Safety and efficacy analysis of one‐stop intervention for treating nonvalvular atrial fibrillation

1 Background

Nonvalvular atrial fibrillation (AF) is a common arrhythmia. The treatment strategy for AF mainly includes controlling symptoms and decreasing the rate of complications. Our study aimed to evaluate the safety and efficacy of combination treatment of catheter ablation and left atrial appendage (LAA) closure (one‐stop intervention) in patients with nonvalvular AF.

2 Methods and results

Thirty‐four patients with symptomatic AF (mean CHA₂DS₂‐VASc score 4.1 ± 1.3, mean HAS‐BLED score 3.8 ± 1.2) were included. Patients first received radiofrequency‐based left atrial ablation, and then the Watchman device (Boston Scientific, Natick, MA, USA) or AMPLATZER Cardiac Plug (ACP) (St. Jude Medical, Inc., St. Paul, MN, USA) was implanted for LAA closure. Follow‐up was performed at 45 days and 3 months after LAA closure to assess for recurrence of AF and prevent stroke. Radiofrequency ablation and LAA closure were successful in 100% of patients without evidence of residual flow at the final transesophageal echocardiography evaluation. A Watchman device was implanted in 29 (85.3%) patients, and an ACP was implanted in five (14.7%) patients. No device‐related thrombus formation or embolization was identified at the 45‐day or 3‐month follow‐up. Serious complications, including death, transient ischemic attack, ischemic or hemorrhagic stroke, or major bleeding, were also not identified during the follow‐ups.

3 Conclusion

For symptomatic patients with nonvalvular AF and a high risk of stroke, the one‐stop intervention is feasible, safe, and efficacious.     

Is extensive atrial fibrosis in the setting of heart failure associated with a reduced atrial fibrillation burden?

Atrial fibrillation (AF) affects 10–50% of patients with chronic heart failure (HF) and is associated with poor long‐term prognosis. AF is commonly associated with atrial structural remodeling (ASR), principally characterized by atrial dilatation and fibrosis. However, the occurrence of AF in the full spectrum of ASR encountered in patients with HF is poorly defined. Experimental studies have presented evidence that extensive ASR can be accompanied with a reduced burden of AF, secondary to a prominent depression of atrial excitability. This reduction in AF burden is associated with severe atrial fibrosis rather than with dilatation. Clinical studies of patients with HF point to the possibility that advanced ASR is associated with a less frequent AF occurrence than moderate ASR. Our goal in this review is to introduce the hypothesis that AF is less likely to occur in severe versus moderate atrial ASR in the setting of HF and that it is severe atrial fibrosis‐associated depression of atrial excitability that reduces AF burden.     

Absence of late gadolinium enhancement on cardiac magnetic resonance imaging in ventricular fibrillation and nonischemic cardiomyopathy

Introduction

Cardiac magnetic resonance (CMR)‐identified late gadolinium enhancement (LGE), representing regional fibrosis, is often used to predict ventricular arrhythmia risk in nonischemic cardiomyopathy (NICM). However, LGE is more closely correlated with sustained monomorphic ventricular tachycardia (SMVT) than ventricular fibrillation (VF). We characterized CMR findings of ventricular LGE in VF survivors.

Methods

We examined consecutively resuscitated VF survivors undergoing contrast‐enhanced 1.5T CMR between 9/2007 and 7/2016. We excluded coronary artery disease, hypertrophic cardiomyopathy, amyloid, sarcoid, arrhythmogenic right ventricular cardiomyopathy, and channelopathy. Preexisting implantable cardioverter‐defibrillator (ICD) was a CMR contraindication. VF patients were divided into three groups: (1) NICM, (2) left ventricular (LV) dilatation with normal LV ejection fraction (LVEF), and (3) normal LV size and LVEF. Two groups of NICM patients with and without SMVT were examined for comparison.

Results

We analyzed 87 VF patients, and found that LGE was seen in 8/22 (36%) with NICM (LVEF 38 ± 11%, LV end‐diastolic volume index [LVEDVI] 134 ± 68 mL/BSA), 11/40 (28%) with LV dilatation and normal LVEF (LVEDVI 103 ± 17 mL/BSA), 4/25 (16%) with normal LV size and LVEF. Incidence of LGE in NICM patients without prior ventricular tachycardia/VF (LVEF 36 ± 12%, LVEDVI 141 ± 46 mL/body surface area [BSA]) was 117/277 and was not lower than those with VF and NICM (42% vs 36%; P = 0.59). By contrast, 22/37 NICM patients with SMVT (LVEF 42 ± 11%, LVEDVI 123 ± 48 mL/BSA) were LGE‐positive (59% NICM‐SMVT vs 36% NICM‐VF; P = 0.04).

Conclusion

Most VF survivors with a diagnosis of NICM did not have LGE on CMR and would not have met primary prevention ICD criteria based on LVEF. Absence of LGE may not portend a benign prognosis in NICM. Novel strategies for determining SCD risk in this cohort are required.

     

Left atrial thrombus two years after placement of a left atrial appendage closure device: Unexplored area of the Watchman

A 72‐year‐old man who underwent a left atrial appendage (LAA) closure device 2 years ago presented with atrial flutter with rapid ventricular rate and was referred for cardioversion. Precardioversion transesophageal echocardiogram showed left atrial thrombus and therefore the procedure was aborted. Currently, there is no guideline on imaging surveillance or anticoagulation in patients with LAA closure device who develop intracardiac thrombus after the initial 6‐month surveillance period.     

Extracardiac ice formation during CoolLoop cryoablation of atrial fibrillation

A 75‐year‐old male patient was referred for longstanding atrial fibrillation ablation. We performed this procedure combining an epicardial and endocardial approach. Under general anesthesia and via a left‐sided thoracoscopic approach, we isolated the pulmonary veins (PVs) and the roofline and inferior line were created using a radiofrequency tool. To isolate the endocardial PVs, a transseptal puncture was performed via the groin, and a cryoablation CoolLoop catheter (AFreeze GmbH, Innsbruck, Austria) was advanced into the left atrium. Ice crystals started to appear on the epicardial surface of the left inferior PV antrum after 121 seconds later, those crystals had formed an ice plaque. For the first time in humans, we were able to visualize the transmural effects of cryothermal energy ablation via a CoolLoop catheter on the epicardial surface of the ostium of the PV.