Incidental and anticipated arrhythmic diagnoses in patients with an implantable cardiac monitor

AIMS

In this study, we investigated a cohort of unselected patients with various indications for an implantable cardiac monitor (ICM). Our main objectives were to determine the incidence of arrhythmic diagnoses, both anticipated and incidental in relation to the ICM indication, and to assess their clinical relevance.

METHODS

We examined remote monitoring transmissions from patients with an ICM at four Italian sites to identify occurrences of cardiac arrhythmias. Concurrently, we collected data on medical actions taken in response to arrhythmic findings.

RESULTS

The study included 119 patients, with a median follow-up period of 371 days. ICM indications were syncope/presyncope (46.2%), atrial fibrillation management (31.1%), and cryptogenic stroke (22.7%). In the atrial fibrillation management group, atrial fibrillation was the most common finding, with an incidence of 36% [95% confidence interval (CI) 22-55%] at 18 months. Rates of atrial fibrillation were not significantly different between patients with cryptogenic stroke and syncope/presyncope [17% (95% CI 7-40%) vs. 8% (95% CI 3-19%), P = 0.229].For patients with cryptogenic stroke, the incidence of asystole and bradyarrhythmias at 18 months was 23% (95% CI 11-45%) and 42% (95% CI 24-65%), respectively, similar to estimates obtained for patients implanted for syncope/presyncope (P = 0.277 vs. P = 0.836).Overall, 30 patients (25.2%) required medical intervention following ICM-detected arrhythmias, predominantly involving atrial fibrillation ablation (10.9%) and medication therapy changes (10.1%).

CONCLUSION

In a real-life population with heterogeneous insertion indications, approximately 25% of patients received ICM-guided medical interventions within a short timeframe, including treatments for incidental findings. Common incidental arrhythmic diagnoses were bradyarrhythmias in patients with cryptogenic stroke and atrial fibrillation in patients with unexplained syncope.

Strategic reprogramming of implantable cardiac monitors reduces the false-positive remote alert burden in a nurse-led service

AIMS

Implantable cardiac monitors (ICMs) can generate false-positive (FP) alerts. Although these devices have an extended programmability, there are no recommendations on their optimization to reduce not-relevant activations.We tested a strategic programming optimization guide based on the type of FP and investigated the safety and feasibility of the nurse-led insertion of ICMs with a long-sensing vector.

METHODS AND RESULTS

Consecutive patients implanted by trained nurses with long-sensing vector ICM were enrolled in a 1-month observational stage (Phase A). Patients who had ≥10 FP episodes underwent ICM reprogramming based on the predefined guide and were followed for an additional month (Phase B). A total of 78 patients had successful ICM insertion by nurses with a mean R wave amplitude of 0.96 ± 0.43 mV and an 86% P wave visibility. Only one patient reported a significant device-related issue, and nurse-delivered ICM was generally well accepted by the patients. During Phase A, 11 patients (14%) generated most of FP (3,627/3,849; 94%) and underwent ICM reprogramming. In the following month (Phase B), five patients (45%) were free from FP and six (55%) transmitted 57 FP alerts (98% reduction compared with Phase A). The median number of FP per patient was significantly reduced after reprogramming [195 (interquartile range, 50-311) vs. one (0-10), P = 0.0002].

CONCLUSION

A strategic reprogramming of ICM in those patients with a high FP alert burden reduces the volume of erroneous activations with potential benefits for the remote monitoring service. No concerns were raised regarding nurse-led insertion of ICMs with a long-sensing vector.

A Nurse-Led Model of Care with Telemonitoring to Manage Patients with Heart Failure in Primary Health Care: A Mixed-Method Feasibility Study

Purpose

To determine whether a nurse-led care model with telemonitoring in primary care for patients with stable heart failure and their caregivers is feasible and acceptable.

Patients and Methods

A mixed-methods feasibility study was conducted. Patients with stable heart failure and their caregivers were consecutively enrolled from March 2021 to April 2022. Participants were managed by nurses in a community health center through education and monitoring with a mobile app. The outcomes were feasibility outcomes, self-care outcomes, and qualitative acceptability and satisfaction. Quantitative and qualitative outcomes were linked to understanding how the model of care might benefit patients.

Results

Twenty-six patients and nine of their caregivers were enrolled. Ten participants used the mobile app. Nineteen patients and eight caregivers were interviewed. Participants who improved their self-care appreciated the help in finding coping strategies, being close to the clinic, and feeling cared for. Participants with fewer improvements in self-care perceived the model of care as useless and were far from the centre. Participants decided to use the app mainly for usefulness prevision, and most of them were satisfied.

Conclusion

The model of care was not successful in recruiting patients, and adjustments are needed to improve the recruitment strategy and to engage people who perceive the model of care as not useful or unable to use the app.

Daily and automatic remote monitoring of implantable cardiac monitors: A descriptive analysis of transmitted episodes

BACKGROUND

Remote Monitoring (RM) is recognized for its ability to enhance the clinical management of patients with implantable cardiac monitor (ICM). This study aims to provide a comprehensive description of the arrhythmic episodes transmitted by a daily and automatic RM system from a cohort of ICM patients.

METHODS

The study retrospectively analyzed daily transmissions from consecutive patients who had been implanted with a long-sensing vector ICM (BIOMONITOR III/IIIm) at four sites. All transmitted arrhythmic recordings were evaluated to determine whether they were true positive episodes or false positives (FP).

RESULTS

A total of 14,136 episodes were transmitted from 119 patients (74.8% male, median age 62 years old) during a median follow-up of 371 days. The rate of arrhythmic episodes was 14.2 per patient-year (interquartile range: 1.8-126), with 97 patients (81.5%) experiencing at least one ICM activation. Fifty-five percent of episodes were identified as FP, and 67 patients (56.3%) had at least one inappropriate activation. The FP rate was 1.4 per patient-year (0-40). The best per-episode predictive positive values were observed for bradycardia and atrial fibrillation (0.595 and 0.553, respectively). Notably, the implementation of an algorithm designed to minimize false detections significantly reduced the prevalence of atrial fibrillation FP episodes (17.6% vs. 43.5%, p = 0.008).

CONCLUSION

Daily and automatic RM appears to be a reliable tool for the comprehensive remote management of ICM patients. However, the number of arrhythmic episodes requiring review is high, and further improvements are needed to reduce FP and facilitate accurate interpretation of transmissions.

The PhysioVP-AF study, a randomized controlled trial to assess the clinical benefit of physiological ventricular pacing vs. managed ventricular pacing for persistent atrial fibrillation prevention in patients with prolonged atrioventricular conduction: design and rationale

AIMS

In patients with prolonged atrioventricular (AV) conduction and pacemaker (PM) indication due to sinus node disease (SND) or intermittent AV-block who do not need continuous ventricular pacing (VP), it may be difficult to determine which strategy to adopt. Currently, the standard of care is to minimize unnecessary VP by specific VP avoidance (VPA) algorithms. The superiority of this strategy over standard DDD or DDD rate-responsive (DDD/DDDR) in improving clinical outcomes is controversial, probably owing to the prolongation of the atrialventricular conduction (PR interval) caused by the algorithms. Conduction system pacing (CSP) may offer the most physiological-VP approach, providing appropriate AV conduction and preventing pacing-induced dyssynchrony.

METHODS AND RESULTS

PhysioVP-AF is a prospective, controlled, randomized, single-blind trial designed to determine whether atrial-synchronized conduction system pacing (DDD-CSP) is superior to standard DDD-VPA pacing in terms of 3-year reduction of persistent-AF occurrence. Cardiovascular hospitalization, quality-of-life, and safety will be evaluated. Patients with indication for permanent DDD pacing for SND or intermittent AV-block and prolonged AV conduction (PR interval > 180 ms) will be randomized (1:1 ratio) to DDD-VPA (VPA-algorithms ON, septal/apex position) or to DDD-CSP (His bundle or left bundle branch area pacing, AV-delay setting to control PR interval, VPA-algorithms OFF). Approximately 400 patients will be randomized in 24 months in 13 Italian centres.

CONCLUSION

The PhysioVP-AF study will provide an essential contribution to patient management with prolonged AV conduction and PM indication for sinus nodal disease or paroxysmal 2nd-degree AV-block by determining whether CSP combined with a controlled PR interval is superior to standard management that minimizes unnecessary VP in terms of reducing clinical outcomes.

Temporal association between drops in thoracic impedance and malignant ventricular arrhythmia: A longitudinal analysis of remote monitoring trends

INTRODUCTION

Thoracic impedance (TI) drops measured by implantable cardioverter-defibrillators (ICDs) have been reported to correlate with ventricular tachycardia/fibrillation (VT/VF). The aim of our study was to assess the temporal association of decreasing TI trends with VT/VF episodes through a longitudinal analysis of daily remote monitoring data from ICDs and cardiac resynchronization therapy defibrillators (CRT-Ds).

METHODS AND RESULTS

Retrospective data from 2384 patients were randomized 1:1 into a derivation or validation cohort. The TI decrease rate was defined as the percentage of rolling weeks with a continuously decreasing TI trend. The derivation cohort was used to determine a TI decrease rate threshold for a ≥99% specificity of arrhythmia prediction. The associated risk of VT/VF episodes was estimated in the validation cohort by dividing the available follow-up into 60-day assessment intervals. Analyses were performed separately for 1354 ICD and 1030 CRT-D patients. During a median follow-up of 2.0 years, 727 patients (30.4%) experienced 3298 confirmed VT/VF episodes. In the ICD group, a TI decrease rate of >60% was associated with a higher risk of VT/VF episode in a 60-day assessment interval (stratified hazard ratio, 1.42; 95% confidence interval (CI), 1.05-1.92; p = .023). The TI decrease preceded (40.8%) or followed (59.2%) the VT/VF episodes. In the CRT-D group, no association between TI decrease and VT/VF episodes was observed (p = .84).

CONCLUSION

In our longitudinal analysis, TI decrease was associated with VT/VF episodes only in ICD patients. Preventive interventions may be difficult since episodes can occur before or after TI decrease.

Multiparametric identification of subclinical atrial fibrillation after an embolic stroke of undetermined source

BACKGROUND

Subclinical atrial fibrillation (SCAF) may represent a cause of embolic stroke of undetermined source (ESUS) and its detection has important implications for secondary prevention with anticoagulation. Indications to implantable cardiac monitors (ICM) include SCAF detection. The aims of this study were to (1) evaluate the frequency of ICM-detected SCAF; (2) determine predictors of SCAF; and (3) identify patients who would benefit most from ICM implantation.

METHODS

Between February 2017 and November 2020, all consecutive patients referred for ICM implantation after a diagnosis of ESUS and without previous history of atrial fibrillation or atrial flutter were included in this study. SCAF was diagnosed if the ICM electrogram demonstrated an episode of irregularly irregular rhythm without distinct P waves lasting > 2 min.

RESULTS

We enrolled 109 patients (age 66, SD = 13 years; 36% females). During a median follow-up of 19.2 (IQR 11.0-27.5) months, SCAF episodes were detected in 36 (33%) patients. Only abnormal P wave terminal force in lead V1, left atrial end-systolic indexed volume > 34 ml/m², and BMI > 25 kg/m² were independently associated with an increased risk of SCAF (HR 2.44, 95% CI 1.14-5.21, p = 0.021; HR 2.39, 95% CI 1.11-5.13, p = 0.026; and HR 2.64, 95% CI 1.06-6.49, p = 0.036 respectively). The ROC curve showed that the presence of all three parameters had the best accuracy (74%) to predict SCAF detection (sensitivity 39%, specificity 91%).

CONCLUSION

A multiparametric evaluation has the best accuracy to predict SCAF in ESUS patients and may help identifying those who would benefit most from ICM.

336 TEMPORAL CONNECTION BETWEEN HOME MONITORING TRENDS OF THORACIC IMPEDANCE AND SUSTAINED VENTRICULAR ARRHYTHMIAS

Introduction

Implantable cardioverter defibrillators (ICDs) provide daily values of thoracic impedance (TI) that are inversely correlated with fluid accumulation in the lungs. Since sustained ventricular arrhythmias (SVA) are known to have a short-term relationship with heart failure exacerbations, our objective was to assess TI trends temporally related to SVA episodes.

Methods

This study analyzed data daily transmitted from patients with ICD or cardiac resynchronization therapy defibrillator (CRT-D) of the nationwide Home Monitoring Expert Alliance network. Device-detected SVAs were adjudicated for appropriateness. Patients were randomly split into a derivation and validation cohort. To identify the most significant TI trend (TI-index), several numerical TI transformations were tested in a cross-sectional analysis of the derivation cohort modelling the odds of first SVA with univariate logistic regressions. In the same cohort, the threshold of the selected transformation was identified to maximize the projected specificity. The relative risk of SVA for TI-index above threshold was estimated in the validation cohort by applying Cox proportional hazard models stratified by individual patients to 60-day duration windows. Analyses were performed separately in the ICD and CRT-D groups.

Results

The study cohort included 2,384 patients with 69 years of age (interquartile range: 60, 77); 19% were women, 42% had coronary artery disease, and 43% had a CRT-D. After a median follow-up of 2.0 (1.0, 3.4) years, there were 3,298 appropriate SVA episodes in 727 patients (30%).

The derived IT-index consisted of the percentage of 6-day intervals of the rolling average of TI values showing monotone decrease in the last 82 days. The increase in the risk of SVA was 3% (p<0.0001) per unit of percentage. The threshold of 60% of intervals with monotone decrease was associated with 99.9% projected specificity and 70.3% accuracy.

In the validation cohort, the TI-Index was associated with a 42% increased risk of SVA episodes in the ICD group (hazard ratio [HR] 1.42, 95% confidence interval [CI] 1.05-1.92, p=0.023). The TI-index exceeded the 60% threshold before the episode in 38% of the detected episodes. The association was not significant in the CRT-D group (HR 0.96, 95% CI 0.62-1.47, p=0.84).

Conclusions

In our analysis of remote monitoring data, a specific monotonic decreasing trend of TI was temporally associated with SVA in patients with ICD. Careful monitoring of TI can identify a period of susceptibility to ventricular arrhythmias that deserves more intensive attention.

Ventricular Arrhythmias and Implantable Cardioverter-Defibrillator Therapy in Women: A Propensity Score-Matched Analysis

BACKGROUND

Causes of sex differences in incidence of sustained ventricular arrhythmias (SVAs) are poorly understood.

OBJECTIVES

This study aims to investigate sex-specific risk of SVAs and device therapies by balancing sex groups in relation to several baseline characteristics with the propensity score (PS).

METHODS

We used a large remote monitoring dataset from implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy defibrillators (CRT-Ds). Study endpoints were time to the first appropriate SVA, time to the first device therapy for SVA, and time to the first ICD shock. Results were compared between females and a PS-matched male subgroup.

RESULTS

In a cohort of 2,532 patients with an ICD or CRT-D (median age, 70 years), 488 patients (19.3%) were women. After selecting 488 men PS-matched for 19 variables relative to baseline demographics, implant indications, principal comorbidities, and concomitant therapy, yet the SVA rate at the 2.1-year median follow-up was significantly lower in women than in man (adjusted HR: 0.65; 95% CI: 0.51-0.81; P < 0.001). Women also showed a reduced risk of any device therapy (HR: 0.59; 95% CI: 0.45-0.76; P < 0.001) and shocks (HR: 0.66; 95% CI: 0.47-0.94; P = 0.021). Differences in sex-specific SVA risk profile were not confirmed in CRT-D patients (HR: 0.78; 95% CI: 0.55-1.09; P = 0.14) nor in those with an ejection fraction <30% (HR: 0.80; 95% CI: 0.52-1.23; P = 0.31).

CONCLUSIONS

After matching demographics, indications, principal comorbidities, and concomitant therapy, women still exhibited a lower SVA risk profile than men, except in the subgroups of CRT-D or/and ejection fraction <30%.

Computational electrophysiology of the coronary sinus branches based on electro-anatomical mapping for the prediction of the latest activated region

This work dealt with the assessment of a computational tool to estimate the electrical activation in the left ventricle focusing on the latest electrically activated segment (LEAS) in patients with left bundle branch block and possible myocardial fibrosis. We considered the Eikonal-diffusion equation and to recover the electrical activation maps in the myocardium. The model was calibrated by using activation times acquired in the coronary sinus (CS) branches or in the CS solely with an electroanatomic mapping system (EAMS) during cardiac resynchronization therapy (CRT). We applied our computational tool to ten patients founding an excellent accordance with EAMS measures; in particular, the error for LEAS location was less than 4 mm. We also calibrated our model using only information in the CS, still obtaining an excellent agreement with the measured LEAS. The proposed tool was able to accurately reproduce the electrical activation maps and in particular LEAS location in the CS branches, with an almost real-time computational effort, regardless of the presence of myocardial fibrosis, even when information only at CS was used to calibrate the model. This could be useful in the clinical practice since LEAS is often used as a target site for the left lead placement during CRT.

[The TeMP_cardio Model for the district management of heart failure patients: a feasibility study for the implementation of the family nurse]

. The TeMP_cardio Model for the district management of heart failure patients: a feasibility study for the implementation of the family nurse.

INTRODUCTION

The need to enhance primary health nursing care and chronic disease management requires the development of complex and feasible models in local contexts.

AIM

To test the feasibility of a complex care model, based on the introduction of the family and community nurse for patients with stable heart failure and their caregivers.

METHODS

A pre-post six-month feasibility study was conducted in 2021-2022 in the Autonomous Province of Trento. Patients with stable heart failure able to access services were taken in charge with a multidisciplinary model, with the nurse as care manager, and technological and telemonitoring support.

RESULTS

26 patients out of 137 were included and nine of their caregivers. Ten participants accepted to use the mobile app. Twenty-three patients and seven caregivers completed the study, and the app was used regularly by five participants. Self-care skills improved in patients, mostly in self-monitoring, less in caregivers. One access to the emergency department for heart failure exacerbation was detected.

CONCLUSIONS

The model was evaluated feasible to retain patients, with the need to build effective strategies for the recruitment, and the regular use of telemonitoring tools.

Left atrial functional remodeling assessed by echocardiography in patients undergoing ablation for atrial fibrillation: correlation with the presence of fibrosis and invasive atrial pressure

Funding Acknowledgements

Type of funding sources: None.

Background

Radiofrequency catheter ablation of pulmonary veins has become a common procedure for treatment of atrial fibrillation (AF). Nevertheless, the procedure is characterized by an extremely variable success rate, which reflects a great heterogeneity of factors implicated in AF recurrence and AF burden.

Purpose

We focused on the role of left atrium (LA) in patients with paroxysmal and persistent AF who underwent catheter pulmonary veins ablation procedure. In particular we paid attention to three factors: echocardiographic evaluation of LA function, LA scar evaluated by electroanatomic mapping and LA pressures (LAP) during ablation procedure. The aim of the study was to investigate the correlation between echocardiographic parameters indicating atrial dysfunction (LA volume indexed, E/E’, LAA contraction velocity, LA stiffness and LA longitudinal strain during reservoir phase (LASr)) and intraprocedural parameters (such as LAPpeak and the amount of fibrosis).

Methods

 The study included 25 patients; mean age was 63 ± 8 years; nineteen patients (76%) had paroxysmal AF, eighteen patients (72%) were in sinus rhythm at the time of ablation. The population was divided into two subgroups according to the amount of fibrosis evaluated by electroanatomic mapping: patients with fibrosis ≥ 5% of the total LA volume were considered as having an atrial scar. All patients underwent a comprehensive transthoracic echocardiography and a transesophageal echocardiography before the ablation procedure. Intraprocedural data regarding LAPpeak and electroanatomic mapping were collected. Measurements were acquired during both sinus rhythm (SR) and AF.

Results

Patients with atrial scar had similar LA volume compared to patients without scar (44  ml vs 37.4 ml, p = 0.108) , but presented a trend towards higher LAPpeak (24.3 mmHg vs 15.9 mmHg, p = 0.053) and had higher E/E’ (11 vs 7, p = 0.037) and consequently increased LA stiffness (0.72 vs 0.23, p= 0.006). Still, they had lower LASr  (16.6% vs 33.2%, p = 0.013) and tended to have reduced LAA contraction velocity (0.4 m/sec vs 0.7 m/sec, p= 0.005).

Conclusions

The present findings suggest that functional remodeling of the LA, more than morphological changes, are correlated with the presence of atrial fibrosis and elevated atrial pressure detected during ablation procedures. These parameters may represent potential criteria to guide patients’ selection for ablation procedure and deserve dedicated studies to be confirmed. Abstract Figure.

Endocavitary electrophysiological study by percutaneous antecubital vein and without X-ray for risk stratification of asymptomatic ventricular pre-excitation in young athletes

•

Evaluation of AP is usually performed by transesophageal and intracardiac studies.

•

In young athletes with AVP, our standard of care is to perform ESnoXR.

•

ESnoXR may considered a less invasive alternative for risk stratification of AP.

Athletes with asymptomatic ventricular pre-excitation (VP) should undergo electrophysiological study for risk stratification. We aimed to evaluate the feasibility, efficacy, safety and tolerability of an electrophysiological study using a percutaneous antecubital vein access and without the use of X-ray (ESnoXr). Methods: We collected data from all young athletes < 18 year-old with AVP, who underwent ESnoXr from January 2000 to September 2020 for evaluation of accessory pathway refractoriness and arrhythmia inducibility using an antecubital percutaneous venous access. Endocavitary signals were used to advance the catheter in the right atrium and ventricle. Results: We included 63 consecutive young athletes (mean age 14.6 ± 1.9 years, 46% male). Feasibility of the ESnoXr technique was 87% while in 13% fluoroscopy and/or a femoral approach were needed. Specifically, fluoroscopy was used in 7 cases to position the catheter inside the heart cavities with an average exposure of 43 ± 38 s while in 2 femoral venous access was needed. The mean procedural time was 35 ± 11 min. The exam was diagnostic in all patients, there were no procedural complications and tolerability was excellent. 53% of the patients had an accessory pathway with high refractoriness and no inducible atrio-ventricular reentry tachycardia: this subgroup was considered eligible to competitive sports and no event was observed during long-term follow-up (13.6 ± 5.2 years) without drug use. The others underwent catheter ablation. Conclusion. ESnoXr has been shown to be a feasible, effective, safe and well-tolerated procedure for the assessment of arrhythmic risk in a population of young athletes with asymptomatic VP.

Detection of subclinical atrial fibrillation after cryptogenic stroke using implantable cardiac monitors

BACKGROUND

Implantable cardiac monitor (ICM) revealed subclinical atrial fibrillation (SCAF) in up to 30% of cryptogenic stroke (CS) patients in randomized trials. However, real world data are limited.

OBJECTIVES

We investigated SCAF occurrence, treatments, clinical outcomes and predictors of SCAF in a multicenter real-world population subjected to ICM after CS.

METHODS

From September 2016 to November 2019, 20 Italian centers collected data of consecutive patients receiving ICM after CS and followed with remote and outpatient follow-up according to clinical practice. All device-detected AF events were confirmed by the cardiologist to diagnose SCAF.

RESULTS

ICM was implanted in 334 CS patients (mean age±SD 67.4±11.5 years, 129 (38.6%) females, 242 (76.1%) with CHA₂DS₂-VASC score≥4). During a follow-up of 23.6 (IQR 14.6-31.5) months, SCAF was diagnosed in 92 (27.5%) patients. First episode was asymptomatic in 81 (88.1%). SCAF daily burden ≥5 minutes was 22.0%, 24.1% and 31.5% at 6, 12, and 24 months after ICM implantation. Median time to first day with AF was 60 (IQR 18-140) days. Female gender, age>69 years, PR interval>160 ms and cortical-subcortical infarct type at enrolment were independently associated with an increased risk of SCAF.

CONCLUSIONS

In a real-world population, ICM detected SCAF in more than a quarter of CS patients. This experience confirms the relevance of implanting CS patients, for maximizing the possibilities to detect AF, following failure of Holter monitoring, according to guidelines. However, there is need to demonstrate that shift to oral anticoagulation following SCAF detection is associated with reduced risk of recurrent stroke.

X-ray management in electrophysiology: a survey of the Italian Association of Arrhythmology and Cardiac Pacing (AIAC)

AIMS

Radiation use in medicine has significantly increased over the last decade, and cardiologists are among the specialists most responsible for X-ray exposure. The present study investigates a broad range of aspects, from specific European Union directives to general practical principles, related to radiation management among a national cohort of cardiologists.

METHODS AND RESULTS

A voluntary 31-question survey was run on the Italian Arrhythmology and Pacing Society (AIAC) website. From June 2019 to January 2020, 125 cardiologists, routinely performing interventional electrophysiology, participated in the survey. Eighty-seven (70.2%) participants are aware of the recent European Directive (Euratom 2013/59), although only 35 (28.2%) declare to have read the document in detail. Ninety-six (77.4%) participants register the dose delivered to the patient in each procedure, in 66.1% of the cases both as fluoroscopy time and dose area product. Years of exposition (P = 0.009) and working in centers performing pediatric procedures (P = 0.021) related to greater degree of X-ray equipment optimization. The majority of participants (72, 58.1%) did not recently attend radioprotection courses. The latter is related to increased awareness of techniques to reduce radiation exposure (96% vs. 81%, P = 0.022), registration of the delivered dose in each procedure (92% vs. 67%, P = 0.009), and X-ray equipment optimization (50% vs. 36%, P = 0.006).

CONCLUSION

Italian interventional cardiologists show an acceptable level of radiation awareness and knowledge of updated European directives. However, there is clear space for improvement. Comparison to other health professionals, both at national and international levels, is needed to pursue proper X-ray management and protect public health.

Impact of COVID-19 Pandemic on Remote Monitoring of Cardiac Implantable Electronic Devices in Italy: Results of a Survey Promoted by AIAC (Italian Association of Arrhythmology and Cardiac Pacing)

The COVID-19 pandemic has had a profound impact on the organisation of health care in Italy, with an acceleration in the development of telemedicine. To assess the impact of the COVID-19 pandemic on the spread of remote monitoring (RM) of cardiac implantable electronic devices (CIEDs) in Italy, a survey addressed to cardiologists operating in all Italian CIED-implanting centres was launched. A total of 127 cardiologists from 116 Italian arrhythmia centres took part in the survey, 41.0% of all 283 CIED-implanting centres operating in Italy in 2019. All participating centres declared to use RM of CIEDs. COVID-19 pandemic resulted in an increase in the use of RM in 83 (71.6%) participating centres. In a temporal perspective, an increase in the median number of patients per centre followed up by RM was found from 2012 to 2017, followed by an exponential increase from 2017 to 2020. In 36 participating centres (31.0%) a telehealth visits service was activated as a replacement for in-person outpatient visits (in patients with or without CIED) during the COVID-19 pandemic. COVID-19 pandemic has caused an acceleration in the use of RM of CIEDs and in the use of telemedicine in the clinical practice of cardiology.

Implementation of tele visit healthcare services triggered by the COVID-19 emergency: the Trentino Province experience

Aim

In response to the SARS-CoV-2 emergency, the Competence Centre on digital health ‘TrentinoSalute4.0’ has developed TreC_Televisita, a tele visit solution that meets the needs of the Trentino healthcare system and maintains high-quality patient–doctor interactions while respecting social distancing. This paper highlights how ‘TreC_Televisita’ was integrated into the Trentino healthcare system and its potential to become a structural and durable solution for the future local healthcare service provisioning.

Subject and methods

This paper presents the multifactorial context that TreC_Televisita has faced for its implementation and the strategies adopted for its structural integration into the healthcare system. The analysis focuses on the main issues faced for the integration of the tele visits (e.g. privacy, payments) and how the context of TrentinoSalute4.0 permitted responding quickly to its implementation during the pandemic. It also describes how TreC_Televisita fits into the healthcare continuum from the organisational and technological standpoint, the end-user perspective and the barriers that could hamper the solution scalability.

Results

TreC_Televisita has demonstrated to be a technological solution that can be contextualised for different clinical domains beyond SARS-CoV-2. Moreover, it has shown its potential to scale up the solution beyond the COVID-19 emergency to the whole healthcare provisioning system in the long term.

Conclusion

Being a positive experience in the first months of its implementation, the long-term goal is to transform TreC_Televisita into a structural pillar of the Trentino healthcare system, setting the bases for a sustainable, win–win situation for all the stakeholders involved in healthcare service provisioning.

Scheduled versus alert transmissions for remote follow-up of cardiac implantable electronic devices: Clinical relevance and resource consumption

BACKGROUND

The remote follow-up of pacemakers and implantable cardiac defibrillators (ICDs) usually includes scheduled checks and alert transmissions. However, this results in a high volume of remote data reviews to be managed. We measured the relative contribution of scheduled and alert transmissions to the detection of relevant conditions, and the workload generated by their management.

METHODS

At our center, the frequency of remote scheduled transmissions is 4/year. Moreover, all system-integrity and clinical alerts are turned on for wireless notification. We calculated the number of transmissions received from January to December 2020, and identified transmissions that necessitated in-hospital access for further assessment and transmissions that required clinical discussion with the physician. For all alert transmissions, we identified whether the alert was clinically meaningful (i.e. center was not previously aware of the condition and no action had yet been taken to treat it).

RESULTS

Of 8545 transmissions received from 1697 pacemakers and ICDs, 5766 (67%) were scheduled and 2779 (33%) were alert transmissions received from 764 patients (45%); 499 (9%) scheduled transmissions required clinical discussion with the physician, but only 2 of these necessitated in-hospital visits for further assessment. Of the alert transmissions, 664 (24%) required clinical discussion, and 75 (3%) necessitated in-hospital visits. The proportion of alerts judged clinically meaningful was 7%.

CONCLUSION

Scheduled transmissions generate 67% of remote data reviews for pacemakers and ICDs, but their ability to detect clinically relevant events is very low. A strategy that relies exclusively on alert transmissions could ensure continuity of patient monitoring while reducing the workload at the center.

Occurrence of persistent atrial fibrillation during pacing for sinus node disease: The influence of His bundle pacing versus managed ventricular pacing

INTRODUCTION

In patients with sinus node disease (SND), the dual-chamber pacemaker (PM) is programmed in DDDR mode with an algorithm to avoid unnecessary right ventricular (RV) pacing. This pacing mode may prolong PR interval with consequently atrioventricular (AV) asynchrony which is associated with a higher risk of atrial fibrillation (AF). We evaluate whether preserving AV synchrony by setting a fixed AV delay during physiological RV pacing, that is, His bundle pacing (HBP), could reduce the risk of AF occurrence in comparison with a standard pacing mode with an algorithm to avoid unnecessary RV pacing (DDD-VPA).

METHODS AND RESULTS

We collected retrospective data from 313 consecutive patients who had undergone PM for SND. The first occurrence of persistent AF (>7 consecutive days) as a function of the pacing mode was evaluated. HBP and DDD-VPA were implemented in 82 and 231 patients, respectively. Persistent AF occurred in 128 (40.9%) patients over a median follow-up of 70 months (67-105). The DDD-VPA pacing mode was significantly correlated with the occurrence of persistent AF only when the basal PR was long (>180 ms). The risk of persistent AF was significantly lower in patients on HBP than in those on DDD-VPA, adjusted HR = .57 (95% CI, .36- .89, p=.014). Other independent predictors of persistent AF occurrence were: A history of AF (HR = 3.91; 95% CI, 2.48-6.19, p = .001), age, and long PR interval (HR = 2.98; 95% CI, 2.00-4.43, p=.001).

CONCLUSION

In SND patients and long basal PR interval, the HBP may reduce the risk of persistent AF in comparison with the DDD-VPA.

Prediction of mortality in patients with implantable defibrillator using CHADS2 score: data from a prospective observational investigation

BACKGROUND

CHADS2 (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, previous stroke/TIA) score has been validated as a risk stratification score to predict stroke in patients with atrial fibrillation (AF). The objective of this analysis was to assess whether patient risk factors, in particular CHADS2 score, identified patients at risk of mortality.

METHODS

821 patients with an implantable cardioverter defibrillator were prospectively followed-up in 11 cardiology centers. Patients were grouped in 3 groups according to pre-specified risk classes: low (CHADS2 = 0), moderate (CHADS2 = 1, 2), and high (CHADS2 = 3-6). Information on clinical status and events, were collected during scheduled and unscheduled follow-up visits. Deaths were retrieved from medical records, or through the Regional Office of Vital Statistics.

RESULTS

Over a mean follow-up of 44±26 months, 135 deaths occurred in the overall population: 6 (7.7%) in the low-risk population, 69 (13.8%) in moderate-risk patients and 60 (24.6%) in high-risk patients. Kaplan-Meier estimated of patient survival were significantly different in 3 patients groups (93.0%, 90.1%, 78.5% in low, moderate and high risk patients respectively, at 4 years P<0.001). A sub-analysis on patients without history of AF showed similar results. Multivariate regression analysis adjusted for baseline characteristics confirmed the high risk status (HR 1.88, 95% CI 1.27-2.80; P = 0.002) as an independent predictor of mortality adjusted for the baseline characteristics.

CONCLUSIONS

In our multicenter research, the long-term mortality was higher in patients with high CHADS2 score than in those with lower risk score regardless the presence of history of AF. CHADS2 score could be considered a toll to predict all causes mortality.

Coronary sinus activation patterns in patients with and without left bundle branch block undergoing electroanatomic mapping system-guided cardiac resynchronization therapy device implantation

BACKGROUND

Implantation of the left ventricular (LV) lead in segments with delayed electrical activation may improve response to cardiac resynchronization therapy (CRT).

OBJECTIVE

The purpose of this study was to evaluate the amount and regional distribution of LV electrical delay (LVED) in patients with or without left bundle branch block (LBBB).

METHODS

We enrolled 60 patients who underwent electroanatomic mapping system-guided CRT device implantation. Activation mapping of the coronary sinus (CS) branches was performed using an insulated guidewire. LVED was defined as the interval between the beginning of the QRS complex on the surface electrocardiogram (ECG) and the local electrogram and expressed in milliseconds or as percentage of the total QRS duration (LVED%).

RESULTS

Forty-three patients showed a LBBB and 17 a non-LBBB electrocardiographic pattern. A total of 148 CS branches (mean 2.5 per patient; range 2-4 per patient) were mapped. Patients with LBBB showed higher maximum LVED (135 ms [108-150 ms] vs 100 ms [103-110 ms]; P < .001) and LVED% (86% [79%-89%] vs 72% [54%-80%]; P < .001) than did patients without LBBB. The maximum LVED was recorded in mid-basal anterolateral or inferolateral LV segments (traditional CRT targets), significantly more often in patients with LBBB than in patients without LBBB (85% vs 59%; P = .02). The number of CS branches showing LVED >50% of the total QRS duration, >75% of the total QRS duration, and >85 ms was significantly higher in patients with LBBB than in patients without LBBB.

CONCLUSION

Patients without LBBB showed lower LVED and more heterogeneous electrical activation of the CS than did patients with LBBB. This finding may contribute to a lower rate of response to CRT of patients without LBBB and suggests the use of activation mapping to guide LV lead placement.

Computational generation of the Purkinje network driven by clinical measurements: the case of pathological propagations

To properly describe the electrical activity of the left ventricle, it is necessary to model the Purkinje fibers, responsible for the fast and coordinate ventricular activation, and their interaction with the muscular propagation. The aim of this work is to propose a methodology for the generation of a patient-specific Purkinje network driven by clinical measurements of the activation times related to pathological propagations. In this case, one needs to consider a strongly coupled problem between the network and the muscle, where the feedback from the latter to the former cannot be neglected as in a normal propagation. We apply the proposed strategy to data acquired on three subjects, one of them suffering from muscular conduction problems owing to a scar and the other two with a muscular pre-excitation syndrome (Wolff-Parkinson-White). To assess the accuracy of the proposed method, we compare the results obtained by using the patient-specific Purkinje network generated by our strategy with the ones obtained by using a non-patient-specific network. The results show that the mean absolute errors in the activation time is reduced for all the cases, highlighting the importance of including a patient-specific Purkinje network in computational models.

Patient-specific generation of the Purkinje network driven by clinical measurements of a normal propagation

The propagation of the electrical signal in the Purkinje network is the starting point for the activation of the ventricular muscular cells leading to the contraction of the ventricle. In the computational models, describing the electrical activity of the ventricle is therefore important to account for the Purkinje fibers. Until now, the inclusion of such fibers has been obtained either by using surrogates such as space-dependent conduction properties or by generating a network based on an a priori anatomical knowledge. The aim of this work was to propose a new method for the generation of the Purkinje network using clinical measures of the activation times on the endocardium related to a normal electrical propagation, allowing to generate a patient-specific network. The measures were acquired by means of the EnSite NavX system. This system allows to measure for each point of the ventricular endocardium the time at which the activation front, that spreads through the ventricle, has reached the subjacent muscle. We compared the accuracy of the proposed method with the one of other strategies proposed so far in the literature for three subjects with a normal electrical propagation. The results showed that with our method we were able to reduce the absolute errors, intended as the difference between the measured and the computed data, by a factor in the range 9-25 %, with respect to the best of the other strategies. This highlighted the reliability of the proposed method and the importance of including a patient-specific Purkinje network in computational models.

[How to identify non-responders to cardiac resynchronization therapy]

Cardiac resynchronization therapy (CRT) has been shown to improve survival, morbidity, symptoms, quality of life and exercise capacity, and to promote a beneficial reverse remodeling of the left ventricle in patients with heart failure, dilated hypokinetic left ventricle and wide QRS. The totality of evidence supports the use of CRT also in patients with mild symptoms (NYHA class II). However, the wider diffusion of CRT is determining a growing clinical and economic impact on national health systems. In clinical practice, in spite of "all-or-none" response, variable degrees of therapy response are commonly observed, but several evidence gaps remain to be addressed. According to recent guidelines for CRT implantation, a multiparametric combination of predictive factors emerging from the analysis of clinical trials, observational studies and registries, represents a useful tool for patient selection.

Permanent His-bundle pacing maintains long-term ventricular synchrony and left ventricular performance, unlike conventional right ventricular apical pacing

AIMS

Right ventricular apical pacing (RVAP) may be deleterious, determining abnormal left ventricular (LV) electrical activation and progressive LV dysfunction. Permanent His-bundle pacing (HBP) has been proposed to prevent this detrimental effect. The aim of our study was to compare the long-term effects of HBP on LV synchrony and systolic performance with those of RVAP in the same group of patients.

METHODS

Our analysis included 26 patients who received both an HBP lead and an RVAP lead, as backup, in our electrophysiology laboratory between 2004 and 2007. After implantation, all devices were programmed to obtain HBP. An intra-patient comparison of the effects of HBP and RVAP on LV dyssynchrony and function was performed at the last available follow-up examination.

RESULTS

After a mean of 34.6 ± 11 months, the pacing modality was temporarily switched to RVAP. During RVAP, LV ejection fraction significantly decreased (50.1 ± 8.8% vs. 57.3 ± 8.5%, P < 0.001), mitral regurgitation significantly increased (22.5 ± 10.9% vs.16.3 ± 12.4%; P = 0.018), and inter-ventricular delay significantly worsened (33.4 ± 19.5 ms vs. 7.1 ± 4.7 ms, P = 0.003) in comparison with HBP. However, the myocardial performance index was not statistically different between the two pacing modalities (P = 0.779). No asynchrony was revealed by tissue Doppler imaging during HBP, while during RVAP the asynchrony index was significantly higher in both the four-chamber (125.8 ± 63.9 ms; P = 0.035 vs. HBP) and two-chamber (126 ± 86.5 ms; P = 0.037 vs. HBP) apical views.

CONCLUSION

His-bundle pacing has long-term positive effects on inter- and intra-ventricular synchrony and ventricular contractile performance in comparison with RVAP. It prevents asynchronous pacing-induced LV ejection fraction depression and mitral regurgitation.

Physiopathologic correlates of intrathoracic impedance in chronic heart failure patients

BACKGROUND

Increased plasma levels of amino-terminal fraction of brain natriuretic peptide (NT-proBNP) and alterations of diastolic filling as described by Doppler transmitral flow pattern are well-known markers of decompensated heart failure (HF). Recently, some implantable defibrillators have allowed monitoring of intrathoracic impedance, which is related to lung water content, potentially indicating HF deterioration. The aim of this study was to assess the correlation between intrathoracic impedance and NT-proBNP and echo-Doppler transmitral flow indexes.

METHODS

Data were collected from 111 HF patients, in six Italian centers. All patients were on optimal medical therapy. Device diagnostics, echographic data, NT-proBNP determination, and clinical status as assessed by the Heart Failure Score (HFS) were registered at baseline, at bimonthly visits, and at unscheduled examinations due to HF decompensation or device alerts.

RESULTS

Over a median follow-up of 413 days, 955 examinations were performed. Intrathoracic impedance was significantly correlated with NT-proBNP (P = 0.013) and with mitral E-wave deceleration time (DtE) (P = 0.017), but not with HFS. At the time of confirmed alert events, NT-proBNP was significantly higher than during confirmed nonalert event examinations; DtE did not differ, whereas impedance was significantly lower.

CONCLUSION

A decrease in intrathoracic impedance is inversely correlated with NT-proBNP and directly correlated with DtE. Intrathoracic impedance monitoring therefore has the physiologic basis for being a useful tool to identify early HF decompensation.

Intrathoracic and ventricular impedances are associated with changes in ventricular volume in patients receiving defibrillators for CRT

BACKGROUND

Some implantable cardioverter defibrillators (ICD) are able to monitor intrathoracic impedance to detect pulmonary fluid overload. This is achieved by measuring impedance between the ICD case and the right ventricular (RV) lead. We hypothesized that the measured impedance would rise with improvement in left ventricular (LV) volumes during cardiac resynchronization therapy (CRT), and that such impedance changes would be more apparent when measured with an alternative pacing vector.

METHODS

We analyzed echocardiographic and impedance data from heart failure patients implanted with a CRT-ICD capable of intrathoracic impedance measurement for fluid accumulation diagnosis, and LV pacing impedance recording for lead integrity monitoring.

RESULTS

In 127 out of 170 patients that received de novo CRT implantation, the LV end-systolic volume (LVESV) decreased at 6-month follow-up (LVESV at 6 month-LVESV at baseline <0: group A). For the remaining 43 patients (group B) the change was > or = 0. Despite comparable values at baseline (P = 0.262), the impedances of groups A and B gradually diverged soon after the implant, resulting in significant difference between the two groups at the 6-month visit (P = 0.001). The changes in LV dimensions produced larger differences between groups in the impedance measured between the LV and the RV leads (P < 0.001). The regression analysis demonstrated an inverse correlation between paired changes of volume and intrathoracic impedance. Higher correlation coefficient was obtained using the LV-to-RV measurement vector (r =-0.635, P < 0.001).

CONCLUSIONS

The changes in ICD-measured impedance seem associated with the LV volume changes induced by CRT. Specifically, the LV-to-RV impedance estimations seem to better correlate with paired changes of ventricular volumes.

Usefulness of intrathoracic fluids accumulation monitoring with an implantable biventricular defibrillator in reducing hospitalizations in patients with heart failure: A case-control study

BACKGROUND

The reduction of hospitalizations in patients with heart failure (HF) may have clinical and economical implications.

MATERIALS AND METHODS

In a case-control study, we compared the number of hospital admissions for congestive HF during the same follow-up period in two homogeneous groups of patients, each consisting of 27 consecutive patients treated with biventricular pacing and back-up defibrillator (B-ICD) in our institution. The first group was implanted with an InSync Sentry, (Medtronic Inc, Minneapolis, MN, US), a B-ICD device with the OptiVol feature for monitoring intrathoracic fluid accumulation and equipped with an active acoustic alarm (Group 1); the second group was implanted with an InSync III Marquis (Medtronic), a B-ICD device with similar features except for the absence of the OptiVol (Group 2). Follow-up visits were performed at 3 month interval or in case of acoustic alarm.

RESULTS

The patient clinical characteristics of the two groups were similar. In Group 1, with 359 +/- 98 days follow-up, 12 of the 27 patients, experienced 18 OptiVol alarms with only one hospital admission for congestive HF occurring in a patient who ignored the acoustic alarm for 13 days. In Group 2, eight HF hospitalizations occurred in seven patients (p < 0.05).

CONCLUSIONS

The OptiVol feature is a useful tool for the clinical management of HF patients as it can result in early treatment during the pre-clinic stage of HF decompensation and in a significant reduction of hospital admissions for congestive HF.

Permanent direct his bundle pacing does not induce ventricular dyssynchrony unlike conventional right ventricular apical pacing. An intrapatient acute comparison study

BACKGROUND

Benefits of A-V synchrony during right ventricular apical pacing are neutralized by induction of ventricular dyssynchrony. Only a few data are reported about direct His bundle pacing influence on ventricular synchronism.

AIM

Was to assess the capability of direct His bundle pacing to prevent pacing-induced ventricular dyssynchrony comparing DDD- (or VVI- in case of Atrial Fibrillation) right ventricular apical pacing with DDD- (or VVI-) direct His bundle pacing in the same patients cohort.

METHODS

23 of 24 patients (mean age 75.1 +/- 6.4 years) with narrow QRS (HV < 65 ms) underwent permanent direct His bundle pacing for "brady-tachy syndrome" (11) or supra-Hisian II/III-degree AV Block (permanent atrial fibrillation 7, AV Node ablation 1). A 4.1 F screw-in lead was fixed in His position, guided by endocardial pacemapping and unipolar recordings. Additional permanent (13 patients) or temporary right ventricular apical pacing leads were also positioned. Inter- and left intra-ventricular dyssynchrony, mitral regurgitation and left systolic ventricular function Tei index were assessed during either direct His bundle pacing or right ventricular apical pacing.

RESULTS

Permanent direct His bundle pacing was obtained in 23 of 24 patients. Indexes of ventricular dyssynchrony were drastically reduced, mitral regurgitation decreased and left systolic ventricular function Tei index improved during direct His bundle pacing (or His bundle and septum pacing) in comparison to apical pacing (p < 0.05). No statistically significant differences were observed between direct His bundle pacing and combined His bundle and septum pacing.

CONCLUSION

Direct His bundle pacing (also fused with adjacent septum capture) prevents pacing-induced ventricular dyssynchrony.