Exclusion of left atrial thrombus by dual-source cardiac computed tomography prior to catheter ablation for atrial fibrillation

Impact of left atrial appendage thrombus location on diagnostic accuracy of cardiac CT: a single-centre case-control study

OBJECTIVE

Cardiac CT (CCT) is an emerging non-invasive modality for assessing left atrial appendage (LAA) thrombus, but the results were conflicting. Our study aims to evaluate the accuracy of CCT for detecting LAA thrombus in patients undergoing catheter ablation of atrial fibrillation, using trans-oesophageal echocardiography (TEE) as the reference standard.

DESIGN

Case-control study.

SETTING

Patient data were collected from a tertiary hospital in China between 2017 and 2022.

PARTICIPANTS

The study enrolled 726 patients (male: 60.2%, age: 61±11 years) who had both TEE and CCT before catheter ablation of atrial fibrillation.

MEASURES

The CCT protocol consisted of one angiographic phase and one delayed scan 30 s later. LAA thrombi were defined as solid masses on TEE or persistent defects on CCT. The thrombus dimension and location, the LAA filling and emptying flow velocity were assessed by TEE.

RESULTS

Of the 57 (7.9%) patients with LAA thrombi identified by TEE, 29 (50.9%) were located at the LAA ostium, and 28 (49.1%) were in the LAA. The former showed higher motility following blood flow and heartbeats than the latter. The CCT detected 14 (48.3%) of the LAA-ostium thrombi but 25 (89.3%) of those in the LAA (p=0.001). The LAA-ostium thrombi with the LAA mean flow velocity >0.35 m/s and maximum diameters <10 mm were more prone to have CCT false-negative results.

CONCLUSION

For patients undergoing catheter ablation for atrial fibrillation, CCT with a 30 s delay scan is less sensitive to LAA thrombi than TEE, especially for LAA-ostium thrombi with smaller sizes and higher LAA flow velocity.

Atrial Fibrillation Ablation in Congenital Heart Disease: Therapeutic Challenges and Future Perspectives

The increasing prevalence of atrial fibrillation (AF) in adults with congenital heart disease raises significant questions regarding its management. The unique underlying anatomic and physiological background further adds to the difficulty in eliminating the AF burden in these patients. Herein, we provide an overview of the current knowledge on the pathophysiology and risk factors for AF in adult congenital heart disease, with a special focus on the existing challenges in AF ablation. Emerging imaging modalities and ablation techniques might have a role to play. Evidence regarding the safety and efficacy of AF ablation in adult congenital heart disease is summarized, especially for patients with an atrial septal defect, Ebstein anomaly of the tricuspid valve, tetralogy of Fallot, and Fontan circulation. Finally, any remaining gaps in knowledge and potential areas of future research are highlighted.

Characteristics, Thrombus Resolution, and Long-Term Outcomes in Patients with Nonvalvular Atrial Fibrillation and Atrial Thrombus

To assess the prevalence and management of atrial thrombus in patients with nonvalvular atrial fibrillation (NVAF) and identify the risk factors of the nonresolution of atrial thrombus. This single-center retrospective observational study consecutively enrolled patients with NVAF and atrial thrombus detected using transesophageal echocardiography (TEE) or cardiac computed tomography angiography (CTA) from January 2012 to December 2020. Patients with prior left atrial appendage (LAA) intervention were excluded. The primary endpoint was the presence of atrial thrombus, while the secondary endpoint was the complete resolution of atrial thrombus. The prevalence of atrial thrombus in patients with NVAF was 1.4%. Ninety patients with atrial thrombus (mean age 62.8 ± 11.9 years and 61.1% men) were finally analyzed. Atrial thrombus was in the LAA in 82 (91.1%) patients. During follow up, 60% of the patients showed complete resolution of atrial thrombus. Congestive heart failure (odds ratio [OR]: 8.94; 95% confidence interval [CI]: 1.67-47.80) and a history of ischemic stroke (OR: 8.28; 95% CI: 1.48-46.42) were independently associated with the risk of the nonresolution of atrial thrombus. The presence of atrial thrombus in patients with NVAF who received anticoagulation therapy is non-negligible. Even in anticoagulated patients, TEE or cardiac CTA might still be needed. Congestive heart failure and a history of ischemic stroke are risk factors of the nonresolution of atrial thrombus.

Atrial fibrillation ablation: the position of computed tomography in pre-procedural imaging

Atrial fibrillation (AF) is the most common supraventricular arrhythmia. Despite significant advances in its treatment, it still remains one of the leading causes of cardiovascular morbidity and mortality. In the last two decades, pulmonary vein isolation (PVI) was developed as the most effective treatment option. The reported effectiveness of a single ablation procedure ranges from 40% to 69% with single, and up to 88% with repeated procedures, with acceptable safety profile. The PubMed database was searched, using terms including ‘atrial fibrillation ablation’, ‘pulmonary vein isolation’, ‘computed tomography’, ‘pulmonary vein anatomy’ and ‘ovality index’. Papers were reviewed for relevance and scientific merit. Different imaging techniques are used for pre-procedural assessment of left atrial (LA) anatomy, of which computed tomography (CT) is the most common. It allows assessing pulmonary vein (PV) anatomy, the LA wall thickness in different regions and the left atrial appendage (LAA) anatomy, together with excluding the presence of intracardiac thrombi. Pre-procedural PVs imaging is important regardless of the selected ablation technique, however, cryoballoon (CB) ablation seems to be particularly anatomy-dependent. Additionally, CT also permits assessment of several PVs characteristics (geometry, dimensions, angulations, the ostium area, orientation and ovality index (OI), which are essential for the patients’ qualification and designing the strategy of AF ablation. In this paper, we have reviewed the role of CT imaging in patients undergoing ablation procedure due to recurrent/symptomatic atrial fibrillation. Moreover, we discussed the relevant literature.

Feasibility and safety of left atrial access for ablation of atrial fibrillation in patients with persistent left superior vena cava

BACKGROUND

In patients with persistent left superior vena cava (PLSVC) ablation procedures can be challenging. We sought to determine the feasibility and safety of left atrial ablations in patients with PLSVC, especially when PLSVC is unknown prior to the ablation procedure.

METHODS AND RESULTS

In this retrospective analysis 15 adult patients (mean age 64.6 ± 14.5 years, 53.3% male) with PLSVC undergoing 27 ablation procedures for atrial fibrillation or left atrial flutter were included. In 5 (33,3%) patients PLSVC was only discovered during the procedure. Transseptal puncture (TSP) was declared "difficult" by the ablating physician in 13 of 27 (48,2%) procedures and was not successfully completed in the first attempt in two patients with known PLSVC. Once TSP was successfully completed, all relevant structures were reached both during mapping and ablation in all procedures independent of whether PLSVC was known prior to the procedure. One major complication (3,7%) occurred in 27 procedures in a patient with known PLSVC. In the patients with unknown PLSVC no complication occurred.

CONCLUSION

In experienced hands, left atrial access and ablation in patients with PLSVC is feasible and safe, particularly with regard to patients in whom the PLSVC is unknown prior to the ablation procedure. This article is protected by copyright. All rights reserved.

Cardiac Computed Tomography Versus Transesophageal Echocardiography for the Detection of Left Atrial Appendage Thrombus: A Systemic Review and Meta-Analysis

Background Transesophageal echocardiography (TEE) has been considered the gold standard for left atrial appendage (LAA) thrombus detection. Nevertheless, TEE may sometimes induce discomfort and cause complications. Cardiac computed tomography has been studied extensively for LAA thrombus detection. We performed this systemic review and meta-analysis to assess the diagnostic accuracy of cardiac computed tomography for LAA thrombus detection compared with TEE. Methods and Results A systemic search was conducted in the PubMed, Embase, and Cochrane Library databases from January 1977 to February 2021. Studies performed for assessment diagnostic accuracy of cardiac computed tomography on LAA thrombus compared with TEE were included. Summary sensitivity, specificity, and posterior probability of LAA thrombus was calculated by using bivariate random-effects model. The Quality Assessment of Diagnostic Accuracy Studies-2 tool was used for the quality assessment. A total of 27 studies involving 6960 patients were included in our study. The summary sensitivity of early imaging studies was 0.95 (95% CI, 0.79-0.99), and the specificity was 0.89 (95% CI, 0.85-0.92). The positive posterior probability was 19.11%, and the negative posterior probability was 0.16%. The summary sensitivity of delayed imaging studies was 0.98 (95% CI, 0.92-1.00), and the specificity was 1.00 (95% CI, 0.98-1.00). The positive posterior probability was 95.76%, and the negative posterior probability was 0.12%. The delayed imaging method significantly improved the specificity (1.00 versus 0.89; P<0.05) and positive posterior probability (95.76% versus 19.11%; P<0.05). Conclusions Cardiac computed tomography with a delayed imaging is a reliable alternative to TEE. It may save the patient and health care from an excess TEE. Registration URL: https://www.crd.york.ac.uk/PROSPERO; Unique identifier: CRD42021236352.

Anatomic characteristics of the left atrium in subjects undergoing radiofrequency ablation for atrial fibrillation

OBJECTIVE

To analyze the anatomic characteristics of the left atrium and pulmonary veins in individuals undergoing ablation for atrial fibrillation and to identify possible anatomic factors related with recurrence.

MATERIAL AND METHODS

We retrospectively reviewed the CT angiography studies done to plan radiofrequency ablation for atrial fibrillation in 95 patients (57 men; mean age, 65 ± 10 y). We reviewed the anatomy of the pulmonary veins and recorded the diameters of their ostia as well as the diameter and volume of the left atrium. We analyzed these parameters according to the type of arrhythmia and the response to treatment.

RESULTS

In 71 (74.7%) patients, the anatomy of the pulmonary veins was normal (i.e., two right pulmonary veins and two left pulmonary veins). Compared to patients with paroxysmal atrial fibrillation, patients with persistent atrial fibrillation had slightly larger diameter of the left pulmonary veins (left superior pulmonary vein 17.9 ± 2.6 mm vs. 16.7 ± 2.2 mm, p = 0.04; left inferior pulmonary vein 15.3 ± 2 mm vs. 13.8 ± 2.2 mm, p = 0.009) and larger left atrial volume (91.9 ± 24.9 cm³ vs. 70.7 ± 20.3 mm³, p = 0.001). After 22.1 ± 12.1 months' mean follow-up, 41 patients had sinus rhythm. Compared to patients in whom the sinus rhythm was restored, patients with recurrence had greater left atrial volume (81.4 ± 23.0 mm³ vs. 71.1 ± 23.2 mm³, p = 0.03). No significant differences in pulmonary vein diameters or clinical parameters were observed between patients with recurrence and those without.

CONCLUSION

The volume of the left atrium is greater in patients with persistent atrial fibrillation and in those who do not respond to ablation.

Safety of catheter ablation of atrial fibrillation without pre- or peri-procedural imaging for the detection of left atrial thrombus in the era of uninterrupted anticoagulation

BACKGROUND

The need for pre- or peri-procedural imaging to rule out the presence of left atrial thrombus in patients undergoing catheter ablation of atrial fibrillation (AF) is unclear in the era of uninterrupted direct oral anticoagulant (DOAC) regimen. We sought to examine the safety of catheter ablation in appropriately selected patients with paroxysmal AF without performing screening for left atrial thrombus.

PATIENTS AND METHODS

Consecutive patients planned for radiofrequency AF catheter ablation between January 2016 and June 2020 were enrolled, and prospectively studied. All subjects were receiving uninterrupted anticoagulation with DOACs for at least 4 weeks before the procedure. All subjects were in sinus rhythm the day of the procedure. The primary outcome of the study was ischemic stroke or transient ischemic attack (TIA) during at 30 days.

RESULTS

A total of 451 patients (age 59.7 ± 10.2 years, 289 males) with paroxysmal AF were included in the study. The mean CHA2DS2-VASc score was 1.4 ± 1.2. The mean left ventricular ejection fraction and left atrial diameter were 60 ± 5% and 39.3 ± 4 mm, respectively. Regarding the anticoagulation regimen, apixaban was used in 197 (43.6%) patients, rivaroxaban in 148 (32.8%) patients, and dabigatran in 106 (23.5%) patients. None of the patients developed clinical ischemic stroke or TIA during the 30-day post-discharged period.

CONCLUSIONS

Catheter ablation can be safely performed in low-risk patients with paroxysmal AF without imaging for the detection of left atrial thrombus in the era of uninterrupted DOAC anticoagulation.

Acute Procedural Complications of Cryoballoon Ablation: A Comprehensive Review

Catheter ablation is increasingly performed for treatment of atrial fibrillation (AF). Balloon based procedures have been developed aiming at safer, easier and more effective treatment as compared to point to point ablation. In the present review article, we aimed to discuss acute procedural complications of cryoballoon ablation.

Association between atrial fibrillation and Helicobacter pylori

The connection between atrial fibrillation (AF) and H. pylori (HP) infection is still matter of debate. We performed a systematic review and metanalysis of studies reporting the association between AF and HF. A systematic review of all available reports in literature of the incidence of HP infection in AF and comparing this incidence with subjects without AF were analysed. Risk ratio and 95% confidence interval (CI) and risk difference with standard error (SE) were the main statistics indexes. Six retrospective studies including a total of 2921 were included at the end of the selection process. Nine hundred-fifty-six patients (32.7%) were in AF, whereas 1965 (67.3%) were in normal sinus rhythm (NSR). Overall, 335 of 956 patients with AF were HP positive (35%), whereas 621 were HP negative (65%). In addition, 643 of 1965 NSR patients (32.7%) were HP positive while 1,322 were negative (67.3%; Chi-square 2.15, p = 0.21). The Cumulative Risk Ratio for AF patients for developing an HP infection was 1.19 (95% CI 1.08-1.41). In addition, a small difference risk towards AF was found (0.11 [SE = 0.04]). Moreover, neither RR nor risk difference were influenced by the geographic area at meta-regression analysis. Finally, there was a weak correlation between AF and HP (coefficient = 0.04 [95% CI -0.01-0.08]). We failed to find any significant correlation between H. pylori infection and AF and, based on our data, it seems unlikely than HP can be considered a risk factor for AF. Further larger research is warranted.