Publications
183 results found
Drakopoulou M, Nashat H, Kempny A, et al., 2018, Arrhythmias in adult patients with congenital heart disease and pulmonary arterial hypertension, Heart, Vol: 104, Pages: 1963-1969, ISSN: 1355-6037
OBJECTIVES: Approximately 5%-10% of adults with congenital heart disease (CHD) develop pulmonary arterial hypertension (PAH), which affects life expectancy and quality of life. Arrhythmias are common among these patients, but their incidence and impact on outcome remains uncertain. METHODS: All adult patients with PAH associated with CHD (PAH-CHD) seen in a tertiary centre between 2007 and 2015 were followed for new-onset atrial or ventricular arrhythmia. Clinical variables associated with arrhythmia and their relation to mortality were assessed using Cox analysis. RESULTS: A total of 310 patients (mean age 34.9±12.3 years, 36.8% male) were enrolled. The majority had Eisenmenger syndrome (58.4%), 15.2% had a prior defect repair and a third had Down syndrome. At baseline, 14.2% had a prior history of arrhythmia, mostly supraventricular arrhythmia (86.4%). During a median follow-up of 6.1 years, 64 patients developed at least one new arrhythmic episode (incidence 3.47% per year), mostly supraventricular tachycardia or atrial fibrillation (78.1% of patients). Arrhythmia was associated with symptoms in 75.0% of cases. The type of PAH-CHD, markers of disease severity and prior arrhythmia were associated with arrhythmia during follow-up. Arrhythmia was a strong predictor of death, even after adjusting for demographic and clinical variables (HR 3.41, 95% CI 2.10 to 5.53, p<0.0001). CONCLUSIONS: Arrhythmia is common in PAH-CHD and is associated with an adverse long-term outcome, even when managed in a specialist centre.
Jarman JWE, Hussain W, Wong T, et al., 2018, Resource use and clinical outcomes in patients with atrial fibrillation with ablation versus antiarrhythmic drug treatment, BMC Cardiovascular Disorders, Vol: 18, ISSN: 1471-2261
BackgroundThe objective of our study was to compare resource use and clinical outcomes among atrial fibrillation (AF) patients who underwent catheter ablation versus antiarrhythmic drug (AAD) treatment.MethodsA retrospective cohort design using the Clinical Practice Research Data-Hospital Episode Statistics linkage data from England (2008–2013) was used. Patients undergoing catheter ablation treatment for AF were indexed to the date of first procedure. AAD patients with at least two different AAD drugs were indexed to the first fill of the second AAD. Patients were matched using 1:1 propensity matching. Primary endpoints including inpatient and outpatient visits were compared between ablation and AAD cohorts in the 4 months-1 year period after index. Secondary endpoints including heart failure, stroke, cardioversion, mortality, and a composite outcome were compared for the 4 months-3 years post-index period in the two groups. Cox-proportional hazards models were estimated for clinical outcomes comparison.ResultsA total of 558 patients were matched in the two groups for resource utilization comparison. The average number of cardiovascular (CV)-related outpatient visits in the 4–12 months post-index period were significantly lower in the ablation group versus the AAD group (1.76 vs 3.57, p < .0001). There was no significant difference in all-cause and CV-related inpatient visits and all-cause outpatient visits among the two groups. For secondary endpoints comparison, 615 matched patients in each group emerged. Ablation patients had 38% lower risk of heart failure (hazard ratio [HR] 0.62, p = 0.0318), 50% lower risk of mortality (HR 0.50, p = 0.0082), and 43% lower risk of experiencing a composite outcome (HR 0.57, p = 0.0009) as compared to AAD treatment cohort.ConclusionAF ablation was associated with significantly lower CV-related outpatient visits, and lower risk of heart failure and mortality v
Shi R, Chen Z, Kontogeorgis A, et al., 2018, Epicardial ventricular tachycardia ablation guided by a novel high-resolution contact mapping system: a multicenter study, Journal of the American Heart Association : Cardiovascular and Cerebrovascular Disease, Vol: 7, ISSN: 2047-9980
Background Mapping using a multipolar catheter with small and closely spaced electrodes has been shown to improve the validity of electrograms to identify endocardial critical sites of reentry isthmus and foci of earliest activation. However, the feasibility, safety, and clinical outcome of using such technology to guide epicardial ventricular tachycardia (VT) ablation has not been reported. Methods and Results Thirty-three consecutive patients from 5 high-volume centers were studied. These patients had 43 epicardial maps using a novel 64-pole mini-basket catheter to guide VT ablation. Activation maps with 17 832 points per map (interquartile range: 7621-32 497 points per map) were acquired in 11 patients with tolerated VT (7 focal, 4 reentry). Substrate maps with 40149 points per map (interquartile range: 20926-49391 points per map) were acquired in 30 patients. Local abnormal ventricular activities were consistently demonstrated at the substrate regions of interest. Epicardial ablation was performed in 31 of 33 patients, with acute VT termination in 10 of 11 patients (91%). Complete elimination of local abnormal ventricular activities was achieved in 25 of 31 patients. At a median follow-up of 10 months (interquartile range: 4-14 months), 64% (7/11) of patients who had acute termination of VT and 55% (11/20) of those who had substrate modification alone were free of VT. There was no immediate complication following epicardial procedure. Conclusions Epicardial VT ablation guided by a mini-basket catheter is feasible and safe. Complete reentry VT circuits and foci of earliest activation were identified in all inducible stable VT. The longer term clinical outcome of ablation guided by this novel mapping technology utilizing small and closely spaced electrodes will have to be determined with a larger study.
Wong C, Zakeri R, Khan H, et al., 2018, Long-Term Outcomes Following Catheter Ablation in Patients With Atrial Fibrillation and Heart Failure: 7-Year Follow-Up of the ARC-HF Trial, Publisher: LIPPINCOTT WILLIAMS & WILKINS, ISSN: 0009-7322
- Author Web Link
- Cite
- Citations: 1
Shi R, Chen Z, Mantziari L, et al., 2018, Multiple atrial tachycardias after orthotopic heart transplantation: A case report and literature review., HeartRhythm Case Reports, Vol: 4, Pages: 538-541, ISSN: 2214-0271
Atrial tachycardia (AT) after orthotopic heart transplantation (OHT) can be complex, occurring in the recipient as well as in the donor atria. Catheter ablation of these multiple ATs is challenging because of the complexity of atrial scar substrates. This case report demonstrates the merit of using a novel multipolar high-density mini-basket mapping catheter for fast, high-resolution mapping of 3 different ATs occurring in both atria of the orthotopic transplant heart.
Yang G, Chen J, Gao Z, et al., 2018, Multiview sequential learning and dilated residual learning for a fully automatic delineation of the left atrium and pulmonary veins from late gadolinium-enhanced cardiac MRI images, 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Publisher: IEEE, Pages: 1123-1127, ISSN: 1557-170X
Accurate delineation of heart substructures is a prerequisite for abnormality detection, for making quantitative and functional measurements, and for computer-aided diagnosis and treatment planning. Late Gadolinium-Enhanced Cardiac MRI (LGE-CMRI) is an emerging imaging technology for myocardial infarction or scar detection based on the differences in the volume of residual gadolinium distribution between scar and healthy tissues. While LGE-CMRI is a well-established non-invasive tool for detecting myocardial scar tissues in the ventricles, its application to left atrium (LA) imaging is more challenging due to its very thin wall of the LA and poor quality images, which may be produced because of motion artefacts and low signal-to-noise ratio. As the LGE-CMRI scan is designed to highlight scar tissues by altering the gadolinium kinetics, the anatomy among different heart substructures has less distinguishable boundaries. An accurate, robust and reproducible method for LA segmentation is highly in demand because it can not only provide valuable information of the heart function but also be helpful for the further delineation of scar tissue and measuring the scar percentage. In this study, we proposed a novel deep learning framework working on LGE-CMRI images directly by combining sequential learning and dilated residual learning to delineate LA and pulmonary veins fully automatically. The achieved results showed accurate segmentation results compared to the state-of-the-art methods. The proposed framework leads to an automatic generation of a patient-specific model that can potentially enable an objective atrial scarring assessment for the atrial fibrillation patients.
Brahmbhatt D, Evans L, Riley J, et al., 2018, Mapping the processes involved in remote monitoring of heart failure patients at a specialist NHS cardiology clinic, Heart Rhythm Congress
Haldar S, Wong T, 2018, London Arrhythmia Summit-2019, EUROPEAN HEART JOURNAL, Vol: 39, Pages: 3410-3410, ISSN: 0195-668X
Martin R, Maury P, Bisceglia C, et al., 2018, Characteristics of scar-related ventricular tachycardia circuits using ultra-high-density mapping, Circulation: Arrhythmia and Electrophysiology, Vol: 11, ISSN: 1941-3084
BACKGROUND: Ventricular tachycardia (VT) with structural heart disease is dependent on reentry within scar regions. We set out to assess the VT circuit in greater detail than has hitherto been possible, using ultra-high-density mapping. METHODS: All ultra-high-density mapping guided VT ablation cases from 6 high-volume European centers were assessed. Maps were analyzed offline to generate activation maps of tachycardia circuits. Topography, conduction velocity, and voltage of the VT circuit were analyzed in complete maps. RESULTS: Thirty-six tachycardias in 31 patients were identified, 29 male and 27 ischemic. VT circuits and isthmuses were complex, 11 were single loop and 25 double loop; 3 had 2 entrances, 5 had 2 exits, and 15 had dead ends of activation. Isthmuses were defined by barriers, which included anatomic obstacles, lines of complete block, and slow conduction (in 27/36 isthmuses). Median conduction velocity was 0.08 m/s in entrance zones, 0.29 m/s in isthmus regions ( P<0.001), and 0.11 m/s in exit regions ( P=0.002). Median local voltage in the isthmus was 0.12 mV during tachycardia and 0.06 mV in paced/sinus rhythm. Two circuits were identifiable in 5 patients. The median timing of activation was 16% of diastole in entrances, 47% in the mid isthmus, and 77% in exits. CONCLUSIONS: VT circuits identified were complex, some of them having multiple entrances, exits, and dead ends. The barriers to conduction in the isthmus seem to be partly functional in 75% of circuits. Conduction velocity in the VT isthmus slowed at isthmus entrances and exits when compared with the mid isthmus. Isthmus voltage is often higher in VT than in sinus or paced rhythms.
Chen J, Yang G, Gao Z, et al., 2018, Multiview two-task recursive attention model for left atrium and atrial scars segmentation, Medical Image Computing and Computer Assisted Intervention – MICCAI 2018, Publisher: Springer, Pages: 455-463, ISSN: 0302-9743
Late Gadolinium Enhanced Cardiac MRI (LGE-CMRI) for detecting atrial scars in atrial fibrillation (AF) patients has recently emerged as a promising technique to stratify patients, guide ablation therapy and predict treatment success. Visualisation and quantification of scar tissues require a segmentation of both the left atrium (LA) and the high intensity scar regions from LGE-CMRI images. These two segmentation tasks are challenging due to the cancelling of healthy tissue signal, low signal-to-noise ratio and often limited image quality in these patients. Most approaches require manual supervision and/or a second bright-blood MRI acquisition for anatomical segmentation. Segmenting both the LA anatomy and the scar tissues automatically from a single LGE-CMRI acquisition is highly in demand. In this study, we proposed a novel fully automated multiview two-task (MVTT) recursive attention model working directly on LGE-CMRI images that combines a sequential learning and a dilated residual learning to segment the LA (including attached pulmonary veins) and delineate the atrial scars simultaneously via an innovative attention model. Compared to other state-of-the-art methods, the proposed MVTT achieves compelling improvement, enabling to generate a patient-specific anatomical and atrial scar assessment model.
Seitzer M, Yang G, Schlemper J, et al., 2018, Adversarial and perceptual refinement for compressed sensing MRI reconstruction, 21st International Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI2018), Pages: 232-240, ISSN: 0302-9743
© Springer Nature Switzerland AG 2018. Deep learning approaches have shown promising performance for compressed sensing-based Magnetic Resonance Imaging. While deep neural networks trained with mean squared error (MSE) loss functions can achieve high peak signal to noise ratio, the reconstructed images are often blurry and lack sharp details, especially for higher undersampling rates. Recently, adversarial and perceptual loss functions have been shown to achieve more visually appealing results. However, it remains an open question how to (1) optimally combine these loss functions with the MSE loss function and (2) evaluate such a perceptual enhancement. In this work, we propose a hybrid method, in which a visual refinement component is learnt on top of an MSE loss-based reconstruction network. In addition, we introduce a semantic interpretability score, measuring the visibility of the region of interest in both ground truth and reconstructed images, which allows us to objectively quantify the usefulness of the image quality for image post-processing and analysis. Applied on a large cardiac MRI dataset simulated with 8-fold undersampling, we demonstrate significant improvements (p<0.01) over the state-of-the-art in both a human observer study and the semantic interpretability score.
Wu F, Li L, Yang G, et al., 2018, Atrial Fibrosis Quantification Based on Maximum Likelihood Estimator of Multivariate Images, 21st International Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI2018), Pages: 604-612, ISSN: 0302-9743
© 2018, Springer Nature Switzerland AG. We present a fully-automated segmentation and quantification of the left atrial (LA) fibrosis and scars combining two cardiac MRIs, one is the target late gadolinium-enhanced (LGE) image, and the other is an anatomical MRI from the same acquisition session. We formulate the joint distribution of images using a multivariate mixture model (MvMM), and employ the maximum likelihood estimator (MLE) for texture classification of the images simultaneously. The MvMM can also embed transformations assigned to the images to correct the misregistration. The iterated conditional mode algorithm is adopted for optimization. This method first extracts the anatomical shape of the LA, and then estimates a prior probability map. It projects the resulting segmentation onto the LA surface, for quantification and analysis of scarring. We applied the proposed method to 36 clinical data sets and obtained promising results (Accuracy: 0.809±150, Dice: 0.556±187). We compared the method with the conventional algorithms and showed an evidently and statistically better performance (p < 0.03).
Sperzel J, Defaye P, Delnoy P-P, et al., 2018, Primary safety results from the LEADLESS Observational Study, EP-Europace, Vol: 20, Pages: 1491-1497, ISSN: 1099-5129
Aims: A prospective, single-arm, multicentre, post-market study was conducted to confirm the short-term safety of the Nanostim™ leadless pacemaker (LP). In this study, we report the primary results of the LEADLESS Observational Study. Methods and results: Subjects meeting VVIR pacemaker indications were enrolled and followed up after successful LP implantation, prior to discharge and post-implantation at 90 days, 180 days, and every 6 months thereafter for the assessment of adverse events. The primary safety endpoint was evaluated in terms of freedom from serious adverse device effects (SADEs) at 6 months in 300 subjects. Data for all enrolled subjects were also presented. A total of 470 subjects were enrolled (75.8 ± 13.1 years, 62.8% male). The study paused in April 2014 following the occurrence of perforation events that led to changes in the protocol and investigator training. Freedom from SADEs, evaluated in 300 subjects enrolled post-pause, was 94.6% (95% confidence interval 91.0-97.2%) and demonstrated non-inferiority to a performance goal of 86% (P < 0.0001). Eighteen SADEs were observed in 16 (5.3%) subjects. The most frequently occurring events were cardiac perforation (1.3%), device dislodgement (0.3%), and vascular complications (1.3%). In the 470 subjects, 34 similar SADEs were observed in 31 (6.6%) subjects. After stratifying the results in relation to the study pause, there was a statistically significant difference in the final LP location (septum vs. apex) (P < 0.0001) and the number of repositioning attempts (<2 vs. ≥2) (P = 0.05) and a decreasing trend in the rates of cardiac perforation and device dislodgement. Conclusion: The primary safety endpoint at 6 months was successfully met for the Nanostim LP. The occurrence of cardiac perforation and device dislodgement declined after changes following the study pause.
Ibrahim M, Panikker S, Lim E, et al., 2018, Relevance of electrical connectivity between the coronary sinus and the left atrial appendage for the intentional electrical isolation of the left atrial appendage in treating persistent atrial fibrillation: insights from the LEIO-AF study, HeartRhythm Case Reports, Vol: 4, Pages: 420-424, ISSN: 2214-0271
Catheter ablation is an accepted therapeutic option for paroxysmal atrial fibrillation (AF), but its role is less certain in patients with persistent AF.1 The difference in response to pulmonary vein (PV) isolation (PVI) between paroxysmal and persistent forms of AF may arise because of triggers from non-PV sites or alterations in atrial substrate favoring maintenance of AF that are unaffected by PVI alone.2 In support of this statement, adjunctive ablation of certain sites (including the superior vena cava, ligament of Marshall [LOM], crista terminalis, coronary sinus [CS], posterior wall of the left atrium [LA], and left atrial appendage [LAA]) as well as more widespread ablation aimed at modifying substrate has been shown to improve the success of catheter ablation of persistent AF.In the case of the LAA, the BELIEF study (Effect of Empirical Left Atrial Appendage Isolation on Long-term Procedure Outcome in Patients With Persistent or Long-standing Persistent Atrial Fibrillation Undergoing Catheter Ablation)3 recently showed that in patients with long-standing persistent AF, empirical electrical isolation of the LAA together with extensive atrial ablation markedly improved freedom from AF at 1 year compared to an extensive atrial ablation strategy alone. However, electrical isolation of the LAA can be challenging and is sometimes impossible to achieve. This may be partly because the electrical connections of the LAA are not completely understood.Here we report 2 patients showing that the CS can be an important electrical conduit to the LAA.
Haldar S, Wong T, 2018, 'London Arrhythmia Summit 2018', EUROPEAN HEART JOURNAL, Vol: 39, Pages: 2337-2338, ISSN: 0195-668X
Shi R, Norman M, Chen Z, et al., 2018, Individualized ablation strategy guided by live simultaneous global mapping to treat persistent atrial fibrillation, Future Cardiology, Vol: 14, Pages: 237-249, ISSN: 1479-6678
Atrial fibrillation (AF) is the most common clinical arrhythmia encountered. Catheter ablation has become the first-line therapy for symptomatic drug-refractory paroxysmal and persistent AF. Although pulmonary vein electrical isolation is still the cornerstone of the ablation strategy, the clinical outcome particularly in treating persistent AF is suboptimal. Significant efforts have been applied with live global chamber mapping of AF aimed to identify patient-specific drivers and/or maintainers located outside of the pulmonary veins to further improve the outcome of catheter ablation. Within this review, we present an overview of contemporary global chamber AF mapping technologies and characteristics, with a particular focus on global, noncontact, dipole density mapping illustrated with a clinical case of persistent AF ablation using this novel methodology.
Yang G, Zhuang X, Khan H, et al., 2018, Fully automatic segmentation and objective assessment of atrial scars for longstanding persistent atrial fibrillation patients using late gadolinium-enhanced MRI, Medical Physics, Vol: 45, Pages: 1562-1576, ISSN: 0094-2405
PURPOSE: Atrial fibrillation (AF) is the most common heart rhythm disorder and causes considerable morbidity and mortality, resulting in a large public health burden that is increasing as the population ages. It is associated with atrial fibrosis, the amount and distribution of which can be used to stratify patients and to guide subsequent electrophysiology ablation treatment. Atrial fibrosis may be assessed non-invasively using late gadolinium-enhanced (LGE) magnetic resonance imaging (MRI) where scar tissue is visualised as a region of signal enhancement. However, manual segmentation of the heart chambers and of the atrial scar tissue is time-consuming and subject to inter-operator variability, particularly as image quality in AF is often poor. In this study, we propose a novel fully automatic pipeline to achieve accurate and objective segmentation of the heart (from MRI Roadmap data) and of scar tissue within the heart (from LGE MRI data) acquired in patients with AF. METHODS: Our fully automatic pipeline uniquely combines: (1) a multi-atlas based whole heart segmentation (MA-WHS) to determine the cardiac anatomy from an MRI Roadmap acquisition which is then mapped to LGE MRI, and (2) a super-pixel and supervised learning based approach to delineate the distribution and extent of atrial scarring in LGE MRI. We compared the accuracy of the automatic analysis to manual ground-truth segmentations in 37 patients with persistent long standing AF. RESULTS: Both our MA-WHS and atrial scarring segmentations showed accurate delineations of cardiac anatomy (mean Dice = 89%) and atrial scarring (mean Dice = 79%) respectively compared to the established ground truth from manual segmentation. In addition, compared to the ground truth, we obtained 88% segmentation accuracy, with 90% sensitivity and 79% specificity. Receiver operating characteristic analysis achieved an average area under the curve of 0.91. CONCLUSION: Compared with previously studied methods with manual interv
Chen G, Wu L, Zheng L, et al., 2018, Combining Percutaneous Ultrasound-Guided Hematoma Aspiration and Compression Repair to Treat Femoral Artery Pseudoaneurysm after Cardiac Catheterization., Int Heart J, Vol: 59, Pages: 333-338
This study aimed to prospectively evaluate the safety and efficacy of a new developed method that uses percutaneous ultrasound-guided hematoma aspiration followed by targeted localized manual compression for treatment of femoral artery pseudoaneurysm after cardiac catheterization, which obviates thrombin use, surgery, and long-time compression.From January 2007 to July 2014, 32 patients (17 women; mean age, 55.3 ± 11.5 years) out of 8,725 consecutive cases undergoing cardiac catheterization via femoral access developed one pseudoaneurysm each ranging in size from 21 × 11 mm to 72 × 39 mm. Under ultrasound guidance, blood within the pseudoaneurysm was aspirated percutaneously using an 18-gauge needle, while the pseudoaneurysm neck and a nearby site over the pseudoaneurysm were manually compressed for 15 min. All patients underwent repeat ultrasound examination 24 hours later.Of the 32 pseudoaneurysms, 31 were successfully occluded, and 1 recurred in a patient with coexisting arteriovenous fistula, yielding an overall success rate of 96.9% (31/32). No further recurrence or procedure related complications were observed. The treatment approach is unlike open surgical repair with hematoma evacuation and arterial defect suturing, in that it entails hematoma aspiration and feeding flow blockage at the pseudoaneurismal neck.In this preliminary experience, combining percutaneous ultrasound-guided hematoma aspiration and manual compression appears safe and effective in treating femoral artery pseudoaneurysms after catheterization and avoids thrombin use, long-time compression, and surgery.
Ma Y, Chen Z, Shi R, et al., 2018, An unusual 'rite of passage' for an ablation catheter during left ventricular tachycardia ablation - a case report, European Heart Journal: Case Reports, Vol: 2, ISSN: 2514-2119
Introduction: Ventricular perforation during radiofrequency ablation of ventricular tachycardia is a recognized serious complication that carries high morbidity and mortality. Perforation is often associated with local intramyocardial injury due to excess heat induced by catheter, 'steam pop'. The complication usually requires emergency surgical repair. Case presentation: We present a case, when the catheter found its way into the epicardium during left ventricular (LV) electroanatomic mapping without any serious complication. Angiography through the ablation catheter confirmed the diagnosis of LV coronary sinus fistula. Discussion: Contrast injection through the irrigation port of the ablation catheter is a useful way of delineating anatomical anomalies during electrophysiology procedure.
Haldar SK, Jones DG, Khan H, et al., 2018, Characterising the difference in electrophysiological substrate and outcomes between heart failure and non-heart failure patients with persistent atrial fibrillation, EUROPACE, Vol: 20, Pages: 451-458, ISSN: 1099-5129
- Author Web Link
- Cite
- Citations: 3
Khan HR, Kralj-Hans I, Haldar S, et al., 2018, Catheter ablation versus thoracoscopic surgical ablation in long standing persistent atrial fibrillation (CASA-AF): study protocol for a randomised controlled trial, Trials, Vol: 19, ISSN: 1745-6215
BACKGROUND: Atrial fibrillation is the commonest arrhythmia which raises the risk of heart failure, thromboembolic stroke, morbidity and death. Pharmacological treatments of this condition are focused on heart rate control, rhythm control and reduction in risk of stroke. Selective ablation of cardiac tissues resulting in isolation of areas causing atrial fibrillation is another treatment strategy which can be delivered by two minimally invasive interventions: percutaneous catheter ablation and thoracoscopic surgical ablation. The main purpose of this trial is to compare the effectiveness and safety of these two interventions. METHODS/DESIGN: Catheter Ablation versus Thoracoscopic Surgical Ablation in Long Standing Persistent Atrial Fibrillation (CASA-AF) is a prospective, multi-centre, randomised controlled trial within three NHS tertiary cardiovascular centres specialising in treatment of atrial fibrillation. Eligible adults (n = 120) with symptomatic, long-standing, persistent atrial fibrillation will be randomly allocated to either catheter ablation or thoracoscopic ablation in a 1:1 ratio. Pre-determined lesion sets will be delivered in each treatment arm with confirmation of appropriate conduction block. All patients will have an implantable loop recorder (ILR) inserted subcutaneously immediately following ablation to enable continuous heart rhythm monitoring for at least 12 months. The devices will be programmed to detect episodes of atrial fibrillation and atrial tachycardia ≥ 30 s in duration. The patients will be followed for 12 months, completing appropriate clinical assessments and questionnaires every 3 months. The ILR data will be wirelessly transmitted daily and evaluated every month for the duration of the follow-up. The primary endpoint in the study is freedom from atrial fibrillation and atrial tachycardia at the end of the follow-up period. DISCUSSION: The CASA-AF Trial is a National Institute for Health
Pearman CM, Poon SS, Bonnett LJ, et al., 2017, Minimally Invasive Epicardial Surgical Ablation Alone Versus Hybrid Ablation for Atrial Fibrillation: A Systematic Review and Meta-Analysis., Arrhythmia & electrophysiology review, Vol: 6, Pages: 202-209, ISSN: 2050-3369
Maintaining sinus rhythm in patients with non-paroxysmal AF is an elusive goal. Some suggest that hybrid ablation, combining minimally invasive epicardial surgical ablation with endocardial catheter ablation, may be more effective than either modality alone. However, randomised trials are lacking. We investigated whether hybrid ablation is more effective than epicardial ablation alone at preventing recurrent AF by performing a systematic review and meta-analysis. The review was prospectively registered with PROSPERO (CRD42016043389). MEDLINE and EMBASE were searched for studies of standalone minimally invasive epicardial ablation of AF and/or hybrid ablation, identifying 41 non-overlapping studies comprising 2737 patients. A random-effects meta-analysis, meta-regression and sensitivity analysis were performed. Single-procedure survival free from atrial arrhythmias without antiarrhythmic drugs was similar between epicardial-alone and hybrid approaches at 12 months (epicardial alone 71.5 %; [95 % CI 66.1-76.9], hybrid 63.2 %; [95 % CI 51.5-75.0]) and 24 months (epicardial alone 68.5 %; [95 % CI 57.7-79.3], hybrid 57.0 %; [95 % CI 33.6-80.4]). Freedom from atrial arrhythmias with AADs and rates of unplanned additional catheter ablations were also similar between groups. Major complications occurred more often with hybrid ablation (epicardial alone 2.9 %; [95 % CI 1.9-3.9], hybrid 7.3 %; [95 % CI 4.2-10.5]). Meta-regression suggested that bipolar radiofrequency energy and thoracoscopic access were associated with greater efficacy, but adjusting for these factors did not unmask any difference between epicardial-alone and hybrid ablation. Hybrid and epicardial ablation alone appear to be equally effective treatments for AF, although hybrid ablation may be associated with higher complication rates. These data derived from observational studies should be verified with randomised data.
Khan HR, Hnatkova K, Kralj-Hans I, et al., 2017, Heart rate variability evaluation in patients with long standing persistent atrial fibrillation treated with thoracoscopic surgical ablation with ganglionic plexi ablation or catheter ablation - recordings from implantable loop recorder, Scientific Sessions of the American-Heart-Association / Resuscitation Science Symposium, Publisher: American Heart Association, ISSN: 0009-7322
Corden B, Jarman J, Whiffin N, et al., 2017, Titin Truncating Variants Predict Life-threatening Arrhythmias in Patients With Dilated Cardiomyopathy, Scientific Sessions of the American-Heart-Association / Resuscitation Science Symposium, Publisher: LIPPINCOTT WILLIAMS & WILKINS, ISSN: 0009-7322
Corden B, Jarman J, Whiffin N, et al., 2017, Titin Truncating Variants Predict Life-threatening Arrhythmias in Patients With Dilated Cardiomyopathy, Scientific Sessions of the American-Heart-Association / Resuscitation Science Symposium, Publisher: American Heart Association, Pages: E96-E96, ISSN: 0009-7322
Introduction: There is an urgent need for better arrhythmic risk stratification in non-ischaemic dilated cardiomyopathy (DCM), where the benefit of ICD implantation is unclear. Titin truncating variants (TTNtv) are the commonest genetic cause of DCM and are associated with early onset non-sustained ventricular tachycardia (NSVT) and atrial fibrillation (AF) in these patients.Hypothesis: We hypothesize that TTNtv status can predict potentially life threatening ventricular tachycardia (VT) or fibrillation (VF) and development of new persistent AF in DCM patients with CRT-D or ICD devices.Methods: We studied 117 DCM patients with an ICD or CRT-D and documented device-recorded arrhythmia over a median period of 4.2 years. Patients were stratified by TTN genotype (28 positive for a TTNtv, 89 negative). The primary outcome was time to first device-treated VT >200bpm or VF. Secondary outcome measures included time to first development of persistent AF.Results: TTNtv predicted the risk of receiving an appropriate ICD therapy for VT/VF (hazard ratio [HR] = 4.9, 95% confidence interval [CI]=2.3-10.7, P<0.0001). This association was independent of all covariates, including replacement fibrosis measured by late-gadolinium enhancement (LGE), (adjusted HR = 8.2, 95% CI 1.9-36.5, P=0.005). Individuals with both a TTNtv and fibrosis had a markedly greater risk for appropriate device therapy than those with neither (HR = 16.6, CI 3.5-79.3, P<0.0001). TTNtv were also a risk factor for developing new persistent AF (HR = 4.4, 95% CI = 1.45-13.1, P=0.006).Conclusion: TTNtv status is an important risk factor for clinically significant arrhythmia in patients with DCM and CRT-D or ICD devices. TTNtv status alone, or more powerfully in combination with fibrosis imaging by MRI, may provide an effective approach for risk stratifying the need for ICD therapy in DCM patients.
Niespialowska-Steuden M, Markides V, Farag M, et al., 2017, Catheter ablation for AF improves global thrombotic profile and enhances fibrinolysis, Journal of Thrombosis and Thrombolysis, Vol: 44, Pages: 413-426, ISSN: 0929-5305
Patients with atrial fibrillation (AF) are atincreased risk of thrombotic events despite oral anticoagulation(OAC). Radiofrequency catheter ablation (RFCA) canrestore and maintain sinus rhythm (SR) in patients with AF.To assess whether RFCA improves thrombotic status. 80patients (71% male, 64±12y) with recently diagnosed AF,on OAC and scheduled to undergo RFCA or DC cardioversion(DCCV) were recruited. Thrombotic status was assessedusing the point-of-care global thrombosis test (GTT), before,and 4–6 weeks after DCCV and 3 months after RFCA. TheGTT first measures the time taken for occlusive thrombusformation (occlusion time, OT), while the second phase ofthe test measures the time taken to spontaneously dissolvethis clot through endogenous thrombolysis (lysis time, LT).3 months after RFCA, there was a significant reduction inLT (1994s [1560; 2475] vs. 1477s [1015; 1878]) in thosewho maintained SR, but not in those who reverted to AF. Atfollow-up, LT was longer in those in AF compared to thosein SR (AF 2966s [2038; 3879] vs. SR 1477s [1015; 1878]).RFCA resulted in no change in OT value, irrespective of hythm outcome. Similarly, there was no change in OT orLT in response to DCCV, irrespective of whether SR wasrestored. Successful restoration and maintenance of SR followingRFCA of AF is associated with improved globalthrombotic status with enhanced fibrinolysis. Larger studiesare required to confirm these early results and investigatewhether improved thrombotic status translates into fewerthromboembolic events.
Haldar SK, Jones DG, Bahrami T, et al., 2017, Catheter ablation vs electrophysiologically guided thoracoscopic surgical ablation in long-standing persistent atrial fibrillation: The CASA-AF Study, Heart Rhythm, Vol: 14, Pages: 1596-1603, ISSN: 1547-5271
BackgroundCatheter ablation (CA) outcomes for long-standing persistent atrial fibrillation (LSPAF) remain suboptimal. Thoracoscopic surgical ablation (SA) provides an alternative approach in this difficult to treat cohort.ObjectiveTo compare electrophysiological (EP) guided thoracoscopic SA with percutaneous CA as the first-line strategy in the treatment of LSPAF.MethodsFifty-one patients with de novo symptomatic LSPAF were recruited. Twenty-six patients underwent electrophysiologically guided thoracoscopic SA. Conduction block was tested for all lesions intraoperatively by an independent electrophysiologist. In the CA group, 25 consecutive patients underwent stepwise left atrial (LA) ablation. The primary end point was single-procedure freedom from atrial fibrillation (AF) and atrial tachycardia (AT) lasting >30 seconds without antiarrhythmic drugs at 12 months.ResultsSingle- and multiprocedure freedom from AF/AT was higher in the SA group than in the CA group: 19 of 26 patients (73%) vs 8 of 25 patients (32%) (P = .003) and 20 of 26 patients (77%) vs 15 of 25 patients (60%) (P = .19), respectively. Testing of the SA lesion set by an electrophysiologist increased the success rate in achieving acute conduction block by 19%. In the SA group, complications were experienced by 7 of 26 patients (27%) vs 2 of 25 patients (8%) in the CA group (P = .07).ConclusionIn LSPAF, meticulous electrophysiologically guided thoracoscopic SA as a first-line strategy may provide excellent single-procedure success rates as compared with those of CA, but there is an increased up-front risk of nonfatal complications.
Whitaker J, Panikker S, Fastl T, et al., 2017, Cardiac CT assessment of tissue thickness at the ostium of the left atrial appendage predicts acute success of radiofrequency ablation., Pacing and Clinical Electrophysiology, Vol: 40, Pages: 1218-1226, ISSN: 0147-8389
BACKGROUND: Tissue thickness at the site of ablation is a determinant of lesion transmurality. We reported the feasibility, safety and efficacy of long-standing persistent atrial fibrillation (PsAF) ablation, incorporating deliberate LAA isolation and occlusion and identified systematic differences in ostial LAA tissue thickness in a matched cohort of cadaveric specimens. METHODS: Pre-procedural CCT scans were acquired from 22 patients undergoing LAA isolation and subsequent occlusion. Using a novel CCT wall thickness algorithm, LAA ostial wall thickness was assessed in vivo, compared with measurements from the cadaveric specimens and analysed for differences between regions that demonstrated acute electrical reconnection and those that did not. RESULTS: Mean tissue thickness calculated for each LAA ostial quadrant was 2.1(+/-0.6)mm (anterior quadrant), 1.9(+/-0.4)mm (superior quadrant), 1.5(+/-0.4)mm (posterior quadrant) and 1.8(+/-0.7)mm (inferior quadrant). Tissue was significantly thicker in the anterior (p = 0.004) and superior quadrants (p = 0.014) than the posterior quadrant. Higher thickness measurements were recorded from quadrants demonstrated to be thicker from histology. Tissue was significantly thicker in regions that demonstrated acute electrical reconnection (1.9(+/-0.6)mm) when compared with those that did not (1.6(+/-0.5)mm) (p = 0.008). CONCLUSIONS: CCT imaging may be used to detect differences in wall thickness at different atrial locations and success of LAA ablation may be affected by local tissue thickness. Atrial wall thickness may need to be considered as a metric to guide titration of radiofrequency (RF) energy for safe and successful ablation. This article is protected by copyright. All rights reserved.
Frontera A, Panniker S, Breitenstein A, et al., 2017, Safety and mid-term outcome of catheter ablation of ventricular tachycardia in octogenarians, EUROPACE, Vol: 19, Pages: 1369-1377, ISSN: 1099-5129
- Author Web Link
- Cite
- Citations: 7
Yang G, Zhuang X, Khan H, et al., 2017, Segmenting atrial fibrosis from late gadolinium-enhanced cardiac MRI by deep-learned features with stacked sparse auto-encoders, MIUA 2017, Publisher: Springer, Pages: 195-206, ISSN: 1865-0929
The late gadolinium-enhanced (LGE) MRI technique is a well-validated method for fibrosis detection in the myocardium. With this technique, the altered wash-in and wash-out contrast agent kinetics in fibrotic and healthy myocardium results in scar tissue being seen with high or enhanced signal relative to normal tissue which is ‘nulled’. Recently, great progress on LGE MRI has resulted in improved visualization of fibrosis in the left atrium (LA). This provides valuable information for treatment planning, image-based procedure guidance and clinical management in patients with atrial fibrillation (AF). Nevertheless, precise and objective atrial fibrosis segmentation (AFS) is required for accurate assessment of AF patients using LGE MRI. This is a very challenging task, not only because of the limited quality and resolution of the LGE MRI images acquired in AF but also due to the thinner wall and unpredictable morphology of the LA. Accurate and reliable segmentation of the anatomical structure of the LA myocardium is a prerequisite for accurate AFS. Most current studies rely on manual segmentation of the anatomical structures, which is very labor-intensive and subject to inter- and intra-observer variability. The subsequent AFS is normally based on unsupervised learning methods, e.g., using thresholding, histogram analysis, clustering and graph-cut based approaches, which have variable accuracy. In this study, we present a fully-automated multi-atlas propagation based whole heart segmentation method to derive the anatomical structure of the LA myocardium and pulmonary veins. This is followed by a supervised deep learning method for AFS. Twenty clinical LGE MRI scans from longstanding persistent AF patients were entered into this study retrospectively. We have demonstrated that our fully automatic method can achieve accurate and reliable AFS compared to manual delineated ground truth.
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.