Implantable defibrillator therapy and mortality in patients with non-ischaemic dilated cardiomyopathy : An updated meta-analysis and effect on Dutch clinical practice by the Task Force of the Dutch Society of Cardiology

BACKGROUND

Primary prophylactic implantable cardioverter-defibrillators (ICDs) in patients with non-ischaemic cardiomyopathy (NICMP) remains controversial. This study sought to assess the benefit of ICD therapy with or without cardiac resynchronisation therapy (CRT) in patients with NICMP. In addition, data were compared with real-world clinical data to perform a risk/benefit analysis.

METHODS

Relevant randomised clinical trials (RCTs) published in meta-analyses since DANISH, and in PubMed, EMBASE and Cochrane databases from 2016 to 2020 were identified. The benefit of ICD therapy stratified by CRT use was assessed using random effects meta-analysis techniques.

RESULTS

Six RCTs were included in the meta-analysis. Among patients without CRT, ICD use was associated with a 24% reduction in mortality (hazard ratio [HR]: 0.76; 95% confidence interval [CI]: 0.62-0.93; P = 0.008). In contrast, among patients with CRT, a CRT-defibrillator was not associated with reduced mortality (HR: 0.74, 95% CI 0.47-1.16; P = 0.19). For ICD therapy without CRT, absolute risk reduction at 3‑years follow-up was 3.7% yielding a number needed to treat of 27.

CONCLUSION

ICD use significantly improved survival among patients with NICMP who are not eligible for CRT. Considering CRT, the addition of defibrillator therapy was not significantly associated with mortality benefit compared with CRT pacemaker.

Acute hemodynamic effects of biventricular pacing studied during cardiovascular magnetic resonance imaging: the PICARIA Trial

Background

Cardiac resynchronization therapy (CRT) is hampered by a relative high rate of non-response whereby device optimization could aid in improving benefit from CRT. Nonetheless, a non-invasive and reproducible clinical tool for device optimization is currently lacking. Recently introduced cardiovascular magnetic resonance (CMR) compatible CRT devices may allow for patient follow-up and device optimization as biventricular (BIV) pacing can be performed during the CMR exam. However, to date, CMR evaluation of acute pump function changes during CRT is limited.

Purpose

To assess the effects of BIV-pacing on change in left ventricular (LV) function and contraction patterns using CMR.

Methods

Ten patients were included in this prospective pilot study. All patients underwent CMR imaging (1.5T system) prior to device implantation (baseline), and 6 weeks after device implantation (CRT-on and CRT-off). LV end systolic volume (ESV), end diastolic volume (EDV), ejection fraction (LVEF), and measures of LV dyssynchrony and dyscoordination (septal systolic rebound stretch (SRSseptal)) were assessed on cine images.

Results

LV function and contraction patterns before and after device implantation are compared and displayed in the figure. LV ESV and EDV decreased in all patients during BIV-pacing as compared to intrinsic rhythm (CRT-off) (ESV; 161.4±36.3ml vs. 194.9±37.1ml, p<0.01 and EDV; 236.2±31.8ml vs. 268.1±42.3ml, p<0.01). A significant improvement in LVEF was observed during BIV-pacing (32.2±8.7% vs. 27.4±5.9%, p<0.01). Both, regional dyssynchrony and regional dyscoordination significantly improved during CRT-on compared to CRT-off (peakseptal-peaklateral; 57±46ms vs. 183±86ms, p<0.01 and SRSseptal; 2.1±2.6% vs. 6.0±3.0%, p<0.01).

Conclusions

Post-CRT implantation CMR assessing acute pump function changes to different CRT pacing settings is feasible and provides important insights in the effects of BIV-pacing on cardiac function and contraction patterns. LV assessment using CMR, potentially in combination with non-invasive pressure measurements, may constitute a future CRT optimization strategy.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Biotronik (Berlin, Germany)

Current state of artificial intelligence-based algorithms for hospital admission prediction in patients with heart failure: a scoping review. EUROPEAN HEART JOURNAL. DIGITAL HEALTH 2022;3:415-425. [PMID: 36712159 PMCID: PMC9707890 DOI: 10.1093/ehjdh/ztac035]

AIMS

Patients with congestive heart failure (HF) are prone to clinical deterioration leading to hospital admissions, burdening both patients and the healthcare system. Predicting hospital admission in this patient group could enable timely intervention, with subsequent reduction of these admissions. To date, hospital admission prediction remains challenging. Increasing amounts of acquired data and development of artificial intelligence (AI) technology allow for the creation of reliable hospital prediction algorithms for HF patients. This scoping review describes the current literature on strategies and performance of AI-based algorithms for prediction of hospital admission in patients with HF.

METHODS AND RESULTS

PubMed, EMBASE, and the Web of Science were used to search for articles using machine learning (ML) and deep learning methods to predict hospitalization in patients with HF. After eligibility screening, 23 articles were included. Sixteen articles predicted 30-day hospital (re-)admission resulting in an area under the curve (AUC) ranging from 0.61 to 0.79. Six studies predicted hospital admission over longer time periods ranging from 6 months to 3 years, with AUC's ranging from 0.65 to 0.78. One study prospectively evaluated performance of a disposable sensory patch at home after hospitalization which resulted in an AUC of 0.89 for unplanned hospital admission prediction.

CONCLUSION

AI has the potential to enable prediction of hospital admission in HF patients. Improvement of data management, adding new data sources such as telemonitoring data and ML models and prospective and external validation of current models must be performed before clinical applicability is possible.

Strategies for repeat ablation for atrial fibrillation: a multicentre comparison of non-pulmonary vein versus pulmonary vein target ablation

Funding Acknowledgements

Type of funding sources: None.

Introduction

Approximately 18% of patients with atrial fibrillation (AF) undergo a repeat ablation within 12 months after their index ablation. Despite the high prevalence, comparative studies on non-pulmonary vein (PV) target strategies in repeat AF ablation are scarce.

Purpose: This study aims to describe 12 months efficacy of non-PV and PV target ablations as a repeat ablation strategy.

Methods

A multicentre retrospective, descriptive study was conducted with data of 280 patients who underwent repeat AF ablation. Ablation strategy for repeat ablation was at the operators’ discretion. Non-PV target ablation (n=140) included posterior wall isolation, mitral line, roofline and/or complex fractionated atrial electrogram ablation. PV target ablation (n=140), included re-isolation and/or wide atrium circumferential ablation. Patients’ demographics and rhythm outcomes during 12-months follow-up were analysed.

Results: Overall, the mean age was 63 ± 9 years, 64% were male, and body mass index was 27.1 ± 4.2. Patients undergoing non-PV target ablation had more frequently persistent AF (47.9% vs 14.3%, p < 0.001), and had a higher CHA2DS2 VASc (2.0 vs 1.3, p < 0.001). At 12 months, more atrial tachyarrhythmias were observed in the non-PV target group (48.6%) compared to the PV target group (29.3%, p=0.001). Similarly, a significantly higher AF and atrial tachycardia (AT) recurrence rate was observed after non-PV target ablation compared to PV target ablation (36.4% versus 22.1% and 22.9% versus 10.7%). After adjusting for several associated covariates, a significantly higher AT recurrence risk remained in the non-PV target group (adjusted OR 2.19 95% CI 1.18 – 4.42, p = 0.023) (Figure 1C). Sensitivity analysis was performed with inverse propensity weighting to assess the robustness of the multivariate model and demonstrated comparable outcomes. Both groups significantly de-escalated anti-arrhythmic drug use, de-escalation was more profound after PV target ablation. Patients with isolated PVs during non-PV target ablation had a significantly higher risk for AF recurrence than those with reconnected PVs (Figure 1B).

Conclusion: Compared to PV target ablation, non-PV target repeat ablation did not improve outcomes after 12 months and was independently associated with a higher risk for AT recurrences.

Benefit of atrial fibrillation ablation on symptoms and quality of life does not differ between patients with paroxysmal and persistent atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Background

Indications for atrial fibrillation (AF) ablation in current ESC and ACC/HRS guidelines are different for paroxysmal and persistent AF patients. Although previous research has established that the AF recurrence rate after AF ablation is lower in paroxysmal AF patients, there is little data on differences in post-ablation improvement of quality of life (QoL) and AF-related symptoms.

Purpose

This study aimed to determine whether QoL and symptom improvement differ between patients with paroxysmal and persistent AF after AF ablation.

Methods

From December 2017 to June 2020, patients undergoing first AF ablation at a medical center were included in a prospective registry. Circumferential pulmonary vein isolation (PVI) was performed using radiofrequency ablation with a contact force-sensing catheter. Patient reported outcomes were assessed at baseline, 4 months follow-up, and 1 year follow-up using the Toronto Atrial Fibrillation Severity Scale (AFSS). The AFSS was used to quantify global well-being (scale 1-10), patient-perceived AF burden (scale 3-30), and AF symptom severity (scale 0-35). AF symptom severity was based on 7 questions (scale 0-5) leading to a 0-35 scale. AF recurrence was defined as any documented episode of AF or atrial flutter after a blanking period of 3 months.

Results

The study population consisted of 306 AF patients (66% paroxysmal AF, 68% male, mean age 64±8 years). AF recurrence during 1 year follow-up occurred in 29% of paroxysmal AF patients and in 42% of persistent AF patients (p=0.021). At baseline, patient perceived AF burden was lower in paroxysmal AF patients than in persistent AF patients (18.4±3.7 vs. 20.2±5.0, p=0.001), whereas symptom severity (10.6±6.5 vs. 9.9±6.7, p=0.384) and global well-being (7.1±1.5 vs. 7.3±1.4, p=0.327) were similar. Paroxysmal AF patients reported more palpitations (2.4±1.3 vs. 1.6±1.5, p<0.001) and less shortness of breath during physical activity (1.9±1.6 vs. 2.3±1.7, p=0.048) than patients with persistent AF.

Significant improvements in global well-being (0.5±1.7, p<0.001), symptom severity (3.8±7.2, p<0.001), and patient-perceived AF burden (7.2±7.5, p<0.001) were found in the entire study cohort between baseline and 1 year follow-up, without differences between paroxysmal and persistent patients (Figure).

Conclusion

Although persistent AF patients have a higher chance of recurrent AF after AF ablation, symptom severity and QoL improve equally in paroxysmal and persistent AF patients. These results suggest that different recommendations for AF ablation to improve symptoms in paroxysmal and persistent AF patients may not be justified.

Left atrial strain for predicting arrhythmia recurrence after atrial fibrillation ablation: cardiac magnetic resonance rapid strain vs. feature tracking strain

Background

Global left atrial (LA) strain is a predictor of atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI). Recently, novel rapid LA strain assessment approaches have emerged: LA long axis strain and LA AV junction strain. Currently, it remains unknown whether these rapid strain approaches can predict AF recurrence after AF ablative therapy and hence may be a simple alternative for the cumbersome LA feature tracking strain analysis.

Purpose

The present study focusses on the predictive value of different atrial strain quantification methods in relation to AF recurrence after PVI. Rapid LA strain analysis is compared to LA feature tracking strain in AF patients.

Methods

A total of 58 AF patients (78% paroxysmal AF, 64% male, mean age 61±7 years) undergoing first radiofrequency PVI ablation were included. Prior to ablation, all patients underwent cardiac magnetic resonance imaging being in sinus rhythm. LA rapid strain (long axis strain and AV junction strain) and LA feature tracking strain were derived from 2-chamber and 4-chamber cine CMR images. All patients were routinely followed up for arrhythmia recurrence through 12-lead ECGs, mobile-based one-lead ECGs, and/or Holter monitoring.

Results

After one year follow-up, arrhythmia recurrence (after the 90-day blanking period) was observed in 21 patients (36%), occurring after a median of 159 (119–320) days. LA long axis strain, AV junction strain, and feature tracking strain were all significantly reduced in patients with AF recurrence compared to patients without AF recurrence (long axis strain: −19.96±11.03% vs. −28.18±9.93%, P=0.005; AV junction strain: −18.08±9.69% vs. −25.60±8.79%, P=0.004; feature tracking strain: −12.54±4.16% vs. −15.94±3.50%, P=0.002, respectively, figure A to C). ROC analysis identified LA feature tracking strain as having the highest area under the curve (AUC) for predicting AF recurrence after ablative therapy (AUC: 0.75 for LA feature tracking strain, 0.71 for LA long axis strain, 0.70 for AV junction strain, figure D). Both LA rapid strain methods had a significant correlation with LA feature tracking strain (LA long axis strain vs. LA feature tracking strain, r=0.76, P<0.001 and LA AV junction strain vs. LA feature tracking strain, r=0.77, P<0.001).

Conclusion

LA rapid strain and LA feature tracking strain both have clinically relevant predictive power for prediction of AF recurrence after index PVI in AF patients. Considering the ease of LA rapid strain analysis, this method may be a valuable parameter to assess in clinical practice.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Phasic left atrial strain predicts arrhythmia recurrence after atrial fibrillation ablation

Funding Acknowledgements

Type of funding sources: None.

Background

Global left atrial (LA) strain is a predictor of atrial fibrillation (AF) recurrence after radiofrequency pulmonary vein isolation (RF-PVI). However, little is known about phasic LA strain (i.e. LA reservoir strain, LA conduit strain, and LA contractile strain) and arrhythmia recurrence after AF ablative therapy.

Aim

This study was conducted to evaluate the impact of phasic LA longitudinal strain on arrhythmia recurrence after catheter ablation.

Methods

A total of 62 AF patients (77% paroxysmal AF, 66% male, mean age 61 ± 7 years) undergoing initial RF-PVI were included in the present analysis. Prior to AF ablation, all patients underwent cardiac magnetic resonance imaging in sinus rhythm. LA reservoir strain, conduit strain and contractile strain were derived from 2-chamber and 4-chamber cine CMR images using feature tracking. All patients were routinely followed up for arrhythmia recurrence through ECGs, Kardia or Holter monitoring.

Results

One year follow-up was incomplete in nine AF patients. Arrhythmia recurrence after the 90-day blanking period was observed in 20 patients (38%), occurring after a median of 159 (119-291) days. Significantly lower LA reservoir strain and LA contractile strain values were found in AF patients with arrhythmia recurrence after RF-PVI, as compared to AF patients without arrhythmia recurrence (-12.8 ± 4.1% vs. -15.6 ± 3.5%, P = 0.02, -5.4 ± 2.2% vs. -7.7 ± 2.3% P < 0.001, respectively). LA conduit strain did not differ between these two groups (-7.4 ± 2.7% vs. -7.9 ± 2.9%, P = 0.53). Arrhythmia-free survival was assessed using the Kaplan Meier method and compared between strain values below and above the median using the log-rank test (median LA reservoir strain: -13.45%, median LA conduit strain: -7.55%, median LA contractile strain: -5.60%). Arrhythmia-free survival was different between AF patients with a high and low LA reservoir strain, and between patients with a high and low LA contractile strain (P = 0.03 and P = 0.006, respectively).

Conclusion

Low LA reservoir strain and low LA contractile strain both are predictive for arrhythmia recurrence after RF-PVI. LA conduit strain did not differ between patients with and without arrhythmia recurrence. LA contractile strain had the highest predictive value and may be a valuable clinical marker to predict success of AF ablative therapy.

Impaired left atrial reservoir and conduit strain in patients with atrial fibrillation and extensive fibrosis

Funding Acknowledgements

Type of funding sources: None.

Background

Atrial fibrillation (AF) is associated with profound structural and functional changes in the atria. Timely interventions may decelerate and perhaps reverse this pathophysiologic process and improve clinical outcome. In this regard, detailed characterization of the atrial remodeling process, and understanding of the interplay between structural remodeling and function is essential.

Purpose

In the present study, we investigated the association between left atrial (LA) phasic function and the extent of LA fibrosis using advanced cardiovascular magnetic resonance (CMR) imaging techniques, including 3-dimensional (3D) late gadolinium enhancement (LGE) and Feature Tracking.

Methods

Patients with paroxysmal and persistent AF (n = 93) underwent CMR in sinus rhythm. LA global reservoir strain, conduit strain and contractile strain were derived from cine CMR images using Feature Tracking. The extent of LA fibrosis was assessed from 3D LGE images. Healthy volunteers underwent CMR and served as controls (n = 19).

Results

Significantly lower reservoir strain, conduit strain and contractile strain were found in AF patients, as compared to controls (-15.7 ± 3.9% vs. -21.1 ± 3.6% P < 0.001, -8.6 ± 2.9% vs. -12.6 ± 2.5% P < 0.001 and -7.1 ± 2.4% vs. -8.6 ± 2.2% P = 0.02, respectively) (Figure A, B, C). Patients with a high degree of LA fibrosis (dichotomized by the median value) had lower reservoir strain and conduit strain compared to patients with a low degree of LA fibrosis (-14.7 ± 4.0% vs. -16.8 ± 3.5%, P = 0.02 and -7.7 ± 2.7% vs. -9.5 ± 2.9%, P < 0.01, respectively). In contrast, no difference was found for LA contractile strain (-7.0 ± 2.3% vs. -7.3 ± 2.5%, P = 0.62) (Figure D, E, F).

Conclusions

This study shows impaired LA reservoir and conduit strain in AF patients with extensive atrial fibrosis. Of interest, LA contractile function was largely unaffected. Future studies are required to study the biologic nature of this association and possible therapeutic implications. Abstract Figure.

Depression and anxiety at time of implantable cardioverter defibrillator implantation and the biological link with cardiovascular disease

Funding Acknowledgements

Type of funding sources: None.

Background

Psychological distress, such as symptoms of anxiety and depression, are frequently present in patients receiving an implantable cardioverter defibrillator (ICD) and they are associated with adverse outcomes. Multiple pathophysiological mechanisms may explain the link between psychological distress and cardiovascular disease, such as autonomic dysfunction, neuro-endocrine alterations and chronic inflammation.

Purpose

The present study aims to examine the prevalence of psychological distress at time of ICD implantation and evaluates the complex interplay between psychological distress, autonomic function, neuro-endocrine alterations and inflammatory status in ICD patients.

Methods

We conducted a prospective study that included ICD patients receiving an ICD for primary and secondary prevention of sudden cardiac death. Prior to implantation, patients underwent extensive psychological evaluation, including validated questionnaires for depression, anxiety and personality traits. Cardiac status was evaluated by left ventricular ejection fraction (LVEF) assessment, New York Heart Association (NYHA) functional class evaluation, 6-minute walk test (6MWT), and 24-hour Holter monitoring for heart rate variability (HRV). Thyroid function, catecholamine levels and inflammatory status were also evaluated.

Results

Of 178 patients included (age 64 ± 12, 79% male, LVEF 35 ± 13%), 35% had symptoms of depression and 32% had symptoms of anxiety. Symptoms of depression and anxiety increased significantly with higher NYHA functional class (P < 0.001). Depressive symptoms were associated with a reduced 6MWT (411 ± 128 m versus 488 ± 89 m, P < 0.001), lower LVEF (29 ± 9% versus 36 ± 13%, P = 0.03), higher heart rate (74 ± 13 bpm versus 70 ± 13 bpm, P = 0.02), higher thyroid stimulating hormone levels (1.8 [1.3-2.8] mU/L versus 1.5 [1.0-2.2] mU/L, P = 0.04) and multiple HRV parameters, indicating reduced HRV. Anxiety symptoms were only associated with a reduced 6MWT (433 ± 112 m versus 477 ± 102, P = 0.02). Symptoms of depression or anxiety were not correlated with c-reactive protein, NT-proBNP or catecholamine levels.

Conclusion

A substantial part of ICD patients has symptoms of depression and anxiety at time of ICD implantation. Depression was correlated with a higher NYHA class, reduced exercise capacity,  reduced LV-function and alterations in autonomic function, suggesting a biological link between depression and cardiac status. Whether depression and anxiety leads to an increase in ventricular arrhythmias will be determined during further follow-up. Abstract Figure. NYHA class and psychological distress

Predictive value of ten risk scores for outcomes of atrial fibrillation patients undergoing radiofrequency pulmonary vein isolation

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction:

A significant number of patients experience recurrent atrial fibrillation (AF) after ablation. Predicting who will or will not benefit from AF ablation is challenging. Although various risk scores have been designed to predict outcomes after AF ablation, comparative data are sparse and external risk score validation is often lacking.

Purpose

In this study, we aimed to compare ten previously described risk scores with regard to their predictive value for post-ablation AF recurrence and procedural complications.

Methods

A total of 482 AF patients (37% non-paroxysmal AF, 66% male, mean age 62 ± 9 years) undergoing initial radiofrequency pulmonary vein isolation (RF-PVI) were included in the present analysis. Prior to ablation, all patients underwent both transthoracic echocardiography and either cardiac computed tomography imaging or cardiac magnetic resonance imaging. The following risk scores were calculated for each patient: APPLE, ATLAS, BASE-AF2, CAAP-AF, CHADS2, CHA2DS2-VASc, DR-FLASH, HATCH, LAGO and MB-LATER. The predictive performance of the risk scores for AF recurrence and complications were assessed separately by receiver operating characteristic (ROC) curves.

Results

Median follow-up was 16 (12-31) months. AF recurrence after the 90-day blanking period was observed in 199 patients (41%), occurring after a median of 183 (124-360) days after ablation. Overall procedural adverse event rate was 6%. The HATCH score was the only score without predictive value for recurrent AF after ablation (area under curve [AUC] 0.545). All other investigated scores demonstrated statistically significant but poor predictive value for recurrent AF after ablation (AUC 0.553-0.669). CHA2DS2-VASc and CAAP-AF were the only risk scores with predictive value for procedural complications (AUC 0.616, p = 0.043; AUC 0.615, p = 0.044; respectively). ROC curve analyses of the studied risk scores for the prediction of AF recurrence and complications are shown in Figure.

Conclusion

Currently available risk scores perform poorly in predicting outcomes after RF-PVI. These data suggest that the utility of these scores for clinical decision-making is limited. Abstract Figure. ROC curve analyses of risk scores

Assessment of a standalone photoplethysmography (PPG) algorithm for detection of atrial fibrillation on wristband-derived data

INTRODUCTION

Atrial fibrillation (AF) is the most common cardiac arrhythmia in the developed world. Using photoplethysmography (PPG) and software algorithms, AF can be detected with high accuracy using smartphone camera-derived data. However, reports of diagnostic accuracy of standalone algorithms using wristband-derived PPG data are sparse, while this provides a means to perform long-term AF screening and monitoring. This study evaluated the diagnostic accuracy of a well-known standalone algorithm using wristband-derived PPG data.

MATERIALS AND METHODS

Subjects recruited from a community senior care organization were instructed to wear the Wavelet PPG wristband on one arm and the Alivecor KardiaBand one-lead-ECG wristband on the other. Three consecutive measurements (duration per measurement: 60 s for PPG and 30 s for one-lead ECG) were performed with both devices, simultaneously. The PPG data were analyzed by the Fibricheck standalone algorithm and the ECG data by the Kardia algorithm. The results were compared to a reference standard (interpretation of the one-lead ECG by two independent cardiologists).

RESULTS

A total of 180 PPGs and one-lead ECGs were recorded in 60 subjects, with a mean age of 70±17. AF was identified in 6 (10%) of the users, two users (3%) were not classifiable by the PPG algorithm and 1 user (2%) was not classifiable by the one-lead ECG algorithm. The diagnostic performance (sensitivity/specificity/positive predictive value/negative predictive value/accuracy) on user level was 100/96/75/100/97% for the PPG wristband and 100/98/86/100/98% for the one-lead ECG wristband.

CONCLUSIONS

In a small real-world cohort of elderly people, the standalone Fibricheck AF algorithm can accurately detect AF using Wavelet wristband-derived PPG data. Results are comparable to the Alivecor Kardia one-lead ECG device, with an acceptable unclassifiable/bad quality rate. This opens the door for long-term AF screening and monitoring.

P1015Left atrial sphericity as a marker of atrial remodeling: comparison of atrial fibrillation patients and controls

Background/Introduction

Left atrial (LA) sphericity has been proposed as a more sensitive marker of atrial fibrillation (AF)-associated atrial remodeling compared to traditional markers such as LA size. However, mechanisms that underlie changes in LA sphericity are not fully understood and studies investigating the predictive value of LA sphericity for AF ablation outcome have yielded conflicting results.

Purpose

The present study aimed to assess correlates of LA sphericity and to compare LA sphericity in subjects with and without AF.

Methods

Measures of LA size (LA diameter, LA volume, LA volume index), LA sphericity and thoracic anteroposterior diameter (APd) at the level of the LA were determined in a total of 293 AF patients (62% paroxysmal AF) and 110 controls. Cardiac computed tomography (CT) images were analyzed offline by a reviewer blinded to clinical parameters. The AF cohort consisted of consecutive patients referred for cardiac CT imaging prior to first AF ablation procedure between January 2015 and January 2018. The control cohort consisted of subjects with no history of AF who underwent cardiac CT imaging between January 2012 and October 2014 to exclude coronary artery disease.

Results

LA diameter (40.1 ± 6.8 mm vs. 35.2 ± 5.1 mm; p < 0.001), LA volume (116.0 ± 33.0 ml vs. 80.3 ± 22.6 ml; p < 0.001) and LA volume index (56.1 ± 15.3 ml/m² vs. 41.6 ± 11.1 ml/m²; p < 0.001) were significantly larger in AF patients compared to controls (Figure), also after adjustment for age and sex. LA sphericity did not differ between AF patients and controls (83.7 ± 2.9 vs. 83.9 ± 2.4; p = 0.642). A moderate correlation was noted between thoracic APd and LA sphericity in both females (R = 0.521, p < 0.001) and males (R = 0.498, p < 0.001). Multivariable linear regression analysis demonstrated that LA diameter, LA volume, female sex, body length and thoracic APd were independently associated with LA sphericity.

Conclusion

The present study suggests that thoracic constraints rather than the presence of AF determine LA sphericity, implying LA sphericity to be unsuitable as a marker of AF-related atrial remodeling.

Abstract Figure. Comparison of LA imaging characteristics

666Impact of local left atrial wall thickness on the incidence of acute pulmonary vein reconnection after ablation index-guided ablation

Background/Introduction

Pulmonary vein reconnection is considered a major determinant of atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI). Ablation Index (AI)-guided ablation allows for the creation of ablation lesions of consistent depth and may reduce the incidence of pulmonary vein reconnection after PVI. However, anatomical and imaging studies have demonstrated an important inter- and intra-patient variability of left atrial wall thickness, which can result in non-transmural ablation lesion formation in thicker segments.

Purpose

The present study aimed to investigate the impact of local left atrial wall thickness on the incidence of acute pulmonary vein reconnection after AI-guided AF ablation.

Methods

Consecutive AF patients who underwent cardiac computed tomography (CT) imaging prior to AI-guided ablation between December 2017 and September 2019 were studied. AI targets were 500 for anterior/roof and 380 for posterior/inferior segments with a maximum interlesion distance of 6 mm. Occurrence of acute pulmonary vein reconnection after initial PVI was assessed after a 30-minute waiting period. Ablation procedures were analysed offline to determine minimum AI, force-time integral, contact force, ablation duration, power, impedance drop and maximum interlesion distance for each segment according to a 16-segment model. Pulmonary vein antrum wall thickness was assessed for each segment on reconstructed CT images based on patient-specific thresholds in Hounsfield Units, using a previously described method.

Results

Seventy patients (63% paroxysmal AF, 67% male, mean age 63 ± 8 years) who underwent preprocedural CT imaging and AI-guided AF ablation were studied. Acute reconnection (AR) occurred in 27/1152 segments (2%, 15 anterior/roof, 12 posterior/inferior) in 17/70 (24%) patients. Anterior/roof segments were thicker than posterior/inferior segments (1.48 [1.23-1.80] vs. 1.13 [1.00-1.30] mm; p < 0.01). Reconnected segments were characterised by a greater local atrial wall thickness, both in anterior/roof (1.83 [1.60-2.00] vs. 1.47 [1.20-1.80] mm; p < 0.01) and posterior/inferior (1.38 [1.25-1.50] vs. 1.13 [1.00-1.27] mm; p < 0.01) segments (Figure 1). Minimum AI, force-time integral, contact force, ablation duration, power, impedance drop and maximum interlesion distance were not associated with acute pulmonary vein reconnection.

Conclusion

Local atrial wall thickness is associated with acute pulmonary vein reconnection after AI-guided PVI. Individualised AI targets based on local wall thickness may be of use to create transmural ablation lesions and prevent pulmonary vein reconnection after PVI.

Abstract Figure. Impact of wall thickness on reconnection

127Diastolic window of interest mapping for fast identification of the critical isthmus in re-entrant ventricular tachycardia

Background/Introduction

Identification of the critical isthmus in re-entrant ventricular tachycardia (VT) should be fast and accurate as the tachycardia is often tolerated for a limited period of time. Using the standard window of interest (WOI) setting with the beginning and end of the window set at mid diastole, mapping systems may incorrectly annotate far field systolic signals instead of smaller diastolic local bipolar signals. The resulting activation map may not show activation pathways through the scar area.

Purpose

We aimed to study if adjustment of the WOI to the diastolic part of the VT cycle during automatic annotated mapping could aid critical tachycardia isthmus identification.

Methods

Consecutive patients with ischemic cardiomyopathy undergoing endocardial VT ablation between January 2018 and July 2019 were studied. VT mapping was performed using a multipolar mapping catheter. All signals were automatically annotated using the algorithm provided by the 3D mapping system which uses the maximum negative slope of the unipolar signal (-dV/dT) concomitant with a bipolar signal to calculate local activation times. Location of the critical isthmus was either identified or confirmed by pacing showing concealed entrainment. Acquired maps were analysed retrospectively using three methods: (1) automatically annotated using conventional WOI settings with onset of the window fixed in mid-diastole and a window duration spanning the tachycardia cycle length minus 20 ms, (2) similar conventional WOI settings with manual correction assuring annotation of the near field signal and (3) automatically annotated with an adjusted WOI focused on the diastolic part of the VT, thus excluding its systolic part.

Results

Forty ischemic cardiomyopathy patients underwent endocardial VT ablation, of which 8 procedures were identified that included activation mapping of re-entrant VT’s. Using conventional WOI settings, local activation was automatically annotated on far field instead of the actual local bipolar activation signal in a mean of 92 (14%) points, range 17 to 260 (3 to 21 %). In all cases, the resulting map did not show diastolic pathways through the scar (Figure A). After manual correction of annotated signals, maps depicted pathways through the scar area (Figure B). All automatically annotated maps with a diastolic WOI indicated the location of the critical isthmus (Figure C). Diastolic pathways are shown by isochronals coloured red/yellow (early diastolic entry) going over in green to light blue (mid-diastolic) adjacent to blue (late diastolic) to pink (exit area), instead of blue/pink and red/yellow (‘early meets late’) during standard WOI mapping.

Conclusions

Diastolic WOI mapping improves rapid critical isthmus identification in re-entrant ventricular tachycardia, without the need for manual correction. Resulting activation maps may require familiarisation as colour coding differs from standard WOI maps.

Abstract Figure. Standard versus diastolic WOI map

Atrial inflammation in different atrial fibrillation subtypes and its relation with clinical risk factors

Objective

Inflammation of the atria is an important factor in the pathogenesis of atrial fibrillation (AF). Whether the extent of atrial inflammation relates with clinical risk factors of AF, however, is largely unknown. This we have studied comparing patients with paroxysmal and long-standing persistent/permanent AF.

Methods

Left atrial tissue was obtained from 50 AF patients (paroxysmal = 20, long-standing persistent/permanent = 30) that underwent a left atrial ablation procedure either or not in combination with coronary artery bypass grafting and/or valve surgery. Herein, the numbers of CD45+ and CD3+ inflammatory cells were quantified and correlated with the AF risk factors age, gender, diabetes, and blood CRP levels.

Results

The numbers of CD45+ and CD3+ cells were significantly higher in the adipose tissue of the atria compared with the myocardium in all AF patients but did not differ between AF subtypes. The numbers of CD45+ and CD3+ cells did not relate significantly to gender or diabetes in any of the AF subtypes. However, the inflammatory infiltrates as well as CK-MB and CRP blood levels increased significantly with increasing age in long-standing persistent/permanent AF and a moderate positive correlation was found between the extent of atrial inflammation and the CRP blood levels in both AF subtypes.

Conclusion

The extent of left atrial inflammation in AF patients was not related to the AF risk factors, diabetes and gender, but was associated with increasing age in patients with long-standing persistent/permanent AF. This may be indicative for a role of inflammation in the progression to long-standing persistent/permanent AF with increasing age.

Graphic abstract

P984Residual gaps in the ablation line and requirement for carina ablation during contact force-guided radiofrequency pulmonary vein isolation: determinants and prognostic implications

Background

Pulmonary vein isolation (PVI) is not always achieved after initial encircling of the pulmonary veins (PVs). Additional touch-up lesions are frequently required to close residual gaps, which may occur both in the initial ablation line and on the intervenous carina.

Purpose

We aimed to identify determinants and prognostic implications of residual gaps during index radiofrequency PVI.

Methods

Two hundred fourteen AF (atrial fibrillation) patients (57% paroxysmal, 61% male, mean age 62±9 years) undergoing contact force-guided PVI were studied. Residual gaps after initial encircling of the PVs were targeted for additional ablation and were classified as either gap ablation in the initial WACA (wide-area circumferential ablation) circle or carina ablation, depending on the site of earliest activation. After a waiting period of at least 30 minutes, persistence of PVI was tested through administration of 9–18 mg intravenous adenosine. Pre-procedural cardiac computed tomography imaging was used to assess left atrial and PV anatomy. Carina width was defined as the distance between ipsilateral superior and inferior PV ostia. Ablation procedures were analyzed to define the perimeter of the WACA circle.

Results

One hundred thirty-three patients (62%) required additional ablation lesions beyond the initial WACA circles to achieve complete PVI. Gap ablation was required in the left WACA circle in 34 patients (16%) and in the right WACA circle in 49 patients (23%). Left and right carina ablation were required in 50 (23%) and 83 (39%) patients, respectively. Multivariate analyses identified carina width and perimeter of the WACA circle as independent predictors of requirement for ipsilateral carina ablation, whereas paroxysmal AF and the perimeter of the WACA circle were associated with requirement of gap ablation in the initial WACA circle. Recurrence of atrial tachyarrhythmias was documented in 73 patients (34%) at 12 months follow-up. Kaplan–Meier survival analyses demonstrated a significantly higher rate of recurrence in patients with one or more residual gaps in the ablation line (43% vs. 30%, p=0.019, figure A), whereas no significant difference between patients with and without requirement of carina ablation was found (38% and 29%, respectively; p=0.111, figure B).

Kaplan-Meier survival analyses

Conclusion

Residual gaps in the initial WACA circle were associated with increased AF recurrence rate after PVI, whereas residual gaps on the intervenous carina had no statistically significant impact on AF recurrence. Consequently, gaps occurring in the ablation line and gaps on the intervenous carina may represent different mechanisms and may have different prognostic implications.

P595Characteristics of the right ventricle in patients with nonischemic dilated cardiomyopathy

Background

In nonischemic dilated cardiomyopathy (DCM), diagnosis and prognosis is based on left ventricular function. Although concomitant right ventricular (RV) dysfunction is frequently observed, the underlying mechanism is currently not fully understood.

Purpose

We aimed to describe the characteristics of right ventricular function in DCM patients with cardiac magnetic resonance (CMR) imaging using cine and late-gadolinium enhancement (LGE) imaging.

Methods

Patients with DCM and left ventricular (LV) dysfunction (ejection fraction (EF) <50%) on LGE-CMR were included prospectively. LV and RV volumes and function were quantified and RV systolic dysfunction was defined as RV ejection fraction (RVEF)<45%. The presence and pattern of LGE were assessed visually and the extent was quantified using the full-width half maximum method. Septal midmyocardial LGE pattern was defined as midwall striae or hinge-point myocardial hyperenhancement. Moreover, left atrial (LA) volumes were calculated using the bi-plane area-length method.

Results

The study included 214 DCM patients (42% female, age 58±14 years) with a mean LVEF of 34±12% and RVEF of 46±12%. RV systolic dysfunction was present in 39% and was associated with the presence of septal midwall LGE (OR 1.96 (95% CI 1.09–3.54) p=0.026). In patients with RV dysfunction, LV dilation was more severe (LV end diastolic volume (EDV) 242±97mL vs. 212±58mL, p=0.011) and LVEF was lowere (26±12% vs. 39±8%, p<0.001) (figure A). There was a weak correlation between septal LGE amount and LVEDV and RVEDV (respectively r=0.36, p=0.003 and r=0.35, p=0.005)

In patients with RV dysfunction, left atrial volumes were enlarged (56±23mL/m2 vs. 46±14mL/m2, p<0.001) and LA emptying fraction was moderately correlated to RVEF (figure B), also after exclusion of patients with a history of atrial fibrillation.

RVEF in DCM patients

Conclusion

In DCM, reduced RVEF predominantly occurred in patients with a) LVEF lower than 30%, b) septal midwall enhancement, indicating progressive LV remodeling, c) LA dilation and d) LA dysfunction. This suggests that RV dysfunction in advanced DCM is drive by LV diastolic dysfunction resulting in increased afterload of the RV.

A mobile one-lead ECG device incorporated in a symptom-driven remote arrhythmia monitoring program. The first 5,982 Hartwacht ECGs

BACKGROUND

In recent years many mobile devices able to record health-related data in ambulatory patients have emerged. However, well-organised programs to incorporate these devices are sparse. Hartwacht Arrhythmia (HA) is such a program, focusing on remote arrhythmia detection using the AliveCor Kardia Mobile (KM) and its algorithm.

OBJECTIVES

The aim of this study was to assess the benefit of the KM device and its algorithm in detecting cardiac arrhythmias in a real-world cohort of ambulatory patients.

METHODS

All KM ECGs recorded in the HA program between January 2017 and March 2018 were included. Classification by the KM algorithm was compared with that of the Hartwacht team led by a cardiologist. Statistical analyses were performed with respect to detection of sinus rhythm (SR), atrial fibrillation (AF) and other arrhythmias.

RESULTS

5,982 KM ECGs were received from 233 patients (mean age 58 years, 52% male). The KM algorithm categorised 59% as SR, 22% as possible AF, 17% as unclassified and 2% as unreadable. According to the Hartwacht team, 498 (8%) ECGs were uninterpretable. Negative predictive value for detection of AF was 98%. However, positive predictive value as well as detection of other arrhythmias was poor. In 81% of the unclassified ECGs, the Hartwacht team was able to provide a diagnosis.

CONCLUSIONS

This study reports on the first symptom-driven remote arrhythmia monitoring program in the Netherlands. Less than 10% of the ECGs were uninterpretable. However, the current performance of the KM algorithm makes the device inadequate as a stand-alone application, supporting the need for manual ECG analysis in HA and similar programs.

Magnetic resonance imaging in patients with cardiac implantable electronic devices

In recent years the prevalence of implantation of a cardiac implantable electronic device (CIED) has increased due to expanding implantation indications and prolonged life expectancy. Diagnostic strategies increasingly employ magnetic resonance imaging (MRI) to aid therapeutic strategies. In earlier guidelines, MRI was contra-indicated in patients with CIEDs, mainly due to previous reports of severe complications. With the development of MRI-conditional CIEDs and recent evidence concerning non-MRI-conditional CIEDs, MRIs in CIED patients can be safely performed in many hospitals.However, there are several questions that need to be addressed. Which patients can we scan? How can the scans be performed safely? And last but not least, can cardiac MRI provide diagnostic yield in patients with CIEDs?Current European guidelines are rather outdated and vague about patient selection and practical issues. There are national guidelines on this topic but several issues need extra attention and those are addressed in this point of view. It is important to create an environment with proper patient selection without unnecessary MRI scans in CIED patients, but also without unnecessary fear of complications, preventing access to MRI in patients who can benefit from this powerful diagnostic tool.

Improved patient selection for cardiac resynchronization therapy by normalization of QRS duration to left ventricular dimension

Aims

This study evaluates the relative importance of two components of QRS prolongation, myocardial conduction velocity and travel distance of the electrical wave front (i.e. path length), for the prediction of acute response to cardiac resynchronization therapy (CRT) in left bundle branch block (LBBB) patients.

Methods and results

Thirty-two CRT candidates (ejection fraction <35%, LBBB) underwent cardiac magnetic resonance (CMR) imaging to provide detailed information on left ventricular (LV) dimensions. Left ventricular end-diastolic volume (LVEDV) was used as a primary measure for path length, subsequently QRSd was normalized to LV dimension (i.e. QRSd divided by LVEDV) to adjust for conduction path length. Invasive pressure-volume loop analysis at baseline and during CRT was used to assess acute pump function improvement, expressed as LV stroke work (SW) change. During CRT, SW improved by +38 ± 46% (P < 0.001). The baseline LVEDV was positively related to QRSd (R = 0.36, P = 0.044). Despite this association, a paradoxical inverse relation was found between LVEDV and SW improvement during CRT (R = -0.40; P = 0.025). Baseline unadjusted QRSd was found to be unrelated to SW changes during CRT (R = 0.16; P = 0.383), whereas normalized QRSd (QRSd/LVEDV) yielded a strong correlation with CRT response (R = 0.49; P = 0.005). Other measures of LV dimension, including LV length, LV diameter, and LV end-systolic volume, showed similar relations with normalized QRSd and SW improvement.

Conclusion

Since normalized QRSd reflects myocardial conduction properties, these findings suggest that myocardial conduction velocity rather than increased path length mainly determines response to CRT. Normalizing QRSd to LV dimension might provide a relatively simple method to improve patient selection for CRT.

Safety and long-term effects of renal denervation: Rationale and design of the Dutch registry

BACKGROUND

Percutaneous renal denervation (RDN) has recently been introduced as a treatment for therapy-resistant hypertension. Also, it has been suggested that RDN may be beneficial for other conditions characterised by increased sympathetic nerve activity. There are still many uncertainties with regard to efficacy, safety, predictors for success and long-term effects. To answer these important questions, we initiated a Dutch RDN registry aiming to collect data from all RDN procedures performed in the Netherlands.

METHODS

The Dutch RDN registry is an ongoing investigator-initiated, prospective, multicentre cohort study. Twenty-six Dutch hospitals agreed to participate in this registry. All patients who undergo RDN, regardless of the clinical indication or device that is used, will be included. Data are currently being collected on eligibility and screening, treatment and follow-up.

RESULTS

Procedures have been performed since August 2010. At present, data from 306 patients have been entered into the database. The main indication for RDN was hypertension (n = 302, 99%). Patients had a mean office blood pressure of 177/100 (±29/16) mmHg with a median use of three (range 0-8) blood pressure lowering drugs. Mean 24-hour blood pressure before RDN was 157/93 (±18/13) mmHg. RDN was performed with different devices, with the Simplicity™ catheter currently used most frequently.

CONCLUSION

Here we report on the rationale and design of the Dutch RDN registry. Enrolment in this investigator-initiated study is ongoing. We present baseline characteristics of the first 306 participants.

The influence of right ventricular stimulation on acute response to cardiac resynchronisation therapy

Background

The contribution of right ventricular (RV) stimulation to cardiac resynchronisation therapy (CRT) remains controversial. RV stimulation might be associated with adverse haemodynamic effects, dependent on intrinsic right bundle branch conduction, presence of scar, RV function and other factors which may partly explain non-response to CRT. This study investigates to what degree RV stimulation modulates response to biventricular (BiV) stimulation in CRT candidates and which baseline factors, assessed by cardiac magnetic resonance imaging, determine this modulation.

Methods and results

Forty-one patients (24 (59 %) males, 67 ± 10 years, QRS 153 ± 22 ms, 21 (51 %) ischaemic cardiomyopathy, left ventricular (LV) ejection fraction 25 ± 7 %), who successfully underwent temporary stimulation with pacing leads in the RV apex (RV_apex) and left ventricular posterolateral (PL) wall were included. Stroke work, assessed by a conductance catheter, was used to assess acute haemodynamic response during baseline conditions and RV_apex, PL (LV) and PL+RV_apex (BiV) stimulation.

Compared with baseline, stroke work improved similarly during LV and BiV stimulation (∆+ 51 ± 42 % and ∆+ 48 ± 47 %, both p < 0.001), but individual response showed substantial differences between LV and BiV stimulation. Multivariate analysis revealed that RV ejection fraction (β = 1.01, p = 0.02) was an independent predictor for stroke work response during LV stimulation, but not for BiV stimulation. Other parameters, including atrioventricular delay and scar presence and localisation, did not predict stroke work response in CRT.

Conclusion

The haemodynamic effect of addition of RV_apex stimulation to LV stimulation differs widely among patients receiving CRT. Poor RV function is associated with poor response to LV but not BiV stimulation.

Electronic supplementary material

The online version of this article (doi:10.1007/s12471-015-0770-x) contains supplementary material, which is available to authorized users.

Renal denervation for the treatment of hypertension: the Dutch consensus

Since 2010, renal denervation (RDN) is being performed in the Netherlands. To make sure RDN is implemented with care and caution in the Netherlands, a multidisciplinary Working Group has been set up by the Dutch Society of Cardiology (NVVC). The main aim of this Working Group was to establish a consensus document that can be used as a guide for implementation of RDN in the Netherlands. This consensus document was prepared in consultation with the Dutch Association of Internal Medicine (NIV) and the Dutch Society of Radiology (NVVR).