ECAP-controlled closed-loop versus open-loop SCS for the treatment of chronic pain: 36-month results of the EVOKE blinded randomized clinical trial

INTRODUCTION

The evidence for spinal cord stimulation (SCS) has been criticized for the absence of blinded, parallel randomized controlled trials (RCTs) and limited evaluations of the long-term effects of SCS in RCTs. The aim of this study was to determine whether evoked compound action potential (ECAP)-controlled, closed-loop SCS (CL-SCS) is associated with better outcomes when compared with fixed-output, open-loop SCS (OL-SCS) 36 months following implant.

METHODS

The EVOKE study was a multicenter, participant-blinded, investigator-blinded, and outcome assessor-blinded, randomized, controlled, parallel-arm clinical trial that compared ECAP-controlled CL-SCS with fixed-output OL-SCS. Participants with chronic, intractable back and leg pain refractory to conservative therapy were enrolled between January 2017 and February 2018, with follow-up through 36 months. The primary outcome was a reduction of at least 50% in overall back and leg pain. Holistic treatment response, a composite outcome including pain intensity, physical and emotional functioning, sleep, and health-related quality of life, and objective neural activation was also assessed.

RESULTS

At 36 months, more CL-SCS than OL-SCS participants reported ≥50% reduction (CL-SCS=77.6%, OL-SCS=49.3%; difference: 28.4%, 95% CI 12.8% to 43.9%, p<0.001) and ≥80% reduction (CL-SCS=49.3%, OL-SCS=31.3%; difference: 17.9, 95% CI 1.6% to 34.2%, p=0.032) in overall back and leg pain intensity. Clinically meaningful improvements from baseline were observed at 36 months in both CL-SCS and OL-SCS groups in all other patient-reported outcomes with greater levels of improvement with CL-SCS. A greater proportion of patients with CL-SCS were holistic treatment responders at 36-month follow-up (44.8% vs 28.4%), with a greater cumulative responder score for CL-SCS patients. Greater neural activation and accuracy were observed with CL-SCS. There were no differences between CL-SCS and OL-SCS groups in adverse events. No explants due to loss of efficacy were observed in the CL-SCS group.

CONCLUSION

This long-term evaluation with objective measurement of SCS therapy demonstrated that ECAP-controlled CL-SCS resulted in sustained, durable pain relief and superior holistic treatment response through 36 months. Greater neural activation and increased accuracy of therapy delivery were observed with ECAP-controlled CL-SCS than OL-SCS.

TRIAL REGISTRATION NUMBER

NCT02924129.

Arrhythmogenic right ventricular cardiomyopathy – evolution of electrocardiographic markers during long-term follow-up prior to ascertainment of diagnosis

Background

Depolarization and repolarization abnormalities are part of the diagnostic Task Force Criteria of 2010 (TFC2010) for arrhythmogenic right ventricular cardiomyopathy (ARVC). These abnormalities are thought to be progressive but have also been described as dynamic and sometimes reversible. Evolution of ECG abnormalities prior to clinical ARVC diagnosis is poorly studied.

Objective

To assess the evolution of ECG depolarization and repolarization characteristics in patients with ARVC prior to diagnosis and to identify markers of disease progression at a preclinical stage.

Methods

353 patients with definite ARVC from Sweden, Denmark, the Netherlands and Canada with at least one 12-lead digital ECG (65% males, 67% probands, 56% mutation carriers, median age at diagnosis 42 [IQR 29–53] years and median age at first ECG 44 [30–55] years) were included. Digital ECGs were extracted from regional ECG archives. ECGs with left bundle branch block, ventricular pacing or recorded either prior to 15 years of age or after heart transplantation were excluded. Remaining 6,871 ECGs were digitally processed and automatically analysed using the Glasgow algorithm. Median values for overall QRS duration, terminal activation delay (TAD) in lead V1 as well as amplitudes of QRS-T-components in precordial leads per patient per year were used for analyses and graphically represented using Lowess smoothing with cubic splines (Figure 1). Blue lines indicate smoothed conditional mean with 95% confidence interval (shadow). Time “0” (red line) indicates the time when TFC2010 were fulfilled for definite diagnosis.

A database of 18,564 anonymized digital ECGs (58% males, median age at latest ECG 41 years [IQR 32–52]) who were in contact with health care during 2020–2021 was processed using the same exclusion criteria and signal-processing methodology as in the ARVC group and used as a reference (black line).

Results

TAD in lead V1 and overall QRS duration demonstrated a significant increase years before ARVC diagnosis, and significant reductions were seen in QRS-T voltages measured as R wave amplitude, QRS amplitude (the absolute sum of R wave and S wave), and T wave amplitude (Table 1 and Figure 1). The changes were seen in all precordial leads, not only the right-sided, and visually diverging from the controls.

Conclusion

Development of the ARVC ECG phenotype started several years before diagnosis and continued afterwards. QRS duration and TAD increased, QRS voltages decrease, and T wave amplitude decreased eventually leading to T wave inversion. These changes might be visually assessed but also measured with available ECG software. These findings may be clinically useful in the screening and follow-up of ARVC relatives.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Governmental funding of clinical research (ALF), Region Ostergotland, Sweden.The Swedish Heart-Lung Foundation.

HLA-II-Associated HIV-1 Adaptation Decreases CD4+ T-Cell Responses in HIV-1 Vaccine Recipients

Epitopes with evidence of HLA-II-associated adaptation induce poorly immunogenic CD4+ T-cell responses in HIV-positive (HIV+) individuals. Many such escaped CD4+ T-cell epitopes are encoded by HIV-1 vaccines being evaluated in clinical trials. Here, we assessed whether this viral adaptation adversely impacts CD4+ T-cell responses following HIV-1 vaccination, thereby representing escaped epitopes. When evaluated in separate peptide pools, vaccine-encoded adapted epitopes (AE) induced CD4+ T-cell responses less frequently than nonadapted epitopes (NAE). We also demonstrated that in a polyvalent vaccine, where both forms of the same epitope were encoded, AE were less immunogenic. NAE-specific CD4+ T cells had increased, albeit low, levels of interferon gamma (IFN-γ) cytokine production. Single-cell transcriptomic analyses showed that NAE-specific CD4+ T cells expressed interferon-related genes, while AE-specific CD4+ T cells resembled a Th2 phenotype. Importantly, the magnitude of NAE-specific CD4+ T-cell responses, but not that of AE-specific responses, was found to positively correlate with Env-specific antibodies in a vaccine efficacy trial. Together, these findings show that HLA-II-associated viral adaptation reduces CD4+ T-cell responses in HIV-1 vaccine recipients and suggest that vaccines encoding a significant number of AE may not provide optimal B-cell help for HIV-specific antibody production. IMPORTANCE Despite decades of research, an effective HIV-1 vaccine remains elusive. Vaccine strategies leading to the generation of broadly neutralizing antibodies are likely needed to provide the best opportunity of generating a protective immune response against HIV-1. Numerous studies have demonstrated that T-cell help is necessary for effective antibody generation. However, immunogen sequences from recent HIV-1 vaccine efficacy trials include CD4+ T-cell epitopes that have evidence of immune escape. Our study shows that these epitopes, termed adapted epitopes, elicit lower frequencies of CD4+ T-cell responses in recipients from multiple HIV-1 vaccine trials. Additionally, the counterparts to these epitopes, termed nonadapted epitopes, elicited CD4+ T-cell responses that correlated with Env-specific antibodies in one efficacy trial. These results suggest that vaccine-encoded adapted epitopes dampen CD4+ T-cell responses, potentially impacting both HIV-specific antibody production and efficacious vaccine efforts.

Longer left ventricular activation time is associated with lower mortality and risk of heart failure hospitalization in CRT recipients

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): ALF Governmental Funding within the Swedish health care system

Introduction

Cardiac resynchronization therapy (CRT) is an established treatment for heart failure in selected patients. Longer QRS duration has been showed to correlate to clinical outcome, but measures global activation time, rather than the left ventricular dyssynchrony that CRT aims to correct. This study therefore evaluated the incremental value of using Left Ventricular Activation Time (LVAT) for prediction of outcome after CRT.

Methods

Medical records of 445 patients receiving CRT implants at a large-volume tertiary care center were retrospectively evaluated. Digital electrocardiograms (ECG) before and after CRT implantation were collected and ECG parameters were analysed in relation to a primary composite endpoint of time to heart failure hospitalisation or death from any cause. LVAT was defined as time from QRS onset to maximum positive deflection in lead V6 (Figure 1).

Results

Patients were followed for up to 6 years (median 2.7), during which 147 patients (33%) reached the primary endpoint (93 deaths and 103 heart failure hospitalisations). LVAT was measured pre-implant (median 71ms [58-88]) and post-implant (median 74ms [57-96]). There was no CRT-mediated reduction in LVAT (delta -2.3ms +/-31ms, p=0.27). When divided into quartiles, preoperative LVAT had a significant association with clinical outcome (HR 0.76 [0.64-0.90] per increasing quartile, p=0.001), also shown in a median-split Kaplan Meier curve (Figure 2, log rank p=0.001). Multivariate hazard ratio (adjusted for relevant clinical variables) was 0.83; [0.69-0.99]; p=0.047). There was an interaction between LVAT and ECG morphology (p=0.033), and when ECG groups were analysed separately, there was only a significant result for those with native left bundle branch block morphology. Post-implant LVAT, or change in LVAT, did not correlate with the primary endpoint (p=0.25 and p=0.38 respectively.

Conclusion

In CRT recipients, longer pre-implant LVAT was associated with lower risk of heart failure hospitalisation and death during a follow-up of up to 6 years. This association was mainly seen in patients with native LBBB prior to implant. No association was seen with post-CRT LVAT and clinical outcome. If confirmed in prospective trials, evaluation of preoperative LVAT may help optimise patient selection for CRT.

Durability of Clinical and Quality-of-Life Outcomes of Closed-Loop Spinal Cord Stimulation for Chronic Back and Leg Pain: A Secondary Analysis of the Evoke Randomized Clinical Trial

Importance

Chronic pain is debilitating and profoundly affects health-related quality of life. Spinal cord stimulation (SCS) is a well-established therapy for chronic pain; however, SCS has been limited by the inability to directly measure the elicited neural response, precluding confirmation of neural activation and continuous therapy. A novel SCS system measures the evoked compound action potentials (ECAPs) to produce a real-time physiological closed-loop control system.

Objective

To determine whether ECAP-controlled, closed-loop SCS is associated with better outcomes compared with fixed-output, open-loop SCS at 24 months following implant.

Design, Setting, and Participants

The Evoke study was a double-blind, randomized, controlled, parallel arm clinical trial with 36 months of follow-up. Participants were enrolled from February 2017 to 2018, and the study was conducted at 13 US investigation sites. SCS candidates with chronic, intractable back and leg pain refractory to conservative therapy, who consented, were screened. Key eligibility criteria included overall, back, and leg pain visual analog scale score of 60 mm or more; Oswestry Disability Index score of 41 to 80; stable pain medications; and no previous SCS. Analysis took place from October 2020 to April 2021.

Interventions

ECAP-controlled, closed-loop SCS was compared with fixed-output, open-loop SCS.

Main Outcomes and Measures

Reported here are the 24-month outcomes of the trial, which include all randomized patients in the primary and safety analyses. The primary outcome was a reduction of 50% or more in overall back and leg pain assessed at 3 and 12 months (previously published).

Results

Of 134 randomized patients, 65 (48.5%) were female and the mean (SD) age was 55.2 (10.6) years. At 24 months, significantly more closed-loop than open-loop patients were responders (≥50% reduction) in overall pain (53 of 67 [79.1%] in the closed-loop group; 36 of 67 [53.7%] in the open-loop group; difference, 25.4% [95% CI, 10.0%-40.8%]; P = .001). There was no difference in safety profiles between groups (difference in rate of study-related adverse events: 6.0 [95% CI, -7.8 to 19.7]). Improvements were also observed in health-related quality of life, physical and emotional functioning, and sleep, in parallel with opioid reduction or elimination. Objective neurophysiological measurements substantiated the clinical outcomes and provided evidence of activation of inhibitory pain mechanisms.

Conclusions and Relevance

ECAP-controlled, closed-loop SCS, which elicited a more consistent neural response, was associated with sustained superior pain relief at 24 months, consistent with the 3- and 12-month outcomes.

Implementation and Evaluation of Gradient Strip Antimicrobial Susceptibility Testing in US Public Health Laboratories to Respond to Resistant Gonorrhea

BACKGROUND

Gradient strip antimicrobial susceptibility testing using Etest is conducted by local public health jurisdictions participating in the Strengthening the US Response to Resistant Gonorrhea (SURRG) program to inform public health responses to resistant gonorrhea. Proficiency testing results across the participating laboratories were analyzed and a comparison of Etest with the agar dilution method was conducted.

METHODS

Laboratories participating in SURRG performed Etest for azithromycin (AZM), cefixime (CFX), and ceftriaxone (CRO). Concurrence between minimum inhibitory concentrations (MICs) obtained with Etest versus the agar dilution method using corresponding isolates was defined as ±1 double dilution. Specific levels of reduced susceptibility were termed "alerts" and included isolates with the following MICs: ≥2.0 μg/mL (AZM), ≥0.25 μg/mL (CFX), and ≥0.125 μg/mL (CRO). Categorical (alert/nonalert) agreement was calculated for MICs determined using Etest and agar dilution methods.

RESULTS

Strengthening the US Response to Resistant Gonorrhea laboratories had high proficiency testing scores (≥98%) and low levels of interlaboratory variations in MICs. The overall concurrence of MICs (essential agreement) determined using agar dilution, and Etest was 96% (CRO), 96% (CFX), and 95% (AZM). Depending on the antibiotic tested, between 27% and 66% of isolates with alert MICs determined by Etest also had alert MICs using the reference agar dilution methodology; however, most of these alert MICs were detected at threshold levels.

CONCLUSIONS

This study demonstrates that MICs produced by SURRG laboratories using Etest have a high level of concurrence with agar dilution. Although confirmation of specific alert MICs varied, Etest facilities rapid detection and response to emerging resistant gonorrhea.

Impact of Human Leukocyte Antigen-Associated Polymorphisms on Variability of HIV-1 Accessory and Regulatory Proteins

HIV-1 escapes by acquiring mutations that differentially influence the course of infection. Unlike HIV-1 structural and enzymatic proteins, it remains elusive what extent the host immune-mediated selection pressure influences the variability of the accessory (Vif, Vpu, Vpr, and Nef) and regulatory (Tat and Rev) proteins. To address this, we analyzed the viral sequences encoding accessory and regulatory proteins from 446 human leukocyte antigen (HLA)-typed, chronically HIV-1 subtype B-infected, and treatment-naive individuals in Japan. We observed that Vpu and Vpr were the most and least polymorphic proteins with the average Shannon entropy scores of 0.63 and 0.38, respectively. Phylogenetically corrected methods identified a total of 161 HLA-associated polymorphisms; whereby Nef and Vpu had the highest (26.6%) and lowest (1.2%) proportion of amino acid sites associated with HLA-class I alleles, respectively. These results add further insight on the role of HLA-mediated selection pressure on HIV-1 sequence polymorphisms of HIV-1 accessory and regulatory proteins.

Clinical risk factors and P wave indices in prediction of atrial fibrillation development during long-term follow-up after acute ST-segment elevation myocardial infarction

Introduction

In patients with high thromboembolic risk detection of atrial fibrillation (AF) is crucial for implementation of proper anticoagulation therapy, which highlights the need for identification of patients at risk for AF. P wave indices reflect atrial structural abnormalities linked to AF development.

Purpose

We aimed to assess the value of clinical risk factors and P wave indices in prediction of incident AF after acute ST-segment elevation myocardial infarction (STEMI) in patients undergoing primary percutaneous intervention (PCI).

Methods

Study sample comprised of 2277 consecutive patients with STEMI admitted to a tertiary care hospital for primary PCI from 2007 to 2010. SWEDEHEART registry was used as the source of information regarding clinical characteristics and events during index admission. Patients without known AF at discharge were included in the current study (n=1837, mean age 65±12 years, 30% females). AF in follow-up (median 9, interquartile range 25–75% (IQR) 7–10 years) was documented by linkage with the Swedish National Patient Register and Swedish Cause-of-Death Register. The closest available ECGs prior to STEMI (median 448, interquartile rate 25–75% 112–1390 days before STEMI) were extracted from the regional electronic ECG databases and automatically processed using Glasgow algorithm. P-wave duration, PR interval, P-wave frontal axis and P terminal force in lead V1 (PTF-V1) were assessed. PTF-V1 &gt;40 mm*ms was considered abnormal.

Results

In follow-up incident AF was documented in 285 patients (15.4%). In univariate Cox regression analysis age, hypertension, history of myocardial infarction, heart failure, history of stroke, smoking status, P wave duration &gt;120 ms, PR interval and abnormal PTF-V1 predicted the AF development during follow-up (Table). In multivariate Cox regression analysis in which significantly associated variables were included only age (hazard ratio (HR) 1.07, 95% CI 1.05–1.08, p&lt;0.001) and abnormal PTF-V1 (HR 1.49, 95% CI 1.08–2.05, p=0.015, Figure) remained independent predictors of incident AF.

Conclusion

In patients with acute STEMI incident AF developed during long-term follow-up after discharge from hospital was strongly associated with age and atrial structural abnormalities reflected as abnormal PTF-V1 on pre-STEMI ECG which might serve as a tool in risk stratification of STEMI patients in regard to AF development.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Scholarship grant from Swedish Institute. Table 1Figure 1

ECG markers of atrial abnormalities are not associated with new onset atrial fibrillation in patients with acute ST-segment elevation myocardial infarction

Introduction

New onset AF is a known complication in patients with acute ST-segment elevation myocardial infarction (STEMI). However, whether new-onset AF is linked to atrial structural abnormalities or has different underlying mechanisms is not fully clarified.

Purpose

We aimed to assess the association of P wave indices as ECG markers of atrial structural abnormalities with new-onset AF in STEMI patients undergoing primary percutaneous intervention (PCI).

Methods

Study sample comprised of 2277 consecutive patients with STEMI admitted to a tertiary care hospital for primary PCI from 2007 to 2010. SWEDEHEART registry was used as the source of information regarding clinical characteristics and events during index admission, including new-onset AF. The closest available ECGs prior to STEMI (median 448, interquartile rate 25–75% 112–1390 days before STEMI) were extracted from the regional electronic ECG databases and automatically processed using Glasgow algorithm. Patients with sinus rhythm ECGs were included in the current analysis (n=1481, mean age 68±12 years, 33% females). P-wave duration, PR interval, P-wave frontal axis and P terminal force in lead V1 (PTF-V1) were assessed. PTF-V1 &gt;40 mm*ms was considered abnormal.

Results

Paroxysmal AF prior to STEMI was known in 77 patients (5.2%). Among patients without pre-existing AF (n=1404), new-onset AF during hospital admission was identified in 102 patients (6.9%). Patients with new-onset AF were older than those without AF history (74±9 vs 67±12 years, p&lt;0.001), but did not differ in regard to other clinical characteristics. In univariate logistic regression analysis P wave duration as continuous variable, P wave duration &gt;120 ms and PR interval were significantly associated with new onset AF (Table 1). However, after adjustment for age both, P wave duration &gt;120 ms (odds ratio (OR) 1.20, 95% CI 0.77–1.89, p=0.418) and PR interval (OR 1.01, 95% CI 1.00–1.01, p=0.068), failed to demonstrate the significant association with new onset AF while age (OR 1.06, 95% CI 1.04–1.08, p&lt;0.001) remained an independent risk factor for AF development.

Conclusion

In patients with acute STEMI new onset AF developed during hospital admission is common and strongly associated with age. P wave indices failed to demonstrate the significant association with new onset AF thus indicating that atrial structural abnormalities are unlikely the underlying cause of AF development in acute STEMI.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Scholarship grant from Swedish Institute. Table 1

Twelve-Month results from multicenter, open-label, randomized controlled clinical trial comparing differential target multiplexed spinal cord stimulation and traditional spinal cord stimulation in subjects with chronic intractable back pain and leg pain

Background

Spinal cord stimulation (SCS) is a well‐established treatment for chronic intractable pain of the trunk and/or limbs; however, low back pain (LBP) is difficult to treat using traditional SCS. Differential Target Multiplexed spinal cord stimulation (DTM SCS) is an advanced approach inspired from animal studies demonstrating improved pain‐related behavior and pain‐relevant biological processes.

Objective

The purpose of this study was to compare the effectiveness of DTM SCS and traditional SCS in treating chronic LBP and leg pain (LP).

Methods

This prospective, postmarket randomized controlled trial compared DTM SCS to traditional SCS in patients with chronic LBP and LP. Primary end point was LBP responder rate (percentage of subjects with ≥ 50% relief) at 3 months. Noninferiority and superiority were assessed. Other outcomes included mean change in back and leg pain, responder rates, disability, global health, satisfaction, and safety profile throughout the 12‐month follow‐up.

Results

One hundred twenty‐eight subjects were randomized across 12 centers (67 DTM SCS and 61 traditional SCS). Of the 94 patients implanted, 46 subjects in each group completed the 3‐month assessment. LBP responder rate of 80.1% with DTM SCS was superior to 51.2% with traditional SCS (p = 0.0010). Mean LBP reduction (5.36 cm) with DTM SCS was greater than reduction (3.37 cm) with traditional SCS (p < 0.0001). These results were sustained at 6 months and 12 months. Safety profiles were similar between treatment groups.

Conclusion

Superiority of DTM SCS compared with traditional SCS for chronic LBP was demonstrated. Clinical improvements provided by DTM SCS were sustained over 12 months and are expected to significantly impact the management of chronic LBP.

Relationship between atrial fibrillatory rate based on analysis of a modified base-apex surface electrocardiogram analysis and the results of transvenous electrical cardioversion in horses with spontaneous atrial fibrillation

OBJECTIVES

To compare the atrial fibrillatory rate (AFR) derived from a local right atrial intracardiac recording (RA-FR) and from a single-lead surface electrocardiogram (ECG) during atrial fibrillation (AF) and to evaluate the correlation with transvenous electrical cardioversion (TVEC) threshold (in Joules), number of shocks and cardioversion success rate in horses.

ANIMALS

ECGs and clinical records of horses with AF treated by TVEC. Horses were included if a simultaneous recording of the right atrial intracardiac electrogram and a modified base-apex ECG were available.

MATERIALS AND METHODS

Clinical records of horses with AF treated by TVEC were reviewed. Three-minute long episodes of simultaneous electrograms and surface ECG during AF were selected for analysis and compared using Bland-Altman analysis. The mean RA-FR was measured from the deflections on the intracardiac electrogram, while the AFR was extracted from the surface ECG using spatiotemporal QRS and T-wave cancellation.

RESULTS

Seventy-three horses satisfied the inclusion criteria. The mean difference between RA-FR and AFR was -13 fibrillations per minute (fpm), the 95% limits of agreement were between -66 and 40 fpm, and there was a moderate (ρ = 0.65) correlation between RA-FR and AFR (p < 0.001). Neither RA-FR nor AFR appeared to influence the TVEC cardioversion threshold or the number of TVEC shocks applied.

CONCLUSIONS

The AFR may allow non-invasive long-term monitoring of AF dynamics. Neither RA-FR nor AFR could be used to predict the minimal defibrillation threshold for TVEC.

HLA tapasin independence: broader peptide repertoire and HIV control

Human leukocyte antigen (HLA) class I allotypes vary in their ability to present peptides in the absence of tapasin, an essential component of the peptide loading complex. We quantified tapasin dependence of all allotypes that are common in European and African Americans (n = 97), which revealed a broad continuum of values. Ex vivo examination of cytotoxic T cell responses to the entire HIV-1 proteome from infected subjects indicates that tapasin-dependent allotypes present a more limited set of distinct peptides than do tapasin-independent allotypes, data supported by computational predictions. This suggests that variation in tapasin dependence may impact the strength of the immune responses by altering peptide repertoire size. In support of this model, we observed that individuals carrying HLA class I genotypes characterized by greater tapasin independence progress more slowly to AIDS and maintain lower viral loads, presumably due to increased breadth of peptide presentation. Thus, tapasin dependence level, like HLA zygosity, may serve as a means to restrict or expand breadth of the HLA-I peptide repertoire across humans, ultimately influencing immune responses to pathogens and vaccines.

Progressive ECG changes over time in arrhythmogenic right ventricular cardiomyopathy precede diagnosis and continue – indices of disease substrate development?

Background

Depolarization and repolarization abnormalities are common in arrhythmogenic right ventricular cardiomyopathy (ARVC), and are included in the diagnostic 2010 Task Force criteria (TFC2010). However, first ARVC symptoms commonly occur before ECG abnormalities reach the diagnostic thresholds and the time course of ECG abnormalities during initial phase of the disease remains obscure. Regional digital ECG archives allow computerized signal-processing and assessment of ECG phenotype during different disease phases, including the time prior to ascertainment of ARVC diagnosis.

Purpose

We aimed to assess the natural course of ECG characteristics associated with ARVC, hypothesizing that ARVC is a progressive disease and that ECG parameters progress over time due to disease substrate development.

Methods

Definite ARVC patients with at least one digital ECG recruited in three tertiary care hospitals in Sweden and Denmark were included (n=102, 66% males, 68% probands, 52% carrying a pathogenic genetic variant, 74% ICD carriers and 25% physically active &gt;4 hours/week). Median age at diagnosis was 41 years (IQR 30–55). 12-lead digital ECGs were extracted from the regional ECG archives, containing all recordings in the hospital catchment areas since 1988. After excluding ECGs with heart rate &lt;40 or &gt;100/min, left bundle branch block or ventricular pacing, and those recorded prior to 14 years of age, the remaining 2067 ECGs were digitally processed and automatically analyzed using the Glasgow algorithm (median 3 [IQR 0–9] ECGs prior to diagnosis and 6 [IQR 2–14] ECGs during follow-up). Overall QRS duration as well as the right precordial lead indices exemplified by the lead V2 (terminal activation delay [TAD], area under the T-wave [T-wave area] and R-prime amplitude) were calculated and graphically represented using generalized additive model (GAM) with cubic splines (Figure 1). A median value for each measurement per patient per year was used for analysis. Blue line indicates smoothed conditional mean with 95% confidence interval (shadow). Time “0” (red line) indicates the time when TFC2010 criteria were fulfilled.

Results

Marked and consistent changes are seen in all studied depolarization and repolarization parameters over 10 years preceding ARVC diagnosis and continue afterwards. TAD demonstrates gradual increase, while T-wave area demonstrates consistent decrease over time before and after diagnosis indicating amplitude reduction and transition to T-wave inversion. The R-prime curve indicates that the terminal part of QRS complex demonstrate abnormalities first late in the course of the disease (Figure 1).

Conclusion

Electrocardiographic ARVC phenotype appears to become detectable long before the time of ARVC diagnosis indicating the progressive nature of ARVC and may explain arrhythmic events that may occur during the subclinical phase before ECG criteria are fulfilled.

Funding Acknowledgement

Type of funding source: None

Impact of new onset atrial fibrillation on long-term prognosis in patients with acute ST-segment elevation myocardial infarction

Introduction

New onset AF is a known complication in patients with acute ST-segment elevation myocardial infarction (STEMI). However, whether new-onset AF affects the long-term prognosis to the same extent as pre-existing AF is not fully clarified and prescription of oral anticoagulants (OAC) in patients with new-onset AF remains a matter of debates.

Purpose

We aimed to assess the impact of new-onset AF in STEMI patients undergoing primary percutaneous intervention (PCI) on outcome during long-term follow-up in comparison with pre-existing AF and to evaluate effect of OAC therapy in patients with new-onset AF on survival.

Methods

Study sample comprised of 2277 consecutive patients with STEMI admitted to a tertiary care hospital for primary PCI from 2007 to 2010 (age 66±12 years, 70% male). AF prior to STEMI was documented by record linkage with the Swedish National Patient Register and review of ECGs obtained from the digital archive containing ECGs recorded in the hospital catchment area since 1988. SWEDEHEART registry was used as the source of information regarding clinical characteristics and events during index admission, including new-onset AF and OAC at discharge. All-cause mortality was assessed using the Swedish Cause-of-Death Register 8 years after discharge.

Results

AF prior to STEMI was documented in 177 patients (8%). Among patients without pre-existing AF (n=2100), new-onset AF was identified in 151 patients (7%). Patients with new-onset AF were older than those without AF history (74±9 vs 65±12 years, p&lt;0.001), but did not differ in regard to other clinical characteristics. Among 2149 STEMI survivors discharged alive, 523 (24%) died during 8 years of follow-up. OAC was prescribed at discharge in 45 (32%) patients with new onset AF and in 49 (31%) patients with pre-existing AF, p=0.901. In a univariate analysis, both new-onset AF (HR 2.18, 95% CI 1.70–2.81, p&lt;0.001) and pre-existing AF (HR 2.80, 95% CI 2.25–3.48, p&lt;0.001) were associated with all-cause mortality, Figure 1. After adjustment for age, gender, cardiac failure, diabetes, BMI and smoking history, new-onset AF remained an independent predictor of all-cause mortality (HR 1.40, 95% CI 1.02–1.92, p=0.037). OAC prescribed at discharge in patients with new-onset AF was not significantly associated with survival (univariate HR 0.86, 95% CI 0.50–1.50, p=0.599).

Conclusion

New-onset AF developed during hospital admission with STEMI is common and independently predicts all-cause mortality during long-term follow-up after STEMI with risk estimates similar to pre-existing AF. The effect of OAC on survival in patients with new-onset AF is inconclusive as only one third of them received OAC therapy at discharge.

Kaplan-Meier survival curve

Funding Acknowledgement

Type of funding source: None

Interatrial Block Predicts Atrial Fibrillation and Total Mortality in Patients with Cardiac Resynchronization Therapy

Background

Interatrial block (IAB) and abnormal P-wave terminal force in lead V1 (PTFV1) are electrocardiographic (ECG) abnormalities associated with new-onset atrial fibrillation (AF) and death. However, their prognostic importance has not been proven in CRT recipients with advanced heart failure (HF).

Purpose

To assess if IAB and abnormal PTFV1 are associated with new-onset AF or death in CRT recipients.

Methods

CRT recipients without AF history before CRT implantation were included (n=210, median age 67 years, 80% male, 55% ischemic heart disease, 70% NYHA Class III/IV, median LVEF 25%, 51% CRT-P). Automated analysis of P-wave duration (PWD) and morphology classified patients as having either No IAB (PWD &lt;120ms), Partial IAB (pIAB: PWD ≥120 ms, positive P waves in leads II and aVF) or Advanced IAB (aIAB: PWD ≥120 ms and biphasic or negative P wave in leads II or aVF). PTFV1 &gt;0.04 mm·s was considered abnormal. Cox regression analyses adjusted for age, NYHA Class, ischemic etiology of HF, LBBB, LVEF and CRT-P vs. CRT-D were performed to assess the impact of IAB and abnormal PTFV1 on the primary endpoint new-onset AF, death or heart transplant (HTx) and the secondary endpoint death or HTx at 5 years of follow up.

Results

IAB was found in 45% (34% pIAB and 11% aIAB) and was associated with both the primary (HR 1.9, 95% CI 1.2–2.9, p=0.004) and the secondary (HR 2.1, 95% CI 1.2–3.4, p=0.006) endpoints. Abnormal PTFV1 was not associated with outcome. See Forest plot for adjusted HRs for individual P-wave indices.

Conclusions

IAB is associated with new-onset AF and death in CRT recipients and may be helpful in risk stratification in the context of HF management. Abnormal PTFV1 did not demonstrate any prognostic value in the setting of CRT-treated patients with advanced HF.

Forest plot

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Swedish Heart and Lung Foundation

BURST(able): A Retrospective, Multicenter Study Examining the Impact of Spinal Cord Stimulation with Burst on Pain and Opioid Consumption in the Setting of Salvage Treatment and "Upgrade"

BACKGROUND

Loss of efficacy (LOE) is a well-known phenomenon associated with spinal cord stimulation (SCS) and is the leading cause of explant. Although recent advances in neuromodulation have resulted in a decreased incidence of LOE, it still occurs. Intuition suggests that when LOE ensues, switching to a different SCS therapy/platform could potentially be a viable clinical option; however, there are no data presently available to validate this theory.

OBJECTIVES

The primary objective was to evaluate the efficacy of SCS therapy rotation with DeRidder Burst on reversing LOE. A subobjective was to evaluate the hypothesis that the body will treat a novel waveform as a "different therapy" when introduced for the first time, regardless of the setting.

STUDY DESIGN

Multicenter, retrospective.

SETTING

Private practice.

METHODS

A total of 307 patients with ongoing SCS therapy had a de novo therapy conversion to DeRidder Burst via surgical revision or software upgrade. Each cohort was split into 2 additional arms/subcohorts: those who were failing their SCS (salvage) versus those who were reporting success with their SCS system but were looking for increased pain relief (upgrade). This study was physician-directed and not commercially funded.

RESULTS

There were statistically significant reductions in Numeric Rating Scale, percent pain relief in both surgical revision and software upgrade arms. A statistical reduction in opioid dosing was seen in the overall population and the salvage group. Larger reductions in pain/opioid consumption were observed in the surgically revised group when the revision was performed earlier. Subgroup analysis showed both salvage and upgrade groups restored treatment efficacy irrespective of time or the previous frequency/waveform.

LIMITATIONS

The retrospective nature of the study and the inability to eliminate potential confounding variables when evaluating the use of opioids in the study population.

CONCLUSIONS

LOE is an unfortunate occurrence with few evidence-based solutions presently available to reverse it. Our findings suggest that implementing D-Burst stimulation may be an effective option for treating LOE, as well as potentially reducing opioid consumption, regardless of the prior SCS system.

Early monomorphic ventricular tachycardia is associated with increased long-term mortality in STEMI

Background

Malignant ventricular arrhythmias occurring early during ST-elevation myocardial infarction (STEMI) are known to markedly contribute to increased in-hospital mortality, but not to influence the long-term prognosis. However recent data advocate differential approach to the type of arrhythmia and indicate long-term hazard of monomorphic ventricular tachycardia (VT).

Purpose

We aimed to evaluate the prognostic value of monomorphic VT compared to non-monomorphic VT or ventricular fibrillation (VF) during the first 48 hours of STEMI in non-selected cohort of STEMI patients admitted for primary PCI.

Methods

Consecutive STEMI patients admitted to a tertiary care hospital for primary PCI during 2007–2010 were included. The Swedish national SWEDEHEART registry was used for assessment of clinical characteristics and the presence of VT/VF during index admission. The occurrence and type of VT/VF during the first 48 hours from symptom onset were verified in medical records. Information on all-cause mortality endpoint 8 years after STEMI was obtained from the Swedish Cause of Death Register.

Results

In total, 2277 patients were included (age 66±12 years, 70% male). Early monomorphic VT during index STEMI was documented in 35 (1.5%) and non-monomorphic VT or VF – in 115 (5.1%) patients. Patients with monomorphic VT had similar clinical characteristics compared to those with non-monomorphic VT/VF with a trend of higher prevalence of history of myocardial infarction by index admission among those with monomorphic VT (31% vs 21%, p=0.256). In total, 22 (63%) patients with monomorphic VT and 43 (37%) with non-monomorphic VT/VF died by 8 years of follow up (p=0.011). Monomorphic VT was associated with a higher risk of all-cause mortality compared to non-monomorphic VT/VF in a univariate analysis (HR 2.03, 95% CI 1.21–3.39, p=0.007) and after adjustment for age and history of myocardial infarction (HR 1.74, 95% CI 1.02–2.97, p=0.041) (Figure).

Conclusion

Monomorphic VT during the first 48 hours of STEMI is associated with a higher risk of all-cause mortality compared to non-monomorphic VT/VF and deserves further studies in order to refine risk stratification strategies.

Survival after STEMI by VT/VF &lt;48 hours

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): The Swedish Heart-Lung Foundation

10-kHz Spinal Cord Stimulation for Chronic Postsurgical Pain: Results From a 12-Month Prospective, Multicenter Study

Background

Chronic postsurgical pain (CPSP) can be caused by peripheral nerve injury (PNI) resulting from surgical procedures and has a significant neuropathic component. This prospective, single‐arm study was conducted to document the effectiveness of 10‐kHz spinal cord stimulation (10‐kHz SCS) as a treatment for patients with CPSP.

Methods

Subjects with CPSP who were refractory to conventional medical interventions and reported pain scores of ≥5 cm on a 10‐cm VAS underwent trial stimulations lasting up to 14 days. Epidural leads were implanted at locations appropriate for the primary area of pain, and trials resulting in ≥40% pain relief were considered successful. Subjects with successful trials underwent implantation with a permanent 10‐kHz SCS system and were followed for 12 months after implantation.

Results

Of the 34 subjects who underwent trial stimulation, 1 was withdrawn early and 29 (87.9%) had a successful trial and received a permanent implant. After 12 months of treatment, the mean VAS score decreased by 6.5 cm, the response rate was 88.0% (22/25), and 18 subjects (62.1%) were remitters with VAS scores sustained at ≤3.0 cm. Scores for all components of the short‐form McGill Pain Questionnaire 2 were significantly reduced, including affective descriptors of pain. Pain catastrophizing and vigilance, patient function, physical and mental well‐being, and sleep quality all improved over the course of the study. No neurologic deficits reported in the study.

Conclusions

10‐kHz SCS is effective and tolerated in patients with CPSP, and further study of its clinical application in this population is warranted.

The potential role of HLA-I associated adaptation in elevated risk of infection among HIV-1 STEP study vaccine recipients

The biological mechanism(s) underlying the elevated risk of HIV-1 acquisition among vaccine recipients in Merck STEP study remain unclear. HIV-1 frequently adapts to CD8 T cell responses, leading to the accumulation of adapted epitopes (AE). Recently, we demonstrated that in chronic HIV infection, CD8 T responses skewed by HLA-I associated adaptation enhanced HIV trans-infection of CD4 T cells by dendritic cells (DCs). However, whether adaptation in HIV vaccines induces a pro-inflammatory status and aids in potentiating infection is unknown. Using in-vitro studies, we evaluated whether an enhanced CD4 T cell trans-infection mediated by AE-specific CD8 T cells could be a potential biological mechanism for the observed increased risk of HIV acquisition in the Step Study. We found that CD8 T cells responding to AE demonstrated a higher capacity in promoting DCs maturation than non-adapted epitope (NAE) (p=0.007). Additionally, DCs matured by AE-specific CD8 T cells, showed a higher trend in inducing HIV trans-infection of CD4 T cells in each of the four vaccinee samples tested. We also analyzed the potential in-vivo impact of adaptation on the rate of infection among vaccine recipients in the STEP study. Our data showed that vaccine recipients with high adaptation to the vaccine immunogen were at an increased risk of HIV acquisition compared to recipients with medium/low adaptation or placebos (HR=2.98, p=0.02, high (n=21), medium (n=639), low (n=192) and placebo (n=865)). Taken together, our results show that in STEP study, AE-specific CD8 T cells may have contributed to an enhanced risk of HIV-1 acquisition by promoting viral trans-infection of CD4 T cells by DC. These findings have important implications for future HIV vaccine design.

Clustering of Four-Component Unitary Fermions

Ab initio nuclear physics tackles the problem of strongly interacting four-component fermions. The same setting could foreseeably be probed experimentally in ultracold atomic systems, where two- and three-component experiments have led to major breakthroughs in recent years. Both due to the problem's inherent interest and as a pathway to nuclear physics, in this Letter we study four-component fermions at unitarity via the use of quantum Monte Carlo methods. We explore novel forms of the trial wave function and find one which leads to a ground state of the eight-particle system whose energy is almost equal to that of two four-particle systems. We investigate the clustering properties involved and also extrapolate to the zero-range limit. In addition to being experimentally testable, our results impact the prospects of developing nuclear physics as a perturbation around the unitary limit.

Long-term safety and efficacy of closed-loop spinal cord stimulation to treat chronic back and leg pain (Evoke): a double-blind, randomised, controlled trial

BACKGROUND

Spinal cord stimulation has been an established treatment for chronic back and leg pain for more than 50 years; however, outcomes are variable and unpredictable, and objective evidence of the mechanism of action is needed. A novel spinal cord stimulation system provides the first in vivo, real-time, continuous objective measure of spinal cord activation in response to therapy via recorded evoked compound action potentials (ECAPs) in patients during daily use. These ECAPs are also used to optimise programming and deliver closed-loop spinal cord stimulation by adjusting the stimulation current to maintain activation within patients' therapeutic window. We aimed to examine pain relief and the extent of spinal cord activation with ECAP-controlled closed-loop versus fixed-output, open-loop spinal cord stimulation for the treatment of chronic back and leg pain.

METHODS

This multicentre, double-blind, parallel-arm, randomised controlled trial was done at 13 specialist clinics, academic centres, and hospitals in the USA. Patients with chronic, intractable pain of the back and legs (Visual Analog Scale [VAS] pain score ≥60 mm; Oswestry Disability Index [ODI] score 41-80) who were refractory to conservative therapy, on stable pain medications, had no previous experience with spinal cord stimulation, and were appropriate candidates for a spinal cord stimulation trial were screened. Eligible patients were randomly assigned (1:1) to receive ECAP-controlled closed-loop spinal cord stimulation (investigational group) or fixed-output, open-loop spinal cord stimulation (control group). The randomisation sequence was computer generated with permuted blocks of size 4 and 6 and stratified by site. Patients, investigators, and site staff were masked to the treatment assignment. The primary outcome was the proportion of patients with a reduction of 50% or more in overall back and leg pain with no increase in pain medications. Non-inferiority (δ=10%) followed by superiority were tested in the intention-to-treat population at 3 months (primary analysis) and 12 months (additional prespecified analysis) after the permanent implant. This study is registered with ClinicalTrials.gov, NCT02924129, and is ongoing.

FINDINGS

Between Feb 21, 2017, and Feb 20, 2018, 134 patients were enrolled and randomly assigned (67 to each treatment group). The intention-to-treat analysis comprised 125 patients at 3 months (62 in the closed-loop group and 63 in the open-loop group) and 118 patients at 12 months (59 in the closed-loop group and 59 in the open-loop group). The primary outcome was achieved in a greater proportion of patients in the closed-loop group than in the open-loop group at 3 months (51 [82·3%] of 62 patients vs 38 [60·3%] of 63 patients; difference 21·9%, 95% CI 6·6-37·3; p=0·0052) and at 12 months (49 [83·1%] of 59 patients vs 36 [61·0%] of 59 patients; difference 22·0%, 6·3-37·7; p=0·0060). We observed no differences in safety profiles between the two groups. The most frequently reported study-related adverse events in both groups were lead migration (nine [7%] patients), implantable pulse generator pocket pain (five [4%]), and muscle spasm or cramp (three [2%]).

INTERPRETATION

ECAP-controlled closed-loop stimulation provided significantly greater and more clinically meaningful pain relief up to 12 months than open-loop spinal cord stimulation. Greater spinal cord activation seen in the closed-loop group suggests a mechanistic explanation for the superior results, which aligns with the putative mechanism of action for spinal cord stimulation and warrants further investigation.

FUNDING

Saluda Medical.

P5683Incremental hazard associated with the degree of advanced intaratrial block in cardiac resynchronization therapy treated heart failure patients

Background

Advanced Inter Atrial Block (aIAB) reflects a disruption of the electrical signal between the atria and develops gradually. It has been predictive of atrial fibrillation and death in patients with Cardiac Resynchronization Therapy (CRT). A higher number of inferior ECG leads demonstrating biphasic P waves was proposed as a measure of aIAB severity, however its prognostic importance has not been proven.

Purpose

To assess if aIAB is associated with poor prognosis in CRT recipients and to see if there is a dose-response relationship between the aIAB severity and the outcome.

Methods

CRT recipients with sinus rhythm on digitally stored preoperative ECG were included (n=565, median age 70 years, 82% male, 55% ischemic heart failure [HF] etiology, 54% CRT-P, 70% left bundle branch block [LBBB]). Automated analysis of P-wave duration [PWD] and morphology in leads II, aVF and III assessed as positive, negative or biphasic +/− was performed and patients classified as having either No IAB (PWD <120ms), Partial IAB (pIAB, PWD ≥120 ms, positive P-waves in inferior leads), aIAB (PWD ≥120 ms and biphasic p-waves in one of the inferior leads). aIAB patients were further stratified by the presence of biphasic P waves in only one (aIAB-1) or more (aIAB-2) inferior leads. Extreme aIAB was defined as biphasic P waves in lead II and negative in leads III and aVF. Cox regression analyses adjusted for age, gender, NYHA class, ischemic HF etiology, left ventricular ejection fraction, LBBB, CRT-P versus CRT-D and PWD were performed to assess the impact of aIAB and its types on the endpoint hospitalization for HF or death at 5 years of follow up.

Results

Advanced IAB was observed in 65 patients (10 with aIAB-1, 53 with aIAB-2 and 2 with extreme aIAB) and pIAB in 151. No clinically relevant significant differences in baseline characteristics were observed between groups. Compared to the NoIAB group, aIAB-2 and extreme aIAB independently predicted the combined endpoint with adjusted HR=1.82 (95% CI 1.14–2.90, p-value 0.012) and HR=4.70 (95% CI 1.10–20.16, p-value 0.037), respectively.

Conclusion

Advanced IAB is associated with HF admissions or death from any cause in HF patients treated with CRT. Our findings indicate dose-response relationship between the severity of aIAB and the outcome.

P2661Ventricular fibrillation during acute STEMI is not associated with early repolarization pattern on ECG recorded prior to the index ischemic episode

Background

Generally considered as benign, ECG early repolarization (ER) pattern was recently claimed to be an indicator of increased susceptibility to fatal arrhythmias during acute ischemia. The victims of sudden cardiac death have been reported to have high prevalence of ER comparing with survivors of acute coronary event.

We aimed to test the association between the ER pattern on resting ECG recorded prior to ST-elevation myocardial infarction (STEMI) and the risk of ventricular fibrillation (VF) during acute phase of STEMI in non-selected population of STEMI patients.

Methods

For STEMI patients admitted to a tertiary care hospital for primary PCI during 2007–2010 (n=2286), all ECGs recorded prior to the date of admission with STEMI were extracted from a digital archive. The latest ECG recorded prior to the index STEMI was used for analysis.

After excluding ECGs with paced rhythm and intraventricular blocks with QRS duration ≥120ms, the remaining ECGs were processed using the Glasgow algorithm allowing automatic ER detection. The association between ER-pattern on historical ECG and VF during the first 48 hours of STEMI was tested using logistic regression.

Results

Historical ECGs were available for 1584 patients; 124 of them were excluded due to a paced rhythm or wide QRS, leaving 1460 patients available for analysis (age 68±12 years, 67% male). The time from historical ECG to STEMI was 16 (IQR 4–49) months. ER pattern was present on historical ECG in 272 of 1460 (18.6%) (ER+ group), among them in 90 (33%) – in inferior leads, in 116 (43%) – in lateral leads, in 66 (24%) – both in inferior and lateral leads.

ER+ patients were younger both at the time of historical ECG (64±13 vs 66±19; p=0.041) and at the time of STEMI (67±12 vs 68±12; p=0.033), and had lower heart rate on historical ECG (68±12 vs 73±15; p<0.001) than ER- patients. ER+ and ER- groups did not differ regarding clinical characteristics and conventional ECG measurements. The course of STEMI was complicated by VF in 106 patients (17 of them from ER+ group). The occurrence of VF during STEMI was not associated with ER-pattern on historical ECG (OR 0.875 95% CI 0.518–1.479; p=0.618). There was no association of ER pattern with VF before reperfusion (OR 0.54 95% CI 0.25–1.21; p=0.135) or reperfusion VF (OR 1.28 95% CI 0.55–3.01; p=0.569). No association was observed with regard to localization (inferior or lateral) of ER-pattern either.

Conclusion

In a non-selected population of STEMI patients the presence of ER-pattern on ECG recorded prior to the acute coronary event was not associated with VF during the first 48 hours of STEMI.

P5653Atrial fibrillation in arrhythmogenic right ventricular cardiomyopathy and its association with left atrial volume index

Background

Recent studies in arrhythmogenic right ventricular cardiomyopathy (ARVC) support atrial involvement in the disease progression and consider atrial fibrillation (AF) as one of the primary manifestations of ARVC. We aimed to assess clinical factors, components of 2010 Task Force criteria (TFC2010) and echocardiographic characteristics of atria associated with AF in the Scandinavian cohort of ARVC patients.

Methods

Study sample comprised of 106 definite ARVC patients by TFC2010 from three tertiary care centers participating in the Nordic ARVC Registry (33% females, median age at ARVC diagnosis 41 years [IQR 30–54 years]). No concomitant diseases were observed in 90 patients (85%) while 16 patients had one or more comorbidities: hypertension (n=6), diabetes mellitus (n=5), coronary artery disease (n=5) or congestive heart failure (n=9). AF was included in the registry protocol as a pre-specified clinical event and verified by processing of the electronic ECG databases which contains all ECG recordings from the involved hospitals catchment areas (earliest ECG from 1988). Left (LA) and right atrial (RA) dimensions were obtained by revisiting cardiac ultrasound examinations performed at the time of ARVC diagnosis. Association between AF and clinical characteristics was assessed using multivariable logistic regression analysis adjusted for age and gender.

Results

AF was diagnosed in 29 patients (27%) at a median age of 53 (IQR 38–63) years, 7 females (24%). Median time from ARVC diagnosis to AF onset was 8 (IQR 2–12) years. AF was univariately associated with right ventricular structural abnormalities meeting the definition of major imaging criterion by 2010TFC, ventricular tachycardia (VT) with superior axis (major criterion) and LA volume index. Significantly associated variables were included in a multivariate model, in which LA volume index (OR=1.07, 95% CI 1.01–1.14, p=0.021) and superior axis VT (OR=7.45, 95% CI 1.82–30.55, p=0.005) remained independently associated with AF. In receiver operating characteristic (ROC) curve analysis, LA volume index was significantly associated with AF (AUC=0.703, p=0.005) and with superior axis VT (AUC=0.703, p=0.021). AF was not associated with either RA volume index (univariate OR=1.03, 95% CI 0.99–1.06, p=0.203) or left ventricular ejection fraction (OR=0.97, 95% CI 0.92–1.03, p=0.299).

Conclusion

In patients with ARVC,AF is primarily associated with LA structural abnormalities without indication of RA involvement and is strongly associated with ventricular arrhythmias thus indicating parallel development of atrial and ventricular arrhythmic substrate.

P2247Pregnancies and childbirth in women with arrhythmogenic right ventricular cardiomyopathy are associated with low risk of ventricular arrhythmias

Background

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with a risk of ventricular arrhythmias (VA) and sudden cardiac death (SCD). Even though female patients with ARVC are considered to be at lower risk of VA, the impact of pregnancy and child birth on the arrhythmic risk and development of arrhythmic substrate in the context of ARVC remains insufficiently studied.

Objective

To assess the risk of VA in relation to childbirth in women with ARVC and the impact of multiple pregnancies on progression of arrhythmic manifestations of the disease.

Methods

The study included 186 females with definite ARVC (n=107, 70 probands) or unaffected mutation-carriers (n=79) with median age at the end of follow up of 48 (IQR 34–60) years. Seventeen women had 1, 59 had 2 and 29 had ≥3 child births by the age of 40 years. VA was defined as ventricular tachycardia, appropriate ICD therapy, aborted cardiac arrest or SCD. Proportions of patients who experienced VA by the age of 40 years were compared between nulliparous women (n=81) and those with reported child births (n=105). VA-free survival after accomplished pregnancies was assessed for women ≥40 years of age (n=119). Cumulative probability of VA for each pregnancy (n=230) was assessed from conception through 2 years after child birth and compared between those that occurred before ARVC diagnosis (Pre-Ds, n=164), after it (Post-Ds, n=11) and in unaffected mutation carriers (No-Ds, n=55).

Results

The nulliparous women had lower age at ARVC diagnosis (37 vs 44, p=0.023) and more often had VA before the age of 40 (31% vs 13%, p=0.003) while the number of child births was not related to the prevalence of VA (18% among women with 1 childbirth, 12% in those with 2 and 14% in those with 3 or more, ns). Three women suffered SCD before the age of 40. VA-free survival after 40 years did not differ between nulliparous and those who gave birth (Figure A). Only four pregnancy-related events were documented (Figure B): 1 in the Post-Ds group and three in the Pre-Ds group. No pregnancy-related events were reported in the unaffected mutation carriers.

Conclusion

In this Scandinavian cohort of women with ARVC we observed no indication of an increased VA risk either associated with pregnancies or during long-term follow up after the last child birth.

3056Orthogonal P wave morphology, traditional P wave indices, and the risk of atrial fibrillation in the general population

Background

A substantial portion of the risk of atrial fibrillation (AF) remains unexplained by the established risk markers. However, accurate assessment of AF risk would be beneficial, especially among stroke patients and subjects with symptoms attributable to arrhythmia.

Purpose

To study the associations of P-wave indices with AF risk in the general population.

Methods

Electrocardiograms, including orthogonal leads, of 7217 Finnish subjects aged over 30 years who took part in the baseline examinations of the Mini-Finland Health Survey in 1978–80, were digitized. P-wave duration, third-degree interatrial block (IAB), and P terminal force (PTF) were assessed manually. PTF was considered abnormal when the amplitude of the negative terminal part of the P wave in lead V1 was ≥0.1mV and duration ≥40ms. Third-degree IAB was defined as P-wave duration ≥120ms and the presence of ≥2 +/− biphasic P-waves in the inferior leads. Orthogonal P-wave morphology, which is related to left atrial breakthrough site and affected by atrial fibrosis (1 being considered benign, 2 borderline, and 3 shown to be associated with adverse events), was assessed with an automated algorithm, and ascertained manually. Subjects were followed 10 years for AF hospitalization and mortality. The risk of AF associated with P wave parameters was assessed using Cox proportional hazards models. Model discrimination improvement was quantified by the change in C index, integrated discrimination improvement (IDI), and continuous net reclassification improvement (cNRI).

Results

There were 5489 subjects (47.8% male, mean age 50.5 years) with a readable ECG, sinus rhythm, no missing data, and a predefined orthogonal P-wave morphology. Type 3 orthogonal P morphology (n=216, multivariate adjusted HR [maHR] 3.01, 95% confidence interval [CI] 1.66–5.45, p<0.001), P-wave duration ≥120ms (n=752, maHR 1.67, 95% CI 1.06–2.64, p=0.027), and third-degree IAB (n=103, maHR 3.18, 95% CI 1.66–6.13, p=0.001) were independently associated with the risk of AF in separate models. PTF did not independently predict AF. Subjects presenting with both Type 1 orthogonal P-wave morphology and P-wave duration <110ms (n=2074) were at low risk of AF (maHR 0.46, 95% CI 0.26–0.83, p=0.006) when compared to the rest of the subjects. The inclusion of variables combining orthogonal P-wave morphology and P-wave duration to a multivariate model including conventional AF risk factors improved C index from 0.815 to 0.832 (change 0.017, 95% CI 0.001–0.033), IDI was 0.012 (95% CI 0.006–0.051), and cNRI was 0.220 (95% CI 0.048–0.357).

Conclusions

P-wave indices and orthogonal P-wave morphology can be used to identify subjects at high and low risk for AF and possibly direct extensive AF screening protocols towards high-risk subjects in the general population in order to decrease the risk of cardioembolic stroke. However, more research is needed in this topic.

Acknowledgement/Funding

Finnish Medical Foundation, Onni and Hilja Tuovinen's Foundation, Orion Research Foundation, Paavo Nurmi's Foundation, Veritas Foundation

Pre-operative smoking history increases risk of infection in deep brain stimulation surgery

Although general risk of deep brain stimulation (DBS) therapy has been previously described, application of risk prediction at the individual patient level is still largely at the discretion of a treating physician or a multidisciplinary team. To explore associations between potentially modifiable patient characteristics and common adverse events following DBS surgery, we retrospectively reviewed consecutive adult patients who had undergone new DBS electrode placement surgeries at two high-volume tertiary referral centers between October 1997 and May 2018. Among 501 patients included in the analysis (mean age (SD), 64.6 (10.4) years), 165 (32.9%) were female, 67 (13.4%) had diabetes, 231 (46.1%) had hypertension, 25 (5.0%) were smokers, 27 (5.4%) developed an infection, 15 (3.0%) had intracranial or intraventricular hemorrhage, and 53 (10.6%) had an unplanned return to the operating room. Patients who developed a surgical site infection were more likely to report history of smoking before DBS surgery (16% vs 5%, p = 0.04). There was a trend for patients with hypertension to be at risk for intracranial hemorrhage (p = 0.11). In conclusion, this multicenter study demonstrated an association between preoperative smoking and increased risk of infection following new DBS implantation surgery. Counseling about this risk should be considered in preoperative evaluation of patients who are considering undergoing a DBS procedure.

Predictive capacity of prodromal symptoms in first-episode psychosis of recent onset

BACKGROUND

Both the nature and number of a wide range of prodromal symptoms have been related to the severity and type of psychopathology in the psychotic phase. However, at present there is an incomplete picture focused mainly on the positive pre-psychotic dimension.

AIM

To characterize the prodromal phase retrospectively, examining the number and nature of prodromal symptoms as well as their relationship with psychopathology at the onset of first-episode psychosis.

METHODS

Retrospective study of 79 patients experiencing a first-episode psychosis of less than 1 year from the onset of full-blown psychosis. All patients were evaluated with a comprehensive battery of instruments including socio-demographic and clinical questionnaire, IRAOS interview, PANSS, stressful life events scale (PERI) and WAIS/WISC (vocabulary subtest). Bivariate associations and multiple regression analysis were performed.

RESULTS

Regression models revealed that several prodromal dimensions of IRAOS (delusions, affect, language, behaviour and non-hallucinatory disturbances of perception) predicted the onset of psychosis, with positive (22.4% of the variance) and disorganized (25.6% of the variance) dimensions being the most widely explained.

CONCLUSION

In addition to attenuated positive symptoms, other symptoms such as affective, behavioural and language disturbances should also be considered in the definitions criteria of at-high-risk people.

Interatrial block in prediction of all-cause mortality after first-ever ischemic stroke

Background

Interatrial block (IAB) is an ECG indicator of atrial fibrosis related to atrial remodeling and thrombus formation thus leading to embolic stroke and increasing mortality. We aimed to assess weather IAB predicted all-cause mortality during 10 years after ischemic stroke.

Methods

The study sample comprised 235 patients (median age 74 (interquartile range 25–75% 65–81) years, 95 female) included in the Lund Stroke Register in 2001–2002, who had sinus rhythm ECGs at stroke admission. IAB was defined as a P-wave duration ≥120 ms without = partial IAB (n = 56) or with = advanced IAB (n = 41) biphasic morphology (±) in the inferior ECG leads. All-cause mortality was assessed via linkage with the Swedish Causes of Death Register.

Results

During follow-up 126 patients died (54%). Advanced IAB, but not partial, was associated with all-cause mortality in univariate Cox regression analysis (hazard ratio (HR) 1.98, 95% CI 1.27–3.09, p = 0.003). After adjustment for age, gender, severity of stroke measured by NIHSS scale and smoking status in patients without additional comorbidities advanced IAB independently predicted all-cause mortality (HR 7.89, 95% CI 2.01–30.98, p = 0.003), while in patients with comorbidities it did not (HR 1.01 95% CI 0.59–1.72, p = 0.966).

Conclusion

Advanced IAB predicted all-cause mortality after ischemic stroke, but mostly in patients without additional cardiovascular comorbidities.