Transcriptomic and proteomic profiling of human diabetic heart disease

 

Studies in animal models demonstrated the capability of type 2 diabetes (T2D) to induce cardiac dysfunction in the absence of vascular disease. However, whether and how T2D also impairs structure and function in human hearts remains poorly understood. Here, we performed transcriptional and proteomic profiling of left ventricular samples of 8 subjects with T2D, preserved EF (63,5%) and no history of ischemic heart disease (= diabetic cardiomyopathy; DbCM), 7 subjects with T2D, reduced EF (26,9%) and ischemic heart disease (= diabetic heart failure; DbHF), and 15 non-diabetic individuals with normal EF (64,7%) serving as controls. Among 1168 proteins identified by LC-MS/MS, 146 proteins were differentially regulated in DbHF, but only 66 in DbCM. Pathway analysis revealed downregulation of energy metabolic proteins, but upregulation of proteins involved in oxidative stress and inflammatory response. In DbCM, pathways of structural remodeling, cardiomyocyte proliferation, and mechanotransduction were upregulated. Bulk RNA sequencing revealed 1795 differentially regulated genes in DbHF, and 527 in DbCM, with only 128 genes being commonly regulated. DbHF, but not DbCM, could be clearly discriminated from controls by hierarchical clustering. While inflammation/immunity were major regulated pathways in DbHF, extracellular matrix remodeling and cellular growth were the most regulated pathways in DbCM. Thus, the differential regulation of biological pathways in DbCM versus DbHF suggests the existence of two distinct disease entities rather than DbHF being an advanced disease stage of DbCM.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Austrian Diabetes Society

Single-center outcome after ablation of atrial fibrillation using very high-power short duration pulmonary vein isolation

Funding Acknowledgements

Type of funding sources: None.

Background

Catheter ablation of atrial fibrillation is (AF) an established second line therapy for patients with symptomatic paroxysmal (PAF) and persistent AF (persAF). Novel ablation catheters with integrated thermocouples allow fast application of radiofrequency lesions with powers up to 90W.

We aimed to describe primary and secondary outcomes after very high-power short duration (vHPSD) ablation.

Methods

126 consecutive patients (78 PAF, 43 persAF, 5 longstanding persistent AF) underwent pulmonary vein isolation (PVI) using the QDOT Micro Catheter (Biosense Webster) with the ablation mode QMODE+ (90W, 4s, interlesion distance ≤4mm anterior, ≤6mm posterior).

Results

Mean age was 62±9 years, 33% were female, median CHA2DS2-VASc Score was 2 (0, 7). Median follow up duration was 204 (14, 461) days. 30% of patients had additional ablation of typical right atrial flutter.

Primary success rate to achieve pulmonary vein isolation was achieved in all patients, no catheter-related complications (e.g., charring, steam pop) occurred. First pass isolation of all 4 PVs was achieved in 48% of patients, re-ablations were necessary in the carina regions (right: 37% of cases, left: 29%) and ridge (14%). Median procedure for PVI only were 102 (45-210) minutes.

Arrhythmia-free survival was 79,6% (see Figure 1). Eight patients underwent re-do procedures during follow-up showing most commonly showing gaps in the right inferior PV (63%) and ridge (50%).

Conclusion

Very high-power short duration ablation allows safe and quick pulmonary vein isolation. However, first pass isolation rate is low due to gaps in the carina regions. Arrhythmia-free survival is comparable to other pulmonary vein isolation techniques.

Figure 1: Left panel: Sample image of a vHPSD-PVI, posterior view of the left atrium. Right panel: Single procedure arrhythmia-free survival after vHPSD-PVI.

Photoplethysmography telemonitoring during the first week after atrial fibrillation ablation: Feasibility and clinical implications

Funding Acknowledgements

Type of funding sources: None.

The incidence of early atrial fibrillation (AF) recurrence within the first week after AF ablation and its predictive value for late AF recurrences are unclear. TeleCheck-AF is a remote on-demand mobile health (mHealth) infrastructure, which is based on a mobile phone app using photoplethysmography (PPG) technology (Fibricheck) allowing rate and rhythm monitoring through teleconsultations. The feasibility and clinical implications of PPG telemonitoring specifically during the first week after atrial fibrillation ablation is unknown.

Methods

Within the TeleCheck-AF project, the Medical University offered a total of 382 consecutive patients undergoing AF ablation (between June 1st 2020 and December 15th 2021) photoplethysmography (PPG) telemonitoring with "FibriCheck" during the first week after the ablation procedure. Patients received a QR code for activation of the software on their smartphone and were connected to the clinician’s telemedicine portal. They were instructed to perform rhythm monitoring three times per day and in case of symptoms. Clinicians assessed the tracings and contacted the patients if therapeutic steps were indicated.

Results

In total, 119 patients (31%) agreed to perform telemonitoring after ablation. Patients undergoing telemonitoring were younger compared to those who refused participation (58±10years vs. 62±10years, p<0.001). 34% were female, median CHA2DS2-VASc-Score was 1 (0-6). 62% of patients had paroxysmal AF and 37% had persistent AF. One of four patients (24%) had already undergone previous ablations. Most index ablations were radiofrequency ablations (89%; 7% cryo; 4% pulsed field ablation). Median follow up duration was 281 (16-620) days.

27% of patients had tracings suggestive of AF in the week following the index ablation. Telemonitoring resulted in clinical interventions ins 24% of patients: amiodarone was started in 8%, class I antiarrhythmic drugs were up titrated in 7%, cardioversion was scheduled in 5%, antiarrhythmic drugs were reduced due to symptomatic bradycardia in 3% of patients.

During follow-up, 22% of patients had ECG-documented AF recurrences. PPG recordings suggestive of AF in the week after ablation were predictive of late recurrences (p<0.001).

Conclusion

Rhythm monitoring with a PPG-based mHealth application was feasible and often resulted in clinical interventions. Due to its high availability, PPG-based follow-up actively involving patients after AF ablation may close a diagnostic and prognostic gap and increase active patient-involvement.

Figure 1: Schematic overview of the telemonitoring process. After the ablation, the patient measures PPGs for one week, dashboard view for clinician shows regular rhythm (green, atrial fibrillation (red) and unclear tracings (blue).

Electroanatomic mapping system guided his bundle pacemaker implantation: experience of the his bundle registry graz

Funding Acknowledgements

Type of funding sources: None.

Background

Patients with bradyarrhythmia in need for ventricular pacing may suffer from pacing-induced heart failure due to unphysiological right ventricular pacing. His bundle pacing (HBP) allows to overcome this common issue with a more physiologic approach but real-life procedural data using this technology is scarce.

Methods

We report a single centre experience of the first 44 consecutive patients being implanted with a His-bundle-based pacemaker 09/2020-11/2021 per 3D-mapping guided implantation due to different types of bradyarrhythmia, or for cardiac resynchronisation therapy in heart failure combined with a left-ventricular lead (HOT-CRT) ± a right ventricular defibrillator lead. The positioning of the His-bundle-lead was done by identifying the His-bundle-location with a 3D electroanatomic mapping system via an introducing sheath that is provided with electrodes at its tip.

Results

Mean age was 70 [16;86] years, 12/44 (27%) patients were female, mean baseline LVEF was 44±18%. Baseline ECG was captured: QRS width was 123±33ms, with typical LBBB in 14/44 (32%), typical RBBB in 4/44 (9%), alternating BBB in one patient (2%) and either no BBB or ventricular escape rhythm in 25/44 (57%). Indications for implantation were AV-block grade II-III in 19/44 (43%), primary prophylactic ICD indication in HFrEF in 13/44 (30%), atrial fibrillation with bradycardic conduction in 7/44 patients (16%), sick-sinus-syndrome in 4/44 (9%) and secondary prophylactic ICD indication in one patient (2%). In 41/44 (93%) a primary device was implanted, in 3/44 (7%) a pre-existent device was upgraded with a HB lead.

Therefore, 14 dual-chamber-pacemaker, 5 single-chamber-pacemaker, 8 single-chamber CRT-P, 11 dual-chamber CRT-P, 4 single-chamber CRT-D, 2 dual-chamber CRT-D were implanted. In 50 patients HBP was attempted, while in 6/50 (12%) patients outside of this analysis the attempt was not successful, these patients were consecutively implanted with a non-HBP-device and therefor excluded from the further analysis.

In the 44 patients included in this analysis with primary successful HBP, 4/44 (9%) his-bundle-leads dislocated within the first 48 hours, leading to a secondary success rate of 91%. There were two post-procedural pneumothorax that needed drainage, no major procedure-related complications occurred. Median skin-to skin procedure time was 109±50 minutes. The paced QRS width at the post-implantation follow up was 115±32ms with a change in QRS width of -10ms (+72;-92ms). When excluding the secondary lead dislocations and including only the successful HB paced QRS complexes, the paced QRS width was 105±30ms and the change in QRS width was -12±42ms. The mean his-bundle threshold was 1,2±1V over 0,5ms (0,5;1,5ms). The proportion of ventricular pacing was 69±38%.

Conclusion

Electroanatomic-guided His bundle pacing is feasible, with high implantation success rate and electric impact, both regarding QRS width and pacing threshold.

Prevention of early sudden cardiac death after myocardial infarction using the wearable cardioverter defibrillator - results from a real-life cohort

Funding Acknowledgements

Type of funding sources: None.

Background

Patients are at elevated risk of sudden cardiac death (SCD) after acute myocardial infarction (MI). The VEST trial failed to show a significant reduction in arrhythmic mortality in patients prescribed with a wearable converter-defibrillator (WCD), having a lower than expected wearing compliance. We aimed to investigate the incidence of WCD treatments and outcomes of all patients with acute MI and LVEF ≤35% in a real life and well-compliant cohort in Austria.

Methods

We performed a retrospective analysis of all patients meeting the in- and exclusion criteria of the original VEST trial within the Austrian WCD registry between 2010 and 2021.

Results

105/896 patients (12%) with an average age of 64±11 years (12% female; LVEF 28±6%) registered in the Austrian WCD registry met the VEST in- and exclusion criteria. 104/105 patients were revascularized and prescribed with a WCD prescription for 69 (1;277) days, the median wearing duration was 23.5 (0;24) hours/day. 4/105 (3.8%) patients received 9 appropriate WCD shocks, the per patient shock rate was 2 (1;5). No inappropriate shock was delivered. During follow-up, 46/105 patients (44%) received an ICD after the WCD period, 4/105 (3.8%) patients died during follow-up. Arrhythmic mortality (1.9% Austria vs. 1.6% VEST, p=ns), as well as all-cause mortality (3.8% vs. 3.1%, p=ns) in the Austrian cohort were comparable to the VEST cohort.

Conclusion

The WCD is a safe treatment option in a highly selected cohort of patients with a LVEF ≤35% after acute myocardial infarction. However, despite excellent WCD compliance as opposed to the VEST study, only 3.8% of patients receive appropriate WCD shocks and the arrhythmic mortality rate was not significantly improved.

Low haemoglobin is associated with increased risk of complications in left atrial appendage closure patients

Introduction

Left atrial appendage closure is associated with a relevant procedural complication rate. Baseline risk factors, such as pre-procedural lab results, may identify patients that develop acute complications.

Methods

We performed a retrospective analysis of the impact of baseline characteristics and preprocedural lab results on the acute procedural outcome in patients undergoing left atrial appendage closure from the Austrian Left Atrial Appendage Closure Registry between 2010 and 2019. The endpoint for procedural complications was defined as death, stroke, major bleeding, necessity for intensive care, other complications requiring invasive interventions or failure to implant the device. We also evaluated a modified endpoint with the exclusion of bleeding events. Logistic regression was performed using stepwise approach (backward method with p_out = 0.1) and forced inclusion of age, left-ventricular function and kidney function.

Results

A total of 320 consecutive patients from 9 centres with a median age of 75 years (36.6% female) were included. Seventy-eight percent had a history of bleeding and 35% had a history of stroke. Median CHA2DS2-VASc score was 5 (interquartile range, 3–5) and median HAS-BLED score was 3 (2–4). Procedural complications occurred in 15.3% of cases. Low haemoglobin and low activated partial thromboplastin time were associated with an increased complication rate. Other significant baseline factors were liver disease, absence of intracranial haemorrhage and severe aortic stenosis. In multivariate analysis, low haemoglobin remained a significant predictor, even after adjustment for age, left-ventricular function and kidney function (Table). In the modified procedural complication endpoint excluding major bleeding events (14.1%), low haemoglobin remained a significant predictor (haemoglobin 11.9±2.0 vs. 12.8±2.0 g/dL in patients with vs. without modified endpoint, p=0.013). A baseline haemoglobin lower than 12 g/dL was present in 39.4% and it increased relative risk of procedural complications by 89% (21.4 vs. 11.3% in patients with reduced vs. normal haemoglobin), and risk of complications without bleeding by 92% (19.8 vs. 10.3%).

Conclusion

Low baseline haemoglobin is independently associated with a higher complication rate after left appendage closure compared to patients with normal haemoglobin levels, even in a modified endpoint excluding bleeding and requirement for transfusion.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Boston Scientific - unrestricted grant Table 1

Ertugliflozin to reduce arrhythmic burden in ICD/CRT patients (ERASe-trial). a phase III study

Background and aim

Sodium glucose cotransporter 2 (SGLT2) have proven profound positive effects in heart failure with reduced ejection fraction (HFrEF). These effects are independent from the presence of diabetes. Since SGLT2 receptors are not expressed in human myocardium, these cardioprotective effects be indirect or pleiotropic. Besides metabolic effects anti-inflammatory anti-fibrotic properties are discussed.

Despite a strong correlation of ventricular arrhythmias with HFrEF, the impact of ertugliflozin on the arrhythmic burden has not been investigated, yet. Therefore, the Ertugliflozin to Reduce Arrhythmic burden in ICD/CRT patientS (ERASe) trial was designed to investigate the efficacy and safety of ertugliflozin in diabetic and non-diabetic HFrEF patients.

Methods

Methods: Within a multicentre, national, randomized, double-blind, placebo-controlled, phase 3b trial we aim to enrol a total of 402 patients across Austria. Patients with HFrEF or HFmrEF and ICD±CRT therapy >3 months and previous ventricular tachycardia (at least 10 documented non-sustained VT episodes within the last 12 months) are randomized in a 1:1 ratio to ertugliflozin (5mg once daily orally administered) or matching placebo.

The primary endpoint of the ERASe trial is to investigate the impact of Ertugliflozin on total burden of ventricular arrhythmias. Further objectives will be the number of therapeutic interventions of implanted devices, atrial fibrillation, heart failure biomarker and changes in physical function quality of life, stress and anxiety.

Conclusion

The ERASe trial will be the first trial to test ertugliflozin in heart failure patients with non-preserved ejection fraction and ongoing ICD/CRT therapy regardless of their diabetic status. The ERASe trial may therefore extend the concept of SGLT2 inhibition to improve cardiac reverse remodelling, including reduced arrhythmic burden.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): unrestricted grant of MSD

Effects of atrial fibrillation on ventricular remodeling in the human heart

 

Atrial fibrillation (AF) is often found in patients with heart failure (HF). Clinical data indicated that the arrhythmic component of AF alone could contribute to left-ventricular (LV) dysfunction. However, the effects of non-tachycardic AF with arrhythmic excitation of the human LV, are unknown.

We investigated human LV myocardium from patients with sinus rhythm (SR) or normofrequent AF (mean EF>50%, matched clinical data, derived from septal resections during AVR). In histological analysis we detected no difference between SR (n=17 patients) and AF patients (n=18) regarding the amount and distribution of fibrosis. We isolated human LV cardiomyocytes (CM) and studied cellular Ca-handling (Fura-2). Systolic Ca-transient amplitude of LV CM was reduced in patients suffering from AF (n=8 AF patients vs. 11 SR), while diastolic Ca-levels and Ca-transient kinetics were not significantly changed. These results were confirmed in LV CM from non-failing donors (NF) with AF (n=4 AF patients vs. 8 SR). For the standardized investigation of a normofrequent arrhythmia, we simulated AF in vitro by using arrhythmic (60 bpm, 40% beat-to-beat variability) or rhythmic (60 bpm) field stimulation. Human LV CM from NF SR patients (n=8) showed an impaired Ca-transient amplitude after 24h arrhythmic culture pacing without changes in diastolic Ca and Ca-transient kinetics. For studying a model suitable for more standardized chronic pacing, we utilized human iPSC cardiomyocytes (iPSC-CM) from healthy donors (n=6). After 7 days, arrhythmically paced iPSC-CM exhibited a reduced systolic Ca-transient amplitude, a trend towards a prolonged Ca-elimination time and a reduced sarcoplasmic reticulum Ca-load. Confocal line-scans of arrhythmically paced cells (Fluo-4 AM) showed an increased diastolic Ca-leak from the sarcoplasmic reticulum, possibly underlying the reduced Ca-load. Coupled with the Ca changes, cytosolic Na was elevated after arrhythmia. We found an increased late INa, which could explain the detrimentally altered Ca/Na-interplay. Accordingly, Patch-clamp experiments revealed a prolonged action potential duration after arrhythmia. We further elucidated the underlying mechanisms of this electrophysiological remodeling by showing that oxidative stress (H2O2, LPO) is increased in the LV of patients suffering from AF (n=6 AF patients vs. 6 SR), which was associated with an enhanced NOX2/-4 activity. Consecutively, Ca2+/calmodulin-dependent protein kinase IIδ (CaMKII) was found to be more oxidized (CaMKII-Met281/282) in the LV of AF patients (n=7 AF patients vs. 7 SR) leading to an increased CaMKII activity, which adversely regulated EC-coupling protein phosphorylation including RyR2 hyperphosphorylation.

Normofrequent arrhythmia/AF impairs human ventricular EC-coupling via increased oxidative stress and enhanced CaMKII. Thus, this translational study provides the first mechanistic characterization and the potential negative impact of isolated AF on the human LV.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Else Kröner-Fresenius-Stiftung (EKFS) and Deutsche Gesellschaft für Innere Medizin

Expert consensus on acute management of ventricular arrhythmias - VT network Austria

The Arrhythmia Working Group of the Austrian Society of Cardiology (ÖKG) has set the goal of systematically structuring and organizing the acute care of patients with ventricular arrhythmias (VA), i.e. ventricular tachycardia (VT) or ventricular fibrillation (VF) in Austria. Within a consensus paper, national recommendations on the basic diagnostic work-up of VA (12-lead ECG, medical history, family history, laboratory analyses, echocardiography, search for reversible causes, ICD interrogation), as well as further medical treatment and therapeutic measures (indication of coronary angiography, ablation therapy) are established. Since acute ablation of VT is indicated in the current ESC guidelines as a class IB indication for scar-associated incessant VT or electrical storm (ES; ≥ 3 ICD therapies in 24 h) as well as for ischemic cardiomyopathy (iCMP) with recurrent ICD shocks, organizational measures must be taken to ensure that these guidelines can be implemented. Therefore, a VT network will be established covering all areas in Austria, consisting of primary and secondary VT centers. Organizational aspects of an acute VT network are defined and should subsequently be implemented by the participating hospitals. All electrophysiologic centers in Austria that deal with VT ablation are to be integrated into the network in the medium-term. Centers that co-operate in the network are divided into primary and secondary VT centers according to predefined criteria.

Cellular mechanisms of early tachycardia-induced ventricular dysfunction in the human heart

Background

Tachycardia-induced cardiomyopathy (TCM) is a reversible form of ventricular dysfunction caused by persistent tachycardia. Characterization of TCM is mainly based on artificially RV paced animal models. Moreover, the underlying mechanisms and time course from compensation to failure remain unclear. This study aimed to investigate early cellular remodeling of tachycardia-induced myocardial dysfunction in human myocardium.

Methods and results

To elucidate early cellular electrophysiological targets mediating the transition to TCM, we chronically paced (120bpm vs 60bpm control) human induced pluripotent stem cell cardiomyocytes (hiPS-CM) for up to 7d. As a major substrate of cellular myocardial dysfunction, we investigated the influence of chronic tachycardia on cellular Ca cycling. After 24h of persistent tachycardia we detected a significant decrease in Ca transient (CaT) amplitude and reduced diastolic Ca levels (Fura-2). Meanwhile, Ca elimination time (RT80) was unchanged compared to control (n=44/42 cells / 8 diff.). Caffeine application was performed to evaluate sarcoplasmic reticulum (SR) Ca load. We found a shortening of caffeine-induced CaT relaxation time, whereas SR Ca load was unchanged (n=12/13 /8). Further illustrating the transition to TCM, CaT amplitude was progressively decreased after 7d of chronic tachycardia. In contrast to 24h of tachycardia, 7d persistent stimulation resulted in slowed relaxation (RT80, n=75/65 /7). These findings could be explained by a significant reduction of SERCA activity (Ksys-Kcaff) and SR Ca load (n=14/12 / 7). Diastolic Ca concentration remained reduced (n=75/65 /7), in total suggesting a shift to transsarcolemmal Ca elimination.

Sodium measurements (SBFI) revealed a significant increase of intracellular sodium concentration (n=69/69 /5) after 7d of tachycardia.

In patch clamp experiments we detected a prolongation of action potential duration as early as 24h after onset of tachycardia (n=26/21 /4), which persisted throughout 7d of pacing (n=8/12 /3). Resting membrane potential and action potential amplitude were not changed.

Finally, we investigated tachycardia-mediated effects on pre-existing human heart failure (HF). 8h tachycardic stimulation (120bpm) of human HF ventricular trabeculae compromised systolic force, while diastolic tension and relaxation time were markedly increased compared to control (60bpm) (n=7/6 trabeculae /6 human hearts).

The extensive molecular characterization of involved ion channels and pathways mediating transition to TCM is currently under investigation.

Conclusion

This study demonstrates that a persistent tachycardia adversely alters cardiomyocyte excitation-contraction coupling via early electrophysiological cellular remodeling. In pre-existing HF persistent tachycardia strongly aggravates ventricular dysfunction. Our first translational investigation in human myocardium may help to understand the pathophysiology of an underrated and very prevalent disease.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Else-Kröner-Fresenius-Stiftung

P956Improved quality of life and symptomatic atrial fibrillation reduction in patients treated with a standardized ablation index workflow

Background/Introduction

The use of a standardized ‘CLOSE’ ablation workflow for pulmonary vein isolation (PVI), with defined inter-tag distance (ITD) with targeted ablation index (AI) values, has been shown in single centre reports to result in good outcomes. The effect of this approach on patients’ quality of life (QoL) has not been studied.

Purpose

To evaluate the effects of paroxysmal atrial fibrillation (PAF) ablation by the CLOSE workflow on QoL and symptomatic AF reduction in the multicenter VISTAX study.

Methods

329 patients with PAF (61.5% male, 61.3 ± 10.1 year) were treated at 17 European centres by point-by-point radiofrequency ablation using the CLOSE protocol to achieve PVI.  An ITD ≤6mm and AI values of ≥400 on the posterior wall and ≥550 on the anterior wall were targeted. The AI value on the posterior wall was lowered as per investigator discretion in case of safety concerns. Patients were monitored for atrial arrhythmia recurrences via weekly and symptom-activated transtelephonic monitoring (TTM), for 12 months post procedure. Patients completed an Atrial Fibrillation Effect on Quality-of-life (AFEQT) questionnaire at their baseline and 12-month follow up visits.

Results

Majority (83.3% [274/329]) of patients experienced freedom from symptomatic atrial recurrence through 12 months. Of the 70 documented recurrences, 34 (49%) were documented by trans-telephonic monitoring only. All domains captured on the AFEQT questionnaire showed improvement with the overall score improving by 25.7, which exceeded the threshold of clinically meaningful improvement (±5) (Table). Patient reported most improvements in PAF control and symptoms relieved. The overall AFEQT score improvement was seen both in patients with or without documented atrial arrhythmia recurrence, with improvement by 21.5 and 26.8, respectively.

Conclusion

PAF ablation using a standardized CLOSE workflow resulted in consistent improvements in QoL. The improved QoL was observed regardless of atrial arrhythmia recurrence likely reflecting the low residual arrhythmia burden in patients with documented recurrence identified only on TTM.

AFEQT Scores Through 12 Months AFEQT Domain Baseline 12 Months Change from Baseline* Daily Activities 59.2 85.3 26.0 Treatment Concerns 62.2 88.1 26.0 Controlling PAF 50.2 87.8 37.5 Symptoms 63.7 89.0 25.1 Symptoms Relieved 52.0 88.4 36.3 Overall AFEQT Score 61.3 87.2 25.7 *only includes patients who completed both baseline and 12 month AFEQT questionnaire

1242The flexibility, ease of using, and leaving curve of a standardized ablation index workflow for catheter ablation of paroxysmal atrial fibrillation

Background/Introduction

The ‘CLOSE’ protocol, incorporating standardized ablation index (AI) targets in conjunction with defined inter-tag distance (ITD) has been shown to improve the acute and long-term success of pulmonary vein isolation (PVI) when treating paroxysmal atrial fibrillation (PAF). The reproducibility and learning curve for this protocol has not been studied.

Purpose

To assess the acute and long-term efficacy of CLOSE PVI across multiple operators (n = 37) in the 17-centre European study ‘VISTAX’.

Methods

329 patients with PAF (61.8% male, 61.3 ± 10.1 years) underwent PVI according to the CLOSE protocol, with target AI values for each lesion of ≥400 on the posterior wall and ≥550 on the anterior wall, and target ITD of ≤6mm. Each 3-dimensional electroanatomic map was evaluated at a core lab where adherence to each of these criteria was assessed. 281/329 patients (85.1%) fulfilled all standardized workflow requirements and were adjudicated as having their PVI per-protocol (PP). First pass PVI and acute effectiveness (adenosine-proof first pass PVI at 30-minute challenge) were recorded. Clinical effectiveness was assessed as freedom from atrial arrhythmia recurrence through 12 months recorded via transtelephonic monitoring (weekly and symptomatically), in addition to holter and electrocardiogram monitoring during 3,6,12 month follow up visits. Learning curve analysis was evaluated on all investigators.

Results

First pass PVI rates were similar in the overall (86%) and PP cohorts (85%), as was acute effectiveness (82% in both cohorts). Freedom from atrial arrhythmia at 12 months too was identical for both cohorts (79%). Total procedure time and total ablation time decreased by an average 8 minutes and 10 minutes respectively after the first procedure and then showed further steady decreases over the number of ablations performed by the investigator (Figure).  The procedural efficiencies and clinical success were reproducible across different centers. No significant deviations were found from individual sites.

Conclusion

The standardized CLOSE workflow is reproducible across centres, and is ‘forgiving’ without impacting on high efficacy of almost 80%. The learning curve is short, suggesting that the excellent clinical results can be replicated widely and easily.

Abstract Figure. Learning Curves- Procedure & Ablation

917Appropriate shocks in WCD patients - Results from the Austrian WCD registry

Background

The wearable cardioverter-defibrillator (WCD) is a temporary treatment option for patients at high risk for sudden cardiac death (SCD) and/or for patients in whom implantation of a cardioverter defibrillator (ICD) is temporarily not possible.

Purpose

To investigate incidence and predictors of appropriate WCD shocks.

Methods

We performed a retrospective analysis of all patients with appropriate shocks delivered by a WCD in the cohort of the Austrian WCD registry between 2010 and 2018. Within this dataset, we identified predictors within the baseline characteristics, the indication for the WCD and preceding alarms automatically recorded by the WCD.

Results: Baseline

Within 879 registered in the Austrian WCD registry, 31 patients (3,5%) received appropriate WCD shocks due to ventricular tachycardia (VT) or ventricular fibrillation (VF). Compared to the total cohort, shocked patients were elder (mean age 67 ± 14 vs. 60 ± 14 years, p = 0,001) and the percentage of female patients was lower (11% vs. 21%, p = 0,262). The mean baseline LVEF at prescription was 33 ± 15% in the population with appropriate shocks compared to 32 ± 14% in the all-over cohort (p = ns).

In the Austrian WCD population, 378/879 patients had a WCD due to secondary prevention. Within this cohort 5,6% (21/378) had shocks for VT/VF again, compared to 10/501 (2%) shocked patients in the primary prevention cohort. 31/879 (3.5%) patients received 57 appropriate shocks, the per patient shock rate was 2 [1;5]. These shocks were induced by 25 ventricular tachycardia and 26 times ventricular fibrillation.

The octagenarians with 11% (7/34) shocked patients, showed a significant higher likelihood to receive shocks (p = 0,008) as well as the cohort of secondary preventive prescribed WCD-patients (p = 0,007). There were more shocks in patients, when prescribed with a WCD due to ICD associated infections (p = 0,001), when used as a bridge to ICD (p = 0,042) and in patients with ongoing risk stratification (p = 0,009).

Looking through the automatically recorded alarms preceding a WCD shock, shocked patients experienced significantly more often non sustained VTs (p < 0,0005) and sustained VTs that were haemodynamically tolerated and did not require a treatment (p < 0,0005).

Conclusion

The WCD is effective in preventing SCD and an important risk stratification tool. We identified advanced age, patients with either already confirmed indication for ICD implantation (either temporary contraindication for implantation or temporary explantation) or risk stratification of an unclear cardiomyopathy, the cohort of secondary prevention and preceding nsVTs and stable VTs as predictors for appropriate WCD therapies.

P2280Incidence and predictors of alarms in patients with wearable cardioverter defibrillator (WCD) - results of the Austrian WCD Registry

Background

The wearable cardioverter-defibrillator (WCD) is a treatment option for patients at high risk for ventricular arrhythmia, either if the risk is potentially reversible or if an implantable cardioverter defibrillator (ICD) implantation is currently not possible.

Methods

We performed a retrospective analysis of all alarms in the cohort of the Austrian WCD registry between 2010 and 2018. Type of arrhythmias was assessed by independent review of two cardiologists.

Results

25.540 automatically recorded ECGs in 605 patients (68%) were analyzed. 1125 ECGs showed sustained ventricular arrhythmias in 117 patients, 65 ECGs showed non sustained VTs.

24.415 ECGs in 488 patients showed inadequate alarms Reasons for inadequate alarms were artefacts (97%), pacemaker or t-wave oversensing (0,3%) and in 2,3% atrial fibrillation or SVTs.

5860 manually recorded ECGs in 608 patients (68%) were analyzed. 298 (5%) of these ECGs showed following arrhythmias: atrial fibrillation (34,7%), SVTs (28%), sinustachycardia (10,7%), non sustained VTs (12%) and sustained VTs or sustained slow VTs (6,7%), premature ventricular beats or bradycardia was identified in 8%. The remaining 5562 ECGs (95%) showed normal sinus rhythm.

Of the 895 patients (60±14 years, 20% female), 34 (3,8%) received a total of 65 automatically triggered shocks (median 2; range 1–5). 31/895 (3.5%) patients received 57 appropriate shocks (median 1, range 1–5) for 49 arrhythmic events, whereas 7/895 (0.8%) patients received 8 inappropriate shocks (median 1, range 1–2).

44 events were successfully terminated with the first shock (85,7%) and 4 events were terminated with the second shock. In one patient, a shock treatment for VF was not successful. The time from event onset to shock was median 60 [40; 1187] sec.

The median time from WCD prescription to a shock event was 8 days [1–151]. 23/ 34 patients (68%) received their first WCD shock within 30 days.

Seven patients (0.8%) received a total of nine inappropriate shocks due to different reasons: artefacts (2 inappropriate shocks), non-shockable rhythms (asystole, weak action, 3 shocks) and atrial fibrillation with a bundle branch block in two cases. In one patient VF terminated spontaneously before the WCD treatment was delivered.

Conclusion

The WCD is an effective treatment option in patients with a high SCD risk but it also triggers a significant amount of alarms. Although many inadequate alarms occurred, adequate alarms led to arrhythmia detection such as in VT/VF events which were successfully terminated by the WCD in 3,4% of patients.

P2614Comparison of global longitudinal strain and ejection fraction in correlation to NT-proBNP in ischemic and non-ischemic heart failure

Background

In chronic heart failure (CHF) NT-proBNP and left ventricular ejection fraction (LVEF) by echocardiography are standard diagnostic as well as follow-up markers and are known to correlate with prognosis. Speckle-tracking echocardiography is a more recent technique to quantify myocardial deformation as a measurement of left ventricular function with potential benefits over LVEF.

Purpose

The purpose of this investigation was to analyse the cross-sectional relationship between 2D speckle tracking-derived global longitudinal strain (GLS) and NT-proBNP plasma levels in a prospective cohort of ischemic and non-ischemic CHF patients.

Methods

We enrolled 205 patients with chronic heart failure. Major inclusion criteria were age over 18 years, stable disease with absence of unplanned hospitalization or change in medication or device therapy in the previous month or major surgery in the previous 3 months. CHF treatment had to be according to the recommendations of the ESC CHF guidelines 2016 and LVEF had to be below 50%.

Patient history, physical examination and an extensive echocardiography exam were performed. Lab results included NT-proBNP. Manual longitudinal strain was calculated using EchoPAC (General Electric Medical Systems, Horten, Norway) by a single and blinded examiner. LVEF was measured using Simpson's biplane method.

Results

205 patients included in the study. The baseline characteristics included mean age 65.0 years and 75% male. Mean GLS was −9.6% (SD ±4.5%) and median NT-proBNP 1269.5 (IQR 379.5–2759.5) ng/ml. The CHF aetiology was 70.0% ischemic vs 30.0% non-ischemic.

There was a significant negative correlation between GLS and NT-proBNP (Pearson r=0.239, p=0.029), this was not significant for LVEF and NT-proBNP (Pearson r=0.149, p=0.228).In a multivariate regression analysis adjusted for age, sex, NYHA classification and HF aetiology, GLS remained significantly correlated with NT-proBNP (adjusted beta-coefficient= 0.289, p=0.011). Furthermore, in contrast to LVEF, GLS showed a significant correlation to NT-proBNP in patients with ischemic (Pearson r=0.266, p=0.049) as well as non-ischemic aetiology of heart failure (Pearson r=0.434, p=0.034).

Conclusion

Global longitudinal strain, not LVEF, was significantly correlated with NT-proBNP in patients with CHF, independently of age, sex, symptoms or heart failure aetiology. This shows that speckle-tracking might be superior to LVEF for the assessment of left ventricular function in CHF.

[Catheter ablation of persistent atrial fibrillation : pulmonary vein isolation, ablation of fractionated electrograms, stepwise approach or rotor ablation?]

Catheter ablation is an established treatment option for patients with atrial fibrillation (AF). In paroxysmal AF ablation, pulmonary vein isolation alone is a well-defined procedural endpoint, leading to success rates of up to 80% with multiple procedures over 5 years of follow-up. The success rate in persistent AF ablation is significantly more limited. This is partly due to the rudimentary understanding of the substrate maintaining persistent AF. Three main pathophysiological concepts for this arrhythmia exist: the multiple wavelet hypothesis, the concept of focal triggers, mainly located in the pulmonary veins and the rotor hypothesis. However, the targets and endpoints of persistent AF ablation are ill-defined and there is no consensus on the optimal ablation strategy in these patients. Based on these concepts, several ablation approaches for persistent AF have emerged: pulmonary vein isolation, the stepwise approach (i.e. pulmonary vein isolation, ablation of fractionated electrograms and linear ablation), magnetic resonance imaging (MRI) and rotor-based approaches. Currently, persistent AF ablation is a second-line therapy option to restore and maintain sinus rhythm. Several factors, such as the presence of structural heart disease, duration of persistent AF and dilatation and possibly also the degree of fibrosis of the left atrium should influence the decision to perform persistent AF ablation.

Untersuchungen über Komplexbildungen von Dehydrogenasen mit Coenzymanalogen / Investigations on Complex Formation of Dehydrogenases with Coenzyme Analogues

The coenzyme analogue nicotinamide 5-iodouracil-dinucleotide was synthesized by condensation of the two mononucleotides with dicyclohexylcarbodiimide in aqueous pyridine. The enzymatic properties of this compound were compared with those of the nicotinamide-uracil-dinucleotide. Both coenzyme analogues reacted slowly when functioning as a hydrogen carrier in enzymatic tests. The properties were similar to those of nicotinamide-benzimidazole-dinucleotide. The difference spectrum between the intact coenzyme analogue and its mononucleotides showed that the intramolecular interaction between the functional and non-functional moiety was smaller than that in NAD. The interaction corresponded to that of nicotinamide-benzimidazole-dinucleotide. The fluorescence excitation spectrum did not show any energy transfer from the non-functional iodouracil to the dihydronicotinamide part of the analogue. Difference spectra between the coenzyme - enzymecomplex and the two isolated components indicated that the unfolded dihydrocoenzyme was bound to the active site of lactate- and alcohol-dehydrogenase, respectively. Furthermore, they showed aromatic interaction of the non-functional part with parts of the protein. Introduction of iodine into the nicotinamide-uracil-dinucleotide did not remarkably alter the behavior of the analogues. As the iodine is bound very strongly to the coenzyme analogue, it may be useful for X-Ray-investigations of the dehydrogenases.

Zum Mechanismus der kollinearen Abstrahlung der 2. Stokes-Linie bei der stimulierten Raman-Streuung / On the collinear Emission of 2nd Order Stokes Radiation in Stimulated Raman Scattering

An attempt is made to check by experiment the assumption that the 2nd order Stokes radiation in collinear direction is generated from the primary light by the same mechanism as the 1st order radiation. If is found that the 1st order Stokes beam does not have a sufficiently high intensity over a sufficiently long interaction lenght to explain the generation of the observed 2nd order Stokes radiation as exclusively attributable to this mechanism. An alternative theory is advanced according to which the molecular vibrations generated in the 1st order Stokes process contribute to this effect in the small-signal range. This allows a more plausible explanation of the experimental results. The experiments were performed with benzene at λ = 0.53 μm because this substance exhibits strong stimulated Raman scattering without selffocusing at this wavelenght.

Near Field Communication-based telemonitoring with integrated ECG recordings

OBJECTIVES

Telemonitoring of vital signs is an established option in treatment of patients with chronic heart failure (CHF). In order to allow for early detection of atrial fibrillation (AF) which is highly prevalent in the CHF population telemonitoring programs should include electrocardiogram (ECG) signals. It was therefore the aim to extend our current home monitoring system based on mobile phones and Near Field Communication technology (NFC) to enable patients acquiring their ECG signals autonomously in an easy-to-use way.

METHODS

We prototypically developed a sensing device for the concurrent acquisition of blood pressure and ECG signals. The design of the device equipped with NFC technology and Bluetooth allowed for intuitive interaction with a mobile phone based patient terminal. This ECG monitoring system was evaluated in the course of a clinical pilot trial to assess the system's technical feasibility, usability and patient's adherence to twice daily usage.

RESULTS

21 patients (4f, 54 ± 14 years) suffering from CHF were included in the study and were asked to transmit two ECG recordings per day via the telemonitoring system autonomously over a monitoring period of seven days. One patient dropped out from the study. 211 data sets were transmitted over a cumulative monitoring period of 140 days (overall adherence rate 82.2%). 55% and 8% of the transmitted ECG signals were sufficient for ventricular and atrial rhythm assessment, respectively.

CONCLUSIONS

Although ECG signal quality has to be improved for better AF detection the developed communication design of joining Bluetooth and NFC technology in our telemonitoring system allows for ambulatory ECG acquisition with high adherence rates and system usability in heart failure patients.

Nomograms based on the Tyrol screening data of 2,271 patients to predict prostate cancer biopsy positivity

203

Background: There are no published nomograms that predict prostate cancer in a screened population. We describe three nomograms that predict for prostate cancer on biopsy derived from a large screening population.

Methods: Patients from the Tyrol screening study of known age, total prostate-specific antigen (tPSA), digital rectal examination (DRE), prostate volume, and percent free PSA (%fPSA), and who underwent an initial prostate biopsy from January 1992 to June 2004, were included (n=2271). Multivariable logistic regression models were used to develop the biopsy positivity predictive nomograms: nomogram 1- age, DRE, tPSA; nomogram 2- age, DRE, tPSA, prostate volume; nomogram 3- age, DRE, tPSA, prostate volume, %fPSA. The predictive accuracy of the models was assessed in terms of discrimination and calibration. External validation of the nomograms was performed by comparison with a urologically referred population of patients who underwent prostate biopsy (n=599).

Results: All three nomograms discriminated well between biopsy positive and biopsy negative patients for both the screening and urologically referred cohorts (nomogram 3 better than nomogram 2 better than nomogram 1). All three nomograms were well calibrated internally, but the nomograms under-predicted the probability of a positive biopsy in the urologically referred cohort.

Conclusions: Our nomogram based on age, total PSA, and DRE has a good predictive ability to differentiate between screened patients that will show cancer on initial prostate biopsy and those that will not. Adding prostate volume and percent free PSA improves this predictive power further. All three nomograms under-predict prostate cancer in a urologically referred cohort. These simple nomograms may be of value in counseling screened men with raised PSA and/or abnormal DRE regarding the need for biopsy.

No significant financial relationships to disclose.

Prognostic factors of cancer recurrence and progression in non-muscle-invasive urothelial carcinoma: A multicenter study of over 4,300 patients

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Background: The outcomes of patients with non-muscle-invasive urothelial carcinoma of the bladder (NMIUCB) remain poorly understood. The aim of our study was to identify prognostic factors of cancer recurrence and progression in patients with primary UCB.

Methods: We performed a combined analysis on individual data from 4,325 patients with primary NMIUCB.

Results: Within a median follow-up of 64 months, 1,960 patients (45.4%) experienced disease recurrence, 498 (11.5%) experienced progression to muscle-invasive stage, 1,155 (26.7%) died of any cause, and 310 (7.2%) died of their cancer. In multivariable Cox regression analysis, advanced age, higher grade, larger tumor size, higher number of tumors, number of prior recurrences, and type of intravesical therapy were independent predictors of disease recurrence and progression. While treatment intravesical chemotherapy was only associated with decreased/delayed cancer recurrence, intravesical BCG therapy was associated with decreased/delayed cancer recurrence and progression. The predictive accuracies of the models for recurrence and progression were 63.5% and 71.3%, respectively.

Conclusions: Even in a heterogenous patient population, BCG therapy appears to decrease frequency and delay time to cancer recurrence and progression in patients with NMIUCB. Predictive tools based on combination of multiple clinical variables which capture the biological and clinical potential of nonmuscle-invasive disease could help with patient counseling and individualized risk assessment for adjuvant intravesical therapy and clinical trial design.

[Table: see text]

No significant financial relationships to disclose.

Mobile phone-based surveillance of cardiac patients at home

We tested the reliability, acceptability and feasibility of a home-monitoring system for cardiac patients. Each participant was equipped with a mobile phone, an automatic blood pressure device and a digital weight scale. In total, 20 patients (14 patients with chronic heart failure, six patients with hypertension; mean age 50 years, standard deviation [SD] 14) were monitored for 90 days each. They were asked to measure their blood pressure, pulse and body weight every day, and to transfer the data together with the dosage of medication to the telemonitoring server using wireless Internet technology in the mobile phone. The physician in charge received email alerts when reported data fell outside pre-defined limits. The patients' compliance with the system was high. During a cumulative monitoring period of 1,735 days, there were 2,040 data transfer sessions, a mean of 102 per patient (SD 43). The mean percentage of successful data transfers was 83% (SD 22). The stability of the telemonitoring system was 98%, meaning that patient data transfer was almost always possible. The accessibility of the secure web server for physicians was above 99%. The web-based home-monitoring system was reliable and easy to handle for both patients and health care professionals. It may be a useful tool for patients with heart failure as well as hypertensive patients.

Automated and manufacturer independent assessment of the battery status of implanted cardiac pacemakers by electrocardiogram analysis

According to international standards, cardiac pacemakers have to indicate the status of their batteries upon magnet application by specific stimulation patterns. The purpose of this study has been to assess whether this concept can be used as a basis for automated and manufacturer independent examination of the depletion level of pacemakers in the framework of a collaborative telemedical pacemaker follow-up system. A prototype of such a system was developed and tested in a real clinical environment. Electrocardiograms (ECGs) were recorded during magnet application and automatically processed to extract the specific stimulation patterns. The results were used to assign each signal a corresponding pacemaker status: "ok," "replace" or "undefined," based on the expected behavior of the devices as specified by the manufacturer. The outcome of this procedure was compared to the result of an expert examination, resulting in a positive predictive value of 100% for the detection of ECGs indicating pacemaker status "ok." The method can, therefore, be utilized to quickly, safely and manufacturer neutrally classify cases into the categories "ok" and "needs further checking," which - in a telemedical setting - may be used to increase the efficiency of pacemaker follow-up procedures in the future.