Clinical Outcomes Associated With Left Atrial Appendage Occlusion Versus Direct Oral Anticoagulation in Atrial Fibrillation

ObjectivesThis study sought to investigate clinical outcomes associated with left atrial appendage occlusion (LAAO) versus direct oral anticoagulants (DOACs) in patients with high-risk atrial fibrillation (AF).BackgroundLAAO has been shown to be noninferior to warfarin for stroke prevention in AF. However, anticoagulation with DOACs is now preferred over warfarin as thromboprophylaxis in AF.MethodsPatients with AF enrolled in the Amulet Observational Registry (n = 1,088) who had successful LAAO with the Amplatzer Amulet device (n = 1,078) were compared with a propensity score–matched control cohort of incident AF patients (n = 1,184) treated by DOACs identified from Danish national patient registries. Propensity score matching was based on the covariates of the CHA₂DS₂-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, prior stroke or transient ischemic attack or thromboembolism, vascular disease, age 65–74 years, sex category) and HAS-BLED (hypertension, abnormal renal or liver function, stroke, bleeding, labile international normalized ratio, elderly, drugs or alcohol) scores for predicting stroke and bleeding. The primary outcome was a composite of ischemic stroke, major bleeding (Bleeding Academic Research Consortium ≥3), or all-cause mortality, and follow-up was 2 years.ResultsAF patients treated with LAAO had a significantly lower risk of the primary composite outcome as compared with patients treated with DOACs (hazard ratio [HR]: 0.57; 95% confidence interval [CI]: 0.49 to 0.67). Total events and event rates per 100 patient-years were (LAAO vs. DOACs) 256 vs. 461 and 14.5 vs. 25.7, respectively. The risk of ischemic stroke was comparable between groups (HR: 1.11; 95% CI: 0.71 to 1.75), while risk of major bleeding (HR: 0.62; 95% CI: 0.49 to 0.79) and all-cause mortality (HR: 0.53; 95% CI: 0.43 to 0.64) were significantly lower in patients treated with LAAO.ConclusionsAmong high-risk AF patients, LAAO in comparison with DOACs may have similar stroke prevention efficacy but lower risk of major bleeding and mortality.     

Atrial septal defects; a clinicopathologic appraisal

In this presentation, the highlights of interatrial septal defects are reviewed from the embryologic, anatomic, pathologic, and clinical aspects. Sxi cases of atrial septal defect and one of Lutembacher's syndrome are discussed, with the salient clinical and autopsy findings. In three cases having high pulmonary arterial pressures, the changes in the pulmonary vasculature are stressed. In two cases of abnormal venous drainage, the problems confronting the surgeon are discussed. The paucity of autopsy material in our series directly reflects the low mortality rate which has been achieved with definitive surgery utilizing the heart-lung bypass.     

Sleep Apnea and Atrial Fibrillation; 2012 Update

Atrial fibrillation (AF) and obstructive sleep apnea (OSA) are very prevalent diseases in modern society. Recent years have seen the emergence of a wide body of literature suggesting an important association between these two diseases. This review will provide a summary of this evidence as it currently exists. First, it will review the literature suggesting an association between AF and OSA by highlighting the prevalence of AF in OSA, the correlation of AF prevalence with OSA severity and the trend towards increased AF recurrence in patients with OSA after treatment for AF. Second, it will identify the possible pathophysiologic mechanisms for this association. In doing so, it will discuss the investigated effects of intrathoracic pressure changes, autonomic instability and atrial remodeling. Finally, it will review the evidence of the effect of treatment of OSA on AF, highlighting the role of continuous positive airway pressure (CPAP) in the treatment of OSA and its impact on AF prevalence and recurrence.     

High‐Resolution Signal‐Averaged Analysis of Atrial Electromagnetic Characteristics in Patients with Paroxysmal Lone Atrial Fibrillation

Background: Abnormalities in the electromagnetic signal of the atria during sinus rhythm could serve as markers of triggering foci or substrate for atrial fibrillation (AF). We examined atrial electrophysiologic properties noninvasively by using magnetocardiographic mapping (MCG) in patients with paroxysmal lone AF to find whether any difference exists between those who have frequent triggers of AF and who don't. Methods: MCG was recorded over anterior chest during sinus rhythm in 80 patients with paroxysmal lone AF (44 ± 12 years, 61 males) and 80 matched controls. Atrial wave duration (Pd) and root mean square amplitudes of the last 40 ms (RMS40) of the averaged filtered atrial complex were determined automatically. Patients expressing atrial arrhythmias triggering AF episodes were classified as focal AF. Results: The Pd was 109 ms in patients and 104 ms in controls (P = 0.007). In focal AF (72%) the Pd was slightly prolonged and its proportion of the PR interval was larger, but RMS40 was normal compared to controls. In other patients, the Pd was close to controls, but the RMS40 was reduced (59 ± 17 vs74 ± 36 fT, P = 0.006). Pd and atrial RMS amplitudes were unrelated to duration of AF history or frequency of recurrences. Conclusion: Clinical subclasses of lone AF seem to possess distinct signal profiles of atrial depolarization. Differences in electrophysiological properties between these subclasses may reflect pathogenetic variation and could have implications on diagnostics and therapy.     

Intracardiac Echocardiographic Atrial Septal Defect Closure

Intracardiac echocardiography (ICE) is an excellent ultrasound modality that can be used to guide atrial septal defect (ASD) closure. Compared with transesophageal echocardiography, ICE offers better imaging of the posterior inferior septum, it does not require deep or general anesthesia, and it allows the operator total control over image acquisition. This latter advantage requires that the operator become an expert in image acquisition and interpretation. The following is intended to serve as a primer on performance and interpretation of ICE to guide ASD closure.     

Impact of Atrial Fibrillation Ablation on Left Ventricular Filling Pressure and Left Atrial Remodeling

Background

Left ventricular (LV) diastolic dysfunction is associated with new-onset atrial fibrillation (AF), and the estimation of elevated LV filling pressures by E/e'' ratio is related to worse outcomes in patients with AF. However, it is unknown if restoring sinus rhythm reverses this process.

Objective

To evaluate the impact of AF ablation on estimated LV filling pressure.

Methods

A total of 141 patients underwent radiofrequency (RF) ablation to treat drug-refractory AF. Transthoracic echocardiography was performed 30 days before and 12 months after ablation. LV functional parameters, left atrial volume index (LAVind), and transmitral pulsed and mitral annulus tissue Doppler (e'' and E/e'') were assessed. Paroxysmal AF was present in 18 patients, persistent AF was present in 102 patients, and long-standing persistent AF in 21 patients. Follow-up included electrocardiographic examination and 24-h Holter monitoring at 3, 6, and 12 months after ablation.

Results

One hundred seventeen patients (82.9%) were free of AF during the follow-up (average, 18 ± 5 months). LAVind reduced in the successful group (30.2 mL/m² ± 10.6 mL/m² to 22.6 mL/m² ± 1.1 mL/m², p < 0.001) compared to the non-successful group (37.7 mL/m² ± 14.3 mL/m² to 37.5 mL/m² ± 14.5 mL/m², p = ns). Improvement of LV filling pressure assessed by a reduction in the E/e'' ratio was observed only after successful ablation (11.5 ± 4.5 vs. 7.1 ± 3.7, p < 0.001) but not in patients with recurrent AF (12.7 ± 4.4 vs. 12 ± 3.3, p = ns). The success rate was lower in the long-standing persistent AF patient group (57% vs. 87%, p = 0.001).

Conclusion

Successful AF ablation is associated with LA reverse remodeling and an improvement in LV filling pressure.     

The Impact of the Distance between the Atrial Electrode and the Atrial Wall on Atrial Undersensing in Patients with VDD Pacemakers: Long‐Term Follow‐Up

Aim: Atrial undersensing (AUS) in single‐lead VDD pacemakers may be due to diminished P‐wave amplitude secondary to local inflammation beneath the electrodes closer to atrial wall. The aim of this study was to assess the potential effect of distance between atrial electrode and atrial wall on immediate and long‐term atrial sensing stability in VDD systems. Methods: A total of 275 patients with normal sinus node function who received VDD pacemakers were enrolled into the study and were followed up for a median duration of 33 months. During each control visit, a standard 12‐lead electrocardiogram (ECG) was obtained and standard pacemaker function assessment was performed including testing for pacing threshold and atrioventricular synchrony. The distance between atrial electrode and atrial wall was measured from chest X‐ray. Results: Of the 275 patients, AUS was detected in 59 patients. Univariate predictors of AUS were use of closely spaced bipolar ring atrial electrode (CSBR) (P = 0.01), wider atrial ring‐spacing (P = 0.03), and atrial sensitivity programmed to a higher level (P = 0.001). Use of CSBR (P = 0.04) and atrial sensitivity ≥0.3 mV (P = 0.02) were observed to be the independent predictors for AUS. When the distance between atrial electrode and atrial wall was <7 mm, AUS was less with diagonally arranged bipolar ring electrodes (DABR) than it was with CSBRs (P = 0.02). Conclusions: The distance between atrial electrode and atrial wall does not appear to affect AUS incidence in VDD pacemakers. For VDD electrodes closer to atrial wall, AUS was significantly less likely in DABR‐type electrodes.     

Atypical Electrocardiographic Features of Cavotricuspid Isthmus‐Dependent Atrial Flutter Occurring during Left Atrial Fibrillation Ablation

Background: Patients who have undergone percutaneous catheter ablation for atrial fibrillation (AF) may develop cavotricuspid isthmus (CTI)‐dependent atrial flutter (AFL), which can occur either spontaneously during left atrial (LA) ablation for AF or by induction from sinus rhythm during the procedure. The electrocardiographic (ECG) characteristics of CTI‐dependent AFL occurring during LA ablation have not been described. The purpose of this study was to describe the ECG features of CTI‐dependent AFL occurring during percutaneous LA catheter ablation for AF. Methods and Results: Of 223 patients presenting for first AF ablation at our institution between May 2004 and February 2008, 20 patients (9%) developed CTI‐dependent AFL during LA ablation for AF. CTI‐dependent AFL developed spontaneously in 4 patients (20%) and was induced in 16 patients (80%). Among these 20 patients, 3 (15%) had typical ECG patterns and 17 (85%) had atypical ECG patterns. Flutter waves in the inferior leads were biphasic in 10 patients (50%), downward in 3 patients (15%), positive in 3 patients (15%), and not fitting the above classifications in 4 patients (20%). There was no statistically significant association between AFL pattern and LA size, left ventricular ejection fraction, total ablation time, duration of prior AF, or type of prior AF. Conclusion: A majority of patients with CTI‐dependent AFL occurring during LA ablation have atypical ECG patterns. Biphasic flutter waves in the inferior leads are common ECG features, occurring in one‐half of patients. Right atrial CTI‐dependent AFL should be suspected even if the ECG appearance is atypical. Ann Noninvasive Electrocardiol 2010;15(3):200–208