Evaluating the novel parameters for assessing the LAA function and thrombus formation with nonvalvular atrial fibrillation

The dysfunction of left atrial appendage (LAA) is prone to form thrombus when atrial fibrillation (AF) sustained more than 48 h. Traditional 2D-TEE (transesophageal echocardiography) can not accurate evaluate the function of LAA. The purpose of this study is to analyze the relationship of LAA function parameters and thrombus formation in patients with non-valvular atrial fibrillation (NVAF) by real-time three-dimensional transesophageal echocardiography (RT-3D-TEE). High risk patients can be identified according to the characteristics of ultrasonic index in patients with left atrial appendage thrombosis, which has important clinical value and significance in the risk assessment, guiding treatment and judging prognosis. We examined the relationship between the echocardiographic parameters of LAA function and the incidence of thrombus in 102 NVAF patients. They underwent RT-3D-TEE and left atrial appendage thrombus (LAAT)/severe spontaneous echocardiographic contrast (SSEC) was found in 67 patients (thrombus group) but absent in the remaining 35 patients (non-thrombus group). After measured by QLAB software, the LAA functional parameters were significantly associated with LAAT/SEC formation. Univariate analysis indicated that AF time, LAD, LVEF, LAA-OAmax, LAAVmax, LAAVI and LAAEF demonstrated a positive association (P < 0.05). However, logistic regression analysis identified that AF time (OR:1.73, P < 0.05)、LAAEF (OR:4.09, P < 0.01)and LAAVI (OR:3.28, P < 0.01) were independent predictors of LAAT/SSEC. In patients with nonvalvular atrial fibrillation, echocardiographic parameters of LAA function are significantly associated with LAAT/SSEC.     

Percutaneous left atrial appendage closure for stroke prevention in atrial fibrillation

Background

Percutaneous left atrial appendage (LAA) closure can be an alternative to coumadin treatment in patients with atrial fibrillation (AF) at high risk for thromboembolic events and/or bleeding complications. We report the initial experience with this new technique.

Methods

Patients were eligible if they had AF with a high stroke risk (CHADS₂ score >1), and/or contraindication for coumadin therapy. The procedure was performed under general anaesthesia, using biplane fluoroscopy and (3D) transoesophageal echocardiography (TEE) guidance. Patients were discharged on coumadin until a TEE was repeated at 45 days after closure to evaluate LAA occlusion. If LAA occlusion was achieved, oral anticoagulation was discontinued and aspirin started.

Results

Percutaneous LAA closure was performed in 10 patients (50% male, age 61.6 ± 9.6 years). The median CHADS₂ score was 3 (range 2–4), median CHA₂DS₂-VASc score 3.5 (range 2–6) and HAS-BLED score 1.5 (range 1–4). Nine patients had a history of stroke and 2 patients had a history of major bleeding while on coumadin. Concomitant pulmonary vein isolation was performed in 9 patients. The device was successfully placed in all patients within a median of 56 min (38–137 min). Asymptomatic catheter thrombus occurred in one patient. At 45-day follow-up, no thromboembolic events occurred, TEE showed minimal residual flow in the LAA in three patients. In one patient the LAA device was dislocated, requiring successful percutaneous retrieval.

Conclusion

Device closure of the LAA may provide an alternative strategy to chronic coumadin therapy in patients with AF and high risk of stroke and/or bleeding complications using coumadin.     

Concomitant epicardial left atrial appendage ligation and left atrial ablation of atrial fibrillation: Safety,feasibility and outcome

IntroductionWe present initial results of patients undergoing a combined procedure of epicardial LAA ligation in addition to left atrial ablation for AF.Methods9 patients were included for additional use of LARIAT as an individual treatment approach for AF. First an epicardial LAA ligation was performed, in the same procedure left atrial ablations consisting of PVI and additional substrate based modifying ablations were performed. Follow–up at 3 months and 12 months was performed.ResultsThere was only 1 minor procedural complication (11%) involving epicardial bleeding and 2 late adverse events of pericardial tamponade and stroke. At the final follow-up (median 20 months) 7 patients were in stable sinus rhythm (78%) and 2 pts had reduced AF burden.ConclusionConcomitant epicardial LAA ligation and ablation is feasible in selected patients with a reasonable risk profile. More prospective data are required to validate the safety and efficacy.     

慢性肾功能不全对中老年非瓣膜性房颤患者全因死亡、心脑血管疾病死亡及血栓终点事件的影响

目的：探讨中老年非瓣膜性房颤患者全因死亡、心脑血管疾病死亡及血栓终点事件的危险因素及慢性肾功能不全是否为其独立危险因素。方法：纳入未应用抗凝药物的中老年非瓣膜性房颤患者825例,平均年龄为76.52±11.80岁,其中女性占18.91%,75岁以上患者占64.73%,记录基线特征及各终点事件发生情况。通过Cox生存分析,探讨肾功能不全对各终点事件的影响。结果：入选患者中位数随访时间为33.5个月,随访期间发生全因死亡209例、心脑血管疾病死亡61例及血栓终点事件139例。合并慢性肾功能不全的房颤患者各终点事件发生率均显著高于对照组,在校正CHA₂DS₂-VASc评分危险因素及其他传统危险因素后,慢性肾功能不全仍是全因死亡、心脑血管疾病死亡及血栓终点事件的独立危险因素。结论：慢性肾功能不全是未服用抗凝药物的中老年非瓣膜性房颤患者全因死亡、心脑血管疾病死亡及发生血栓事件的独立危险因素之一。     

左心耳封堵术后房颤患者生活质量评价及其影响因素研究

摘要 目的：探讨左心耳封堵术（LAAC）术后对房颤（AF）患者的生活质量的影响,并分析其影响因素。方法：回顾性分析兰州大学第二医院2019年3月至2022年3月期间接受LAAC治疗的213例AF患者的临床资料。根据简明健康调查量表（SF-36）将213例LAAC术后AF患者分为低生活质量组（总分≤50分,n=107）和高生活质量组（总分＞50分,n=106）。收集并比较AF患者术前基线资料、实验室资料和影像学资料。采用多因素Logistic回归模型分析LAAC术后AF患者生活质量的影响因素。结果：低生活质量组心房颤动血栓发生危险度（CHA2DS2-VASc）评分高于高生活质量组（P<0.05）。低生活质量组的凝血酶原时间百分比高于高生活质量组（P<0.05）。高生活质量组红细胞水平高于低生活质量组（P<0.05）。高生活质量组的左心室射血分数（LVEF）高于低生活质量组（P<0.05）。多因素Logistic回归分析结果显示：CHA2DS2-VASc评分偏高、LVEF偏低是影响LAAC术后AF患者生活质量的危险因素（P<0.05）。结论：CHA2DS2-VASc评分偏高、LVEF偏低是影响LAAC术后AF患者生活质量的危险因素,可降低LAAC术后AF患者的生活质量。     

High-density activation map of atrial tachycardia within left atrial appendage

Identification of the critical isthmus of the reentrant tachycardia is essential to maximize the effect of catheter ablation (CA) and to minimize the myocardial injury of CA. An 81-year-old woman presented recurrent palpitations after CA of atrial fibrillation (AF) and atrial tachycardia (AT). She had moderate aortic valve stenosis and coronary artery disease. She had received a pulmonary vein isolation, left atrial (LA) posterior wall isolation, and LA anterior linear ablation for atrial fibrillation 1 year prior. At the start of the procedure, she was in sinus rhythm. Atrial burst pacing induced an AT (230msec). High-density mapping revealed a figure-of-eight activation pattern within the LA appendage (LAA), accounting for 99% of the tachycardia cycle length. The critical isthmus was identified at the mid LAA and the local electrogram of the critical isthmus was not fractionated. A single radiofrequency application at the critical isthmus of the AT, terminated the AT. She was free from any ATs for 28 months.Radiofrequency ablation of the localized reentrant AT was usually performed targeting long fractionated electrograms. In our case, the local electrogram at the critical isthmus was not fragmented compared with the LAA distal part. Long fractionated electrograms were recorded at a more distal part of the LAA than the common isthmus and we could avoid the potential risk of a perforation. A recent developed 3-dimensional electro-anatomical mapping system can identify the critical isthmus and allow us to select a new therapeutic strategy for a critical isthmus ablation of an AT within the LAA.     

Detection of oesophageal course during left atrial catheter ablation

BackgroundOesophageal changes and injuries were recorded after atrial fibrillation(AF) ablation procedures. The reduction of power in the posterior left atrial(LA) wall(closest to the oesophagus) and the monitoring of temperature in the oesophagus(OE) reduced oesophageal injuries. The intracardiac-echocardiography(ICE) with a Cartosound module provides two-dimensional imaging (2D) to assess detailed cardiac anatomy and its relationship with the OE. The aim of this study was to highlight the safety and feasibility of 3D-reconstruction of the oesophageal course in left atrial catheter ablation(CA) procedures without OE temperature probe or quadripolar catheter to guide ICE OE reconstruction.Methods180 patients(PT) underwent left atrial ablation. AF ablation were 125(69.5%); incisional left atrial tachycardias(IAFL) were 37(20.6%); left atrial tachycardias(LAT) were 19(10.6%). The LA and pulmonary vein anatomies were rendered by traditional electroanatomic mapping(EAM) and merged with an ICE anatomic map. In 109 PT ICE imaging was used to create a geometry of the OE(group A). A quadripolar catheter was used in 71 PT to show OE course associated to ICE(group B).ResultsAblation energy delivery was performed outside the broadest OE anatomy borders. The duration of procedures was longer in group B vs group A Fluoroscopy time was lower in Group A than Group B(Group A 7 ± 3.2 vs 19.2 ± 2.4 min; p < 0.01).ConclusionsOE monitoring with ICE is safe and feasible. Oesophageal anatomy is complex and variable. Many PT will have a broad oesophageal boundary, which increases the risk of untoward thermal injury during posterior LA ablation. ICE with 3D construction of the OE enhances border detection of the OE, and as such, should decrease the risk of oesophageal injury by improving avoidance strategies without intra-oesophageal catheter visualization.     

Impact of left atrial appendage location on risk of thrombus formation in patients with atrial fibrillation

Biomechanics and Modeling in Mechanobiology - Most strokes in patients with atrial fibrillation (AF) are thought to arise from thrombus formation in the left atrial appendage (LAA). Assessing the...     

Catheter Ablation in Combination With Left Atrial Appendage Closure for Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, affecting millions of individuals worldwide ^1-3. The rapid, irregular, and disordered electrical activity in the atria gives rise to palpitations, fatigue, dyspnea, chest pain and dizziness with or without syncope ^{4, 5}. Patients with AF have a five-fold higher risk of stroke ⁶.Oral anticoagulation (OAC) with warfarin is commonly used for stroke prevention in patients with AF and has been shown to reduce the risk of stroke by 64% ⁷. Warfarin therapy has several major disadvantages, however, including bleeding, non-tolerance, interactions with other medications and foods, non-compliance and a narrow therapeutic range ^8-11. These issues, together with poor appreciation of the risk-benefit ratio, unawareness of guidelines, or absence of an OAC monitoring outpatient clinic may explain why only 30-60% of patients with AF are prescribed this drug ⁸.The problems associated with warfarin, combined with the limited efficacy and/or serious side effects associated with other medications used for AF ^12,13, highlight the need for effective non-pharmacological approaches to treatment. One such approach is catheter ablation (CA), a procedure in which a radiofrequency electrical current is applied to regions of the heart to create small ablation lesions that electrically isolate potential AF triggers ⁴. CA is a well-established treatment for AF symptoms ^{14, 15}, that may also decrease the risk of stroke. Recent data showed a significant decrease in the relative risk of stroke and transient ischemic attack events among patients who underwent ablation compared with those undergoing antiarrhythmic drug therapy ¹⁶.Since the left atrial appendage (LAA) is the source of thrombi in more than 90% of patients with non-valvular atrial fibrillation ¹⁷, another approach to stroke prevention is to physically block clots from exiting the LAA. One method for occluding the LAA is via percutaneous placement of the WATCHMAN LAA closure device. The WATCHMAN device resembles a small parachute. It consists of a nitinol frame covered by fabric polyethyl terephthalate that prevents emboli, but not blood, from exiting during the healing process. Fixation anchors around the perimeter secure the device in the LAA (Figure 1). To date, the WATCHMAN is the only implanted percutaneous device for which a randomized clinical trial has been reported. In this study, implantation of the WATCHMAN was found to be at least as effective as warfarin in preventing stroke (all-causes) and death (all-causes) ¹⁸. This device received the Conformité Européenne (CE) mark for use in the European Union for warfarin eligible patients and in those who have a contraindication to anticoagulation therapy ¹⁹.Given the proven effectiveness of CA to alleviate AF symptoms and the promising data with regard to reduction of thromboembolic events with both CA and WATCHMAN implantation, combining the two procedures is hoped to further reduce the incidence of stroke in high-risk patients while simultaneously relieving symptoms. The combined procedure may eventually enable patients to undergo implantation of the WATCHMAN device without subsequent warfarin treatment, since the CA procedure itself reduces thromboembolic events. This would present an avenue of treatment previously unavailable to patients ineligible for warfarin treatment because of recurrent bleeding ²⁰ or other warfarin-associated problems.The combined procedure is performed under general anesthesia with biplane fluoroscopy and TEE guidance. Catheter ablation is followed by implantation of the WATCHMAN LAA closure device. Data from a non-randomized trial with 10 patients demonstrates that this procedure can be safely performed in patients with a CHADS₂ score of greater than 1 ²¹. Further studies to examine the effectiveness of the combined procedure in reducing symptoms from AF and associated stroke are therefore warranted.     

Trimethylamine N‐oxide as a risk marker for ischemic stroke in patients with atrial fibrillation

Trimethylamine N‐oxide (TMAO) is an independent risk factor of cardiovascular disease. Our objective was to explore the relation between TMAO and ischemic stroke (IS) in patients with atrial fibrillation (AF). A total of 68 patients with AF with IS and 111 ones without IS were enrolled. The plasma levels of TMAO remarkably increased in IS‐AF patients (8.25 ± 1.58 µM) compared with patients with AF (2.22 ± 0.09 µM, P < 0.01). The receiver operating characteristic analysis revealed that the best cutoff value of TMAO to predict IS in patients with AF was 3.53 µM with 75.0% sensitivity and 92.8% specificity (area under the curve: 0.917, 95% confidence intervals: 0.877‐0.957). Univariate and multivariate logistic regression analysis showed that TMAO was an independent predictor in IS. The level of TMAO was correlated with the CHA2DS2‐VASc score. In conclusion, TMAO was an independent predictor of IS, which could potentially refine stroke stratification in patients with AF.     

Safety and efficacy of cryoballoon versus radiofrequency ablation for atrial fibrillation in elderly patients: A real-world evidence

BackgroundThere are limited data describing the experience of radiofrequency (RF) vs. cryoballoon (CB) ablation for atrial fibrillation (AF) among elderly patients in the United States.MethodsWe conducted a retrospective analysis of patients ≥75 years of age undergoing index RF vs. CB ablation between January 2014 and May 2020 at our center. The choice of ablation technique was left to the operator's discretion. Major complications and efficacy, defined as freedom from any atrial tachyarrhythmia (ATA) lasting ≥30 s after one year of follow-up, were assessed in patients with index RF vs. CB ablation.ResultsIn our cohort of 186 patients, the median age was 78 (76–81) years, 54.8% were men, and 39.2% had persistent AF. The median CHA₂DS₂-VASc score was 4 (3–4), while the median duration of AF was 3 (1–7) years. The majority (n = 112, 60.2%) underwent RF ablation. The median procedure time was significantly lower in CB group (197 vs 226.5 min, p=<0.01). The incidence of complications was similar in the two sub-groups (RF: 1.8% vs. CB: 2.7%, p = 0.67). Similarly, arrhythmia-free survival rate on antiarrhythmic drugs at 1-year follow-up remained statistically comparable (63.4% vs. 68.9%, p = 0.33) between patients receiving RF vs. CB ablation.ConclusionThe safety and efficacy of RF vs. CB ablation for AF remained comparable in our cohort of patients older than 75 years. CB ablation was associated with a shorter procedure time.     

Galectin-3 in Patients with Atrial Fibrillation Undergoing Radiofrequency Catheter Ablation

Background

Galectin-3 (Gal-3) is an emerging biomarker in heart failure that is involved in fibrosis and inflammation. However, its potential value as a prognostic marker in atrial fibrillation (AF) is unknown. The aim of this study was to assess the impact of AF catheter ablation on Gal-3 and evaluate its prognostic impact for predicting rhythm outcome after catheter ablation.

Methods

Gal-3 was measured at baseline and after 6 months using specific ELISA. AF recurrences were defined as any atrial arrhythmia lasting longer than 30 sec within 6 months after ablation.

Results

In 105 AF patients (65% males, age 62±9 years, 52% paroxysmal AF) undergoing catheter ablation, Gal-3 was measured at baseline and after 6 months and compared with an AF-free control cohort (n=14, 50 % males, age 58±11 years). Gal-3 was higher in AF patients compared with AF-free controls (7.8±2.9 vs. 5.8±1.8, ng/mL, p=0.013). However, on multivariable analysis, BMI (p=0.007) but not AF (p=0.068) was associated with Gal-3. In the AF cohort, on univariable analysis higher Gal-3 levels were associated with female gender (p=0.028), higher BMI (p=0.005) and both CHADS2 (p=0.008) and CHA2DS2-VASC (p=0.016) scores, however, on multivariable analysis only BMI remained significantly associated with baseline Gal-3 (p=0.016). Gal-3 was similar 6 months after AF catheter ablation and was not associated with sinus rhythm maintenance.

Conclusions

Although galectin-3 levels are higher in AF patients, this is driven by cardiometabolic co-morbidities and not heart rhythm. Gal-3 is not useful for predicting rhythm outcome of catheter ablation.     

Effects of procainamide on electrical activity in thoracic veins and atria in canine model of sustained atrial fibrillation

Focal discharges (FDs) are present in thoracic veins during atrial fibrillation (AF). We hypothesize that procainamide exerts its anti-AF action by suppressing FDs in the thoracic veins. We studied six mongrel dogs (22-27 kg) with sustained (>6 h) AF induced by 47 +/- 20 days of chronic rapid LA appendage (LAA) or pulmonary vein (PV) pacing. Procainamide was infused intravenously until AF was terminated or a cumulative dose of 20 mg/kg was reached. High-resolution mapping during AF showed FDs in the vein of Marshall, PVs, and the LAA. Procainamide significantly (P < 0.05) reduced the frequency of these FDs and suppressed the interactions of wave fronts between PVs and LA. The cumulative dose of PA needed to terminate AF correlated negatively (r =-0.9, P < 0.05) with the baseline effective refractory period (ERP) of PV and positively (r = 0.8, P < 0.05) with the baseline maximum dominant frequency (DF) of AF. In four of five dogs, AF converted to atrial tachycardia originating from the PVs before termination. Attempts to reinduce sustained AF were unsuccessful in these five dogs. AF was resistant to procainamide in the sixth dog. In conclusion, procainamide reduced the rate of FDs in the thoracic veins and the LA and suppressed the interaction between PVs and LA. Second, FDs in the PV are more resistant to procainamide's action than FDs in the atria. Third, inherent PV ERP is important in determining the antifibrillatory efficacy of procainamide.     

Left Atrial Appendage Dysfunction in a Patient with Premature Ventricular Contractions - A Risk Factor for Stroke?

A 16-year-old female with ventricular dysfunction and frequent ventricular arrhythmia presented with a cardioembolic stroke. Prior electrophysiology study and ablation was performed for ventricular tachycardia (VT). For remaining ventricular ectopy, the patient was maintained on carvedilol and mexiletine. After one year on this regimen, she presented with an acute stroke. Transesophageal echocardiography revealed no evidence of an intracardiac or ventricular thrombus but demonstrated markedly decreased left atrial appendage (LAA) flow velocity worsened during frequent premature ventricular contractions (PVC). In the absence of atrial fibrillation (AF), the LAA dysfunction was considered secondary to the frequent PVCs and was thought to be the underlying cause for the stroke. We present this case to highlight a potential under recognized association between LAA dysfunction and ventricular arrhythmia, similar to that observed with atrioventricular dyssynchronous pacing.     

Successful ablation of biatrial tachycardia with preserved electrical activation of left atrial appendage by unidirectional connection via Bachmann’s bundle: A case report

A 57-year-old man underwent his seventh ablation session for atrial tachycardia (AT). His previous ablations involved several regions of the right atrium (RA) and left atrium (LA). The AT was characterized as biatrial tachycardia with a circuit involving the mitral annulus and septal RA. The AT was terminated by ablation through the insertion site of Bachmann’s bundle (BB) in both atria. After 3 months, the patient underwent his eighth ablation session because of AT recurrence. Activation maps showed that the connection from the RA to LA and vice versa was maintained via BB and the coronary sinus, respectively. The ablation target to interrupt the AT circuit was the mitral isthmus (MI), not BB, because BB supplied the electrical activation of the left atrial appendage (LAA) via a unidirectional electrical connection from the RA to LA. Ablation attempts from within the coronary sinus were performed to target the epicardial connection in the MI and led to complete blockage of the connection from the LA to RA. Otherwise, the connection from the RA to LA was preserved via BB. The patient was free of symptoms and anti-arrhythmic drugs at the 4-month follow-up. However, he had a high risk of electrical isolation of the LAA because extensive ablations had been performed; the strategy of targeting the MI contributed to the balance between preserving the electrical activation of the LAA and treating the biatrial tachycardia. Verification of the connective pathway between the two atria might be helpful to determine the optimal target.     

Hydrogen sulphide increases pulmonary veins and atrial arrhythmogenesis with activation of protein kinase C

Hydrogen sulphide (H₂S), one of the most common toxic air pollutants, is an important aetiology of atrial fibrillation (AF). Pulmonary veins (PVs) and left atrium (LA) are the most important AF trigger and substrate. We investigated whether H₂S may modulate the arrhythmogenesis of PVs and atria. Conventional microelectrodes and whole‐cell patch clamp were performed in rabbit PV, sinoatrial node (SAN) or atrial cardiomyocytes before and after the perfusion of NaHS with or without chelerythrine (a selective PKC inhibitor), rottlerin (a specific PKC δ inhibitor) or KB‐R7943 (a NCX inhibitor). NaHS reduced spontaneous beating rates, but increased the occurrences of delayed afterdepolarizations and burst firing in PVs and SANs. NaHS (100 μmol/L) increased I_KATP and I_NCX in PV and LA cardiomyocytes, which were attenuated by chelerythrine (3 μmol/L). Chelerythrine, rottlerin (10 μmol/L) or KB‐R7943 (10 μmol/L) attenuated the arrhythmogenic effects of NaHS on PVs or SANs. NaHS shortened the action potential duration in LA, but not in right atrium or in the presence of chelerythrine. NaHS increased PKC activity, but did not translocate PKC isoforms α, ε to membrane in LA. In conclusion, through protein kinase C signalling, H₂S increases PV and atrial arrhythmogenesis, which may contribute to air pollution‐induced AF.     

Comparison of peri-procedural anticoagulation with rivaroxaban and apixaban during radiofrequency ablation of atrial fibrillation

IntroductionProspective studies on rivaroxaban and apixaban have shown the safety and efficacy of direct anticoagulation agents (DOAC)s used peri-procedurally during radiofrequency ablation (RFA) of atrial fibrillation (AF). Studies comparing the two agents have not been performed.MethodsConsecutive patients from a prospective registry who underwent RFA of AF between April 2012 and March 2015 and were on apixaban or rivaroxaban were studied. Clinical variables and outcomes were noted.ResultsThere were a total of 358 patients (n = 56 on apixaban and n = 302 on rivaroxaban). There were no differences in baseline characteristics between both groups. The last dose of rivaroxaban was administered the night before the procedure in 96% of patients. In patients on apixaban, 48% of patients whose procedure was in the afternoon took the medication on the morning of the procedure. TIA/CVA occurred in 2 patients (0.6%) in rivaroxaban group with none in apixaban group (p = 0.4). There was no difference in the rate of pericardial effusion between apixaban and rivaroxaban groups [1.7% vs 0.6% (p = 0.4)]. Five percent of patients in both groups had groin complications (p = 0.9). In apixaban group, all groin complications were small hematomas except one patient who had a pseudoaneurysm (1.6%). One pseudo-aneurysm, 1 fistula and 3 large hematomas were noted in patients on rivaroxaban (1.7%) with the rest being small hematomas. DOACs were restarted post procedure typically 4 h post hemostasis.ConclusionsPeri-procedural uninterrupted use of apixaban and rivaroxaban during AF RFA is safe and there are no major differences between both groups.     

Comparison of non-triggered magnetic resonance imaging and echocardiography for the assessment of left atrial volume and morphology

Background

Advanced atrial fibrillation (AF) patients have persistent AF, failed previous catheter ablation and/or an enlarged left atrium (LA), which is associated with a reduced success of AF ablation. Transthoracic echocardiography (TTE) and contrast enhanced magnetic resonance angiography (CE-MRA) are available to assess LA volume. However, it is unknown how these modalities relate in patients with advanced AF. We therefore compared the reproducibility of TTE and non-triggered CE-MRA in advanced AF patients and their ability to select patients with successful thoracoscopic AF ablation.

Methods

Two independent observers measured LA volumes on 65 TTE and CE-MRA exams of advanced AF patients prior to AF ablation. Patients were followed after AF ablation with rhythm monitoring every 3 months for 1 year to determine AF recurrence. Inter-modality, inter- and intra-observer variability were determined using intraclass correlation coefficients (ICC). Receiver-operating characteristic (ROC) analysis was performed to determine sensitivity and specificity of TTE and CE-MRA volume and CE-MRA dimensions to identify patients with AF recurrence during follow-up.

Results

LA enlargement ≥?34 ml/m² was present in 60% of the patients. CE-MRA and TTE demonstrated a good correlation for LA volume assessment (intraclass correlation, ICC?=?0.86; p?<?0.001) with larger volumes consistently measured by CE-MRA. Major discrepancies were mostly attributed to TTE acquisition. Craniocaudal enlargement discriminated patients with AF recurrence (AUC 0.67 [95% CI 0.55–0.85], p?=?0.01).

Conclusions

Non-triggered CE-MRA is a viable and reproducible 3D alternative for 2D TTE to assess LA volume in advanced AF patients. Craniocaudal enlargement was the only discriminator of AF recurrence after AF ablation.

     

Stroke risk in patients with device-detected atrial high-rate episodes

Cardiovascular implantable electronic devices (CIEDs) can detect atrial arrhythmias, i.?e. atrial high-rate episodes (AHRE). The thrombo-embolic risk in patients showing AHRE appears to be lower than in patients with clinical atrial fibrillation (AF) and it is unclear whether the former will benefit from oral anticoagulants. Based on currently available evidence, it seems reasonable to consider antithrombotic therapy in patients without documented AF showing AHRE >24 hours and a CHA₂DS₂-VASc score (congestive heart failure, hypertension, age ≥75 years [doubled], diabetes mellitus, prior stroke [doubled], vascular disease, age 65–74 years and female sex) ≥1, awaiting definite answers from ongoing randomised clinical trials. In patients with AHRE <24 hours, current literature does not support starting oral anticoagulation. In these patients, intensifying CIED read-outs can be considered to find progression in AHRE duration sooner, enhancing timely stroke prevention. The notion that AHRE and stroke coincide perseveres but should be abandoned since CIED data show a clear disconnect.