bluuebunny/crossref_metadata_2025 huggingface dataset:
Single center experience of ICD implantation in pediatric age
Authors: Fumanelli J , Reffo E , Castaldi B , Sirico D , Di Salvo G , Leoni L
Published: May 2021

Funding Acknowledgements

Type of funding sources: None.

Background

Despite sudden cardiac death (SCD) is a rare phenomenon in pediatric age, the use of the implantable defibrillator (ICD) is progressively increasing in consideration of its life-saving role both in primary and in secondary prevention. Our work aims at evaluating our pediatric population from the point of view of distribution according to heart disease, indication and implantation technique. We also want to verify the protective role of the device in terms of SCD prevention, acute and chronic complications and to evaluate the role played by the device as a bridge to transplantation.

METHODS The retrospective study includes patients under the age of 18 underwent ICD implantation, following the guidelines and recommendations currently in force, in the time period between March 2000 and July 2020. Each device has been programmed in a personalized way based on age and cardiac pathology. The subjects were divided into three groups depending on the cardiac pathology. All patients were then followed-up by evaluating the appropriate shocks, the acute and chronic complications, especially the inappropriate shocks.

RESULTS The study group includes 55 subjects (41 males and 12 females) with a mean age of 14 ± 4 years and a mean follow-up time of 6.2 years. Thirty subjects had cardiomyopathy (CM), 15 electrical disease (ED) and 10 congenital heart disease (CHD) respectively. We used three different implantation technique (endocavitary, subcutaneus and hybrid technique) depending on the size of the patient and the cardiac anatomy.

There is no gender difference as regards the indication to the implant in primary/secondary prevention (67% in secondary prevention vs 33% in primary prevention). CHD and CM are mostly implanted in primary prevention. The rate of appropriate shocks in secondary prevention is higher than that in the primary one regardless of the disease.

Thirty-eight percent of patients received appropriate shock, of which 66.7% were patients who had received defibrillator as a bridge to heart transplant. Two patients (3.6%) received inappropriate shocks on supraventricular tachycardia. There were no acute post-implantation complications. None dysfunctions or ruptures of the shock catheter or episodes of T wave oversensing took place. Peri-procedural and post-transplant mortality is zero, except for a deceased subject awaiting transplantation due to congestive heart failure.

CONCLUSIONS The study confirmed the protective role of the device, in terms of prevention of sudden cardiac death, and its relevance as bridge to heart transplantation in pediatric age. An implant technique adequate to the size, age and heart disease of the patient associated with an adequate programming of the device significantly reduced inappropriate shocks in our patients.
The value of c-reactive protein to albumin ratio in predicting long term mortality among hfref patients with implantable cardiac defibrillators
Authors: Cinier G , Hayiroglu MI , Kolak Z , Tezen O , Yumurtas AC , Pay L , Eren S , Cetin T , Ozcan S , Turkkan C , Ozbilgin N , Tekkesin AI , Alper AT , Gurkan K
Published: May 2021

Funding Acknowledgements

Type of funding sources: None.

Background

Patients with heart failure with reduced ejection fraction (HFrEF) who received implantable cardiac defibrillator (ICD) still remain at high risk due to pump failure and comorbid conditions. C-reactive protein to albumin ratio (CAR) may be of value for identifying those with high risk for mortality despite ICD implantation.

Methods

Those who were implanted ICD for HFrEF in our institution between 2009 and 2019 were included. CAR was calculated as ratio of C-reactive protein (CRP) to serum albumin concentration. Patients were grouped into tertiles in accordance to CAR at the time of implantation. After follow up of 48 ± 35 months, survival times of tertiles were compared by using Kaplan-Meier survival method.

Results

Thousand and eleven patients constituted study population. Ischemic cardiomyopathy was primary diagnosis in 92.3%. Of those 14.5% had died after discharge. Patients in tertile 3 (T3) had higher risk of appropriate shock (19.3% vs 23.7% vs 38.0%) and mortality (4.2% vs 11.0% vs 28.5%) compared to those in other tertiles. Multivariable analysis revealed that when patients in T1 were considered as reference, both those in T2 and T3 had independently higher risk of appropriate shocks and mortality. These effects were consistent in the unadjusted and adjusted multivariable models.

Conclusion

Among patients with HFrEF and ICD, elevated CAR increased the risk of appropriate device shock and mortality at long term. Table 1Admission C-reactive protein/Albumin ratio (n = 1011)T1 (n = 337)T2 (n = 337)T3 (n = 337)Mortality, %4.211.028.5Mortality, HR (95% CI)Model 1: unadjusted1[Reference]3.85 (2.12 - 11.20)8.14 (2.46 - 28.56)Model 2: adjusted for age, sex1[Reference]3.20 (1.90 - 9.48)6.32 (2.12 - 20.12)Model 3: adjusted for comorbiditesa1[Reference]4.85 (2.06 - 14.12)10.86 (4.12 - 44.82)Model 4: adjusted for covariatesb1[Reference]2.72 (1.66 - 7.12)5.72 (2.04 - 18.05)Frequency, %19.323.738.0Appropriate shock, HR (95% CI)Model 1: unadjusted1[Reference]1.38 (0.44 - 6.88)2.48 (1.34 - 5.82)Model 2: adjusted for age, sex1[Reference]1.42 (0.48 - 7.24)3.02 (1.52 - 6.24)Model 3: adjusted for comorbiditesa1[Reference]1.34 (0.38 - 6.66)2.74 (1.40 - 7.28)Model 4: adjusted for covariatesb1[Reference]1.30 (0.34 - 5.68)2.28 (1.16 - 8.28)Cox proportional analysis and logistic regression models for the appropriate shock and the long-term mortality by CAR.Abstract Figure 1
Are His bundle pacing or His bundle plus coronary sinus pacing superior to conventional cardiac resynchronization therapy in improving heart failure? Results from a controlled study
Authors: Senes JS , Mascia GM , Bottoni NB , Oddone DO , Donateo PD , Grimaldi TG , Calogero CM , Bertolozzi JB , Puggioni EP , Brignole MB , Coluccia GC
Published: May 2021

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND

His bundle pacing (HBP), alone or optimized in association with coronary sinus pacing (HBP + LV) has recently been proposed as an alternative to conventional cardiac resynchronization therapy (CRT). However, there is lack of controlled studies that assessed clinical outcome.

METHODS

We did a single-centre, propensity-score matched, case-control study of comparison of HBP and HBP + LV versus conventional CRT in patients with heart failure (HF) and standard indications for CRT. The study group patients (n = 27) were consecutively enrolled in the years 2019. The control group patients (n = 27) were selected, by propensity score matching, among those CRT implantations performed, in the years 2015-2018.

RESULTS

In the active group, HBP alone was preferred in 12 (44%) patients, HBP + LV pacing in 12 (44%) patients and HBP failed in 3 (11%) patients. In the control group, conventional CRT was achieved in 26 (96%) patients and failed in one. Paced QRS width was shorter in the active than in the control group (128 ± 18 ms vs 148 ± 27 ms, p = 0.004). During a mean of 9.6 months of follow-up, in the intention-to-treat analysis, a composite clinical outcome of death, hospitalization for HF or worsening HF occurred in 3 (11%) in the active group and in 4 (15%) in the control group, p = 0.58. No difference was also observed with softer endpoints: NYHA class (1.9 ± 0.7 versus 2.1 ± 0.7), subjective improvement (74% versus 74%) and LV ejection fraction (40.7% versus 40.7%).

CONCLUSION

Compared with standard CRT, a shorter QRS width can be obtained with HBP alone or HBP + LV but we were unable to show a better clinical outcome. There is urgent need for large, randomized trials. Results by intention-to-treat analysisVariableActive groupN = 27Control groupN = 27PFollow-up, months9.7 ± 4.89.5 ± 4.50.90QRS width, ms128 ± 18148 ± 270.004Combined primary endpoint3 (11%)4 (15%)0.58• Death for HF10• Hospitalization for HF24• Worsening HF-1Subjective improvement20 (74%)20 (74%)1.24NYHA class1.9 ± 0.72.1 ± 0.70.15LV ejection fraction (%)40.7 ± 11.540.7 ± 12.21.00HF = heart failure; NYHA = New York Heart Association; LV = left ventricleAbstract Figure. Flow of active group patients
Reduction in QRS area correlates with hemodynamic response during CRT-device implantation
Authors: Ghossein MA , Van Stipdonk AMW , Salden FCWM , Engels EB , Zanon F , Westra S , Maass AH , Rienstra M , Prinzen FW , Vernooy K
Published: May 2021

Funding Acknowledgements

Type of funding sources: None.

Background Previous studies have shown that reduction in QRS area after cardiac resynchronization therapy (CRT) is associated with improved long-term clinical outcome.

Purpose To investigate whether reduction in QRS area is associated with hemodynamic improvement and whether QRS area reduction could be used for CRT optimization, with respect to LV lead position and device programming in individual patients.

Methods A total of 78 patients with indication for CRT were prospectively included in 4 hospitals. QRS area was calculated from vectorcardiograms that were synthesized from 12-lead ECG’s. Acute hemodynamic response was assessed invasively as the maximum rate of percentual left ventricular (LV) pressure (%LVdP/dtmax) rise.  QRS area reduction was studied in relation to LV-lead position (n = 26), proximal versus distal LV lead position (n = 27), and VV-delay (n = 25).

Results Combining all measurements in all patients showed a significant correlation between QRS area reduction and %LVdP/dTmax increase (R = 0.49, P < 0.0001).  Also, when one fixed routine implantation setting was used for each patient (lateral lead position, distal, AV-delay 120-150ms, VV-delay 0ms) this correlation was present (R = 0.45, p < 0.0001, figure panel A). In 21 patients in which at least 3 lead positions were available there was also a significant correlation between QRS area reduction and %LVdP/dtmax increase (average R = 0.69, p < 0.0001, panel B). For VV-delay, 25 other patients as well showed a significant correlation (average R = 0.53, p < 0.0001).

Conclusion Within patients, QRS area reduction is associated with %LVdP/dtmax increase with various LV lead positions and VV-intervals. Therefore, QRS area, which is an easily obtainable and objective parameter, might be a promising tool for optimization of LV lead position and device programming in CRT. Abstract Figure.
The pacemaker ventricular lead position and outcomes in patients upgrading to crt
Authors: Silva BV , Brito J , Rodrigues T , Silverio Antonio P , Couto Pereira S , Alves Da Silva P , Lima Da Silva G , Cunha N , Teixeira P , Carpinteiro L , Cortez -Dias N , Pinto FJ , Sousa J
Published: May 2021

Funding Acknowledgements

Type of funding sources: None.

Introduction

 

Adverse hemodynamic effects of right ventricular pacing are known, and the optimal right ventricular lead position is still being a matter of debate. According to the guidelines, upgrade to cardiac resynchronization therapy (CRT) is recommended in patients with indication for pacemaker and left ventricular ejection fraction less than 50% or who need more than 40% of ventricular pacing.

Purpose

 

To compare clinical outcomes and ejection fraction in patients with previous pacemaker (apical versus septal right ventricular pacing) who are upgrated to CRT. 

Methods

 

Single-center retrospective study of 94 consecutive patients who had previous pacemaker and upgraded to CRT over a 4-year period. Of these patients, 64 had previous apical lead pacemaker and 30 had previous septal lead pacemaker. Data on comorbidities, New York Heart Association (NYHA), left ventricular ejection fraction and hospitalizations due to heart failure were collected.

The results were obtained using Chi-square, Mann-Whitney and t-test.

Results

Patients with septal pacemaker had significantly more diabetes (p = 0.04) and chronic obstructive pulmonary disease (p = 0.01), tended to be more symptomatic (p = 0.198) and had more days of hospitalization before and after pacemaker implantation (12 ± 3 versus 7 ± 2 days and 8 ± 4 versus 3 ± 1 days, respectively), mostly due heart failure decompensation. 

Although there were no significant differences in the initial ejection fraction in patients with apical or septal pacemaker implantation (31.2 ± 1.2% and 29.1 ± 1.5%, respectively, p = 0.323), the time to upgrade to CRT was significantly shorter in patients with septal pacemaker implantation (1999 ± 227 days versus 3005 ± 279 days, p = 0.005). 

After upgrading to CRT, patients with apical lead had a significant increase in ejection fraction (8.2%, p = 0.011), while patients with septal lead had a non-significant improvement of ejection fraction (4.5%, p = 0.448). In both, apical and septal lead patients, there was a significant improvement in NYHA class after upgrade to CRT (p = 0.03 and p = 0.02, respectively).

Conclusion

 

Although patients with septal lead had more comorbidities and hospitalizations due to heart failure, they do not benefit from the upgrade to CRT, unlike what happens in patients with apical lead. These findings can be explained by the fact that the septal lead minimizes ventricular desynchrony induced by right ventricular pacing.
Impact of homeometric autoregulation using a stepwise change in heart rate on dP/dtmax and time to peak dP/dt with resynchronization therapy
Authors: Odland H , Ross S , Gammelsrud LO , Cornelussen R , Kongsgard E
Published: May 2021

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Norwegian South East heath Authorities

Background

We investigated the homeometric autoregulation utilizing a stepwise change in heart rate on dP/dtmax and time to peak dP/dt (Td) with biventricular pacing (BIVP) and the LV lead positioned in the apical, anterior and lateral positions. Pacing at low HR (LHR) and high heart rates (HHR) changes contractility through homeometric autoregulation (Bowditch effect) without changing the resynchronization itself.

Purpose

To determine the effect of a change in contractility through homeometric autoregulation on two different effect measures of resynchronization therapy.

Methods

Twenty-nine patients in heart failure with LBBB underwent CRT implantation with continuous LV pressure registration. The LV lead was first placed in either apical or anterior position followed by a permanent placement in a lateral position. Sequential BIVP pacing was performed for one minute, at a rate 10% above intrinsic heart rate (LHR = 75 ± 9bpm), before dP/dtmax measurements were recorded, and the sequence was repeated with pacing rate increased by 30% (HHR = 98 ± 11bpm). Td was defined as the time from pacemaker stimuli to peak dP/dt. Mixed linear models were used for statistics, numbers are estimated marginal means ± SEM. Significance was set at p < 0.05.

Results

DP/dtmax was higher with HHR in lateral position (1036 ± 41mmHg/s) than with LHR (933mmHg/s). The same was observed for all other lead positions. However, there was no difference between lateral position with LHR and apical position with HHR (930 ± 44mmHg/s). There were no differences in Td between LHR and HHR, but Td was shorter with BIVP in lateral position at pacing LHR (158 ± 4ms) and HHR (155 ± 4ms) than in all other positions. Overall dP/dtmax increased by 10% from LHR to HHR (888 ± 41mmHg/s vs. 980 ± 41 mmHg/s), while overall Td decreased by 2.4% from 168 ± 4ms to 164 ± 4ms. We found a linear relationship between Td and dP/dtmax (R = 0.7) with β=-0.07 that would indicate a 6ms reduction in Td going from LHR to HHR. The overall change in Td from LHR to HHR could therefore be attributed to the change in dP/dtmax.

Conclusion

Homeometric regulation does not influence Td, but Td is sensitive to changes in resynchronization and pacing lead position. Td is shorter with BIVP in lateral position at both high and low HR as would be expected from a biomarker of resynchronization. HR influences dP/dtmax so distinction between optimal and non-optimal positions using dP/dtmax may be difficult without knowledge of homeometric state.
Is diversity harmful? - Mixed-brand cardiac implantable electronic devices undergoing magnetic resonance imaging
Authors: Koenig C , Hellebart P , Koch J , Egger F , Puntus T , Kriz R , Huber K , Nuernberg M , Zweiker D
Published: May 2021

Funding Acknowledgements

Type of funding sources: None.

Introduction

Many patients with cardiac implantable electronic devices (CIED) need to undergo magnetic resonance imaging (MRI). However, a significant proportion has a CIED system in place that has not been classified "MRI-conditional" because of generators and leads from different brands ("mixed-brand" group), although the individual components per se are MRI-conditional. There is only limited data available concerning the outcome of these patients with "mixed-brand" CIED systems undergoing MRI.

Purpose

To analyse complications or adverse effects in "mixed-brand" CIED patients undergoing MRI, compared to patients with a fully "MRI-conditional" CIED system.

Methods

A retrospective single-centre study was performed, including patients undergoing MRI between January 2013 until May 2020. Short- and long-term outcomes were compared between both groups. We defined the primary endpoint as death or any adverse event necessitating hospitalization or CIED revision in association with the MRI examination. Secondary endpoints were the occurrence of any surrogate for beginning device or lead failure or patient discomfort during MRI.

Results

A total of 227 MRI examinations, including 10 thoracic MRIs, were carried out in 158 patients, with a range of 1-9 MRIs per patient. Mean age was 73 years and 52 (32.9%) patients were female. We identified 38 patients undergoing 54 procedures in the "mixed-brand" group and 89 patients undergoing 134 MRI procedures in the "MRI-conditional" group. In 31 patients undergoing 39 MRI examinations the MRI-conditionality could not be determined. "Mixed-brand" patients were older than MRI-conditional patients (mean 77 vs. 72 years, p = 0.003). The primary endpoint occurred in 0% in the "mixed-brand" group and in 2.2% in the "MRI conditional" group (p = 1.000). Complications were as follows: Two patients had first diagnosed atrial fibrillation directly associated with the procedure, of whom one additionally had a transient CIED dysfunction. No patient in the "mixed-brand" group and three patients (3.4%) in the "MRI conditional" group met the secondary endpoints (p = 0.554). In patients with undeterminable MRI conditionality the complication rate was similar (0% for both the primary and secondary endpoints).

Conclusion

The complication rate of CIED patients undergoing MRI was low. There was no signal for increased risk of adverse events in patients with a CIED without MRI certification due to mixed brands systems compared to patients with "MRI-conditional" CIED systems.
PROMET: the effect of age on patient outcomes in non-laser transvenous lead extraction
Authors: Akhtar Z , Elbatran A , Starck CT , Leung L WM , Sohal M , Gallagher MM
Published: May 2021

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

PROMET group

Background

Cardiac implantable electronic devices (CIEDs) improve morbidity and mortality. This has fuelled an upsurge in implantation of these devices across all patient cohorts, simultaneously increasing the need for transvenous lead extractions (TLE). As the global population expands and life-expectancy extends, TLE will play a significant role in CIED management. Advancing patient age is a recognised risk factor for poor outcomes however the association between patient age and TLE outcomes remains unclear. 

We sought to evaluate the relationship between patient age and non-laser TLE outcomes.

Method

Data of 2205 patients (3849 leads) was collected retrospectively from six high-volume TLE institutes across Europe (PROMET) between January 2005-December 2018. Propensity 1:1 score matching was performed to limit the effects of confounding variables, pairing 353 patients in the >80 years of age category with 353 patients in <80 years of age group. Procedural outcomes were compared between the two age groups and multivariate regression analysis was used for predictors of 30-day mortality.

Results

In the <80 and >80 years-of-age cohorts, there was a similar proportion of male patients (65.3% vs 67.9%, p = 0.47) treated under general anaesthesia (96.5% vs 93.4%, p = 0.078) for a pre-dominant infectious indication (56.7% vs 60.3%, p = 0.52) but with a higher requirement of the EvolutionTM sheath in the octogenarians (39.4% vs 48.4%, p = 0.015). A similar clinical success per lead was achieved between the two age groups (96.6% vs 98%, <80 vs >80 years, p = 0.245) as was complete lead extraction (95.5% vs 96.6%, <80 vs >80 years, p = 0.44) with a comparable minor complication rate (2.3% vs 3.1%, <80 vs >80 years, p = 0.29) and major complications (1.1% vs 1.4%, <80 vs >80 years, p = 0.74). Thirty-day mortality was higher in the octogenarian cohort than the <80-year-olds without reaching statistical significance (5.4% vs 2.6%, p = 0.08); peri-procedural mortality was similar in both age groups (0.3% vs 0.6%, respectively, p = 0.56). Multivariate regression analysis revealed age (p = 0.013, OR 1.06 [1.01-1.12]), systemic infection (p = 0.026, OR 3.4 [1.16-10.35]) and lead dwell time (p = 0.007, OR 1.01 [1.003-1.017]) increased the odds of 30-day mortality.

Conclusion

Transvenous lead extraction is similar in efficacy and safety across all age groups. Thirty-day mortality is higher in the advanced age group, signifying the importance of post-procedural management in this cohort.
Brugada syndrome in Hong Kong: long term outcome prediction through machine learning
Authors: Lee S , Zhou J , Li KHC , Leung KSK , Lakhani I , Liu T , Wong ICK , Mok NS , Jeevaratnam K , Zhang Q , Tse G
Published: May 2021

Funding Acknowledgements

Type of funding sources: None.

Introduction

 Brugada syndrome (BrS) is an ion channelopathy that predisposes affected patients to spontaneous ventricular tachycardia/fibrillation (VT/VF) and sudden cardiac death (SCD). Despite its greater prevalence in Asia and epidemiological heterogeneity in disease manifestation, the majority of the conducted cohort studies available in current literature are based in Western countries. 

Purpose

The aim of this study is to examine the clinical and electrocardiographic predictive factors of spontaneous VT/VF for Asian BrS patients.

Methods

This was a territory-wide retrospective cohort study of patients diagnosed with BrS between 1997 and 2019. The primary outcome was spontaneous VT/VF detected either during hospital admission or by implantable-cardioverter defibrillator (ICD) data. Cox regression was used to identify significant clinical and electrocardiographic risk predictors. Non-linear interactions between variables (latent patterns) were extracted using non-negative matrix factorization (NMF) and used as inputs into the random survival forest (RSF) model.

Results

This study included 516 consecutive BrS patients (mean age of initial presentation= 50 ± 16 years, male= 92%) with a median follow-up of 86 (interquartile range: 45-118) months. The cohort was divided into subgroups based on initial disease manifestation: asymptomatic (n = 314), syncope (n = 159) or VT/VF (n = 41). Annualized event rates per person-year were 1.70%, 0.05% and 0.01% for the VT/VF, syncope and asymptomatic subgroups, respectively. Multivariate Cox regression analysis revealed initial presentation of VT/VF (HR = 24.0, 95% CI = [1.21, 479] , P= 0.037) and standard deviation of P-wave duration (HR = 1.07, 95% CI = [1.00, 1.13], P = 0.044) were significant predictors. The NMF-RSF showed the best predictive performance compared to RSF and Cox regression models (precision: 0.87 v.s. 0.83 v.s. 0.76, recall: 0.89 v.s. 0.85 v.s. 0.73, F1-score: 0.88 v.s. 0.84 v.s. 0.74).

Conclusions

This is one of the largest territory-wide cohort studies on BrS and the largest study in Asia published to date, with an extensive median follow-up duration of 7 years. Clinical history, electrocardiographic markers and investigation results provide important information for risk stratification. Machine learning techniques using NMF and RSF significantly improves overall risk stratification performance.
The use of vector electrocardiography for pulmonary hypertension screening in patients with atrial septal defects
Authors: El-Bokl A , Cortez D
Published: May 2021

Funding Acknowledgements

Type of funding sources: None.

Background

Patients with unrepaired atrial septal defects accumulate yearly risk of developing pulmonary arterial hypertension due to vascular remodeling in response to chronically increased pulmonary circulation. Electrocardiography, though readily available, has so far been of limited screening utility in this population. We hypothesize that vectorcardiographic parameters will aid in identifying increased ventricular afterload and thus provide an additional screening tool for pulmonary hypertension in this patient population.

Purpose

To establish whether vector electrocardiography can be used as a non-invasive screening tool for pulmonary hypertension screening in patients with atrial septal defects.

Methods

Retrospective chart review of patients with the diagnosis of secundum atrial septal defect who underwent cardiac catheterization at the University of Minnesota from January 2012 to September 2020. We excluded patients with other congenital heart diagnoses, insufficient hemodynamic data, or no sinus rhythm electrocardiogram. An electrocardiogram prior to or on the day of the intervention was assessed. Parameters analyzed include: Sokolow-Lion right ventricular hypertrophy criteria, PR duration, QRS duration, corrected QT intervals, QRS and Twave frontal plane axes, rSR’, rSR’ with the R’ of 5mm or more, as well as vectorcardiographic parameters (Kohr’s regression-related method) the QRS vector magnitude, T wave vector magnitude, and spatial QRS-T angle. These results were then used to compare those with and without pulmonary hypertension (diagnosed by mean pulmonary artery pressure of 25mmHg or more along with body surface area-indexed pulmonary vascular resistance of 3 Woods units/meter squared with normal left atrial/pulmonary vein wedge pressure). Mann-Whitney U-testing was used for non-parametric testing for significance within the dataset.

Results

Three hundred and five patients were identified with secundum atrial septal defects, but after exclusion, there were a total of 122 patients meeting criteria for assessment.  Eight ASD patients had pulmonary hypertension (37% male, median age 7.5 years, interquartile range 0.4 to 23 years) while 114 patients did not (31% male, median age 5 years, interquartile range 3 to 13 years, p-value 0.68). Only the spatial QRS-T angle significantly differentiated pulmonary hypertension (median 104 degrees, interquartile range 55 to 137 degrees) from those ASD patients without pulmonary hypertension (median 37 degrees, interquartile range 21 to 63 degrees) with a p-value of 0.002. At a cut-off of 124 degrees, the positive and negative predictive values for identification of pulmonary hypertension was 36.4% and 96.4%, respectively, with an odds ratio of 13.4 (95% confidence interval of 2.9 to 63.7).

Conclusions

The spatial QRS-T angle may be a useful, non-invasive screening tool for pulmonary hypertension in patients with secundum atrial septal defects.
Associations of exercise-based cardiac rehabilitation with all-cause mortality among patients with atrial fibrillation
Authors: Buckley B , Harrison S , Fazio-Eynullayeva E , Underhill P , Lane D , Thijssen D , Lip G
Published: May 2021

Funding Acknowledgements

Type of funding sources: None.

Background

There is limited evidence of long-term impact of exercise-based CR on clinical endpoints for patients with AF. We therefore compared 18-month all-cause mortality, hospitalisation, stroke, and heart failure in patients with AF and an electronic medical record (EMR) of exercise-based CR to matched controls.

Methods and Results

This retrospective cohort study included patient data obtained on 11 December 2020, from a global federated health research network. AF patients undergoing exercise-based CR were propensity score matched to AF patients without exercise-based CR by age, sex, race, medication, and co-morbidities. We ascertained 18-month incidence of all-cause mortality, hospitalisation, stroke, and heart failure.

Of 1,350,886 patients with AF, 10,625 patients had an EMR of exercise-based CR within 6-months of incident AF. The propensity score matched cohort of 21,250 patients with AF demonstrated that exercise-based CR was associated with 64% lower odds of all-cause mortality (odds ratio 0.36, 95% confidence interval (CI) 0.33-0.40), 41% lower odds of hospitalisation (0.59, 95% CI 0.56-0.63), and 17% lower odds of incident stroke (0.83, 95% CI 0.71-0.98) compared to propensity score matched controls. No significant associations were shown for heart failure at 18-months (0.92, 95% CI 0.81-1.02). The beneficial association of exercise-based CR on all-cause mortality was independent of sex, older age, comorbidities, and AF subtype.

CONCLUSIONS

Exercise-based CR among patients with incident AF was associated with lower odds of all-cause mortality, hospitalisation, and stroke at 18-months follow-up. The longitudinal nature of this retrospective follow-up study strongly supports the provision of exercise programmes for patients with incident AF.
Explanation-visualised deep learning model for accessory pathway localisation using 12-lead electrocardiography
Authors: Chan CP , Arnold AD , Howard JP , Shun-Shin MJ , Maclean E , Cullen B , Chow J , Lim PB , Ng FS , Linton NWF , Peters NS , Schilling RJ , Kanagaratnam P , Francis DP , Whinnett ZI
Published: May 2021

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): British Heart Foundation Imperial Centre of Research Excellence

Background/Introduction

ECG algorithms for identifying accessory pathway (AP) locations are inaccurate and difficult to use. Human expert interpretation is poorly reproducible. Artificial intelligence (AI) techniques such as machine learning can improve accuracy in classification tasks by eschewing theory-driven predictions. More reproducible and accurate AP localisation could shorten procedure time and personalise ablation consent.

Purpose

We developed a neural network to perform AP localisation using 12-lead ECGs. Its decision-making process was analysed to enable explainability of the neural network.

Methods

A convolutional neural network was trained on raw, digital, intra-procedural 12-lead ECGs of patients with manifest APs who underwent successful ablation. ECGs were labelled with AP locations as left-sided, septal or right-sided using procedure reports, fluoroscopy and electro-anatomical maps. Accuracy of the neural network was assessed via 4-fold cross-validation and was compared to the Arruda algorithm. Five cardiologists were also assessed for their accuracy in determining locations in sub-groups of cases. The neural network was retrospectively analysed to identify areas of ECGs most influential to its predictions using importance mapping.

Results 

In 156 cases, accuracy of the neural network (92.9%) was significantly higher than the Arruda algorithm (76.9%; p < 0.0001) and all five cardiologists (37.5% to 65.9%; p = 0.0001 to 0.0290). Importance mapping demonstrated that the QRS complexes of leads aVL and V1 were perceived as most influential, indicating interrogation of the lateral and anterior-posterior axes respectively.

The figure shows (A) architecture of the neural network, (B) accuracy of the neural network, Arruda algorithm and five cardiologists, (*, p = 0.05 – 0.01; **, p = 0.01 – 0.001; ***, p = 0.001 - 0.0001; ****, p < 0.0001; as compared to the neural network) and (C) example importance maps for 12-lead ECGs of left-sided, septal and right-sided APs (in order from left to right), with darker regions corresponding to greater relative importance. 

Conclusion 

AI ECG interpretation allows accurate, reproducible prediction of AP locations, superior to conventional algorithms and human interpretation. Although AI decision-making is thought of as a ‘black box’, explanation visualisation techniques such as importance mapping allow humans to understand aspects of how a neural network make decisions. A prospectively validated neural network could be integrated into clinical practice to improve pre-procedural AP localisation. Abstract Figure. Summary of results
Electrocardiogram-based mortality prediction in patients with COVID-19 using machine learning
Authors: Bleijendaal H , Van Der Leur RR , Taha K , Mast T , Gho JMIH , Winter MM , Zwinderman AH , Doevendans PA , Pinto YM , Asselbergs FW , Van Es R , Tjong FVY
Published: May 2021

Funding Acknowledgements

Type of funding sources: Public hospital(s). Main funding source(s): The Netherlands Organisation for Health Research and Development (ZonMw) University of Amsterdam Research Priority Area Medical Integromics

OnBehalf

CAPACITY-COVID19 Registry

Background

The electrocardiogram (ECG) is an easy to assess, widely available and inexpensive tool that is frequently used during the work-up of hospitalized COVID-19 patients. So far, no study has been conducted to evaluate if ECG-based machine learning models are able to predict all-cause in-hospital mortality in COVID-19 patients.

Purpose

With this study, we aim to evaluate the value of using the ECG to predict in-hospital all-cause mortality of COVID-19 patients by analyzing the ECG at hospital admission, comparing a logistic regression based approach and a DNN based approach. Secondly, we aim to identify specific ECG features associated with mortality in patients diagnosed with COVID-19. 

Methods and results

We studied 882 patients admitted with COVID-19 across seven hospitals in the Netherlands. Raw-format 12-lead ECGs recorded after admission (<72 hours) were collected, manually assessed, and annotated using pre-defined ECG features. Using data from five out of seven centers (n = 634), two mortality prediction models were developed: (a) a logistic regression model using manually annotated ECG features, and (b) a pre-trained deep neural network (DNN) using the raw ECG waveforms. Data from two other centers (n = 248) were used for external validation. Performance of both prediction models was similar, with a mean area under the receiver operating curve of 0.69 [95%CI 0.55–0.82] for the logistic regression model and 0.71 [95%CI 0.59–0.81] for the DNN in the external validation cohort. After adjustment for age and sex, ventricular rate (OR 1.13 [95% CI 1.01–1.27] per 10 ms increase), right bundle branch block (3.26 [95% CI 1.15–9.50]), ST-depression (2.78 [95% CI 1.03–7.70]) and low QRS voltages (3.09 [95% CI 1.02-9.38]) remained as significant predictors for mortality.

Conclusion

This study shows that ECG-based prediction models at admission may be a valuable addition to the initial risk stratification in admitted COVID-19 patients. The DNN model showed similar performance to the logistic regression that needs time-consuming manual annotation. Several ECG features associated with mortality were identified.

Figure 1: 

Overview of methods, using and example case: (left) logistic regression and (right) deep learning. This specific case had a high probability of in-hospital mortality (above the threshold of 30%). Follow-up of this case showed that the patient had died during admission. Abstract Figure. Overview of ML methods used
Artificial intelligence: an attempt to automate remote device follow-up
Authors: Ferreira HDS , Ferrer F , Cabanelas N , Nelumba T , Ferreira AR , Faustino M , Antunes S , Vasconcelos H , Beringuilho M , Polena C , Borralho C , Madeira F , Morais C
Published: May 2021

Funding Acknowledgements

Type of funding sources: None.

Introduction

Artificial intelligence (AI) through machine learning (ML) refers to the simulation of human intelligence with the capacity for achieving goals within computers. In electrophysiology, ML has many applications in electrocardiography, intracardiac mapping and cardiac implantable electronic devices (CIEDs).

Remote monitoring (RM) of patients equipped with CIEDs associates the analysis of event reports and calendar-based remote follow-ups (FU). ML applications have allowed for risk stratification, improved arrhythmia localisation and streamlined remote monitoring which may significantly reduce the workload faced by electrophysiologists.

Aim

To develop a system that automates cardiac implantable electronic devices remote follow-up.

Methods and Results

We created a Java software application, that uses the latest optical character recognition techniques combined with artificial intelligence and natural language processing to extract information from PDF reports of RM of CIEDs from different manufacturers. The current version is HIPAA (Health Insurance Portability and Accountability Act) complaint and runs on local computers only.

Using the current system, we were able to run and extract data from 30 remote follow-up PDF reports of Cardiac Implantable Defibrillators (ICDs) and Cardiac Resynchronization Therapy with Defibrillator (CRT-Ds).

Time taken from data extraction to conversion of all 30 device PDFs was under 5 minutes.

Process and data extracted are presented in the figure below. (Figure 1)

Conclusion

This machine learning algorithm proved that it is possible to facilitate and automate remote follow-up of cardiac implantable electronic devices.

In a near future this will allow to us to efficiently increase productivity, by speeding and facilitating interpretation of remote device follow-ups, leading to improvements in patientcare and precision cardiovascular medicine.

Furthermore, in the current and future pandemics it may help prevent unnecessary in-person medical visits, avoiding additional, unnecessary strain on an already overburdened and overwhelmed healthcare system, and saving costs. Abstract Figure 1
Clinic time required to manage remote monitoring of cardiac implantable electronic devices: impact of outsourcing initial data review and triage
Authors: Nicolle E , Lanctin D , Rosemas S , De Melis M
Published: May 2021

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Medtronic

Background

Remote monitoring is guideline-recommended to manage cardiac implantable electronic device (CIED) patients. With the continuous growth of implanted patients, clinic workload to review transmissions is increasing. Outsourcing initial data review and triage to an external monitoring center could be a valuable option for more efficient allocation of staff time, as high-skilled healthcare professionals can focus on patients in need rather than non-actionable data.

Purpose

The objective was to estimate the potential clinic staff time saved when outsourcing part of remote transmission review.

Methods

A previous time and motion evaluation described workflow tasks and time required for remote transmission review (4 EU sites, 674 observations). From real-world experience with a third-party monitoring service, the steps that can be outsourced were determined considering existing clinic-driven protocols for triage and transmission escalation. Staff time required with and without the monitoring service was thus modeled and compared.

Results

Outsourcing to an external monitoring center can reduce clinic staff time between 77.4% and 84.7% depending on device type. Absolute time savings range from 32.7 to 82.6 hours per year per 100 patients for therapeutic devices, and 301.3 hours for insertable cardiac monitor (ICM) patients, due to the higher frequency of transmissions in diagnostic devices.

Conclusion

Time to review remote transmissions can become overwhelming for clinics as growing CIED population often outpaces available staffing resources. Outsourcing initial review and triage to an external monitoring center (ensuring quality and regulatory compliance) can be an efficient option to save dedicated staff and facility time for other crucial healthcare activities. Clinic Staff Time Savings Per YearPacemakerICDCRTICMTRANSMISSIONS PER PATIENT PER YEARGreen (no further review required when outsourcing)3.04.35.020.8Yellow/Red (medical action/decision required)0.60.80.93.8ANNUAL STAFF TIME PER PATIENT, minutesNo outsourcing25.346.658.5219.7Outsourcing to monitoring center5.77.78.938.9ANNUAL STAFF TIME PER 100 PATIENTS, hoursNo outsourcing42.277.697.4366.2Outsourcing to monitoring center9.612.914.964.8TIME SAVED PER 100 PATIENTS, hours (%)32.7 (77.4%)64.7 (83.4%)82.6 (84.7%)301.3 (82.3%)Abstract Figure. Outsourcing Remote Transmission Review
Head-to-head comparison of proprietary PPG and single-lead ECG algorithms for atrial fibrillation detection
Authors: Gruwez H , Evens S , Proesmans T , Smeets C , Haemers P , Pison L , Vandervoort P
Published: May 2021

Funding Acknowledgements

Type of funding sources: None.

Background

Population based screening for atrial fibrillation (AF) has been suggested to reduce stroke. Photoplethysmography (PPG) deriving smartphone apps and single-lead electrocardiography (ECG) tools are attractive devices for screening due to their low cost, convenience, and accessibility. Automated algorithm analysis can serve as pre-screening or remote monitoring for AF, while confirmation on an ECG trace >30s is required to establish the diagnosis. This work directly compares the performance of proprietary algorithms on PPG vs single-lead ECG for the detection of AF.

Purpose

To evaluate and compare the diagnostic performance of a PPG-deriving smartphone app and a single-lead ECG-deriving handheld device for AF detection.

Methods

Patients were recruited from the cardiology ward. After obtaining written informed consent, demographic and medical information were collected. Patients were instructed to perform one measurement using a pulse-deriving smartphone app and one via a single-lead ECG handheld device. A 12-lead electrocardiogram (ECG) was collected and interpreted by a cardiologist as gold standard. Patients with atrial flutter were excluded, with additional exclusions for insufficient quality measurements and unsuccessful measurements resulting due to technical errors. Unclassified single-lead ECG measurements were handled as test-negative. Sensitivity, specificity and accuracy were calculated with respect to the reference diagnosis. McNemar’s analysis was performed to compare the sensitivity and specificity of the proprietary PPG and single-lead ECG AF detection algorithms.

Results

The median age in the study population (n = 300) was 70 years (interquartile range: 51-78), 56.3% were men, and the median CHA2DS2-VASc was 3 (interquartile range: 1-4) with an AF-prevalence of 32.3%. PPG signal and single‑lead ECG quality was sufficient in 272/300 (91.0%) and 278/298 (93.3%) participants, respectively. After excluding atrial flutter patients (n = 25) and insufficient quality measurements, the sensitivity and specificity were 97.6% (95% CI 93.8 to 99.3) and 94.1% (95% CI 86.8 to 98.1) for the PPG signal versus 95.7% (95% CI 91.4 to 98.3) and 91.1% (95% CI 83.2 to 96.1) for the single‑lead ECG signal, respectively. Results demonstrated a 96.4% (95% CI 93.2 to 98.3) accuracy for PPG and 94.1% (95% CI 90.4 to 96.6) for single-lead ECG. No significant differences in sensitivity (P = 0.453) or specificity (P = 0.219) between the proprietary PPG and single-lead ECG algorithms were found.

Conclusion

This study demonstrated equivalent diagnostic performance of PPG and single-lead ECG proprietary AF detection algorithms in smartphone apps.
Does industry funding differ between men and women in electrophysiology and devices research?
Authors: Camm CJF , Crawford W , Olivarius-Mcallister J , Prachee I , Schaefer A , Raouf Z , Bello A , Ginks M , Nicol E
Published: May 2021

Funding Acknowledgements

Type of funding sources: None.

Background

A significant gender bias has been identified in cardiology. Industry funding may be important developing electrophysiology (EP) and devices research. Such funding leads to potential conflicts of interest (COI) which must be disclosed on research presentations. There is limited evidence whether the gender bias in cardiology extends to industry funding of research.

Purpose

To assess whether COI disclosures in EP and devices presentations at the ESC Annual Congress differ between men and women.

Methods

Recorded presentations from the Arrhythmia & Devices section of ESC Annual Congresses 2016-2020 were assessed. Presentations were excluded if the original presentation contained no slides, it was a panel discussion, it was a non-scientific presentation, or part of the presentation was missing. Presentations with multiple speakers were also excluded. Chi-squared and Mann-Whitney U tests were used to assess differences between groups for dichotomous and continuous data respectively.

Results

Of 1,153 presentations assessed, 999 were suitable for inclusion. Women made up 22% (n = 221) of presenters. There was no difference in whether COI declaration slides were missing between women (5.9%, n = 13) and men (7.6%, n = 56), p = 0.38. In those with COI disclosure slides (n = 927), women declared significantly lower median number of COIs (0, IQR 0-3) compared with men (2, IQR 0-8), p < 0.0001. In contrast, women spent a greater time-per-word on their COI disclosure slides (250ms, IQR 125-375ms) compared with men (200ms, IQR 118-333ms), p < 0.0001.

Conclusions

Women made up a minority of presenters in EP/devices talks at the ESC annual congress. Women were less likely to have COIs which may suggest that they are less likely to receive industry funding. Despite this, women spent a greater amount of time-per-word on their COI slides. The lower number of declared COIs in women highlights another potential area of gender bias in cardiology that needs further investigation so that it can be addressed.