Evolution of ventricular and valve function in patients with right ventricular pacing - A randomized controlled trial comparing leadless and conventional pacing

BACKGROUND

Leadless pacemakers (PMs) were recently introduced to overcome lead-related complications. They showed high safety and efficacy profiles. Prospective studies assessing long-term safety on cardiac structures are still missing.

OBJECTIVE

The purpose of this study was to compare the mechanical impact of Micra with conventional PM on heart function.

METHODS

We conducted a non-inferiority trial in patients with an indication for single chamber ventricular pacing. Patients were 1:1 randomized to undergo implantation of either Micra or conventional monochamber ventricular pacemaker (PM). Patients underwent echocardiography at baseline, 6 and 12 months after implantation. Analysis included left ventricular ejection fraction (LVEF), global longitudinal strain (GLS) and valve function. N-terminal-pro hormone B-type natriuretic peptide (NT-pro-BNP) levels were measured at baseline and 12 months.

RESULTS

Fifty-one patients (27 in Micra group and 24 in conventional group) were included. Baseline characteristics were similar for both groups. At 12 months, (1) the left ventricular function as assessed by LVEF and GLS worsened similarly in both groups (∆LVEF -10 ± 7.3% and ∆GLS +5.7 ± 6.4 in Micra group vs. -13.4 ± 9.9% and +5.2 ± 3.2 in conventional group) (p = 0.218 and 0.778, respectively), (2) the severity of tricuspid valve regurgitation was significantly lower with Micra than conventional pacing (p = 0.009) and (3) median NT-pro-BNP was lower in Micra group (970 pg/dL in Micra group versus 1394 pg/dL in conventional group, p = 0.041).

CONCLUSION

Micra is non inferior to conventional PMs concerning the evolution of left ventricular function at 12-month follow-up. Our data suggest that Micra has a comparable mechanical impact on the ventricular systolic function but resulted in less valvular dysfunction.

Adherence to oral anticoagulation measured by electronic monitoring in a Belgian atrial fibrillation population

INTRODUCTION

Stroke prevention using oral anticoagulation (OAC) is the first management priority in atrial fibrillation (AF). Despite the importance of good therapy adherence, real-world adherence is still suboptimal. Patient education and adherence monitoring with new technologies are recommended. The main purpose of this sub-analysis of the AF-EduCare trial was to evaluate the effect of personalized follow-up strategies on adherence to OAC.

METHODS

Regimen adherence was monitored by the electronic Medication Event Monitoring System cap at the start of the trial (M1) and after 12 months (M2), each for three months. Patients were part of one of three education groups (In-person, Online or App-based) or the standard care (SC) group. All are qualified for OAC therapy.

RESULTS

A total of 768 patients were evaluated (11.8% SC vs. 86.8% any education group, mean age: 70.1 ± 7.9 years). Patients were taking non-vitamin K OAC (once daily 53.8%; twice daily 35.9%) or vitamin K antagonists (9.4%), equally distributed over the different study arms (p = 0.457). Mean therapy adherence was high (M1:93.8 ± 10.8%; M2:94.1 ± 10.1%). During both monitoring periods, the education group scored significantly higher than SC (M1:94.2 ± 10.0% vs. 91.3 ± 15.0%; p = 0.027; M2:94.4 ± 9.3% vs. 91.6 ± 14.0%; p = 0.006). More patients in the In-person and Online groups were able to keep or improve their adherence to > 90% compared to the SC.

CONCLUSION

Overall adherence to OAC in all study groups, even in SC, was very high, without attrition over time. Nevertheless, targeted education led to a small but significantly improved adherence compared to SC.

Baseline demographics of a contemporary Belgian atrial fibrillation cohort included in a large randomised clinical trial on targeted education and integrated care (AF-EduCare/AF-EduApp study)

Background

As the prevalence of atrial fibrillation (AF) increases worldwide and AF management becomes ever more diversified and personalised, insights into (regional) AF patient demographics and contemporary AF management are needed. This paper reports the current AF management and baseline demographics of a Belgian AF population recruited for a large multicenter integrated AF study (AF-EduCare/AF-EduApp study).

Methods

We analyzed data from 1,979 AF patients, assessed between 2018 and 2021 for the AF-EduCare/AF-EduApp study. The trial randomised consecutive patients with AF (irrespective of AF history duration) into three educational intervention groups (in person-, online-, and application-based), compared with standard care. Baseline demographics of both the included and excluded/refused patients are reported.

Results

The mean age of the trial population was 71.2 ± 9.1 years, with a mean CHA₂DS₂-VASc score of 3.4 ± 1.8. Of all screened patients, 42.4% were asymptomatic at presentation. Being overweight was the most common comorbidty, present in 68.9%, while 65.0% were diagnosed with hypertension. Anticoagulation therapy was prescribed in 90.9% of the total population and in 94.0% of the patients with an indication for thromboembolic prophylaxis. Of the 1,979 assessed AF patients, 1,232 (62.3%) were enrolled in the AF-EduCare/AF-EduApp study, with transportation problems (33.4%) as the main reason for refusal/non-inclusion. About half of the included patients were recruited at the cardiology ward (53.8%). AF was first diagnosed, paroxysmal, persistent and permanent in 13.9%, 47.4%, 22.8% and 11.3%, respectively. Patients who refused or were excluded were older (73.3 ± 9.2 vs. 69.8 ± 8.9 years, p < 0.001) and had more comorbidities (CHA₂DS₂-VASc 3.8 ± 1.8 vs. 3.1 ± 1.7, p < 0.001). The four AF-EduCare/AF-EduApp study groups were comparable across the vast majority of parameters.

Conclusions

The population showed high use of anticoagulation therapy, in line with current guidelines. In contrast to other AF trials about integrated care, the AF-EduCare/AF-EduApp study managed to incorporate all types of AF patients, both out-patient and hospitalised, with very comparable patient demographics across all subgroups. The trial will analyze whether different approaches to patient education and integrated AF care have an impact on clinical outcomes.

Clinical Trial Registration

https://clinicaltrials.gov/ct2/show/NCT03707873?term=af-educare&draw=2&rank=1, identifier: NCT03707873; https://clinicaltrials.gov/ct2/show/NCT03788044?term=af-eduapp&draw=2&rank=1, identifier: NCT03788044.

Individualized QT interval (QTi) is a powerful diagnostic tool in long QT syndrome: results from a large validation study

Aims

Diagnosis of Long QT syndrome (LQTS) is based on prolongation of the QT interval corrected for heart rate (QTc) on surface ECG and genotyping. However, up to 25% of genotype positive patients have a normal QTc interval. We recently showed that individualized QT interval (QTi) derived from 24 h holter data and defined as the QT value at the intersection of an RR interval of 1,000 ms with the linear regression line fitted through QT-RR data points of each individual patient was superior over QTc to predict mutation status in LQTS families. This study aimed to confirm the diagnostic value of QTi, fine-tune its cut-off value and evaluate intra-individual variability in patients with LQTS.

Methods

From the Telemetric and Holter ECG Warehouse, 201 recordings from control individuals and 393 recordings from 254 LQTS patients were analysed. Cut-off values were obtained from ROC curves and validated against an in house LQTS and control cohort.

Results

ROC curves indicated very good discrimination between controls and LQTS patients with QTi, both in females (AUC 0.96) and males (AUC 0.97). Using a gender dependent cut-off of 445 ms in females and 430 ms in males, a sensitivity of 88% and specificity of 96% were achieved, which was confirmed in the validation cohort. No significant intra-individual variability in QTi was observed in 76 LQTS patients for whom at least two holter recordings were available (483 ± 36 ms vs. 489 ± 42 ms, p = 0.11).

Conclusions

This study confirms our initial findings and supports the use of QTi in the evaluation of LQTS families. Using the novel gender dependent cut-off values, a high diagnostic accuracy was achieved.

Noninvasive neurological monitoring to enhance pLVAD-assisted ventricular tachycardia ablation - a Mini review

For critically ill patients, hemodynamic fluctuations can be life-threatening; this is particularly true for patients experiencing cardiac comorbidities. Patients may suffer from problems with heart contractility and rate, vascular tone, and intravascular volume, resulting in hemodynamic instability. Unsurprisingly, hemodynamic support provides a crucial and specific benefit during percutaneous ablation of ventricular tachycardia (VT). Mapping, understanding, and treating the arrhythmia during sustained VT without hemodynamic support is often infeasible due to patient hemodynamic collapse. Substrate mapping in sinus rhythm can be successful for VT ablation, but there are limitations to this approach. Patients with nonischemic cardiomyopathy may present for ablation without exhibiting useful endocardial and/or epicardial substrate-based ablation targets, either due to diffuse extent or a lack of identifiable substrate. This leaves activation mapping during ongoing VT as the only viable diagnostic strategy. By enhancing cardiac output, percutaneous left ventricular assist devices (pLVAD) may facilitate conditions for mapping that would otherwise be incompatible with survival. However, the optimal mean arterial pressure to maintain end-organ perfusion in presence of nonpulsatile flow remains unknown. Near infrared oxygenation monitoring during pLVAD support provides assessment of critical end-organ perfusion during VT, enabling successful mapping and ablation with the continual assurance of adequate brain oxygenation. This focused review provides practical use case scenarios for such an approach, which aims to allow mapping and ablation of ongoing VT while drastically reducing the risk of ischemic brain injury.

Is it feasible to outsource the remote monitoring of implantable cardiac defibrillators in a large tertiary hospital?

AIM

To provide a detailed description of the workflow at our telecardiology centre and to analyse the workload of real-world remote monitoring with the aim to assess the feasibility to outsource this service.

METHODS

A retrospective analysis was conducted on the telecardiology service provided at the University Hospitals of Leuven by extracting patient demographic data, general time usage and detailed information about the type of remote contacts. 10,869 contacts in 948 patients have been included. A 2-week prospective study was conducted on the same service by documenting and monitoring every action performed by specialised nurses when analysing and solving remote monitoring transmissions. 337 contacts in 262 patients were collected during this period.

RESULTS

Both analyses indicated similar numbers of events and interventions. Unplanned transmissions were more challenging and required more interventions than planned transmissions. Relatively little time (retrospective median: 1.83 min; prospective median: 1.56 min, per event) was spent on incoming non-actionable 'normal' transmissions (retrospective: 46%; prospective: 40% of all events). Retrospectively 54% and prospectively 60% of transmissions showed abnormalities and were responsible for most of the time expended. Disease-related issues were the most frequent cause for these 'abnormal' alerts. Contacting patients and physicians were key interventions undertaken. Interaction initiated by patients mainly involved the installation process (42%) and bedside monitoring problems (32%).

CONCLUSION

External data centres could deal with 40% of the transmissions, but the decline in workload would be negligible for the in-hospital remote monitoring team, because very little time is spent dealing with the many 'non-event' transmissions whereas most of the time is spent solving clinical problems. Providing sufficient resources and optimising communication protocols is necessary to aid in managing the workload of the remote monitoring team.

Implications for practiceContacting patients and physicians are key interventions for specialist nurses in remote monitoring centres.Detailed timing confirmed that most time was spent on relevant disease-related clinical problems.Despite dealing with ∼40% of transmissions, outsourcing to external data centres would decrease the workload only by 15-25%.Patient initiated contacts with questions concerning remote monitoring form a high burden and should be countered by scaling the service and creating communication protocols.

The effect of leadless pacing on LV and RV systolic function is not inferior to conventional RV pacing

Introduction

Leadless right ventricular (RV) pacing has been recently proposed as alternative to conventional pacemakers (PM's). While RV pacing with a conventional PM is known to cause deterioration of left ventricular (LV) and RV systolic function over time, the effects of leadless PM's are currently under-explored. In this prospective and randomized study, we hypothesized that the effect of leadless RV pacing over time on both LV and RV systolic function is not inferior to conventional RV pacing.

Methods

Fifty-one age-matched patients with a guideline indication for a PM were prospectively recruited and randomized to undergo implantation of either (i) a leadless PM, or (ii) a conventional PM. Patients underwent echocardiography prior to (BL), and at 6 and 12 months (M6 & M12) after PM implantation. All imaging after implantation was performed during active pacing. Analysis included LV ejection fraction (LVEF), LV global longitudinal strain (GLS), and RV free wall (FW) strain.

Results

Twenty-seven patients were implanted with a leadless PM, while twenty-four received a conventional PM. Median age was 82 (80–87) years. At BL, average LVEF and LV GLS were normal and similar in both groups. At M12, both LVEF (−12%) and LV GLS strain (−5%) decreased significantly in both study groups (ANOVA p&lt;0.0001, see Figure 1). RV FW strain decreased only significantly in patients with conventional PM (−4%; ANOVA p=0.031, see Figure 1; post-hoc test BL vs. M12: p=0.029). None of the tested variables, at none of the time points, showed significant difference between the leadless and conventional PM study groups (all p&gt;0.05). Median pacing percentage was 68.2% and similar in both study groups (at all time-points p&gt;0.05).

Conclusions

Both patients with leadless and conventional PM's demonstrate a decrease in LV and RV systolic function, 12 months after implantation. While LV function decrease was similar between both groups, RV function decrease was most prominent in patients treated with conventional PM's. Our data suggest that leadless pacing is not inferior to conventional pacing with regard to the effect on cardiac function.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Research Foundation Flanders (FWO) post-doc grant

Time investments and questions raised by atrial fibrillation patients following a personalized educational follow-up strategy

Background

Atrial fibrillation (AF) has a complex treatment strategy. As stated in the recent guidelines for AF management, AF management requires a holistic and multidisciplinary approach in which a personalized follow-up strategy is important to involve patients in their care. This also includes the need for an improved communication method in which patients can contact the healthcare team between in-hospital follow-up moments to easily ask questions with a low threshold.

Purpose

Two personalized follow-up methods for AF management (in-person and online) are currently being studied in a prospective, randomized controlled trial. The aim of this subanalysis is to evaluate time investment to answer patients' questions.

Methods

At three Belgian hospitals, a total of 1.038 AF patients were randomized to two groups with personalized education and follow-up, and a control group. The educational intervention focuses on four elements: improving patients' AF knowledge, improving OAC therapy adherence, encouraging self-care capabilities based on personal AF risk factors, and the reachability of an AF specialized team. Patients in the in-person group were followed personally at the hospital at regular time points, while the patients in the online group received education via an online platform. During the whole follow-up period, patients of both intervention groups could ask questions via e-mail or by phone contact.

Results

A total of 628 questions were raised by 275 patients (137 in-person and 138 online patients) with a mean number of 4.85±2.57 questions per patient. Patients in the online group had a trend towards asking more questions than the in-person group (2.46±2.08 vs. 2.11±1.74; p=0.061). However, there was no significant difference when looking at medical questions (online 2.12±1.80; in-person 2.16±2.42; p=0.55). In both groups, most questions were asked by phone contact (in-person: 72%; online: 51%; Fig. 1, red bars), although significantly less by the online group (p&lt;0.001). In the in-person group, most questions were related to their study visit appointments (27.3%), symptoms (23.9%) and medication (23.2%). In the online group, most questions were related to the online platform (38.9%), symptoms (16.5%) and medication (11.2%). The research team spent on average 7.37±8.18 minutes to answer a question. There was a significant difference in duration to answer questions of the specific categories (p&lt;0.001, Fig, 2). The top three categories on which the most time was spent were questions about symptoms (14.94±12.455 min), treatment and clinical investigations (9.29±7.9 min) and follow-up of clinical parameters (6.94±5.79 min).

Conclusion

A personalized educational follow-up method includes the possibility for patients to ask questions if needed. Most questions are related to AF symptoms and treatment. This indicates that a specialized AF team can be supportive in the management of AF patients.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The AF-EduCare study is a project supported by the Fund for Scientific Research, Flanders (T002917N).

Which educational follow-up method do atrial fibrillation patients prefer: in-person, online or app-based education?

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): The AF-EduCare study is a project supported by the Fund for Scientific Research, Flanders (T002917N). The AF-EduApp study is supported by an BMS/Pfizer European Thrombosis Investigator Initiated Research Program (ERISTA) grant.

Background

Atrial fibrillation (AF) is a common cardiac arrhythmia with a complex treatment strategy based on three pillars: anticoagulation, rate and rhythm control, and risk factor management. Compliance with these pillars leads to improved outcomes. Patient education and involvement are fundamental to optimize AF patients’ care. There is a need for new strategies to involve patients in their care and raise their awareness of their condition.

Purpose

We are studying three personalized follow-up methods for AF management and wanted to evaluate patients’ preference.

Methods

An open, prospective, randomized trial is currently performed at three Belgian hospitals. A total of 1.232 AF patients hospitalized or coming for an out-patient visit were included and randomized to a control group or three education groups: in-person, online or app-based education. The educational intervention focuses on four elements: Improving patients’ knowledge about AF, highlighting the importance of OAC adherence using electronic tools, improving self-care capabilities based on their AF risk factors, and reachability of an AF specialized team. Patients in the in-person group were followed personally at the hospital, while the patients in the online and app group received education via an online platform or mobile application, respectively. Patients were followed up for at least 12 months, at which they received a questionnaire to assess their satisfaction about the educational intervention.

Results

On-treatment analyses were performed for 643 patients (292 in-person, 233 online, 118 app-based). When asked for a general score (on ten) to describe their appreciation of the educational intervention, in-person education scored significantly higher (in-person: 8.75±1.25; online: 8.30±1.55; app: 8.10±1.69; p&lt;0.001). Evaluating which follow-up method(s) they would prefer for the future, in-person scored highest (Fig 1), still there was a clear appreciation for the approach they had received in the year before: online scored higher in the online group than in the other groups (in-person: 12.8%; online: 19.9%; app: 10.5%; p=0.023) and app-based higher in the app-group than in the other groups (in-person: 11.5%; online: 13.3%; app: 32.6%; p&lt;0.001). Moreover, most patients in all groups were satisfied with the answers given to their questions (in-person: 91.6%; online: 89.1%; app: 96.6%; p=0.059) and acknowledged that they had learned more about AF due to the extra education (in-person: 84.2%; online: 85.8%; app: 89.7%; p=0.345). The educational effort improved their motivation to be aware of, and be involved in their health, most significantly in the app group (in-person: 75.4%; online: 77.0%, app: 87.2%; p=0.021).

Conclusion

AF patients are satisfied about additional educational follow-up in general. Despite new electronic tools and the need to come to the hospital, in-person education is subjectively still the preferred modality.

Adherence to oral anticoagulation in a Belgium atrial fibrillation population measured by a medical event monitoring system

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): The AF-EduCare study is a project supported by the Fund for Scientific Research, Flanders (T002917N). The AF-EduApp study is supported by an BMS/Pfizer European Thrombosis Investigator Initiated Research Program (ERISTA) grant.

Background

Treatment with oral anticoagulation (OAC) is one of the main pillars in the management of atrial fibrillation (AF). Therapy adherence to both VKA and NOAC is important. Education and intake monitoring are recommended to improve therapy adherence.

Purpose

The main purpose of this project was to evaluate the effect of personalized follow-up strategies on therapy adherence to OAC in AF patients.

Methods

In a multicentre, Belgian randomized controlled trial, the AF-EduCare/AF-EduApp study, the effect of different personalized education strategies (i.e. in-person, online or app-based education) is evaluated on clinical outcome parameters of AF patients compared to standard care (SC). One of the outcome parameters is therapy adherence to OAC. During the first 3 months of the trial, patients’ adherence to NOAC or VKA was measured with the Electronic Medication Event Monitoring System (MEMS). The MEMS cap fits on a medication bottle and registers the date and time of every bottle opening. Regimen adherence was defined as the the number of days with the correct number of openings according to the specific OAC regimen divided by the total number of monitored days. As dabigatran has to be stored in the original package to protect it from moisture and VKAs have a variable scheme between patients, a proxy-medication (i.e. another oral drug that needed to be taken once or twice daily and on the same moment of the day as dabigatran or VKA) was chosen to measure medication adherence. Patients in the education groups received a MEMS cap with LCD screen providing direct feedback by showing the number of openings within 24h. A small sample of the SC group also received a MEMS cap as controls, but without LCD screen to minimally trigger these patients.

Results

A total of 593 AF patients underwent adherence monitoring, of which 514 (86.7%) in the intervention group and 79 (13.3%) in the SC group. The mean age was 70.1±7.7 years, mean time since AF diagnosis was 5.8±6.9 years, and mean CHA2DS2-VASc score was 3.2±1.5. Overall adherence was high: 94.8% of the patients had an adherence &gt;80% and 80.9% had an adherence &gt;90%. A small but significant difference in adherence was observed between the intervention groups and the standard care group (intervention group 97% (5-100); SC 96%(24-100); p=0.024; Figure1). Also between the four study groups a significant difference was seen (in-person 97% (93.5-99); online 98% (94-100); app-based 98% (92-99); p=0.049) driven by a significant difference between the online and SC group (p=0.009).

Conclusion

Overall adherence to OAC in all study groups and even in SC was high. The high adherence percentage in the SC group could be related to the Hawthorne effect of using the MEMS. Nevertheless, electronic monitoring and targeted education slightly improved therapy adherence further in the intervention groups.

Quality of life outcomes in cryoablation of atrial fibrillation-A literature review

BACKGROUND

Cryoballoon ablation (CRYO) for pulmonary vein isolation (PVI) in atrial fibrillation (AF) has become an established treatment option as alternative for radiofrequency catheter ablation (RFCA). As symptom relief is still the main indication for PVI, quality of life (QoL) is a key outcome parameter. This review summarizes the evidence about the evolution of QoL after CRYO.

METHODS

A search for clinical studies reporting QoL outcomes after CRYO was performed on PUBMED and COCHRANE. A total of 506 publications were screened and 10 studies met the in- and exclusion criteria.

RESULTS

All studies considered QoL as a secondary endpoint and reported significant improvement in QoL between baseline and 12 months follow-up, independent of the QoL instruments used. The effect size of CRYO on QoL was comparable between studies and present in both paroxysmal and persistent AF. Direct comparison between CRYO and RFCA was limited to two studies, there was no difference between ablation modalities after 12 months FU. Two studies in paroxysmal AF reported outcome beyond 12 months follow-up and QoL improvement was maintained up to 36 months after ablation. There were no long-term data available for persistent AF.

CONCLUSION

CRYO of AF significantly improves QoL. The scarce amount of data with direct comparison between subgroups limits further exploration. Assessment of QoL should be considered a primary outcome parameter in future trials with long-term follow-up.

Durable Physiological Changes and Decreased Syncope Burden 12 Months After Unifocal Right-Sided Ablation Under Computed Tomographic Guidance in Patients With Neurally Mediated Syncope or Functional Sinus Node Dysfunction

[Figure: see text].

Extrasystoles in adults with congenital heart disease: treatment options

The prevalence of congenital heart disease (CHD) is estimated to be almost one in 100 newborns, with > 90% of patients with CHD surviving into adulthood due to medical and surgical advances in recent decades. The rationale for treatment of ventricular premature beats (VPBs) in the general population without underlying structural heart disease is mainly based on the presence of symptoms and/or the risk for developing VPB-induced cardiomyopathy in patients with very frequent VPBs. In CHD, the same general principles apply, but the clinical picture is often more complicated due to the presence of symptoms and/or systolic dysfunction resulting from the underlying heart disease itself. Sudden cardiac death due to ventricular arrhythmias is a major concern in the CHD population, although its incidence is relatively low (<0.1%/year). Beta-blockers are the first-line medical treatment for CHD patients with VPBs, although no dedicated studies are available on the use of beta-blockers or anti-arrhythmic drugs in patients with CHD for this indication. Catheter ablation has evolved in recent years as an important treatment modality for cardiac arrhythmias, generally showing superior efficacy over medical treatment for most types of arrhythmias. However, recent technological advances have led to improved methods for ablation even in complex underlying anatomical substrates, with possibilities for image fusion between three-dimensional imaging modalities and electroanatomical mapping systems during the procedure. In addition to a discussion of the above, the article also presents two examples of VPB ablation in CHD patients.

Real-world adherence to non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation measured by an electronic medication event monitoring system

Background

Non-vitamin K antagonist oral anticoagulants (NOACs) are recommended as first choice therapy for thrombo-embolic prevention in patients with non-valvular atrial fibrillation (AF) and an elevated CHA2DS2-VASc score. A critical determinant for both safety and effectiveness of NOAC treatment is adherence to the prescribed medication regimen. Real-life adherence is suboptimal for many cardiovascular drugs. Measuring and improving NOAC adherence is primordial for optimising AF care.

Purpose

We measured adherence to any of the four NOACs in a population of AF patients who participate to a clinical trial during which they received targeted education on AF and its treatment.

Methods

This analysis is part of a prospective, multicenter, randomized controlled trial which is currently ongoing at three Belgian hospitals (AF-EduCare study). Ambulatory or hospitalised AF patients of that trial, treated with a NOAC, and who received a short targeted education session about AF and NOAC therapy at initiation, form the study group of this analysis. Monitoring of NOAC intake was performed by an electronic Medication Event Monitoring System (MEMS), starting immediately after initiation of the study and the education session (for 3 months). A special cap fits on a medication bottle and records the exact date and time of bottle openings. An LCD screen on the cap displays the number of openings of the medication bottle over a period of 24 hours, providing feedback about the correct intake. Dabigatran was replaced by a proxy medication as Dabigatran should be stored in the original package in order to protect it from moisture. Regimen adherence was calculated as the number of days on which one bottle opening in case of Rivaroxaban or Edoxaban and two bottle openings in case of Apixaban or Dabigatran is/are registered, divided by the total number of monitored days and multiplied by 100.

Results

A total of 233 patients (mean age 71.0±7.7 years; 71.2% males; CHA2DS2-VASc score 3.4±1.5; mean duration of AF history 5.8±7.5 years) were given a MEMS. Of these patients 32.2%, 31.3%, 26.2% and 10.3% were respectively on Edoxaban, Apixaban, Rivaroxaban and Dabigatran. Regimen adherence for these NOACs was 95.9±9.3%, 91.6±13.7%, 95.6±5.6% and 94.0±7.1% respectively. Overall, 94.4% of the patients had an adherence &gt;80% and 81.1% had an adherence &gt;90%. Adherence for the once and twice daily regimens was 95.8±0.7% and 92.2±1.3%, respectively (p=0.0003; Mann-Whitney U test).

Conclusions

This is a first prospective study investigating adherence for all NOACs using electronic monitoring. In this sample of AF patients who underwent a targeted education session before the 3 month monitoring period, mean adherence to NOAC intake was &gt;90% for all NOACS. This high adherence may be related to both the education and the use of MEMS, which provided direct feedback to the patient.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): The AF-EduCare study is a project supported by the Fund for Scientific Research, Flanders (T002917N).

Re-implantation after extraction of a cardiac implantable electronic device

Background: With increasing cardiovascular implantable electronic device (CIED) implantations, growing number of extractions of leads and devices are noted, mainly for complications such as infection and lead dysfunction. The optimal timing for re-implantation remains uncertain. We  investigated the time to eventual re-implantation of CIEDs in the University Hospitals Leuven, Belgium.Methods: All consecutive patients, referred for extraction between January 2005 and December 2016, were analysed for the timing of eventual re-implantation.Results: Two-hundred and forty-three patients were included. Mean follow-up was 77 ± 37 months. Global re-implantation rate was 89.3%: 100% for lead dysfunctions versus 80.7% following infections. Median time to re-implantation (TTR) was 0 [0-111] days and 8.5 [0-3025] days, respectively (p < .001). Globally 0 [0-3025] days. Re-implantation was performed in 83.2% of pacemaker patients, compared to 95.8% of defibrillator patients (p < .001). Median TTR was 4 [0-3025] days and 0 [0-345] days, respectively (p < .001). In AV-block related pacemaker indications, 90% were re-implanted, compared to 78% for symptomatic indications (p = .09). Median TTR was 2 [0-3025] and 6 [0-2047] days, respectively (p = .02). Re-implantation was performed in 96.7% of defibrillator patients with a secondary prevention indication, compared to 94.7% with primary prevention indication (p = .59). Median TTR was 0 [0-164] and 0 [0-345] days, respectively (p = .472).Conclusions: Ten percent of CIEDs is not re-implanted after extraction. CIEDs are re-implanted more often and earlier after extraction for lead dysfunction than after extraction for infectious reasons. Pacemakers are re-implanted less and later than defibrillators. Re-implantation is performed faster in stronger clinical CIED indications.

Long-Term Follow-Up of Idiopathic Ventricular Fibrillation in a Pediatric Population: Clinical Characteristics, Management, and Complications

Background

The natural history and long‐term outcome in pediatric patients with idiopathic ventricular fibrillation (IVF) are poorly characterized. We sought to define the clinical characteristics and long‐term outcomes of a pediatric cohort with an initial diagnosis of IVF.

Methods and Results

Patients were included from an International Registry of IVF (consisting of 496 patients). Inclusion criteria were: (1) VF with no identifiable cause following comprehensive analysis for ischemic, electrical or structural heart disease and (2) age ≤16 years. These included 54 pediatric IVF cases (age 12.7±3.7 years, 59% male) among whom 28 (52%) had a previous history of syncope (median 2 syncopal episodes [interquartile range 1]). Thirty‐six (67%) had VF in situations associated with high adrenergic tone. During a median 109±12 months of follow‐up, 31 patients (57%) had recurrence of ventricular arrhythmias, mainly VF. Two patients developed phenotypic expression of an inherited arrhythmia syndrome during follow‐up (hypertrophic cardiomyopathy and long QT syndrome, respectively). A total of 15 patients had positive genetic testing for inherited arrhythmia syndromes. Ten patients (18%) experienced device‐related complications. Three patients (6%) died, 2 due to VF storm.

Conclusions

In pediatric patients with IVF, a minority develop a definite clinical phenotype during long‐term follow‐up. Recurrent VF is common in this patient group.

Diagnosis and treatment of atrioventricular nodal reentrant tachycardia: a case report illustrating clinical management and ablation strategy

BACKGROUND

Atrioventricular nodal reentrant tachycardia (AVNRT) is a common supraventricular arrhythmia that is frequently encountered in an otherwise healthy patient population. Recent guidelines of the European Society of Cardiology underline the role of catheter ablation in the long-term management of these patients.

CASE SUMMARY

This case describes the clinical presentation and treatment options in a patient with typical slow/fast AVNRT, the most common subform of AVNRT, where antegrade conduction occurs over the slow pathway and retrograde conduction over the fast pathway. The ablation strategy in these patients is illustrated based on intracardiac recordings in combination with per-procedural three-dimensional imaging.

DISCUSSION

Atrioventricular nodal reentrant tachycardia is a common arrhythmia with good prognosis but significant impact on quality of life of affected patients. Catheter ablation should be considered early as it can be performed safely and with a very high success rate.

Premature ventricular contractions cause a position shift in 3D mapping systems: analysis, quantification, and correction by hybrid activation mapping

Aims

Using a modified CARTO 3D mapping system, we studied if premature ventricular contractions (PVCs) cause position shifts within the 3D co-ordinate system. We quantified magnitude of the phenomenon and corrected for it, by creating both an activation map that represents the conventional local activation time (LAT) and one corrected for this position shift (hybrid LAT map).

Methods and results

We prospectively enrolled patients planned for PVC ablation. Distances between the earliest LAT, the earliest hybrid-LAT, and the best pacemap positions were calculated in a 3D model. Ablation was performed at the best hybrid-LAT location. Efficacy was evaluated by acute response to ablation as well as clinical outcome on 24-h Holter at 1 year. One hundred and twenty-seven LAT-hybrid pairs were studied in 18 patients (age 48.3 ± 18.0 years, 12 female). Baseline PVC burden was 16 ± 12%. The mean position shift between LAT-hybrid and its associated LAT position was 8.9 ± 5.5 mm. The mean position shift between best LAT-hybrid and best pacemap was 6.2 ± 5.0 mm and the mean shift between best conventional LAT and best pacemap was 13.5 ± 7.0 mm (P &lt; 0.0001 for all pairwise comparisons). Exclusive targeting of best LAT-hybrid position resulted in acute abolition of PVC activity in all patients. After 1-year follow-up, mean PVC burden reduction was 16% (baseline) to &lt;1%.

Conclusion

Premature ventricular contractions cause a position shift in 3D mapping systems compared with the same endocardial position in sinus rhythm. An approach to account for this phenomenon, correct it and target exclusively the adjusted 3D position is feasible and highly efficient in terms of acute and 1-year clinical outcome after radiofrequency ablation.

Increased Cardiac Uptake of Ketone Bodies and Free Fatty Acids in Human Heart Failure and Hypertrophic Left Ventricular Remodeling

BACKGROUND

Deranged energy metabolism contributes to the pathophysiology of heart failure (HF). Recent studies showed diminished free fatty acid (FFA) oxidation in experimental HF models with a shift towards oxidation of ketone bodies. However, conflicting clinical data on FFA metabolism and limited knowledge on ketone body metabolism in human HF mandate additional metabolic profiling studies. We, therefore, investigated cardiac uptake of FFAs and ketone bodies (β-hydroxybutyrate and acetoacetate) in patients with HF with reduced ejection fraction (HFrEF) or with aortic stenosis (AS)-induced left ventricular hypertrophy. We hypothesized that FFA oxidation is impaired in HFrEF and in AS and results in decreased concentrations of free carnitine, the necessary carrier for mitochondrial entry of activated FFAs, and in accumulation of metabolic intermediates.

METHODS AND RESULTS

We collected arterial and coronary sinus blood samples in patients with HFrEF (n=15), in AS patients with preserved systolic function (n=15), and in control patients (n=15). Plasma concentration gradients across the heart show significantly greater uptake of ketone bodies in patients with HFrEF than in controls. Patients with AS show significantly increased uptake of β-hydroxybutyrate and FFAs. Free carnitine concentration and concentration gradients of intermediates of FFA oxidation were comparable between groups.

CONCLUSIONS

In conclusion, our results show significantly increased cardiac uptake of ketone bodies in patients with stable HFrEF and AS and increased uptake of FFAs in AS compared with control patients. The lack of myocardial release of acyl-carnitine species or change in free carnitine uptake suggests no impairment of FFA oxidation.

Leadless pacing with Micra TPS: A comparison between right ventricular outflow tract, mid-septal, and apical implant sites

BACKGROUND

With its steerable transcatheter delivery system, the Micra can be deployed in nonapical positions within the right ventricle, potentially allowing reduction of the paced QRS width. We sought to evaluate the safety and long-term performance of the right ventricular outflow tract (RVOT) pacing using the Micra transcatheter pacing system (TPS). We also compared the paced QRS between RVOT, mid-septal, and apical implant positions.

METHODS

All patients who underwent a Micra TPS implantation at the University Hospitals of Leuven were enrolled in this observational study. Right ventricular (RV) position of the device was assessed on per-procedural ventriculography. Paced QRS was analyzed and follow-up completed at 1 month and then every 6 months.

RESULTS

Among the 133 patients included (mean follow-up: 13 ± 11 months), 45 were implanted in the RVOT, 58 midseptally, and 30 at the apex. All implant procedures were successful and no pericardial effusion was encountered within the 30 days post-implant. Two major complications were reported with devices implanted at the apex. Pacing impedance was significantly higher in the RVOT compared to the mid-septal and apical position (P < .001). Pacing threshold and R-wave amplitude did not differ over time in either position. The median narrowest paced QRS duration was observed in the RVOT (142 ms) compared to mid-septal (159 ms; P < .001), and apical position (181 ms; P < .001).

CONCLUSION

Implantation of the Micra TPS in the RVOT is safe and feasible. Electrical performance over time was comparable to mid-septal and apical positions. The narrowest paced QRS complexes is achieved with RVOT pacing.

High-Detailed evaluation of the right atrial anatomy by three-dimensional rotational angiography during ablation procedures for atrioventricular nodal reentrant tachycardia and atrial flutter

AIM

3D Rotational angiography (3DRA) allows for detailed reconstruction of atrial anatomy and is often used to facilitate pulmonary vein isolation. This study aimed to reappraise the anatomy of the right atrium (RA) using 3DRA, specifically looking at Koch's triangle and the cavotricuspid isthmus (CTI) in atrio-ventricular reentrant tachycardia (AVNRT) and atrial flutter (AFl) ablation.

METHODS AND RESULTS

3DRA was performed in 97 patients: AVNRT = 51 and AFl = 46. Dimensions of Koch's triangle and CTI were highly variable between individuals but were not different in both ablation groups. RA volume was significantly larger in AFl patients (p = .004) while indexed RA volume to the body surface area (RAVI) was lightly different (p = .024). In univariate Cox analysis, age (p = .003), RAVI (p < .001) and previous ablation of AFl (p = .003) were predictors of AF occurrence . In multivariate Cox analysis, RAVI was the only independent predictor of AF occurrence. RAVI >80 ml/m² was a strong predictor for AF during follow-up.

CONCLUSION

3DRA allows for detailed per-procedural evaluation of RA anatomy and revealed a great variability in Koch's triangle and CTI dimensions and morphology. RA enlargement as measured by RAVI was an independent predictor for AF occurrence during follow-up.

Monocentric experience of leadless pacing with focus on challenging cases for conventional pacemaker

AIM

Leadless cardiac pacemaker has been developed to reduce complications related to cardiac pacing and is considered as an alternative to conventional pacemaker although safety and efficacy data in clinical practice are limited. The purpose of this study was to investigate the safety and efficacy profile of Micra Transcatheter Pacing System (TPS) used in daily clinical activity with a focus on challenging cases for conventional pacing.

METHODS

A total of 66 patients (46 men, 79.1 ± 9.7 years) having a Class I or II indication for ventricular pacing underwent a Micra TPS implant procedure. All patients were enrolled in a prospective registry. Follow-up visits were scheduled at discharge and after 1, 3, 6 and 12 months.

RESULTS

Primary indication for pacing was third degree atrioventricular block (30.3%), sinus node dysfunction (21.2%) or permanent atrial fibrillation with bradycardia (45.5%). The device was successfully implanted in 65 patients (98.5%). During follow-up of 10.4 ± 6.1 months (range 1-23 months), electrical measurements remained stable. Mean pacing capture threshold, pacing impedance and R-wave sensing were respectively 0.57 ± 0.32 V, 580 ± 103 Ohms, 10.62 ± 4.36 mV at the last follow-up. One major (loss of function) and three minor adverse events occurred. Pericardial effusion, dislodgement, device related infection or pacemaker syndrome were not observed. Micra TPS implantation was straightforward for patients with congenital or acquired cardiac and/or vascular abnormalities, previous tricuspid surgery and after heart transplantation.

CONCLUSION

Our experience confirms that implantation of Micra is safe and efficient in a real world population including patients who present a challenging condition for conventional pacing.

Combining noninvasive risk stratification parameters improves the prediction of mortality and appropriate ICD shocks

BACKGROUND

Sudden cardiac death (SCD) results from a complex interplay of abnormalities in autonomic function, myocardial substrate and vulnerability. We studied whether a combination of noninvasive risk stratification tests reflecting these key players could improve risk stratification.

METHODS

Patients implanted with an ICD in whom 24-hr holter recordings were available prior to implant were included. QRS fragmentation (fQRS) was selected as measure of myocardial substrate and a high ventricular premature beat count (VPB >10/hr) for arrhythmic vulnerability. From receiver operating characteristics analysis, detrended fluctuation analysis (DFA), turbulence slope, and deceleration capacity were selected for autonomic function. Adjusted Cox regression analysis with comparison of C-statistics was performed to predict first appropriate shock (AS) and total mortality.

RESULTS

A total of 220 patients were included in the analysis with an overall follow-up of 4.3 ± 3.1 years. A model including VPB >10/hr, inferior fQRS, and abnormal nonedited DFA was the best for prediction of AS after 1 year of follow-up with a trends toward improvement of the C-statistics compared to baseline (p = 0.055). The risk increased significantly with every abnormal test (HR 1.793, 95%CI 1.255-2.564). A model including fQRS in any region and abnormal edited DFA was the best for prediction of mortality after 3 years of follow-up with significant improvement of the C-statistics (p = 0.023). Each abnormal test was associated with a significant increase in mortality (HR 5.069, 95%CI 1.978-12.994).

CONCLUSION

Combining noninvasive risk stratification tests according to their physiological background can improve the risk prediction of SCD and mortality.

Prognostic value of electrocardiographic time intervals and QT rate dependence in hypertrophic cardiomyopathy

INTRODUCTION

Preventing sudden cardiac death (SCD) is one of the main goals in hypertrophic cardiomyopathy (HCM). Many variables have been proposed, however the European and American guidelines do not incorporate any ECG or Holter monitoring derived variables other than the presence of ventricular arrhythmia in their risk stratification models. In the present study we evaluated electrocardiographic parameters in risk stratification of HCM.

METHODS AND RESULTS

Novel electrocardiographic parameters including the index of cardio-electrophysiological balance (iCEB), individualized QT correction (QTi) and QT rate dependence were evaluated along with established risk factors. A composite endpoint of SCD was defined as out of hospital cardiac arrest, appropriate ICD shock and sustained ventricular tachycardia. Cox regression analysis was used to evaluate predictors of SCD. Out of the 466 HCM patients, 31 reached the composite endpoint during a follow up of 75 ± 86 months. In a multivariate model, nor iCEB, QTi or QT rate dependence were predictors of SCD. Only male gender (p < 0.01; OR 13.1; CI 1.74-98.83), negative T waves in the inferior leads (p = 0.04; OR 2.51; CI 1.03-6.13) and familial sudden death (p < 0.01; OR 3.03; CI 1.39-6.59) were significant predictors. On top of either the ESC risk score or the 3 traditional 'American risk factors', only male gender was a significant predictor of SCD.

CONCLUSION

No ECG or Holter monitoring parameters added in risk stratification for SCD in HCM. However, male gender and negative T waves in the inferior leads are promising novel markers to evaluate in larger cohorts.

Predictors of a high defibrillation threshold test during routine ICD implantation

BACKGROUND

There is growing evidence that routine defibrillation threshold (DFT) testing during implantable cardioverter defibrillator (ICD) implantation is not necessary. However a small group of patients might be at risk if no DFT testing is performed.

METHODS

Patients with a new pectoral ICD implantation in our hospital between 2006 and 2014 were included in a retrospective registry. A clinical high DFT was defined as a safety margin <10 J of the maximal device output. Logistic regression for prediction of high DFT was performed using patient characteristics, clinical, echocardiographic and device-related parameters.

RESULTS

DFT testing was performed in 788/864 (91.2%) procedures. In 76 (8.8%) patients no DFT testing was performed mainly due to atrial fibrillation, intra-cardiac thrombus, hemodynamic instability or logistical reasons. A high DFT was present in 44 (5.6%) patients. A QRS duration ≥150 ms, a low left ventricular ejection fraction (LVEF ≤25%), a severely dilated left ventricle ≥60 mm and right sided pre-pectoral implantations were univariate predictors of a high DFT. Independent predictors of a high DFT were a LVEF ≤25% (HR 2.195, 95%CI 1.085-4.443) and right sided pre-pectoral implantations (HR 3.135, 95% CI 1.186-8.287).

CONCLUSIONS

A high DFT is still present in about 5% of patients and is more frequent in patients with a severely dilated left ventricle, a very low LVEF, right sided pre-pectoral implantation and wider QRS duration. It might be clinically important to continue DFT testing in these high risk patients.

Genotype-phenotype relationship and risk stratification in loss-of-function SCN5A mutation carriers

INTRODUCTION

Loss-of-function (LoF) mutations in the SCN5A gene cause multiple phenotypes including Brugada Syndrome (BrS) and a diffuse cardiac conduction defect. Markers of increased risk for sudden cardiac death (SCD) in LoF SCN5A mutation carriers are ill defined. We hypothesized that late potentials and fragmented QRS would be more prevalent in SCN5A mutation carriers compared to SCN5A-negative BrS patients and evaluated risk markers for SCD in SCN5A mutation carriers.

METHODS

We included all SCN5A loss-of-function mutation carriers and SCN5A-negative BrS patients from our center. A combined arrhythmic endpoint was defined as appropriate ICD shock or SCD.

RESULTS

Late potentials were more prevalent in 79 SCN5A mutation carriers compared to 39 SCN5A-negative BrS patients (66% versus 44%, p = .021), while there was no difference in the prevalence of fragmented QRS. PR interval prolongation was the only parameter that predicted the presence of a SCN5A mutation in BrS (OR 1.08; p < .001). Four SCN5A mutation carriers, of whom three did not have a diagnostic type 1 ECG either spontaneously or after provocation with a sodium channel blocker, reached the combined arrhythmic endpoint during a follow-up of 44 ± 52 months resulting in an annual incidence rate of 1.37%.

CONCLUSION

LP were more frequently observed in SCN5A mutation carriers, while fQRS was not. In SCN5A mutation carriers, the annual incidence rate of SCD was non-negligible, even in the absence of a spontaneous or induced type 1 ECG. Therefore, proper follow-up of SCN5A mutation carriers without Brugada syndrome phenotype is warranted.

Individualized corrected QT interval is superior to QT interval corrected using the Bazett formula in predicting mutation carriage in families with long QT syndrome

BACKGROUND

Long QT syndrome (LQTS) is characterized by reduced penetrance and variable QT prolongation over time, resulting in an estimate of 25% carriers of a pathogenic mutation with a normal corrected QT (QTc) interval on the resting electrocardiogram (ECG).

OBJECTIVE

The purpose of this study was to test the hypothesis that an individualized corrected QT interval derived from 24-hour Holter data more accurately predicts carriage of a pathogenic LQTS mutation than did QT derived from a standard 12-lead ECG and corrected using the Bazett formula (QTc interval).

METHODS

Carriers of a pathogenic LQTS mutation and their genotype-negative family members who had both resting ECG and Holter recordings available were included. Automated and manual measurements of QTc were performed. QTi was derived from 24-hour Holter recordings and defined as the QT value at the intersection of an RR interval of 1000 ms, with the linear regression line fitted through QT-RR data points of each individual patient.

RESULTS

In total, 69 patients with LQTS (23 long QT type 1, 39 long QT type 2, and 7 long QT type 3) and 55 controls were selected. Demographic characteristics were comparable. A comparison of the receiver operating characteristic curves indicates that the test added diagnostic value compared to manual measurement (P = .02) or automated measurement (P = .005). The diagnostic accuracy of manually measured QTc using conventional cutoff criteria was 72%, while it was 92% using a sex-independent QTi cutoff of 445 ms. This was caused by a 39% increase in sensitivity without compromising the specificity.

CONCLUSION

QTi derived from Holter recordings is superior to conventional QTc measured from a standard 12-lead ECG in predicting the mutation carrier state in families with LQTS.

Inter- and intra-observer variability of visual fragmented QRS scoring in ischemic and non-ischemic cardiomyopathy

BACKGROUND

Fragmented QRS (fQRS) on a 12-lead ECG has been linked with adverse outcome. However, the visual scoring of ECGs is prone to inter- and intra-observer variability.

METHODS

Five observers, two experienced and three novel, assessed fQRS in 712 digital ECGs, 100 were re-evaluated to assess intra-observer variability. Fleiss and Cohen's Kappa were calculated and compared between subgroups.

RESULTS

The inter-observer variability for assessing fQRS in all leads combined was substantial with a Kappa of 0.651. Experienced observers only had a better agreement with a Kappa of 0.823. Intra-observer variability ranged from 0.736 to 0.880. In the subgroup with ventricular pacing the inter-observer variability was even significantly larger when compared to ECGs with normal QRS duration (Kappa 0.493 vs 0.664, p<0.001).

CONCLUSION

The visual assessment of QRS fragmentation is prone to inter- and intra-observer variability, mainly influenced by the experience of the observers, the underlying rhythm and QRS morphology.