHA2DS2–VASc and HAS–BLED scores). This method resulted in 554 matched patients (277 patients per group; mean age: 79±7y; 57.4% F; CHA2DS2–VASc: 5.8±0.9). The primary endpoint was a composite of cardiovascular (CV) death, TE events (Stroke/TIA/peripheral embolism) and clinically significant bleeding. The annual TE and major bleeding risks were estimated based on the CHA2DS2–VASc score and compared with the annualized observed risk.

Results

After a mean follow–up of 26±7 months, total events were 55 (9.4 event rates per 100 patient–years) in LAAO group vs. 78 (14.9 event rates per 100 patient–years) in DOAC group. DOACs had a significantly higher risk of the primary endpoint (hazard ratio [HR]: 1.30; 95% confidence interval [CI]: 1.08 to 1.56; p = 0.03). TE events (HR: 1.15; 95% CI: 0.84 to 1.57; p = 0.63) and CV death (HR: 1.13; 95% CI: 0.84 to 1.54; p = 0.63) did not differ between groups. Major bleeding events were significantly lower in LAAO patients (HR: 0.75; 95% CI: 0.51 to 0.82; p = 0.04). The unadjusted estimated risk of TE events was 12.3% with LAAO and 12.4% with DOACs. The annualized incidence of TE was 3.2% with LAAO and 4.1% with DOACs, which led to a risk reduction of 74% and 67%, respectively.

Conclusion

In a large cohort of AF patients at very high TE risk (CHA2DS2–VASc ≥ 5), LAAO showed similar stroke prevention but a significantly lower risk of major bleeding than DOACs during a > 2year follow–up.

C32 TRANSCATHETER LEAK OCCLUSION WITH ENDOVASCULAR COILS FOLLOWING LEFT ATRIAL APPENDAGE CLOSURE: PROCEDURAL SUCCESS AND OUTCOMES BEFORE AND AFTER LEAK CLOSURE

Background

Whether residual peri–device leaks after left atrial appendage occlusion (LAAO) portend a higher risk of thromboembolism (TE), it is still a matter of debate.

Objectives

We report the TE risk in patients with incomplete LAA closure before and after leak closure with endovascular coils.

Methods

One hundred twenty–four Watchman patients with a significant (≥3mm) leak (mean age: 74 ± 9 years; 66.9% males; CHA2DS2–VASc: 4.4 ± 1.7; HAS–BLED: 3.1 ± 1) underwent LAA leak coiling. The expected annual TE risk was estimated based on the patients’ CHA2DS2–VASc and compared with the annualized incidence observed before and after coiling (Fig.1B).

Results

The time between LAAO and leak coiling was 8±6 months [83 patients–year (PY)]; before leak closure, 6 (4.8%) patients had a TE event (annualized rate: 7.2%). Coil deployment was successful in all cases [median n. of coils deployed: 5 (IQR: 2–10)]. Procedure time was 79 ± 40 min; the mean volume of iodinated contrast medium used was 80 ± 43mL. The overall complication rate was 2.4% (1 pericardial tamponade, 2 pericardial effusion). Follow–up TEE after 61±14 days revealed complete LAA sealing or a negligible leak in 117 cases (94.4%); the remaining 7 patients had a moderate leak. During 14±6 months post–coiling (145 PY), 1 (0.8%) patient suffered from stroke. The incidence of TE events was significantly lower after leak closure than before coiling (0.8% vs 4.8%; log–rank p = 0.02; Fig.1A). The annualized TE rates were 7.2% before and 0.7% after leak closure (Fig. 1A). According to the expected rate estimated from the patients’ CHA2DS2–VASc (9.8%), LAAO with and without significant leaks yielded to a risk reduction of 26.5% and 92.9% (Fig. 1B).

Conclusions

Transcatheter leak occlusion via endovascular coils was safe. LAA closure led to a significant reduction in TE events.

P4 LEFT ATRIAL APPENDAGE ANATOMICAL CHANGES FOLLOWING RADIOFREQUENCY–BASED OSTIAL ISOLATION

Background

Left atrial appendage (LAA) electrical isolation (ei) may be achieved via radiofrequency (RF) energy applications at the level of the appendage ostium targeting the sites of earliest activation recorded by a mapping catheter. Notably, RF has long been used in vascular, orthopedic, and aesthetic surgery to promote thermal–induced collagen matrix contraction, fibrosis, and tissue retraction. LAA anatomical changes associated to RF–induced tissue retraction have never been reported.

Objective

To quantify the anatomical changes of the LAA ostium following RF–based LAAei.

Methods

Thirty–four consecutive patients requiring AF ablation with LAAei underwent transesophageal echocardiography (TEE) within 7 days before (baseline TEE) and >6 months after (follow–up TEE) ablation. The diameter of LAA orifice and landing zone were measured at 4 different views (0°, 45°, 90°, 135°). Measurements were performed by two independent reviewers blinded to the patient’s identity.

Results

Among 34 AF patients (68±7yrs, 73.5% males), the LAA morphology was classified as chicken wing in 15 (44%) patients, windsock in 10 (29%), cactus in 6 (18%), and cauliflower in 3 (9%). At baseline TEE, the mean maximum and mean minimum ostial diameters were 25±4mm and 22±4mm, respectively. The mean maximum and mean minimum diameters of the landing zone were 26±4mm and 23±3mm, respectively. On average, LAAei was achieved after 16±7 minutes of RF at a power of 45–47W. Follow–up TEE was performed 257±148 days after LAAei. The median LAA contraction velocity was 0.1 m/s (IQR: 0.04–0.18) and was significantly impaired in all patients. At follow–up TEE, the mean maximum and mean minimum ostial diameters were 19±4mm and 17±3mm, respectively. The mean maximum and mean minimum diameters of the landing zone were 20±4mm and 18±4mm, respectively. The mean relative reduction of the ostium and the landing zone were –24.4% and –22.5%, respectively. Box–Whisker plots of the maximum and minimum ostial diameters before and after LAAei are reported in Fig. 1.

Conclusion

RF led to a > 20% reduction of the diameters of the ostium and the landing zone. These changes may have important implications for a successful percutaneous occlusion procedure and justify a staged approach of isolation and occlusion.

Optimal ablation targets during second catheter ablation in patients with persistent AF

Introduction

Pulmonary vein isolation (PVI) is the cornerstone of ablative therapy in atrial fibrillation (AF). However, the one-year success rate after single ablation procedure is known to be up to 60%, necessitating repeat procedures in many.

Purpose

We evaluated the impact of different ablation strategies on procedural success at the second ablation in patients with persistent AF (PerAF).

Methods

Consecutive PerAF patients scheduled to undergo their second ablation were screened and only those that have received PVI plus isolation of left atrial posterior wall (PWI) and superior vena cava (SVC) at the first procedure (n=1390), were included in the analysis. At the second ablation, all reconnected structures were ablated. Additionally, based on operators' decision, non-PV triggers were targeted for ablation.

Patients were classified into two groups based on the ablation strategy: group 1: Re-isolation of reconnected PVs, PW, SVC and group 2: additional ablation of non-PV triggers (from inter-atrial septum, coronary sinus (CS), left atrial appendage (LAA) and crista terminalis). Arrhythmia-monitoring was performed quarterly for 1 year and biannually afterwards. Ablation success was assessed off-antiarrhythmic drugs (AAD).

Results

Of the 1390 patients included in the analysis, 698 were in group 1 and 692 were in group 2.

In group 1, reconnected PV, PW and SVC were re-isolated in 98 (14%), 311 (44.5%) and 173 (24.8%) respectively. In 131 (18.7%) patients, in the absence of any reconnection, CS was empirically isolated.

In group 2, PV, PW and SVC were re-isolated in 83 (12%), 270 (39%) and 113 (16.3%) patients respectively. Additionally, non-PV triggers were ablated in 505 (73%) and empirical isolation of LAA and CS in the absence of detectable triggers and PV reconnection was performed in 187 (27%).

At 2 years of follow-up, 425 (61%) and 602 (87%) from group 1 and 2 were arrhythmia-free off-AAD (p<0.001).

Conclusion

Including non-PV triggers as targets for ablation at the repeat procedure was associated with significantly higher success rate in persistent AF.

Funding Acknowledgement

Type of funding sources: None.

Long-term outcome of endocardial-only versus combined endocardial-epicardial homogenization of the scar for treatment of ventricular tachycardia in patients with ischemic cardiomyopathy

Introduction

We investigated the ablation success of scar homogenization with combined (epicardial + endocardial) versus endocardial-only approach for ventricular tachycardia (VT) in patients with ischemic cardiomyopathy (ICM) at 5 years of follow-up.

Method

Consecutive ICM patients undergoing VT ablation at our center were classified into group 1: endocardial scar homogenization and group 2: endocardial +epicardial scar homogenization. Patients with previous open heart surgery were excluded.

All patients underwent bipolar substrate mapping with standard scar settings defined as normal tissue >1.5 mV and severe scar <0.5 mV. Non-inducibility of monomorphic VT was the procedural endpoint in both groups. Patients were followed up twice a year for 5 years with implantable device interrogations.

Results

A total of 361 (Group 1: 291 and group 2: 70) patients were included in the study (mean age: 67 years, male: 88.4%).

At 5 years, significantly higher number of patients from group 2 remained arrhythmia-free (figure 1). Of those patients, 87 (45%) and 51 (89%) from group 1 and 2 respectively were off-anti-arrhythmic drugs (AAD) (p<0.001). After adjusting for age, gender, hypertension, diabetes, and obstructive sleep apnea, scar homogenization using endo-epicardial approach was associated with 51% less recurrence compared to the endocardial ablation strategy (Hazard Ratio: 0.49, 95% CI: 0.27–0.89, p: 0.02).

Conclusion

In this series of patients with ischemic cardiomyopathy and VT, endo-epicardial scar homogenization was associated with a lower need for AAD and a significantly lower recurrence rate at 5-years of follow-up compared to the endocardial ablation alone.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Linear increase in the number of non-pulmonary vein triggers from paroxysmal to persistent and long-standing persistent AF in patients undergoing repeat procedure after successful isolation of pulmona

Introduction

This study evaluated the prevalent triggers responsible for recurrence following successful PVI in different types of atrial fibrillation (AF).

Methods

Consecutive AF patients undergoing repeat catheter ablation with permanently isolated PV were included in the analysis. High-dose isoproterenol challenge (20- 30μg/min for 15–20min) was used to confirm PV reconnection and identify non-PV triggers.

Circular mapping catheter (CMC) was used to map the site of origin of significant ectopic activity by comparing the activation sequence of the sinus beat with that of the ectopic beat. For the coronary sinus (CS), ablation catheter was positioned at the level of the mitral valve annulus, parallel to the one positioned in the CS. Left atrial appendage (LAA) firing was detected by placing the CMC in the left superior PV and thus recording far-field potentials from the LAA.

Results

This prospective study included 1850 AF patients undergoing repeat AF ablation (Table 1), of which 573 (31%) had received one and the remaining 1277 patients had received 2 earlier ablations. Permanent PVI was confirmed with isoproterenol challenge.

Table 1 shows the distribution of non-PV triggers. A linear increase in the number of non-PV triggers was observed from PAF to PerAF to LSPAF. Significantly higher number of LSPAF patients had detectable non-PV triggers compared to PerAF and PAF cases.

Conclusion

We observed a linear increase in the number of non-PV triggers in PAF to PerAF and LSPAF patients experiencing recurrence with successful isolation of PVs. As non-PV triggers are often not targeted by operators, this could be the underlying mechanism for more frequent recurrences in non-paroxysmal AF.

Funding Acknowledgement

Type of funding sources: None. Table 1

Benefits of early intervention with catheter ablation in patients with atrial fibrillation

Background

Radiofrequency catheter ablation, a widely recognized therapeutic option for atrial fibrillation (AF) has limited success rate as it is influenced by several factors including duration of AF.

Purpose

We evaluated the ablation success in AF patients intervened early versus late in the disease course.

Methods

Consecutive AF patients undergoing their first catheter ablation in 2015–16 at our center were included in the analysis. Patients were classified into two groups based on the time to ablation after AF diagnosis; 1) early: ≤12 months and 2) late: >12 months.

All received PV isolation plus isolation of posterior wall and superior vena cava. Additionally, in non-paroxysmal AF cases, non-PV triggers were identified with isoproterenol-challenge and ablated. Patients were prospectively followed up for 3 years with regular rhythm monitoring.

Results

A total of 752 and 1248 patients were included in the “early” and “late” group respectively. Baseline characteristics of the study population is provided in Table 1 A. At 4 years of follow-up, overall success rate off-antiarrhythmic drugs was significantly higher in the “early” group (65.4% vs 57%, p<0.001). After stratification by AF type, “early” group was still associated with significantly higher success rate compared to the “late” group (Table 1B).

Conclusion

In this large series with standardized ablation strategy, early intervention with catheter ablation was associated with higher success rate in all AF types.

Funding Acknowledgement

Type of funding sources: None. Table 1

Recovery of conduction following high power short duration approach in radiofrequency catheter ablation for atrial fibrillation: a single-center experience

Introduction

High-power short-duration (HPSD) ablation is currently being adopted by many as the preferred procedural technique in atrial fibrillation (AF). However, the optimal duration of energy delivery to successfully create a durable lesion is not clear yet.

Purpose

We evaluated the association of electrical reconnection with lesion-duration in HPSD ablation.

Methods

Consecutive AF patients undergoing repeat procedure after a prior HPSD ablation with or without isolation of left atrial appendage (LAA) and coronary sinus (CS) were included in this analysis. HPSD ablation was defined as ablation with maximum temperature setting at 420C and power delivery at 45 W for 10–15 sec (5 seconds in the CS area and posterior wall near the esophagus). In some patients a mechanical esophageal deviation tool was used to deflect the esophagus away from the ablation site.

Results

A total of 2249 AF patients (with LAA and CS isolation: 1451; without LAA and CS isolation: 798) receiving redo ablation after a prior HPSD procedure were included in the analysis. At the prior procedure with the HPSD approach, mean duration of ablation was significantly shorter in the area facing the esophagus compared to elsewhere (5.2±1.5 vs 12.5±1.7 seconds, p<0.001). Application duration was reduced to <10 sec to avoid overheating and steam pops in 1221 (84%) patients receiving LAA and CS isolation.

At the redo, recovery of conduction was noted in the CS (592, 40.8%), LAA (493, 34%), and PV and left atrial posterior wall (LAPW) (310, 13.8%). Of the 310 patients with LAPW reconnection, 91% (n=282) had the conduction recovered in the area facing the esophagus.

In 73 patients, esophageal displacement device was used during the prior HPSD ablation. Average duration of ablation lesions in LAPW among those 73 patients was 9.2±2 seconds. PV-LAPW reconnection was observed in 3/73 (4.1%) patients.

Conclusion

HPSD ablation with lesion duration of <10 sec was associated with conduction recovery in the LAA, CS and the LAPW area facing esophagus.

Funding Acknowledgement

Type of funding sources: None.

Evaluation of a novel cardiac signal processing system for electrophysiology procedures: The PURE EP 2.0 study

Background

Intracardiac electrogram data remain one of the primary diagnostic inputs guiding complex ablation procedures. However, the technology to collect, process, and display intracardiac signals has known shortcomings and has not advanced in several decades.

Objective

The purpose of this study was to evaluate a new signal processing platform, the PURE EP™ system (PURE), in a multi‐center, prospective study.

Methods

Intracardiac signal data of clinical interest were collected from 51 patients undergoing ablation procedures with PURE, the signal recording system, and the 3D mapping system at the same time stamps. The samples were randomized and subjected to blinded, controlled evaluation by three independent electrophysiologists to determine the overall quality and clinical utility of PURE signals when compared to conventional sources. Each reviewer assessed the same (92) signal sample sets and responded to (235) questions using a 10‐point rating scale. If two or more reviewers rated the PURE signal higher than the control, it was deemed superior.

Results

A total of 93% of question responses showed consensus amongst the blinded reviewers. Based on the ratings for each pair of signals, a cumulative total of 164 PURE signals out of 218 (75.2%) were statistically rated as Superior for this data set (p < .001). Only 14 PURE signals out of 218 were rated as Inferior (6.4%).

Conclusion

The PURE intracardiac signals were statistically rated as superior when compared to conventional systems.

Risk factors for progression of paroxysmal to persistent atrial fibrillation following successful PV isolation

Background

Progression from paroxysmal (PAF) to persistent atrial fibrillation (PerAF) following effective PV isolation (PVI) has important clinical implications, as it is relevant for subsequent management of the arrhythmia.

Objective

We evaluated risk factors responsible for progression of PAF to PerAF following successful PVI.

Methods

Consecutive AF patients that received their first catheter ablation as well as the first redo at our center were identified (n=1352). Patients were included in group 1 if the diagnosis was PAF at both first and redo procedure (PAF to PAF) and group 2 if PAF at index progressed to PerAF at redo. All patients received PVI plus isolation of LA posterior wall and SVC at the first procedure.

Results

A total of 822 patients remained as PAF at redo, whereas 530 (39%) progressed from PAF to PerAF. Clinical characteristics of the study population are presented in table 1. In multivariate analysis, BMI (OR 1.02, 1.01–1.04, p=0.04), hypertension (1.4, 1.08–1.8, p=0.01), heart failure (1.67, 1.03–2.69, p=0.03), LA size (2.75, 2.29–3.31, p&lt;0.001) were independent predictors of progression of PAF to PerAF. Data on serum-transthyretin level was available for 37 and 48 patients in group 1 and 2 respectively. It was &lt;18 mg/dL (normal) in 33 (68.7%) patients in group 2 vs 6 (16.2%) in group 1 (p&lt;0.001).

Conclusion

In our patients, after successful PVI, progression of PAF to PerAF was mediated by independent risk factors such as high BMI, heart failure, hypertension, larger LA size and lower LVEF.

Funding Acknowledgement

Type of funding source: None

Extended Pulmonary Vein Isolation: is it sufficient to achieve long-term sinus rhythm in octogenarian women with atrial fibrillation?

Background

Atrial fibrillation (AF) is a disease of the elderly and women typically present with AF at an older age than men do. Moreover, they tend to experience more symptoms and post-ablation recurrences, have worse quality of life and increased risk of stroke and mortality.

Objective

We evaluated long-term efficacy of our standard ablation approach of extended pulmonary vein isolation (PVI) in octogenarian women undergoing their first AF ablation.

Methods

Consecutive female AF patients aged ≥80 years receiving their first catheter ablation at our center were included in the analysis. Our standard ablation approach at the first procedure includes PVI + empirical isolation of left atrial posterior wall (LAPW) and superior vena cava (SVC). Complete abolition of all potentials rather than decrease in amplitudes was the procedural end point. Patients were prospectively monitored at regular intervals for 3 years after the index procedure with event recorders, 12-lead ECG, cardiology evaluation at office visits and 7-day Holter monitoring.

Results

A total of 194 patients with mean age of 84.2±1.4 years were included in the analysis. Of the 194, 120 (61.8%) had non-paroxysmal AF. All received PVI+ isolation of LAPW and SVC. Acute procedural success was achieved in 100% of cases.

At 3 years of follow-up, 24 (12.4%) patients remained in sinus rhythm; 22 on- and 2 off-antiarrhythmic drugs (AAD). All of the 23 patients had paroxysmal AF as their initial diagnosis.

Of the 170 patients experiencing recurrence, 147 underwent repeat ablation. PV/PW/SVC reconnection was noted in only 6 (4.1%) patients at redo. Triggers originating from non-PV sites were targeted for ablation in all. At 1.5 years after the repeat procedure, 136 (92.5%) patients were in sinus rhythm; 131 off-AAD and 5 patients on-AAD.

Conclusion

Extended PVI including isolation of posterior wall and SVC was not sufficient to maintain long-term sinus rhythm in majority of octogenarian women, regardless of AF type. Moreover, non-PV triggers rather than PV reconnection was the major cause of recurrence in this subset of AF population.

Funding Acknowledgement

Type of funding source: None

Risk factors and effective ablation strategy in patients presenting with left atrial flutter with no previous ablation for atrial fibrillation

Background

A typical left atrial flutter (LAFL) may occur as a proarrhythmic complication of ablation for atrial fibrillation (AF).

Objective

We evaluated the risk factors and the best ablation strategy for LAFL in patients with no prior AF ablation.

Methods

Consecutive patients undergoing first catheter ablation for AFL with no prior procedure for AF were included in this prospective analysis. Based on the ablation strategy, patients were divided into, Group 1: PVI+ Flutter ablation (ablation of re-entry circuits) and Group 2: PVI+ Non-PV trigger ablation (targeting areas of focal activity as triggers). 3-D mapping of the LA was performed during tachycardia to identify the reentrant circuit.

PV isolation was performed in all patients. In group 1, ablation line was chosen to transect the area critical for the circuit (roof and mitral line). In group 2, ectopic beats arising from extra-PV foci detected by isoproterenol challenge were ablated. Off-drug success rate was assessed in all.

Results

A total of 92 and 90 patients were included in group 1 and 2 respectively. Baseline characteristics are provided in table 1. Pre-existent LA scar was detected in 91.3% and 90% of patients in group 1 and 2 respectively.

At 2 years of follow-up, 11/92 (12%) from group 1 and 60/90 (66.7%) from group 2 remained arrhythmia-free off-drugs (p&lt;0.001). In the multivariate analysis, PVI +flutter ablation was detected to be associated with significantly high risk of recurrence [HR: 3.92 (95% CI: 2.52–6.1, p&lt;0.001)]

Conclusion

In this series of patients presenting with LAFL with no earlier AF ablations, pre-existent left atrial scar was detected in majority of cases and PVI+ non-PV trigger ablation provided significantly better success rate than PVI+ flutter ablation.

Funding Acknowledgement

Type of funding source: None

State of Fluoroless Procedures in Cardiac Electrophysiology Practice

In the past decade, the use of interventional electrophysiological (EP) procedures for the diagnosis and treatment of cardiac arrhythmias has exponentially increased. These procedures usually require fluoroscopy to guide the advancement and frequent repositioning of intracardiac catheters, resulting in both the patient and the operator being subjected to a considerable degree of radiation exposure. Although shielding options such as lead gowns, glasses, and pull-down shields are useful for protecting the operator, they do not lessen the patient’s level of exposure. Furthermore, the prolonged use of lead gowns can exponentiate the onset of orthopedic problems among operators. Recent advancements in three-dimensional cardiac mapping systems and the use of radiation-free imaging technologies such as magnetic resonance imaging and intracardiac ultrasound allow operators to perform EP procedures with minimal or even no fluoroscopy. In this review, we sought to describe the state of fluoroless procedures in EP practice.

P4761Impact of focal ablation versus isolation of the coronary sinus in patients undergoing repeat radiofrequency catheter ablation of persistent atrial fibrillation

Introduction

Non-pulmonary vein (PV) triggers originating from the coronary sinus (CS) are a common finding in atrial fibrillation (AF) patients. To date, no studies have investigated the clinical impact of focal ablation versus isolation of the CS in patients presenting triggers from this area.

Purpose

This study analyzed the effectiveness of two different approaches for CS ablation (total isolation vs focal ablation) in persistent AF patients undergoing repeat AF ablation.

Methods

Consecutive persistent AF patients undergoing repeat ablation were enrolled in this prospective analysis. All patients had triggers from the CS documented during high-dose isoproterenol. Pulmonary vein antrum isolation (PVAI) extended to the posterior wall (PW) plus superior vena cava (SVC) isolation was performed in all patients at first procedure. At repeat procedure, PV, PW, and SVC were re-isolated, if needed. Focal ablation or isolation of the CS was performed based on operator's choice either at first and/or repeat procedure, along with ablation of other non-PV triggers. Patients with triggers from left atrial appendage were excluded from the study.

Results

Overall, 628 consecutive patients (73.4% male, age 66.9±9.0 years) were enrolled. On the basis of the CS ablation strategy, patients were categorized into two groups: Group I received CS isolation (n=389) and Group II received CS focal ablation (n=239). Major clinical characteristics were not different between groups. PV reconnection was documented in 55 (14.1%) patients of Group I and 33 (13.8%) of Group II. The incidence of procedure-related complications was similar between the two groups (10 [2.6%] in Group I vs 6 [2.5%] in Group II; p=0.9). After a follow-up of 18±8 months, 276 (71%) patients in Group I and 115 (48%) in Group II remained arrhythmia-free (p<0.001, figure.1). After adjusting for age, gender and clinically relevant variables, CS isolation was associated with a significantly higher arrhythmia-free survival rate (HR: 0.47; 95% CI: 0.37–0.61, p-value<0.001).

Conclusions

In patients with documented triggers from the CS undergoing repeat ablation of persistent AF, isolation rather than focal ablation of the CS significantly increased freedom from atrial tachyarrhythmias in the long term.

Should fast pathway ablation be reconsidered in typical atrioventricular nodal re-entrant tachycardia?

INTRODUCTION

Atrioventricular nodal re-entry tachycardia (AVNRT) is the most common, regular narrow-complex tachycardia. The established treatment is catheter ablation of the AV nodal slow pathway (SP). However, in a select group of patients with long PR intervals in sinus rhythm, SP ablation can lead to AV block due to the absence of robust anterograde conduction through the fast pathway (FP). This report aims to demonstrate that AV nodal FP ablation is a reasonable approach in patients with AVNRT and poor or absent anterograde FP conduction.

METHODS AND RESULTS

Standard electrophysiology study techniques were used in the electrophysiology laboratory. Catheter ablations were performed using radiofrequency energy. Mapping of intracardiac activation was performed with electroanatomical mapping systems. Outcomes were assessed acutely during the procedure and during routine clinical follow-up. Six patients with first-degree AV block and recurrent AVNRT who underwent ablation of their tachycardia at our institution are presented. One patient underwent ablation of AV nodal SP resulting in high-degree AV block necessitating pacemaker implantation. The remaining five patients underwent ablation of the AV nodal FP guided by electroanatomical mapping of the earliest atrial activation in tachycardia. These five had successful treatment of the tachycardia with preservation of anterograde AV nodal conduction. Mapping and ablation approach to eliminate retrograde FP conduction are described.

CONCLUSION

In select patients with AVNRT and poor anterograde FP conduction, retrograde FP ablation is reasonable and is less likely to result in AV block and pacemaker dependency.

Programming Cardiac Resynchronization Therapy for Electrical Synchrony: Reaching Beyond Left Bundle Branch Block and Left Ventricular Activation Delay

BACKGROUND

QRS narrowing following cardiac resynchronization therapy with biventricular (BiV) or left ventricular (LV) pacing is likely affected by patient-specific conduction characteristics (PR, qLV, LV-paced propagation interval), making a universal programming strategy likely ineffective. We tested these factors using a novel, device-based algorithm (SyncAV) that automatically adjusts paced atrioventricular delay (default or programmable offset) according to intrinsic atrioventricular conduction.

METHODS AND RESULTS

Seventy-five patients undergoing cardiac resynchronization therapy (age 66±11 years; 65% male; 32% with ischemic cardiomyopathy; LV ejection fraction 28±8%; QRS duration 162±16 ms) with intact atrioventricular conduction (PR interval 194±34, range 128-300 ms), left bundle branch block, and optimized LV lead position were studied at implant. QRS duration (QRSd) reduction was compared for the following pacing configurations: nominal simultaneous BiV (Mode I: paced/sensed atrioventricular delay=140/110 ms), BiV+SyncAV with 50 ms offset (Mode II), BiV+SyncAV with offset that minimized QRSd (Mode III), or LV-only pacing+SyncAV with 50 ms offset (Mode IV). The intrinsic QRSd (162±16 ms) was reduced to 142±17 ms (-11.8%) by Mode I, 136±14 ms (-15.6%) by Mode IV, and 132±13 ms (-17.8%) by Mode II. Mode III yielded the shortest overall QRSd (123±12 ms, -23.9% [P<0.001 versus all modes]) and was the only configuration without QRSd prolongation in any patient. QRS narrowing occurred regardless of QRSd, PR, or LV-paced intervals, or underlying ischemic disease.

CONCLUSIONS

Post-implant electrical optimization in already well-selected patients with left bundle branch block and optimized LV lead position is facilitated by patient-tailored BiV pacing adjusted to intrinsic atrioventricular timing using an automatic device-based algorithm.

Initial Experience With High-Risk Patients Excluded From Clinical Trials: Safety of Short-Term Anticoagulation After Left Atrial Appendage Closure Device

BACKGROUND

The implantation of left atrial appendage closure device (WATCHMAN, Boston Scientific, Natick, MA) is an alternative option to oral anticoagulation (OAC) for stroke prevention in atrial fibrillation. Patients require short-term OAC after implantation to avoid device thrombosis. The 2 clinical trials that assessed this device excluded patients thought not to be candidates for OAC. As such, little is known about the safety of this strategy in patients with previous major bleeding events.

METHODS AND RESULTS

All 20 consecutive patients with history of spontaneous major bleeding while on OAC who had subsequently undergone WATCHMAN device implantation at our institution were included. A newly conceived multidisciplinary Atrial Fibrillation Stroke Prevention Center evaluated patients for candidacy for device implantation and subsequent antithrombotic therapy. The primary outcome was spontaneous major bleeding while receiving short-term postprocedural OAC. Median CHA2DS2-VASc and HAS-BLED scores were 5 (quartiles 5-6) and 5 (quartiles 4-5), respectively. Previous major bleeding events were major gastrointestinal bleeding, intracranial bleeding, spontaneous hemopericardium with cardiac tamponade, and hemarthrosis in 11, 7, 1, and 1 patients, respectively. None of the patients had spontaneous major bleeding during the course of OAC after device implantation. In 1 patient, OAC was discontinued after 40 days because of mechanical fall with head trauma resulting in subdural hematoma with no associated neurological deficits; this was managed conservatively.

CONCLUSIONS

With careful multidisciplinary evaluation, a short course of OAC after WATCHMAN device implantation in patients with previous spontaneous major bleeding events is associated with low risk of recurrent spontaneous major bleeding.

Radiofrequency Ablation of Persistent Atrial Fibrillation: Diagnosis-to-Ablation Time, Markers of Pathways of Atrial Remodeling, and Outcomes

BACKGROUND

Various ablation strategies of persistent atrial fibrillation (PersAF) have had disappointing outcomes, despite concerted clinical and research efforts, which could reflect progressive atrial fibrillation-related atrial remodeling.

METHODS AND RESULTS

Two-year outcomes were assessed in 1241 consecutive patients undergoing first-time ablation of PersAF (2005-2012). The time intervals between the first diagnosis of PersAF and the ablation procedures were determined. Patients had echocardiograms and measures of B-type natriuretic peptide and C-reactive protein before the procedures. The median diagnosis-to-ablation time was 3 years (25th-75th percentiles 1-6.5). With longer diagnosis-to-ablation time (based on quartiles), there was a significant increase in recurrence rates in addition to an increase in B-type natriuretic peptide levels (P=0.01), C-reactive protein levels (P<0.0001), and left atrial size (P=0.03). The arrhythmia recurrence rates over 2 years were 33.6%, 52.6%, 57.1%, and 54.6% in the first, second, third, and fourth quartiles, respectively (P(categorical)<0.0001). In Cox Proportional Hazard analyses, B-type natriuretic peptide levels, C-reactive protein levels, and left atrial size were associated with arrhythmia recurrence. The diagnosis-to-ablation time had the strongest association with the ablation outcomes which persisted in multivariable Cox analyzes (hazard ratio for recurrence per +1Log diagnosis-to-ablation time 1.27, 95% confidence interval 1.14-1.43; P<0.0001; hazard ratio fourth versus first quartile 2.44, 95% confidence interval 1.68-3.65; P(categorical)<0.0001).

CONCLUSIONS

In patients with PersAF undergoing ablation, the time interval between the first diagnosis of PersAF and the catheter ablation procedure had a strong association with the ablation outcomes, such as shorter diagnosis-to-ablation times were associated with better outcomes and in direct association with markers of atrial remodeling.

Long-term outcomes in patients with ambulatory new york heart association class III and IV heart failure undergoing cardiac resynchronization therapy

Patients with ambulatory New York Heart Association (NYHA) class IV heart failure were significantly underrepresented in clinical trials of cardiac resynchronization therapy (CRT). The natural long-term trajectory of survival free of left ventricular assist device (LVAD) or heart transplant in patients with ambulatory class IV symptoms who underwent CRT has not been established. We extracted clinical data on 723 consecutive patients with NYHA class III or ambulatory class IV heart failure, left ventricular ejection fraction ≤35%, and a QRS duration ≥120 ms who underwent CRT from September 30, 2003, to August 6, 2007. Chart notes immediately before CRT were reviewed to confirm NYHA class status before CRT. Kaplan-Meier curves and a multivariate Cox proportional hazards model were constructed to determine long-term survival free of heart transplant and LVAD based on NYHA class status. Of the 723 patients, 52 had ambulatory class IV symptoms. Over a mean follow-up of 5.0 ± 2.5 years controlling for many possible confounders, ambulatory NYHA class IV status was independently associated with poor long-term outcomes. The 1-, 2-, 3-, 4-, and 5-year survival free of LVAD or heart transplant for class III versus ambulatory class IV patients was 92.0%, 84.0%, 75.0%, 68.1%, and 63.2% versus 75.0%, 61.5%, 52.0%, 45%, and 40.4%, respectively. Although patients with ambulatory class IV heart failure receiving CRT have inferior long-term outcomes compared with those with class III symptoms, survival in class IV patients continues to parallel class III patients over an extended follow-up. At 5 years, survival free of LVAD or heart transplant in ambulatory class IV patients receiving CRT is 40%.

Omega-3 fatty acids, vitamin C and Zn supplementation in asthmatic children: a randomized self-controlled study

OBJECTIVES

Bronchial asthma is a chronic inflammatory airways disease. Nutritional intervention is an important tool to decrease the severity of many chronic inflammatory diseases including asthma. The aim of this study is to evaluate the role of omega-3 fatty acids, vitamin C and Zn in children with moderately persistent asthma.

PATIENTS AND METHODS

Randomly assigned, placebo-self-controlled 60 children with moderate persistent asthma completed the study, were subjected to alternating phases of supplementation with omega-3 fatty acids, vitamin C and Zn either singly or in combination separated with washout phases. Childhood asthma control test (C-ACT), pulmonary function tests and sputum inflammatory markers were evaluated at the beginning of the study and at the end of each therapeutic phase.

RESULTS

There was a significant improvement of C-ACT, pulmonary function tests and sputum inflammatory markers with diet supplementation with omega-3 fatty acids, vitamin C and Zn (p < 0.001*). There was also significant improvement with the combined use of the three supplementations than single use of any one of them (p < 0.001*).

CONCLUSION

Diet supplementation with omega-3 fatty acids, Zn and vitamin C significantly improved asthma control test, pulmonary function tests and pulmonary inflammatory markers in children with moderately persistent bronchial asthma either singly or in combination.

HLA in Egyptian children with biliary atresia

We studied the human leukocytes antigens in 18 Egyptian children with biliary atresia (BA) without extrahepatic congenital malformations. There was a significant increased frequency of both B8 and DR3 (83.3% and 94.4% in patients with BA compared with 6.5% and 14.9% in the general population, respectively). Ten patients had the B8/DR3 haplotype. Our results support the hypothesis that genetic factors may play a role in susceptibility to BA.

Experimental intravenous inoculation of Klebsiella rhinoscleromatis bacilli in albino rats: a histopathological and bacteriological study

Scleroma, chronic specific granuloma of the nose and upper respiratory tract, is endemic in Egypt and many other countries. The exact pathogenesis of the disease as regards the aetiological role of Klebsiella rhinoscleromatis is contradictory. This work investigated the effect of experimental intravenous injection of K. rhinoscleromatis in albino rats to demonstrate that the micro-organism can fulfil Koch's postulates. Micro-organisms were isolated from biopsy specimens taken from nasal lesions of 10 patients in the granulomatous stage of scleroma. Specimens were subjected to bacteriological and histopathological examinations to confirm the diagnosis. A 100 microl volume of freshly prepared bacterial inoculum containing 10(8) cfu/ml was injected weekly in the tail vein of each of 30 albino rats for 5 consecutive weeks. Biopsy specimens were taken from sacrificed animals and subjected to bacteriological and histopathological examinations. Positive histopathological diagnosis of scleroma was reported in the nose of 66.7% of rats, the larynx of 46.7%, the lungs of 26.7% and liver of 20% of rats. Bacteriological techniques were successful in revealing K. rhinoscleromatis from the nose of 36.7% of rats, the larynx of 30% and the lungs of 20% of rats. Various techniques were carried out to demonstrate the micro-organisms in tissue sections. Two histochemical stains for bacteria were employed: silver and Periodic Acid Schiff (PAS) stains. Immunoperoxidase technique using Klebsiella capsular type 3 antiserum was applied. It gave positive results in 66.7% of the 6 stained liver sections in spite of negative bacteriological cultures. The histiocytic nature of the Mikulicz cells was confirmed using alpha-1 antitrypsin, an immunohistochemical marker of histiocytes, and by studying the ultrastructural features of Mikulicz cells using the transmission electron microscope.

U74389G prevents vasospasm after subarachnoid hemorrhage in dogs

OBJECTIVE

Oxygen-derived free radicals may contribute to vasospasm after the rupture of an intracranial aneurysm through direct vasoconstricting effects occurring within the arterial wall or, secondarily, by causing lipid peroxidation in the subarachnoid erythrocytes with secondary induction of vasoconstriction. U74389G is a potent inhibitor of lipid peroxidation and a scavenger of oxygen-derived free radicals. This study determined the relative contributions of oxygen-derived free radicals and lipid peroxidation to vasospasm in the double-hemorrhage dog model.

METHODS

Sixteen dogs underwent baseline (Day 0) cerebral angiography and induction of subarachnoid hemorrhage by two injections of blood into the cisterna magna 2 days apart. They were randomized to receive drug vehicle (n=8) or U74389G (n=8, 3 mg/kg of body weight/d) intravenously. Drug administration and end point analysis were blinded. The end points were angiographic vasospasm, as assessed by comparison of angiograms obtained before and 7 days after subarachnoid hemorrhage, and the levels of malondialdehyde and salicylate hydroxylation products (dihydroxybenzoic acids) in cerebrospinal fluid and of malondialdehyde in subarachnoid blood clots and basilar arteries 7 days after hemorrhage.

RESULTS

Comparisons within groups of Day 0 and Day 7 angiograms and between groups of angiograms obtained at Day 7, showed significant vasospasm in animals in the vehicle group (mean+/-standard error, 51%+/-4) but not in the U74389G group (25%+/-11, P < 0.05, unpaired t test). High-pressure liquid chromatographic assays of malondialdehyde and dihydroxybenzoic acids in cerebrospinal fluid, subarachnoid blood clots, and basilar arteries showed no significant differences between groups.

CONCLUSION

The significant prevention of vasospasm by U74389G without change in levels of indicators of free radical reactions suggests that the effect of the drug is related to other processes occurring in the arterial wall and that cerebrospinal fluid levels of oxygen radicals and lipid peroxides are not useful markers of vasospasm.

Topical levocabastine for the treatment of perennial allergic rhinitis

The ultrastructure of the nasal mucosa following the use of intranasal levocabastine was studied in 20 patients suffering from perennial allergic rhinitis. The patients received twice daily 0.05 per cent levocabastine spray with a treatment duration of four weeks. At the end of the treatment period regression of the allergic process was evidenced by progressive reappearance of normal cilia and microvilli on the columnar cells, decrease of intercellular oedema and cytoplasmic vacuoles, increased number of mucous acinar cells, gradual decrease of vascular congestion, as well as diminished oedema fluid formation. The drug, however, had no effect on mast cell degranulation nor on eosinophilic infiltration. Normalization of the ultrastructural features correlated well with clinical improvement. Considering the results of the present study, levocabastine nasal spray appears to be an effective treatment for perennial allergic rhinitis and can be used with, or as an alternative to, other anti-allergic medications.

Effect of BQ-123 and tissue plasminogen activator on vasospasm after subarachnoid hemorrhage in monkeys

BACKGROUND AND PURPOSE

We aimed to determine the effect of intracisternal administration of an endothelin-A receptor antagonist (BQ-123) against vasospasm in a monkey model and to determine whether this drug would have adverse interactions with intracisternal tissue plasminogen activator (TPA).

METHODS

Thirty-three monkeys were randomly allocated to undergo baseline cerebral angiography, creation of right subarachnoid hemorrhage (SAH), and intracisternal delivery of (1) placebo (n = 10); (2) low-dose BQ-123 (5 mg/kg per day, n = 7); (3) high-dose BQ-123 (10 mg/kg per day, n = 9); or (4) BQ-123 10 mg/kg per day plus TPA 1 mg every 12 hours for three doses (n = 7). Angiography was repeated after 7 days, and animals were killed. Vasospasm was assessed by comparisons of angiograms within groups across time by paired t test and by comparisons across groups at each time by ANOVA.

RESULTS

Significant clot remained in the basal cisterns in all groups except those receiving TPA, in whom complete clot clearance was noted. Comparisons of angiograms at baseline and after 7 days showed significant vasospasm of the right middle cerebral artery in animals receiving placebo (mean +/- SEM reduction in diameter, 36 +/- 7%; P < .05) and low- and high-dose BQ-123 (16 +/- 4% and 18 +/- 7%, respectively). Animals that received TPA did not develop significant right cerebral artery vasospasm. Comparisons of arterial diameters at day 7 revealed significant variance in right middle cerebral artery diameter, with animals in the placebo group having significantly more and animals in the TPA group having significantly less vasospasm than the BQ-123 groups. Histopathological examination of the brains did not show inflammation or pathological change in animals that received BQ-123 or BQ-123 plus TPA.

CONCLUSIONS

Intracisternal TPA was efficacious against vasospasm in monkeys. Combination therapy with TPA and BQ-123 was not associated with reduction in efficacy of either drug or with evidence of toxicity.

Beta 2-transferrin confirms perilymphatic fistula in children

beta 2-Transferrin is a protein that is unique to the cerebrospinal fluid and aqueous humor. On the basis of this information and a recent study from our institution that demonstrated that beta 2-transferrin was also unique to human perilymph, a prospective, double-blind study to evaluate perilymphatic fistula in children was performed. Attending otolaryngologists at Children's Hospital of Pittsburgh evaluated and recommended surgery for 10 children (10 ears) who were suspected of having a congenital perilymphatic fistula. During the operation, the surgeon decided whether a perilymphatic fistula existed, on the basis of otomicroscopic findings, and then separate pieces of gelatin sponge were placed on the oval and round windows, respectively, and sent to the immunopathology laboratory where they were analyzed for beta 2-transferrin. Ten patients (10 ears) undergoing tympanoplasty or tympanomastoidectomy were used as controls and tested in a similar fashion. During the study, both the surgeons and patients were blinded from the results of the test. Of the 10 control patients, none was observed to have a perilymphatic fistula, and all were negative for beta 2-transferrin. Of the 10 patients undergoing exploratory tympanotomy for perilymphatic fistula, 1 ear was thought to be negative for perilymphatic fistula on microscopic visual examination, whereas 9 were considered to be positive for perilymphatic fistula. No beta 2-transferrin was identified from the ear that was considered not to have a perilymphatic fistula, whereas six of the nine ears that were thought to have perilymphatic fistula tested positive for beta 2-transferrin.(ABSTRACT TRUNCATED AT 250 WORDS)

Beta 2 transferrin application in otology

The diagnosis and management of perilymphatic fistula has received considerable attention in recent years. Despite the use of sophisticated technology, the diagnosis of perilymphatic fistula continues to rest primarily upon clinical suspicion and the exclusion of other disorders. In addition, the confirmation of a perilymphatic fistula during surgical exploration is usually based upon the subjective observation of fluid pooling in niches of the middle ear. A sensitive and objective laboratory test for identifying perilymph in the middle ear would be a useful adjunct for the diagnosis and management of perilymphatic fistula. The objective of this paper is to demonstrate the potential utility of beta 2 (beta 2) transferrin assay in the diagnosis of perilymphatic fistula. To accomplish this objective, we confirmed that beta 2 transferrin is present in living human perilymph and is absent in the normal or inflamed middle ear. In addition, the utility of beta 2 transferrin assay in the diagnosis of cerebrospinal fluid otorrhea is presented.