2021 PACES Expert Consensus Statement on the Indications and Management of Cardiovascular Implantable Electronic Devices in Pediatric Patients: Developed in collaboration with and endorsed by the Heart Rhythm Society (HRS), the American College of Cardiology (ACC), the American Heart Association (AHA), and the Association for European Paediatric and Congenital Cardiology (AEPC) Endorsed by the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS)

In view of the increasing complexity of both cardiovascular implantable electronic devices (CIEDs) and patients in the current era, practice guidelines, by necessity, have become increasingly specific. This document is an expert consensus statement that has been developed to update and further delineate indications and management of CIEDs in pediatric patients, defined as ≤21 years of age, and is intended to focus primarily on the indications for CIEDs in the setting of specific disease categories. The document also highlights variations between previously published adult and pediatric CIED recommendations and provides rationale for underlying important differences. The document addresses some of the deterrents to CIED access in low- and middle-income countries and strategies to circumvent them. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by class of recommendation and level of evidence. Several questions addressed in this document either do not lend themselves to clinical trials or are rare disease entities, and in these instances recommendations are based on consensus expert opinion. Furthermore, specific recommendations, even when supported by substantial data, do not replace the need for clinical judgment and patient-specific decision-making. The recommendations were opened for public comment to Pediatric and Congenital Electrophysiology Society (PACES) members and underwent external review by the scientific and clinical document committee of the Heart Rhythm Society (HRS), the science advisory and coordinating committee of the American Heart Association (AHA), the American College of Cardiology (ACC), and the Association for European Paediatric and Congenital Cardiology (AEPC). The document received endorsement by all the collaborators and the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS). This document is expected to provide support for clinicians and patients to allow for appropriate CIED use, appropriate CIED management, and appropriate CIED follow-up in pediatric patients.

One-year mortality after implantable defibrillator implantation: do risk stratification models help improving clinical practice?

PURPOSE

The purpose of this study was to assess the available mortality risk stratification models for implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy defibrillator (CRT-D) patients.

METHODS

We conducted a review of mortality risk stratification models and tested their ability to improve prediction of 1-year survival after implant in a database of patients who received a remotely controlled ICD/CRT-D device during routine care and included in the independent Home Monitoring Expert Alliance registry.

RESULTS

We identified ten predicting models published in peer-reviewed journals between 2000 and 2021 (Parkash, PACE, MADIT, aCCI, CHA2DS2-VASc quartiles, CIDS, FADES, Sjoblom, AAACC, and MADIT-ICD non-arrhythmic mortality score) that could be tested in our database as based on common demographic, clinical, echocardiographic, electrocardiographic, and laboratory variables. Our cohort included 1,911 patients with left ventricular dysfunction (median age 71, 18.3% female) from sites not using any risk stratification score for systematic patient screening. Patients received an ICD (53.8%) or CRT-D (46.2%) between 2011 and 2017, after standard physician evaluation. There were 56 deaths within 1-year post-implant, with an all-cause mortality rate of 2.9% (95% confidence interval [CI], 2.3-3.8%). Four predicting models (Parkash, MADIT, AAACC, and MADIT-ICD non-arrhythmic mortality score) were significantly associated with increased risk of 1-year mortality with hazard ratios ranging from 3.75 (CI, 1.31-10.7) to 6.53 (CI 1.52-28.0, p ≤ 0.014 for all four). Positive predictive values of 1-year mortality were below 25% for all models.

CONCLUSION

In our analysis, the models we tested conferred modest incremental predicting power to ordinary screening methods.

Myocardial strain assessment using cardiovascular magnetic resonance imaging in recipients of implantable cardioverter defibrillators

BACKGROUND

Cardiovascular magnetic resonance (CMR) is increasingly used in the evaluation of patients who are potential candidates for implantable cardioverter-defibrillator (ICD) therapy to assess left ventricular (LV) ejection fraction (LVEF), myocardial fibrosis, and etiology of cardiomyopathy. It is unclear whether CMR-derived strain measurements are predictive of appropriate shocks and death among patients who receive an ICD. We evaluated the prognostic value of LV strain parameters on feature-tracking (FT) CMR in patients who underwent subsequent ICD implant for primary or secondary prevention of sudden cardiac death.

METHODS

Consecutive patients from 2 Canadian tertiary care hospitals who underwent ICD implant and had a pre-implant CMR scan were included. Using FT-CMR, a single, blinded, reader measured LV global longitudinal (GLS), circumferential (GCS), and radial (GRS) strain. Cox proportional hazards regression was performed to assess the associations between strain measurements and the primary composite endpoint of all-cause death or appropriate ICD shock that was independently ascertained.

RESULTS

Of 364 patients (mean 61 years, mean LVEF 32%), 64(17.6%) died and 118(32.4%) reached the primary endpoint over a median follow-up of 62 months. Univariate analyses showed significant associations between GLS, GCS, and GRS and appropriate ICD shocks or death (all p < 0.01). In multivariable Cox models incorporating LVEF, GLS remained an independent predictor of both the primary endpoint (HR 1.05 per 1% higher GLS, 95% CI 1.01-1.09, p = 0.010) and death alone (HR 1.06 per 1% higher GLS, 95% CI 1.02-1.11, p = 0.003). There was no significant interaction between GLS and indication for ICD implant, presence of ischemic heart disease or late gadolinium enhancement (all p > 0.30).

CONCLUSIONS

GLS by FT-CMR is an independent predictor of appropriate shocks or mortality in ICD patients, beyond conventional prognosticators including LVEF. Further study is needed to elucidate the role of LV strain analysis to refine risk stratification in routine assessment of ICD treatment benefit.

Sudden death after inappropriate shocks of implantable cardioverter defibrillator in a catecholaminergic polymorphic ventricular tachycardia case with a novel RyR2 mutation

BACKGROUND

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmogenic syndrome and a cause of exercise-related sudden death. CPVT has been reported to be caused by gain of function underlying a mutation of cardiac ryanodine receptor (RyR2).

METHODS

In a family with a CPVT patient, genomic DNA was extracted from peripheral blood lymphocytes, and the RyR2 gene underwent target gene sequence using MiSeq. The activity of wild-type (WT) and mutant RyR2 channel were evaluated by monitoring Ca²⁺ signals in HEK293 cells expressing WT and mutant RyR2. We investigated a role of a RyR2 mutation in the recent tertiary structure of RyR2.

RESULTS

Though a 17-year-old man diagnosed as CPVT had implantable cardioverter defibrillator (ICD) and was going to undergo catheter ablation for the control of paroxysmal atrial fibrillation, he suddenly died at the age of twenty-one because of ventricular fibrillation which was spontaneously developed after maximum inappropriate ICD shocks against rapid atrial fibrillation. The genetic test revealed a de novo RyR2 mutation, Gln4936Lys in mosaicism which was located at the α-helix interface between U-motif and C-terminal domain. In the functional analysis, Ca²⁺ release from endoplasmic reticulum via the mutant RyR2 significantly increased than that from WT.

CONCLUSION

A RyR2 mutation, Gln4936Lys, to be documented in a CPVT patient with exercise-induced ventricular tachycardias causes an excessive Ca²⁺ release from the sarcoplasmic reticulum which corresponded to clinical phenotypes of CPVT. The reduction of inappropriate shocks of ICD is essential to prevent unexpected sudden death in patients with CPVT.

Worldwide differences in primary prevention implantable cardioverter defibrillator utilization and outcomes in hypertrophic cardiomyopathy

AIMS

Risk stratification algorithms for sudden cardiac death (SCD) in hypertrophic cardiomyopathy (HCM) and regional differences in clinical practice have evolved over time. We sought to compare primary prevention implantable cardioverter defibrillator (ICD) implantation rates and associated clinical outcomes in US vs. non-US tertiary HCM centres within the international Sarcomeric Human Cardiomyopathy Registry.

METHODS AND RESULTS

We included patients with HCM enrolled from eight US sites (n = 2650) and five non-US (n = 2660) sites and used multivariable Cox-proportional hazards models to compare outcomes between sites. Primary prevention ICD implantation rates in US sites were two-fold higher than non-US sites (hazard ratio (HR) 2.27 [1.89-2.74]), including in individuals deemed at high 5-year SCD risk (≥6%) based on the HCM risk-SCD score (HR 3.27 [1.76-6.05]). US ICD recipients also had fewer traditional SCD risk factors. Among ICD recipients, rates of appropriate ICD therapy were significantly lower in US vs. non-US sites (HR 0.52 [0.28-0.97]). No significant difference was identified in the incidence of SCD/resuscitated cardiac arrest among non-recipients of ICDs in US vs. non-US sites (HR 1.21 [0.74-1.97]).

CONCLUSION

Primary prevention ICDs are implanted more frequently in patients with HCM in US vs. non-US sites across the spectrum of SCD risk. There was a lower rate of appropriate ICD therapy in US sites, consistent with a lower-risk population, and no significant difference in SCD in US vs. non-US patients who did not receive an ICD. Further studies are needed to understand what drives malignant arrhythmias, optimize ICD allocation, and examine the impact of different ICD utilization strategies on long-term outcomes in HCM.

Device-detected atrial high rate episodes and the risk of stroke/thrombo-embolism and atrial fibrillation incidence: a systematic review and meta-analysis

BACKGROUND

Atrial High Rate Episodes (AHRE) are asymptomatic atrial tachy-arrhythmias detected through continuous monitoring with a cardiac implantable electronic device. The risks of stroke/Thromboembolic (TE) events and incident clinical Atrial Fibrillation (AF) associated with AHRE varies markedly.

OBJECTIVES

To assess the relationship between AHRE and TE events, and between AHRE and incident clinical AF.

METHODS

This systematic review and meta-analysis was conducted following the PRISMA recommendations. PubMed, Scopus, and Google Scholar were searched from inception to 18/02/2021 for studies reporting TE events and incident clinical AF in patients with AHRE, as compared with patients without.

RESULTS

Ten out of 8081 records fulfilled the inclusion criteria, for a total of 37 266 patients. Seven out of ten studies excluded patients with prior history of clinical AF (4961 patients), embracing the most recent definition of AHRE. The risk ratio (RR) for TE events in AHRE patients was 2.13 (95% CI: 1.53-2.95, I²: 0%). The incidence of clinical AF was reported in four studies excluding patients with a history of clinical AF (3574 patients). The RR for incident clinical AF was 3.34 (95%CI: 1.89-5.90, I²: 73%).

CONCLUSIONS

AHRE are significantly associated with systemic thromboembolism and incident clinical AF. Further studies are needed to improve patients' risk stratification and management.

Association between cardiac autonomic function and physical activity in patients at high risk of sudden cardiac death: a cohort study

Background

High levels of physical activity (PA) and heart rate variability (HRV) are associated with cardiovascular benefits in patients with cardiovascular diseases. HRV, representing cardiac autonomic function, is positively associated with PA. However, the impacts of PA and cardiac autonomic function on cardiovascular outcomes were not analysed in the same study population. This lack of evidence supported our hypothesis that PA might contribute to cardiovascular benefits via enhanced cardiac autonomic function.

Methods

Patients with implantable cardioverter defibrillator (ICD) or cardiac resynchronisation therapy defibrillator (CRT-D) implantation were included from the SUMMIT registry. HRV and PA values were assessed during the first 30–60 days post device implantation using a continuous home monitoring system. Causal mediation analysis was conducted to explore the possible mediation function of HRV in the association of PA with long-term cardiac death and all-cause mortality in patients at a high risk of sudden cardiac death.

Results

Over a mean follow-up period of 47.7 months, 63 cardiac deaths (18.9%) and 85 all-cause death events (25.5%) were observed among 342 patients with ICD/CRT-D implantation. A positive linear association between HRV and PA was demonstrated and the β value of HRV was 0.842 (95% confidence interval [CI]: 0.261–1.425, P = 0.005) in the multiple linear regression analysis. Multivariable Cox proportional hazards analysis revealed that high levels of PA (≥11.0%) and HRV (≥75.9 ms) were independent protective factors against cardiac death (PA: hazard ratio [HR] = 0.273; 95% CI, 0.142–0.526, P < 0.001; HRV: HR = 0.224; 95% CI, 0.103–0.489, P < 0.001) and all-cause mortality (PA: HR = 0.299; 95% CI, 0.177–0.505, P < 0.001; HRV: HR = 0.394; 95% CI, 0.231–0.674, P = 0.001). Causal mediation analysis demonstrated partial mediation effects of PA that were mediated through HRV on cardiac death (mediation proportion = 12.9, 95%CI: 2.2–32.0%, P = 0.006) and all-cause mortality (mediation proportion = 8.2, 95%CI: 1.6–20.0%, P = 0.006).

Conclusions

HRV might be a modest mediator in the association between high levels of PA and the reduced risks of cardiac death and all-cause mortality in ICD/CRT-D recipients. This finding supports that enhanced cardiac autonomic function might be one of the underlying mechanisms by which regular PA contributes to cardiovascular benefits.

Primary care heart failure service identifies a missed cohort of heart failure patients with reduced ejection fraction

AIMS

We explored whether a missed cohort of patients in the community with heart failure (HF) and left ventricular systolic dysfunction (LVSD) could be identified and receive treatment optimization through a primary care heart failure (PCHF) service.

METHODS AND RESULTS

PCHF is a partnership between Inspira Health, National Health Service Cardiologists and Medtronic. The PCHF service uses retrospective clinical audit to identify patients requiring a prospective face-to-face consultation with a consultant cardiologist for clinical review of their HF management within primary care. The service is delivered via five phases: (i) system interrogation of general practitioner (GP) systems; (ii) clinical audit of medical records; (iii) patient invitation; (iv) consultant reviews; and (v) follow-up. A total of 78 GP practices (864 194 population) have participated. In total, 19 393 patients' records were audited. HF register was 9668 (prevalence 1.1%) with 6162 patients coded with LVSD (prevalence 0.7%). HF case finder identified 9725 additional patients to be audited of whom 2916 patients required LVSD codes adding to the patient medical record (47% increase in LVSD). Prevalence of HF with LVSD increased from 0.7% to 1.05%. A total of 662 patients were invited for consultant cardiologist review at their local GP practice. The service found that within primary care, 27% of HF patients identified for a cardiologist consultation were eligible for complex device therapy, 45% required medicines optimization, and 47% of patients audited required diagnosis codes adding to their GP record.

CONCLUSION

A PCHF service can identify a missed cohort of patients with HF and LVSD, enabling the optimization of prognostic medication and an increase in device prescription.

A broken lead to an open heart: implantable cardioverter defibrillator vegetations with lead fracture

Implantable cardiac devices are widely used devices that serve several purposes. Complications from devices are not uncommon and include localized or systemic infections, device-related endocarditis, and device malfunction leading to serious outcomes, including death. Another possible complication that has been reported in the literature is thrombus formation on the device leads. We present a rare case of large thrombi forming on the leads of an implantable cardioverter defibrillator leading to lead fracture and device malfunction. After the device alerted for malfunction, the patient underwent a transesophageal echocardiogram which demonstrated masses on the right atrium and ventricle. He subsequently had a right atrial exploration and lead extraction which revealed large thrombi on the leads which histologically were identified as sterile vegetations.

New onset anxiety and depression in patients with an implantable cardioverter defibrillator during 24 months of follow-up (data from the national DEFIB-WOMEN study)

OBJECTIVE

To examine the cumulative incidence of and covariates' association with new onset anxiety and depression in implantable cardioverter defibrillator (ICD) patients during 24 months of follow-up in patients without depression and anxiety at implant.

METHODS

Patients (n = 1040; 155 (14.9%) women; mean age: 64.2 ± 10.6) with a first-time ICD enrolled in the national, multi-center prospective observational DEFIB-WOMEN study comprised the study cohort. We obtained information on demographic and clinical data from the Danish Pacemaker and ICD Register.

RESULTS

During 24 months of follow-up, 138 (14.5%) patients developed new onset anxiety and 109 (11.3%) new onset depression. Age ≥ 60 [HR:0.60;95%CI:0.40-0.90] and an anxiety score between 3 and 4 [HR:2.85; 95%CI:1.71-4.75] and 5-7 [HR:5.97; 95%CI:3.77-9.45] on the Hospital Anxiety and Depression Scale (HADS) were associated with different hazards of new onset anxiety during follow-up. Age ≥ 60 [HR:0.62;95%CI:0.42-0.93] and a HADS depression score between 3 and 4 [HR:2.99;95%CI:1.80-4.95] and 5-7 [HR:6.45; 95%CI:4.12-10.10] were associated with different hazards of new onset depression.

CONCLUSION

During 24 months of follow-up, respectively 14.5% and 11.3% of patients developed new onset anxiety and depression, suggesting that screening patients at several timepoints, and in particular those with even minimally elevated HADS scores at baseline, may be warranted to identify patients at risk for poor health outcomes.

Implantable vagus nerve stimulation system performance is not affected by internal or external defibrillation shocks

Purpose

Autonomic regulation therapy (ART) for heart failure (HF) is delivered using vagus nerve stimulation (VNS), and has been associated with improvement in cardiac function and HF symptoms. VNS is delivered using an implantable pulse generator (IPG) and a lead placed around the cervical vagus nerve. Because HF patients may receive concomitant cardiac defibrillation therapy, testing was conducted to determine the effect of defibrillation (DF) on VNS system performance.

Methods

Normal swine (n = 4) with VNS system implants on the right cervical vagus nerve received sequential defibrillation shocks with three defibrillation systems: an implantable cardioverter defibrillator (ICD), a subcutaneous ICD (S-ICD), and an external cardioverter defibrillator (ECD). Each system delivered a series of bipolar high-energy shocks and reverse-polarity high-energy shocks.

Results

The specified cardiac defibrillation shocks were delivered successfully from each of the three defibrillation systems to all animals. After each shock series, interrogation of the IPG confirmed that software and data were unchanged from pre-programmed values. After all of the defibrillation shocks were delivered, the IPGs underwent and passed comprehensive electrical testing demonstrating proper system function. No shifts in IPG parameters or ART system failures were observed, and histologic evaluation of the vagus nerve revealed no anatomic changes.

Conclusions

Implantable VNS systems were tested in vivo for immunity to defibrillation via ICD, S-ICD, and ECD, and were found to be unaffected by a series of high-energy defibrillation shocks. These results confirm that ART systems are capable of continuing to function after defibrillation and the cervical vagus nerve is anatomically unaffected.

Prediction of ventricular arrhythmia in phospholamban p.Arg14del mutation carriers-reaching the frontiers of individual risk prediction

Aims

This study aims to improve risk stratification for primary prevention implantable cardioverter defibrillator (ICD) implantation by developing a new mutation-specific prediction model for malignant ventricular arrhythmia (VA) in phospholamban (PLN) p.Arg14del mutation carriers. The proposed model is compared to an existing PLN risk model.

Methods and results

Data were collected from PLN p.Arg14del mutation carriers with no history of malignant VA at baseline, identified between 2009 and 2020. Malignant VA was defined as sustained VA, appropriate ICD intervention, or (aborted) sudden cardiac death. A prediction model was developed using Cox regression. The study cohort consisted of 679 PLN p.Arg14del mutation carriers, with a minority of index patients (17%) and male sex (43%), and a median age of 42 years [interquartile range (IQR) 27–55]. During a median follow-up of 4.3 years (IQR 1.7–7.4), 72 (10.6%) carriers experienced malignant VA. Significant predictors were left ventricular ejection fraction, premature ventricular contraction count/24 h, amount of negative T waves, and presence of low-voltage electrocardiogram. The multivariable model had an excellent discriminative ability {C-statistic 0.83 [95% confidence interval (CI) 0.78–0.88]}. Applying the existing PLN risk model to the complete cohort yielded a C-statistic of 0.68 (95% CI 0.61–0.75).

Conclusion

This new mutation-specific prediction model for individual VA risk in PLN p.Arg14del mutation carriers is superior to the existing PLN risk model, suggesting that risk prediction using mutation-specific phenotypic features can improve accuracy compared to a more generic approach.

Health status measured by Kansas City Cardiomyopathy Questionnaire-12 in primary prevention implantable cardioverter defibrillator patients with heart failure

Background

Self-reported health status as measured by the Kansas City Cardiomyopathy Questionnaire (KCCQ) in patients with primary prevention implantable cardioverter defibrillators (ICDs) has mainly been reported from randomized trials. However, these studies are often limited to short follow-up and are subject to selection bias. The aim of this study was to assess KCCQ-12 in patients with primary prevention ICD due to either ischemic or nonischemic heart failure.

Methods

This cross-sectional observational study included all patients in Region Gävleborg, Sweden, who because of primary prevention due to heart failure, had an ICD or underwent device replacement between 2007 and 2017. After validation using medical records patients were sent and returned the KCCQ-12 by regular mail.

Results

A total of 118 questionnaires were analyzed (response rate 71.1%). The mean age was 70.9 ± 9.8 years, and a minority was female (n = 20, 16.9%). The mean overall summary score was 71.5 ± 22.4, there was no significant difference between ischemic and nonischemic heart failure (69.5 ± 23.1 vs. 74.4 ± 21.3; p = 0.195). Atrial fibrillation at baseline was associated with lower score for the domains Symptom frequency (70.2 ± 23.2 vs. 82.2 ± 19.2; p = 0.006) and Social limitation (62.1 ± 26.0 vs. 75.6 ± 26.6; p = 0.006) as well as the overall summary score (63.9 ± 21.3 vs. 74.8 ± 22.2; p = 0.004).

Conclusion

In a real-world setting, primary prevention ICD patients with heart failure report an acceptable disease-specific health status at long-term follow-up. Ischemic and nonischemic etiology showed similar health status whereas atrial fibrillation was associated with worse outcome.

Phantom Shocks Associated With a Wearable Cardioverter Defibrillator

Wearable cardioverter defibrillators (WCDs) are external devices capable of continuous cardiac rhythm monitoring as well as automatic detection and defibrillation of potentially life-threatening arrhythmias such as ventricular tachycardia (VT) and ventricular fibrillation (VF). They are an alternative approach for patients when an implantable cardioverter defibrillator (ICD) is not appropriate. Although treatment with ICD is considered highly effective for the primary and secondary prevention of sudden cardiac death (SCD) in high-risk patients susceptible to VT and VF, patients may still experience psychological difficulties such as fear of shock, avoidance of normal behaviors and reduced quality of life. One of these phenomena is phantom shock (PS), which is defined as a perception of having received a shock with no evidence of recorded defibrillation upon device interrogation. While PS has been reported in the ICD literature, to the best of our knowledge, we present the first known case of WCD-related PS. We also present a review of the current literature to explore the prevalence of PS, the factors associated with its pathogenesis and interventional studies aimed at reducing its occurrence. We highlight this case because PS is considered a phenomenon that few recognize, which should be discriminated from real device shocks before clinicians initiate treatment, device reprogramming or device discontinuation. We describe the psychosocial factors associated with PS to emphasize the importance of managing any associated psychiatric disorders and psychosocial factors both before and after initiation of device treatment.

Corynebacterium striatum Cardiac Device-Related Infective Endocarditis: The First Case Report in a Patient With a Cardiac Resynchronization Therapy Defibrillator Device and Review of the Literature

Corynebacterium striatum (C. striatum) is a skin commensal agent, rarely described as a cause of infective endocarditis. We describe a case of a 48-year-old man, with multiple comorbidities with cardiac resynchronization therapy defibrillator (CRT-D) device implanted 1 year before. A cardiac device-related infective endocarditis (CDRIE) due to C. striatum, with vegetations in the tricuspid valve adjacent to the electrode lead and concomitant lumbar spondylodiscitis were diagnosed. The patient was treated initially with a 6-week course of vancomycin with sterile blood cultures and reduction of inflammatory parameters. Surgery was refused at this stage. Six weeks later, he was readmitted due to C. striatum bacteriemia recurrence, with vegetations adhering to the electrode wire, being treated with daptomycin 10mg/kg body weight, after presenting renal toxicity to vancomycin. CRT-D device was removed with implantation of epicardial cardiac resynchronization therapy pacemaker (CRT-P). To our knowledge, this might be the first description of C. striatum CDRIE in a patient with a CRT-D. In the five cases described in the literature of CDRIE by this agent, early removal of the pacemaker was performed with good results. In this case, the device was removed only after failure of medical treatment alone.

Deep Learning-Based Algorithm for the Detection and Characterization of MRI Safety of Cardiac Implantable Electronic Devices on Chest Radiographs

Objective

With the recent development of various MRI-conditional cardiac implantable electronic devices (CIEDs), the accurate identification and characterization of CIEDs have become critical when performing MRI in patients with CIEDs. We aimed to develop and evaluate a deep learning-based algorithm (DLA) that performs the detection and characterization of parameters, including MRI safety, of CIEDs on chest radiograph (CR) in a single step and compare its performance with other related algorithms that were recently developed.

Materials and Methods

We developed a DLA (X-ray CIED identification [XCID]) using 9912 CRs of 958 patients with 968 CIEDs comprising 26 model groups from 4 manufacturers obtained between 2014 and 2019 from one hospital. The performance of XCID was tested with an external dataset consisting of 2122 CRs obtained from a different hospital and compared with the performance of two other related algorithms recently reported, including PacemakerID (PID) and Pacemaker identification with neural networks (PPMnn).

Results

The overall accuracies of XCID for the manufacturer classification, model group identification, and MRI safety characterization using the internal test dataset were 99.7% (992/995), 97.2% (967/995), and 98.9% (984/995), respectively. These were 95.8% (2033/2122), 85.4% (1813/2122), and 92.2% (1956/2122), respectively, with the external test dataset. In the comparative study, the accuracy for the manufacturer classification was 95.0% (152/160) for XCID and 91.3% for PPMnn (146/160), which was significantly higher than that for PID (80.0%,128/160; p < 0.001 for both). XCID demonstrated a higher accuracy (88.1%; 141/160) than PPMnn (80.0%; 128/160) in identifying model groups (p < 0.001).

Conclusion

The remarkable and consistent performance of XCID suggests its applicability for detection, manufacturer and model identification, as well as MRI safety characterization of CIED on CRs. Further studies are warranted to guarantee the safe use of XCID in clinical practice.

2021 PACES Expert Consensus Statement on the Indications and Management of Cardiovascular Implantable Electronic Devices in Pediatric Patients

In view of the increasing complexity of both cardiovascular implantable electronic devices (CIEDs) and patients in the current era, practice guidelines, by necessity, have become increasingly specific. This document is an expert consensus statement that has been developed to update and further delineate indications and management of CIEDs in pediatric patients, defined as ≤21 years of age, and is intended to focus primarily on the indications for CIEDs in the setting of specific disease categories. The document also highlights variations between previously published adult and pediatric CIED recommendations and provides rationale for underlying important differences. The document addresses some of the deterrents to CIED access in low- and middle-income countries and strategies to circumvent them. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by class of recommendation and level of evidence. Several questions addressed in this document either do not lend themselves to clinical trials or are rare disease entities, and in these instances recommendations are based on consenus expert opinion. Furthermore, specific recommendations, even when supported by substantial data, do not replace the need for clinical judgment and patient-specific decision-making. The recommendations were opened for public comment to Pediatric and Congenital Electrophysiology Society (PACES) members and underwent external review by the scientific and clinical document committee of the Heart Rhythm Society (HRS), the science advisory and coordinating committee of the American Heart Association (AHA), the American College of Cardiology, (ACC) and the Association for European Paediatric and Congenital Cardiology (AEPC). The document received endorsement by all the collaborators and the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS). This document is expected to provide support for clinicians and patients to allow for appropriate CIED use, appropriate CIED management, and appropriate follow-up in pediatric patients.

2021 PACES Expert Consensus Statement on the Indications and Management of Cardiovascular Implantable Electronic Devices in Pediatric Patients

In view of the increasing complexity of both cardiovascular implantable electronic devices (CIEDs) and patients in the current era, practice guidelines, by necessity, have become increasingly specific. This document is an expert consensus statement that has been developed to update and further delineate indications and management of CIEDs in pediatric patients, defined as ≤21 years of age, and is intended to focus primarily on the indications for CIEDs in the setting of specific disease categories. The document also highlights variations between previously published adult and pediatric CIED recommendations and provides rationale for underlying important differences. The document addresses some of the deterrents to CIED access in low- and middle-income countries and strategies to circumvent them. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by class of recommendation and level of evidence. Several questions addressed in this document either do not lend themselves to clinical trials or are rare disease entities, and in these instances recommendations are based on consensus expert opinion. Furthermore, specific recommendations, even when supported by substantial data, do not replace the need for clinical judgment and patient-specific decision-making. The recommendations were opened for public comment to Pediatric and Congenital Electrophysiology Society (PACES) members and underwent external review by the scientific and clinical document committee of the Heart Rhythm Society (HRS), the science advisory and coordinating committee of the American Heart Association (AHA), the American College of Cardiology (ACC), and the Association for European Paediatric and Congenital Cardiology (AEPC). The document received endorsement by all the collaborators and the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS). This document is expected to provide support for clinicians and patients to allow for appropriate CIED use, appropriate CIED management, and appropriate CIED follow-up in pediatric patients.

2021 PACES Expert Consensus Statement on the Indications and Management of Cardiovascular Implantable Electronic Devices in Pediatric Patients: Executive Summary

Guidelines for the implantation of cardiac implantable electronic devices (CIEDs) have evolved since publication of the initial ACC/AHA pacemaker guidelines in 1984 [1]. CIEDs have evolved to include novel forms of cardiac pacing, the development of implantable cardioverter defibrillators (ICDs) and the introduction of devices for long term monitoring of heart rhythm and other physiologic parameters. In view of the increasing complexity of both devices and patients, practice guidelines, by necessity, have become increasingly specific. In 2018, the ACC/AHA/HRS published Guidelines on the Evaluation and Management of Patients with Bradycardia and Cardiac Conduction Delay [2], which were specific recommendations for patients >18 years of age. This age-specific threshold was established in view of the differing indications for CIEDs in young patients as well as size-specific technology factors. Therefore, the following document was developed to update and further delineate indications for the use and management of CIEDs in pediatric patients, defined as ≤21 years of age, with recognition that there is often overlap in the care of patents between 18 and 21 years of age.

This document is an abbreviated expert consensus statement (ECS) intended to focus primarily on the indications for CIEDs in the setting of specific disease/diagnostic categories. This document will also provide guidance regarding the management of lead systems and follow-up evaluation for pediatric patients with CIEDs. The recommendations are presented in an abbreviated modular format, with each section including the complete table of recommendations along with a brief synopsis of supportive text and select references to provide some context for the recommendations. This document is not intended to provide an exhaustive discussion of the basis for each of the recommendations, which are further addressed in the comprehensive PACES-CIED document [3], with further data easily accessible in electronic searches or textbooks.

Remote Monitoring of Permanent Pacemakers and Implantable Cardioverter Defibrillators

Remote monitoring of permanent pacemakers and implantable cardiac defibrillators has undergone considerable advances over the past several decades. Advancement of technology has created the ability for remote monitoring of implantable cardiac devices; a device can monitor its own function, record arrhythmias, and transmit data to health care providers without frequent in-office checks, shown to be as safe as in-office interrogation. Remote monitoring allows earlier detection of clinically actionable events, reduces incidence of inappropriate shocks, and allows earlier detection of atrial fibrillation. App-based remote monitoring provides patients with rapid access to their cardiac data, which may improve compliance with remote monitoring.

The prognostic role of late gadolinium enhancement on cardiac magnetic resonance in patients with nonischemic cardiomyopathy and reduced ejection fraction, implanted with cardioverter defibrillators for primary prevention. A systematic review and meta-analysis

BACKGROUND

Previous studies suggest that late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) is associated with arrhythmic events in patients with nonischemic cardiomyopathy (NICM), while others have questioned the role of left ventricular ejection fraction (LVEF) as a sole predictor of future events.

OBJECTIVES

To evaluate the role of LGE on CMR in identifying patients with NICM and reduced LVEF for whom a benefit from defibrillator implantation for primary prevention is not anticipated, thus they are mainly exposed to potential risks.

METHODS

Major electronic databases were searched for studies reporting the incidence of appropriate device therapy (ADT), sudden cardiac death (SCD), and cardiac death based on the presence of LGE on CMR, among patients with NICM and reduced LVEF, implanted with a cardioverter defibrillator for primary prevention.

RESULTS

Eleven studies (1652 patients, 947 with LGE) were included in the final analysis. LGE presence was strongly associated with ADT (logOR: 1.95, 95%CI: 1.21-2.69) and cardiac death (logOR: 0.91, 95%CI: 0.14-1.68), but not with SCD (logOR: 0.26, 95%CI: -1.09-1.6). Diagnostic accuracy analysis demonstrated that contrast enhancement is a sensitive marker of future ADT and cardiac death (93%, 95%CI: 85.8-96.7%; 82.9%, 95%CI: 70.6-90.7%; respectively), with moderate specificity ( 44%, 95%CI: 27.2-62.6%; 37.7%, 95%CI: 23.4-54.6%; respectively).

CONCLUSION

LGE is a highly sensitive predictor of ADT and cardiac death in NICM patients implanted with a defibrillator for primary prevention. However, due to moderate specificity, derivation of a cutoff with adequate predictive values and probably a multifactorial approach are needed to improve discrimination of patients who will not benefit from ICDs.

Sex-specific differences in outcome and risk stratification of ventricular arrhythmias in implantable cardioverter defibrillator patients

AIMS

Risk stratification models of sudden cardiac death (SCD) are based on the assumption that risk factors of SCD affect risk to a similar extent in both sexes. The aim of the study is to evaluate differences in clinical outcomes between sexes and evaluate whether risk factors associated with appropriate device therapy (ADT) differ between men and women.

METHODS AND RESULTS

We performed a cohort study of implantable cardioverter defibrillator (ICD) patients referred for primary or secondary prevention of SCD between 2009 and 2018. Multivariable Cox regression models for prediction of ADT were constructed for men and women separately. Of 2300 included patients, 571 (25%) were women. Median follow-up was 4.6 (inter-quartile range: 4.4-4.9) years. Time to ADT was shorter for men compared with women [hazard ratio (HR) 1.71, P < 0.001], as was time to mortality (HR 1.37, P = 0.003). In women, only secondary prevention ICD therapy (HR 1.82, P < 0.01) was associated with ADT, whereas higher age (HR 1.20, P < 0.001), absence of left bundle branch block (HR 0.72, P = 0.01), and secondary prevention therapy (HR 1.80, P < 0.001) were independently associated with ADT in men. None of the observed parameters showed a distinctive sex-specific pattern in ADT.

CONCLUSIONS

Male ICD patients were at higher risk of ADT and death compared with female ICD patients, irrespective of an ischaemic or non-ischaemic underlying cardiomyopathy. Our study highlights the importance to stratify outcomes of ICD trials by sex, as study results differ between men and women. However, none of the available clinical parameters showed a clear sex-specific relation to ventricular arrhythmias. As a consequence, sex-specific risk stratification models of SCD using commonly available clinical parameters could not be derived.

Prognostic value of cardiovascular magnetic resonance left ventricular volumetry and geometry in patients receiving an implantable cardioverter defibrillator

BACKGROUND

Current indications for implantable cardioverter defibrillator (ICD) implantation for sudden cardiac death prevention rely primarily on left ventricular (LV) ejection fraction (LVEF). Currently, two different contouring methods by cardiovascular magnetic resonance (CMR) are used for LVEF calculation. We evaluated the comparative prognostic value of these two methods in the ICD population, and if measures of LV geometry added predictive value.

METHODS

In this retrospective, 2-center observational cohort study, patients underwent CMR prior to ICD implantation for primary or secondary prevention from January 2005 to December 2018. Two readers, blinded to all clinical and outcome data assessed CMR studies by: (a) including the LV trabeculae and papillary muscles (TPM) (trabeculated endocardial contours), and (b) excluding LV TPM (rounded endocardial contours) from the total LV mass for calculation of LVEF, LV volumes and mass. LV sphericity and sphere-volume indices were also calculated. The primary outcome was a composite of appropriate ICD shocks or death.

RESULTS

Of the 372 consecutive eligible patients, 129 patients (34.7%) had appropriate ICD shock, and 65 (17.5%) died over a median duration follow-up of 61 months (IQR 38-103). LVEF was higher when including TPM versus excluding TPM (36% vs. 31%, p < 0.001). The rate of appropriate ICD shock or all-cause death was higher among patients with lower LVEF both including and excluding TPM (p for trend = 0.019 and 0.004, respectively). In multivariable models adjusting for age, primary prevention, ischemic heart disease and late gadolinium enhancement, both LVEF (HR per 10% including TPM 0.814 [95%CI 0.688-0.962] p = 0.016, vs. HR per 10% excluding TPM 0.780 [95%CI 0.639-0.951] p = 0.014) and LV mass index (HR per 10 g/m2 including TPM 1.099 [95%CI 1.027-1.175] p = 0.006; HR per 10 g/m2 excluding TPM 1.126 [95%CI 1.032-1.228] p = 0.008) had independent prognostic value. Higher LV end-systolic volumes and LV sphericity were significantly associated with increased mortality but showed no added prognostic value.

CONCLUSION

Both CMR post-processing methods showed similar prognostic value and can be used for LVEF assessment. LVEF and indexed LV mass are independent predictors for appropriate ICD shocks and all-cause mortality in the ICD population.

Cost-effectiveness of implantable cardioverter-defibrillators for primary prevention of sudden cardiac death

INTRODUCTION AND OBJECTIVES

Implantable cardioverter-defibrillators (ICD) are a cost-effective alternative for secondary prevention of sudden cardiac death, but their efficiency in primary prevention, especially among patients with nonischemic heart disease, is still uncertain.

METHODS

We performed a cost-effectiveness analysis of ICD plus conventional medical treatment (CMT) vs CMT for primary prevention of cardiac arrhythmias from the perspective of the national health service. We simulated the course of the disease by using Markov models in patients with ischemic and nonischemic heart disease. The parameters of the model were based on the results obtained from a meta-analysis of clinical trials published between 1996 and 2018 comparing ICD plus CMT vs CMT, the safety results of the DANISH trial, and analysis of real-world clinical practice in a tertiary hospital.

RESULTS

We estimated that ICD reduced the likelihood of all-cause death in patients with ischemic heart disease (HR, 0.70; 95%CI, 0.58-0.85) and in those with nonischemic heart disease (HR, 0.79; 95%CI, 0.66-0.96). The incremental cost-effectiveness ratio (ICER) estimated with probabilistic analysis was €19 171/quality adjusted life year (QALY) in patients with ischemic heart disease and €31 084/QALY in those with nonischemic dilated myocardiopathy overall and €23 230/QALY in patients younger than 68 years.

CONCLUSIONS

The efficiency of single-lead ICD systems has improved in the last decade, and these devices are cost-effective in patients with ischemic and nonischemic left ventricular dysfunction younger than 68 years, assuming willingness to pay as €25 000/QALY. For older nonischemic patients, the ICER was around €30 000/QALY.

Changes in quality of life, depression, general anxiety, and heart-focused anxiety after defibrillator implantation

Aims

The Anxiety‐CHF (Anxiety in patients with Chronic Heart Failure) study investigated heart‐focused anxiety (HFA, with the dimensions fear, attention, and avoidance of physical activity), general anxiety, depression, and quality of life (QoL) in patients with heart failure. Psychological measures were assessed before and up to 2 years after the implantation of an implantable cardioverter defibrillator (ICD) with or without cardiac resynchronization therapy defibrillator (CRT‐D).

Methods and results

One hundred thirty‐two patients were enrolled in this monocentric prospective study (44/88 CRT‐D/ICD, mean age 61 ± 14 years, mean left ventricular ejection fraction 31 ± 9%, and 29% women). Psychological assessment was performed before device implantation as well as after 5, 12, and 24 months. After device implantation, mean total HFA, HFA‐fear, HFA‐attention, general anxiety, and QoL improved significantly. Depression and HFA‐related avoidance of physical activity did not change. CRT‐D patients compared with ICD recipients and women compared with men reported worse QoL at baseline. Younger patients (<median of 63 years) had higher levels of general anxiety and lower levels of HFA‐avoidance at baseline than older patients. After 24 months, groups no longer differed from each other on these scores. Patients with a history of shock or anti‐tachycardia pacing (shock/ATP; N = 19) reported no improvements in psychological measures and had significantly higher total HFA and HFA‐avoidance levels after 2 years than participants without shock/ATP.

Conclusions

Anxiety and QoL improved after device implantation, and depression and HFA‐avoidance remained unchanged. HFA may be more pronounced after shock/ATP. Psychological counselling in these patients to reduce HFA and increase physical activity should be considered.

Driving following defibrillator implantation: a nationwide register-linked survey study

AIMS

Patients are restricted from driving following implantable cardioverter defibrillator (ICD) implantation or shock. We sought to investigate how many patients are aware of, and adhere to, the driving restrictions, and what proportion experience an ICD shock or other cardiac symptoms while driving.

METHODS AND RESULTS

We performed a nationwide survey of all living Danish residents 18 years or older who received a first-time ICD between 2013 and 2016 (n = 3913) and linked their responses with nationwide registers. Of 2741 respondents (47% primary prevention, 83% male, median age 67 years), 2513 (92%) held a valid driver's license at ICD implantation, 175 (7%) of whom had a license for professional driving. Many drivers were unaware of driving restrictions: primary prevention 58%; secondary prevention 36%; post-appropriate shock 28%; professional drivers 55%. Almost all (94%) resumed non-professional driving after ICD implantation, more than one-third during the restricted period; 35% resumed professional driving. During a median follow-up of 2.3 years, 5 (0.2%) reported receiving an ICD shock while driving, one of which resulted in a traffic accident. The estimated risk of harm was 0.0002% per person-year.

CONCLUSION

In this nationwide study, many ICD patients were unaware of driving restrictions, and more than one third resumed driving during a driving restriction period. However, the rate of reported ICD shocks while driving was very low.

Left ventricular involvement assessed by LGE-CMR in predicting the risk of adverse outcomes of arrhythmogenic cardiomyopathy with ICDs

BACKGROUND

Arrhythmogenic cardiomyopathy (ACM) is characterized by a high incidence of ventricular tachyarrhythmia and sudden death. Implantable cardioverter-defibrillator (ICD) implantation is the cornerstone of management.

OBJECTIVE

This study aims to reveal the prognostic value of the contrast-enhanced cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) amount in predicting varying lethal outcomes among ACM patients with ICDs.

METHODS

The 88 patients with definite ACM who were all referred for contrast-enhanced CMR received an ICD and were followed up for a median of 4.0 years.

RESULTS

Fifty-four patients had no left ventricular (LV) involvement and sixteen had an LV LGE amount > 15%. During the follow-up time, appropriate ICD therapy was seen in 57, electrical storm (ES) in 19, and cardiac death in 9 patients. Compared with those without LV involvement, patients with LV LGE amount > 15% had a higher risk of cardiac death (log-rank P = 0.021). LV LGE amount was associated with an increased risk of ICD therapy [adjusted hazard ratio (HR) 1.035, 95% confidence interval (CI) 1.008-1.062, P = 0.010], and cardiac death (adjusted HR 1.082, 95% 1.006-1.164, P = 0.034), independently of LV ejection fraction. LV LGE mass of >15% demonstrated an over 2-fold increase in ICD therapy (adjusted HR 2.180, 95%CI 1.058-4.488, P = 0.035) and an over 7-fold increase in cardiac death (unadjusted HR 7.198, 95%CI 1.399-37.043, P = 0.018) than those without LV involvement, respectively.

CONCLUSIONS

The LV LGE-CMR in ACM shows a dose-dependent association with ICD therapy and cardiac death. And LV LGE amount of >15% is a strong predictor.

Impact of COVID-19 lockdown in patients with implantable cardioverter and cardiac resynchronization therapy defibrillators: insights from daily remote monitoring transmissions

In Italy, a strict lockdown was imposed from 8 March 2020 to stop the spread of the coronavirus disease 2019 (COVID-19). We explored the effect of this lockdown on data transmitted by remote monitoring (RM) of implantable cardioverter and cardiac resynchronization therapy defibrillators (ICDs/CRT-Ds). RM daily transmissions from ICDs and CRT-Ds were analyzed and compared in two consecutive 1 month frames pre and post-lockdown: period I (7 February–7 March 2020) and period II (8 March–7 April 2020). The study cohort included 180 patients (81.1% male, 63.3% ICDs and 36.7% CRT-Ds) with a median age of 70 (interquartile range 62–78) years. The median value of physical activity provided by accelerometric sensors showed a significant reduction between period I and II [13.1% (8.2–18.1%) versus 9.4% (6.3–13.8%), p < 0.001]. Eighty nine % of patients decreased their activity, for 43.3% the relative reduction was ≥ 25%. The mean heart rate decreased significantly [69.2 (63.8–75.6) bpm vs 67.9 (62.7–75.3) bpm, p < 0.001], but with greater reduction (≈3 beats/minute) in patients aged < 70 years. Resting heart rate and thoracic impedance showed minor variations. No differences were observed in device pacing % and arrhythmias. In cardiac patients, the lockdown imposed to contain COVID-19 outbreak significantly reduced the amount of physical activity and the mean heart rate. These side effects of in-home confinement quarantine should be taken in consideration for frail patients.

Remote monitoring of implantable defibrillators is associated with fewer inappropriate shocks and reduced time to medical assessment in a remote and rural area

BACKGROUND

Implantable cardioverter defibrillators (ICDs) and cardiac resynchronisation therapy with defibrillators (CRT-D) reduce mortality in certain cardiac patient populations. However, inappropriate shocks pose a problem, having both adverse physical and psychological effects on the patient. The advances in device technology now allow remote monitoring (RM) of devices to replace clinic follow up appointments. This allows real time data to be analysed and actioned and this may improve patient care.

AIM

To determine if RM in patients with an ICD is associated with fewer inappropriate shocks and reduced time to medical assessment.

METHODS

This was a single centre, retrospective observational study, involving 156 patients implanted with an ICD or CRT-D, followed up for 2 years post implant. Both appropriate and inappropriate shocks were recorded along with cause for inappropriate shocks and time to medical assessment.

RESULTS

RM was associated with fewer inappropriate shocks (13.6% clinic vs 3.9% RM; P = 0.030) and a reduced time to medical assessment (15.1 ± 6.8 vs 1.0 ± 0.0 d; P < 0.001).

CONCLUSION

RM in patients with an ICD is associated with improved patient outcomes.

The efficacy of catheter ablation versus ICD for prevention of ventricular tachycardia in patients with ischemic heart disease: a systematic review and meta-analysis

Purpose

Although implantable cardioverter defibrillator (ICD) could prevent the sudden death of ventricular tachycardia (VT) in patients with ischemic heart disease, it could not effectively prevent the recurrence of ventricular tachycardia. Several studies have suggested that catheter ablation may effectively decrease the incidence of ICD events, but relevant dates from randomized controlled trials were limited.

Methods

A systematic review and meta-analysis of randomized controlled trials were performed to evaluate the effect of catheter ablation for the prevention of VT in patients with ischemic heart disease. Random-effects model with inverse-variance weighting method was used to pool odds ratios. Egger method was performed to evaluate whether there was public bias in each outcome.

Results

Four studies enrolling a total of 605 patients were included in the present meta-analysis. Compared with the control group (ICD ± AAD), catheter ablation could significantly reduce the incidence of ICD therapy (OR, 0.49; 95% CI, 0.28 ~ 0.87), ICD shock (OR, 0.50; 95% CI, 0.28 ~ 0.87), VT storm (OR, 0.60; 95% CI, 0.40 ~ 0.90), and cardiovascular-related hospitalization (OR, 0.66; 95% CI, 0.45 ~ 0.9). But there was no significant difference among the risk of all-cause mortality (OR, 0.89; 95% CI, 0.59 ~ 1.34), cardiovascular mortality (OR, 0.76; 95% CI, 0.44 ~ 1.30), and complication (OR, 0.89; 95% CI, 0.30 ~ 2.67).

Conclusion

These results showed that catheter ablation combined with ICD could reduce ICD therapy, ICD shock, and VT storm in patients with ischemic heart disease, but there was no improvement in all-cause mortality. Meanwhile, it also provided a basic guidance for the design of larger clinical randomized trials with longer follow-up in the future.

Electronic supplementary material

The online version of this article (10.1007/s10840-020-00848-1) contains supplementary material, which is available to authorized users.

Management and outcomes of hypertrophic cardiomyopathy in young adults

BACKGROUND

Management of young adults with hypertrophic cardiomyopathy (HCM) is challenging.

AIMS

To evaluate the profile of young adults (16-25 years) with HCM included in the French prospective HCM registry.

METHODS

Patients were compared according to occurrence of major adverse cardiac events (MACE), comprising sudden cardiac death (SCD) events (implantable cardioverter defibrillator [ICD] discharge, SCD, sustained ventricular tachycardia), atrial fibrillation/embolic stroke, heart failure hospitalisation and unexplained syncope, at a mean follow-up of 4.4±2.2 years.

RESULTS

At baseline, among 61 patients (20.5±3.0 years; 16 women, 26.2%), 13 (21.3%) had a prophylactic ICD, 24.6% a family history of SCD, 29.5% obstruction, 86.0% magnetic resonance imaging myocardial fibrosis, 11.8% abnormal exercise blood pressure and 52.8% a European Society of Cardiology (ESC) 5-year SCD score<4% (24.5%≥6%). At follow-up, 15 patients (24.6%; seven women; all with fibrosis) presented 17 MACE, comprising: SCD events (n=7, 41.2%; including three patients with an ICD, five with at least one SCD major classical risk factor and an ESC score≥5% and two with no risk factors and an ESC score<4%); atrial fibrillation/stroke (n=6, 35.3%); heart failure (n=1, 5.9%); syncope (n=3, 17.6%). An ICD was implanted in 11 patients (four for secondary prevention), but in only 61.5% of patients with a score≥6%. Only obstruction significantly increased MACE risk (odds ratio 3.96; P=0.035), with a non-significant trend towards a lower risk in men (OR 0.29; P=0.065).

CONCLUSIONS

In young adults with HCM, MACE are common in the short term, especially in obstructive HCM and women, mostly arrhythmic in origin. Prophylactic ICD implantation is frequent and does not strictly follow the guidelines, while the use of European/USA guidelines is helpful but imperfect in identifying SCD risk.

Downgrade of cardiac defibrillator devices to pacemakers in elderly heart failure patients: clinical considerations and the importance of shared decision-making

Implantable cardioverter defibrillators are implanted on a large scale in patients with heart failure (HF) for the prevention of sudden cardiac death. There are different scenarios in which defibrillator therapy is no longer desired or indicated, and this is occurring increasingly in elderly patients. Usually device therapy is continued until the device has reached battery depletion. At that time, the decision needs to be made to either replace it or to downgrade to a pacing-only device. This decision is dependent on many factors, including the vitality of the patient and his/her preferences, but may also be influenced by changes in recommendations in guidelines. In the last few years, there has been an increased awareness that discussions around these decisions are important and useful. Advanced care planning and shared decision-making have become important and are increasingly recognised as such. In this short review we describe six elderly patients with HF, in whose cases we discussed these issues, and we aim to provide some scientific and ethical rationale for clinical decision-making in this context. Current guidelines advocate the discussion of end-of-life options at the time of device implantation, and physicians should realise that their choices influence patients’ options in this critical phase of their illness.

Analysis of causes of death in patients with implanted defibrillators

AIMS

Implantable cardioverter defibrillators (ICDs) are used for primary or secondary prevention of sudden cardiac death. We sought to clarify prognosis and causes of death after ICD implantation.

METHODS AND RESULTS

A total of 2743 patients with ICDs implanted during 1990-2020 were analyzed. Median age was 68.5 (59.6-74.6) years; 21% women, median left ventricular ejection fraction (LVEF) was 30 (23-35), 52% had an ischemic etiology and 77% had a primary preventive indication. Mortality rate after 10 years was 22, 44, 55, and 72% in the 1st, 2nd, 3rd, and 4^th age quartile, respectively. The calculated median sex and age adjusted loss of life years compared to the average German population was 9.7 (6.1-14.0) years. Prognosis was independently related to sex, age, LVEF, and glomerular filtration rate. 713 out of 852 deaths could be classified to a specific cause. Congestive heart failure (CHF) accounted for death in 214 (30%) and sudden death (SD) for 144 patients (20%). Postmortem interrogation of devices in 74 patients revealed VT/VF in 39 and no episodes in 35 patients. Cancer was identified as the cause of death in 121 patients (17% of cases), of which 36 were bronchial carcinomas. 73 (10%) of patients died due to infection. 67 patients (9%) died within 24 h of procedures. Compared to other causes, significantly more life years were lost associated with procedures and SD: 9.3 (5.7-12.9) versus 12.1 (7.4-15.2) and 11.9 (7.6-17.8) years.

CONCLUSION

Life expectancy of ICD patients is lower than for the general population. Mortality is predominantly due to CHF, but there is still a considerable rate of SD. The occurrence of cancers, most importantly bronchial carcinomas, and infections, warrants protective measures. Some deaths during procedures are possibly preventable. Patients with ICDs comprise a vulnerable cohort, and treatment has to be optimized in many directions to improve prognosis.

Benefits of cardiac pacing in ICD recipients with hypertrophic cardiomyopathy

PURPOSE

Implantable cardiac defibrillator (ICD) is the only definitive therapy for prevention of sudden cardiac death in hypertrophic cardiomyopathy (HCM). Conventional transvenous ICDs can provide cardiac pacing unlike new subcutaneous ICD, but the usefulness of cardiac pacing in HCM patients is not well defined. We sought to assess the usefulness of ICD pacing in HCM.

METHODS

We retrospectively analyzed 93 HCM patients who had undergone ICD implantation at our center. Usefulness of pacing was defined as follows: 1) need of pacing due to bradycardia or AV conduction disturbances, 2) improvement of LV outflow tract obstruction by sequential AV pacing, 3) need for CRT pacing, or 4) successful antitachycardia pacing without a subsequent shock. Independent predictors of useful pacing were investigated by multivariable analysis.

RESULTS

During a mean follow-up of 91.3 ± 5.5 months, 43 patients (46.2%) reached the composite endpoint. Independent predictors of pacing usefulness were older age (HR 1.36; 95%CI: 1.088-1.709; p=0.007) and NYHA functional class ≥ II (HR 2.15; 95%CI: 1.083-4.301; p=0.029). Twenty-eight (30.1%) patients had appropriate ICD interventions, triggered by a monomorphic ventricular tachycardia (MVT) in 22 of them (78.5%). In 17 individuals with MVT (77%), antitachycardia pacing successfully treated MVT.

CONCLUSIONS

In our HCM series of patients with ICD, 46% of individuals benefitted from cardiac pacing. MVT were documented in nearly 80% of the patients with ventricular arrhythmias and antitachycardia pacing successfully treated them in 77% of cases.

Recent temporal trends in hospital costs for non-surgical patients receiving implantable cardioverter defibrillators

PURPOSE

Many studies have analyzed the cost-effectiveness of implantable cardioverter defibrillators (ICDs), but hospital costs have not been as thoroughly reported. This study reviewed the associated hospital costs for non-surgical patients who received ICDs from 2015 to 2019.

METHODS

We performed a retrospective single-center analysis of patients who received an ICD between 2015 and 2019. ICD cost was analyzed with respect to time using linear regression t-test analysis.

RESULTS

For 304 patients, we trended cost of the devices over time. 168 (55.2%) cases were single-chamber devices, 53 (17.4%) were dual-chamber, 59 (19.4%) were cardiac resynchronization therapy-defibrillators (CRT-D), and 24 (7.9%) were subcutaneous devices. The cost of all ICDs decreased by -$1.82/day (p<0.001), R² = 0.056. By type, cost of single-chamber devices decreased by -$2.56/day (p<0.001), R² = 0.47, dual-chamber ICD by -$3.50/day (p<0.001), R² = 0.51, CRT-D by -$4.07/day (p<0.001), R² = 0.47, and subcutaneous by -$3.33/day (p<0.001), R² = 0.83.

CONCLUSION

This is the first detailed analysis of ICD costs that we are aware of. The cost of all ICDs decreased modestly and became much greater when categorized by type. Overall hospital cost associated with ICD implantation did not show a significant trend, but total supply cost showed a significant decrease over time.

Secondary Prevention of Potentially Life-Threatening Arrhythmia Using Implantable Cardioverter Defibrillators in Patients with Biopsy-Proven Viral Myocarditis and Preserved Ejection Fraction

BACKGROUND

Arrhythmia and sudden cardiac death (SCD) are known complications of acute viral myocarditis, regardless of ejection fraction (EF) at presentation. Whether such complications confer long-term risk is unknown, especially in those who present with preserved left ventricular (LV) function. No guidelines exist to the long-term reduction of arrhythmic death in such patients.

METHOD

In this retrospective study, we analyzed the long-term results of implantable cardioverter defibrillator (ICD) treatment in patients after an acute phase of myocarditis with life-threatening arrhythmia.

RESULTS

We identified 51 patients who had ICDs implanted following life-threatening arrhythmia presentation of confirmed acute viral myocarditis, despite preserved LVEF. Overall, 72.5% of patients had a clinical history of chest pain and viral infection with fever. Viral myocarditis was confirmed by cardiac magnetic resonance imaging (all had late enhancement) plus endomyocardial biopsies (most frequent were Epstein-Barr virus 29.4%, adenovirus 17.6%, and Coxsackie 17.6%), and 88.2% were discharged on anti-arrhythmic drugs. Overall, 12 patients (23.5%) required ICD intervention within the first 3 months, a further 7 patients (37.3% overall) between 3 and 12 months, and a further 12 patients (60.8% overall) until 58 months. During the follow-up, 3 of 51 patients (5.9%) died-deaths were due to cardiac events (n = 1), fatal infection (n = 1), and car accidents (n = 1). Of the 31 patients who had ventricular tachycardias after the acute phase of myocarditis, 11 needed radiofrequency ablation due to a high number of events or electrical storm. No baseline variables were identified that would serve as a basis for risk stratification.

CONCLUSION

Malignant arrhythmic events due to viral myocarditis are potential predictors of future SCD in patients not only with a reduced but also with a preserved EF.

Usefulness of remote monitoring for the early detection of back-up mode in implantable cardioverter defibrillators

BACKGROUND

Reversion of an implantable cardioverter defibrillator (ICD) to back-up mode degrades the operating capabilities of the device, puts patients at risk and requires rapid intervention by a manufacturer's technician.

AIM

To illustrate the usefulness of remote monitoring of ICDs for the early detection of reversion to back-up mode.

METHODS

In our centre, all patients implanted with an ICD, with or without resynchronisation, were offered remote monitoring as soon as the technology became available. Alerts triggered by the remote monitoring system were included prospectively in a register. During a mean follow-up of 5.7±1.3 years, a total of 1594 patients with an ICD (441 with resynchronisation function) followed with remote monitoring were included in the register.

RESULTS

Among 15,874 alerts, only 10 were related to a reversion to back-up mode. Among those, seven reversions were caused by radiotherapy, two were fake events and one was caused by magnetic resonance imaging. Except for the two fake events, the eight other patients had an emergency admission for the resetting and reprogramming of their ICD. None of the reversion to back-up mode alerts was followed by a clinical alert (i.e. a shock alert) before the ICD problem was resolved.

CONCLUSIONS

Reversion to back-up mode is a very rare event, accounting for 0.06% of total alerts; remote monitoring facilitates the early detection of this critical event to resolve the problem faster than the next scheduled follow-up. Remote monitoring can prevent serious damage to the patient and avoids systematic ambulatory control of the ICD after each radiotherapy session.

Remote monitoring temporal trends during COVID-19 pneumonia in patients with implanted defibrillators

It is unknown whether some of the clinical parameters transmitted by remote monitoring (RM) of cardiac implanted devices could show recurrent patterns caused by COVID-19 infection. Our aim was to describe RM daily temporal trends for implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy defibrillator (CRT-D) recipients during COVID-19 infection. A 65-year-old woman with a CRT-D had a sudden increase of approximately 15 bpm and 10 bpm in nocturnal and mean heart rate, respectively, 11 days before hospitalization for COVID-19 pneumonia. At the same time physical activity decreased progressively and continuously. A 78-year-old woman with an ICD showed significant changes in RM trends starting from the COVID-19-related symptoms: strong decrease in physical activity, progressive increase in mean and nocturnal heart rate, irregular trend of heart rate variability, and rapid drop in thoracic impedance. Two months later, on hospitalization, computed tomography showed a "crazy-paving" pattern of the lungs, which is a clinical picture of COVID-19 pneumonia with concomitant pleural effusion. <Learning objective: Patients with complications related to the COVID-19 infection appeared to show variations in the remote monitoring (RM) temporal trends of clinical variables daily transmitted from implanted cardiac devices. These changes may not be specific to COVID-19, but owing to the severity of the pandemic, the use of RM to capture patient's condition makes intuitive sense for early diagnosis, intervention, and additional follow-up in this high-risk population.>.

Rationale and feasibility of the atrioventricular single-lead ICD systems with a floating atrial dipole (DX) in clinical practice

Cardiac implantable electronic devices establish proper therapy for the prevention of sudden cardiac death, significantly reducing the morbidity and mortality of patients with arrhythmias and heart failure. It is well-known that the number of electrodes increases the risk of complications. To preserve the benefit of atrial sensing without the need to implant an additional lead, a single-lead ICD system with a floating atrial dipole (DX ICD lead) has been developed. Besides all of the potential benefits, the necessity of a reliable and stable atrial sensing via the floating dipole could be the main concern against the use of this lead type. In the current generation of DX devices, the specially filtered atrial signal seems to be high enough and stable over time, which is crucial in the early detection of atrial arrhythmias, discrimination between different forms of tachycardias in order to prevent inappropriate ICD therapy, and achieving an optimal atrioventricular and interventricular synchrony in patients with a two-lead CRT-DX system. The present review summarizes the benefits and potential drawbacks of the DX ICD systems based on the available literature, furthermore, proposes an evidence-based algorithm of ICD type selection.

Prognosis of Japanese Patients With Coronary Artery Disease Who Underwent Implantable Cardioverter Defibrillator Implantation - The JID-CAD Study

Background: There has been no large multicenter clinical trial on the prognosis of implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy with a defibrillator (CRT-D) in Japanese patients with coronary artery disease (CAD). The aim of the present study was to compare differences in the prognoses of Japanese patients with CAD between primary and secondary prevention, and to identify potential predictors of prognosis.

Methods and Results: We investigated 392 CAD patients (median age 69 years, 90% male) treated with ICD/CRT-D enrolled in the Japan Implantable Devices in CAD (JID-CAD) Registry. The primary endpoint was all-cause death, and the secondary endpoint was appropriate ICD therapies. Endpoints were assessed by dividing patients into primary prevention (n=165) and secondary prevention (n=227) groups. The mean (±SD) follow-up period was 2.1±0.9 years. The primary endpoint was similar in the 2 groups (P=0.350).

Conclusions: The mortality rate in Japanese patients with CAD who underwent ICD/CRT-D implantation as primary prevention was not lower than that of patients who underwent ICD/CRT-D implantation as secondary prevention, despite the lower cardiac function in the patients undergoing ICD/CRT-D implantation as primary prevention.

Safety of lung stereotactic ablative radiotherapy for the functioning of cardiac implantable electronic devices

BACKGROUND AND PURPOSE

The prevalence of patients with a cardiac implantable device (CIED) developing cancer and requiring a course of radiotherapy (RT) is increasing remarkably. Previously published reports agree that standard and conventionally fractionated RT is usually safe for CIEDs, but no "in-vivo" reports are available on the potential effects of thoracic stereotactic ablative radiotherapy (SABR) regimens to CIEDs functioning. The purpose of our study is therefore to evaluate the effects of SABR on CIEDs (pacemakers [PM] or implantable cardiac defibrillators [ICD]) in a cohort of patients affected by primary or metastatic lung lesions.

MATERIALS AND METHODS

We retrospectively collected all CIED-bearing patients undergoing SABR between 2007 and 2019 at our Institution. All CIEDs were interrogated before and after the SABR course to check for any malfunction. Prescription dose, beam energy and maximum dose (Dmax) to CIEDs were retrieved for each patient. Electrical records of the CIEDs were reviewed by the medical records.

RESULTS

Thirty-four consecutive patients (24 with a PM and 10 with an ICD), who underwent 38 separate SABR courses, were included in the study. Eight patients (24%) were PM-dependent. Prescription dose of SABR ranged 26-60 Gy in 1-8 fractions, with a photon energy ranging 6-to-10 MV (76.3% and 23.7%, respectively) and a median Dmax to CIEDs of 0.17 Gy (range 0.04-1.97 Gy). Electrical parameters were stable in post-treatment device programming visits and no transient or persistent alteration of the CIED function was recorded in any patient. No inappropriate interventions were recorded in the 10 ICD-bearing patients during the treatment fractions.

CONCLUSIONS

Thoracic SABR proved to be safe for CIEDs when the dose is kept <2 Gy and the beam energy is ≤10 MV, irrespective of the pacing-dependency and of the CIED type.

Antibiotic Prophylaxis and Treatment in Early Cardiac Implantable Electronic Devices Infection

Background

Cardiac implantable electronic devices - PM, ICD, and CRTs- are well-proven life-sustaining and the ultimate destination for many heart conditions. Based on scientific evidence, there is a worldwide incremental increase in CIED implantations numbers.

Objective

Early infection of cardiac implantable electronic devices (CIED)- pacemaker (PM), implantable cardioverter-defibrillator (ICD), and cardiac resynchronization therapy (CRT)- is a growing health challenge. We examined the effectiveness of antibiotic prophylaxis and treatment of early infection of CIED in a single center.

Methods

This is a retrospective, single-center observational study. Data were collected from patients' records from July 2017-July, 2019. All Patients received intravenous ceftriaxone 2gm before incision, Gentamicin 120mg pocket irrigation, and oral Amoxicillin/Clavulanate for 5 days post-implantation.

Results

A 639 consecutive CIED implantations - PM (n=474, mean age, 64yr, female=49%), ICD (n=106, mean age 56yr, female=17%) and CRT (n=59, mean age, 54yr, female=20%)- were performed over 3years. The incidence of early infection was 1.9% (12 cases), female=41%. PM=5/474, ICD=5/106, and CRT=2/59. Three out of the 12 patients had total device explant due to pocket abscess; one PM had a generator changed; one ICD who had a pneumothorax, and the third one had reimplantation after ICD lead perforation. Nine cases were managed conservatively using saline dressing and oral Amoxicillin/Clavulanate, 3/9 patients developed a hematoma, 4/9 patients developed purulent suture line infection. None of them had infection recurrence on three months follow up.

Conclusion

Early infection of CIED is a rare complication with multiple predisposing factors. Our protocol is reassurance and prompt initiation of management protocol to prevent and treat this issue's sequences.

Comparison of cost-effectiveness of implantable cardioverter defibrillator therapy in patients for primary prevention in Latin America: an analysis using the Improve SCA study

OBJECTIVE

The mortality benefit of implantable cardioverter defibrillators (ICDs) for primary prevention (PP) of sudden cardiac arrest (SCA) has been well-established, but ICD therapy remains globally underutilized. The results of the Improve SCA study showed a 49% relative risk reduction in all-cause mortality among ICD patients with 1.5 primary prevention (1.5PP) characteristics (patients with one or more risk factors, p < 0.0001). We evaluated the cost-effectiveness of ICD compared to no ICD therapy among patients with 1.5PP characteristics in three Latin American countries and analyzed the factors involved in cost-effectiveness.

METHODS

We used a published Markov model that compares costs and outcomes of ICD to no ICD therapy from local payers' perspective and included country-specific and disease-specific inputs from the Improve SCA study and current literature. We used WHO-recommended willingness-to-pay (WTP) thresholds to assess cost-effectiveness and compared model outcomes between countries.

RESULTS

Incremental costs per QALY (quality-adjusted life year) saved by ICD compared to no ICD therapy are Colombian Pesos COP$46,729,026 in Colombia, Mexican Pesos MXN$246,016 in Mexico, and Uruguayan Pesos UYU$1,213,614 in Uruguay in the base case scenario; all three figures are between 1-3-times GDP per capita for each country. One-way and probabilistic sensitivity analyses confirm the base case scenario results. Non-cardiac accumulated deaths are lower in Mexico, resulting in a comparatively increased cost-effective ICD therapy.

LIMITATIONS

The Improve SCA study was not randomized, so clinical results could be biased; however, measures were taken to reduce this bias. Costs and benefits were modelled beyond the timeline of direct observation in the Improve SCA study.

CONCLUSIONS

ICD therapy is cost-effective in Mexico and Uruguay and potentially cost-effective in Colombia for a 1.5PP population. Variability in ICER estimates by country can be explained by differences in non-cardiac deaths and cost inputs.

Remote monitoring and telemedicine in heart failure: implementation and benefits

PURPOSE OF REVIEW

Remote monitoring (RM) of cardiac implantable electronic devices (CIEDs) is recommended as part of the individualized multidisciplinary follow-up of heart failure (HF) patients. Aim of this article is to critically review recent findings on RM, highlighting potential benefits and barriers to its implementation.

RECENT FINDINGS

Device-based RM is useful in the early detection of CIEDs technical issues and cardiac arrhythmias. Moreover, RM allows the continuous monitoring of several patients' clinical parameters associated with impending HF decompensation, but there is still uncertainty regarding its effectiveness in reducing mortality and hospitalizations. Implementation of RM strategies, together with a proactive physicians' attitude towards clinical actions in response to RM data reception, will make RM a more valuable tool, potentially leading to better outcomes.

Comparison of second appropriate defibrillator therapy occurrence in patients implanted for primary prevention and secondary prevention - Sub-analysis of the Nippon Storm Study

Background

Patients with implantable cardioverter defibrillator (ICD) use for primary prevention (primary prevention patients) of sudden cardiac death have lower incidence of appropriate ICD therapy (app-Tx) compared with those with ICD use for secondary prevention (secondary prevention patients). However, detail analysis of a second app-Tx after a first app-Tx is still lacking.

Objective

This study aimed to compare the incidence of a second app-Tx in primary vs secondary prevention patients.

Methods

We conducted sub-analysis of the Nippon Storm Study, which was a prospective, observational study involving 985 patients with structural heart disease (left ventricular ejection fraction ≤ 50%). Of these, we selected 251 patients (62 ± 14 years old, 82% men) who experienced at least one appropriate ICD therapy, and compared occurrence of a second app-Tx between primary (n = 116) and secondary (n = 135) prevention patients.

Results

There was no significant difference in the incidence of a second app-Tx between primary and secondary prevention patients (the cumulative incidence for a second app-Tx was 59% at 1 year and 79% at 3 years in primary prevention patients vs the cumulative incidence for the second app-Tx was 59% at 1 year and 75% at 3 years in secondary prevention patients).

Additionally, we evaluated the incidence of a second app-Tx according to basal structural disease (ischemic and non-ischemic cardiomyopathy) and found no significant difference between primary and secondary prevention patients.

Conclusion

Once app-Tx occurs, primary prevention patients acquire the high risk of subsequent ventricular arrhythmias because there is a comparable incidence of a second app-Tx in secondary prevention patients.

A Qualitative Analysis of Patient-Related Factors Associated With Implantable Cardioverter Defibrillator Acceptance

INTRODUCTION

Patient-related factors determining implantable cardioverter-defibrillator (ICD) use for primary prevention of sudden cardiac death in patients with cardiomyopathy have not been well explored. To assess race and sex differences regarding ICD preferences in this patient population, we sought to analyze a diverse cohort of patients with heart failure (HF) with reduced ejection fraction.

METHODS

We conducted qualitative interviews of 28 adults with severe HF and either (1) an ICD or (2) no ICD. Interviews were recorded, transcribed, and coded using an inductively developed codebook by independent investigators. Coding was fully adjudicated and transcripts were reviewed to identify themes.

RESULTS

We recruited patients between 12/2015 and 06/2017, primarily from the outpatient cardiology clinic (24/28 = 86%). Half were women (50%) and 13/28 (46%) were black. Eight did not have an ICD. Neither race nor sex was associated with ICD. Four themes emerged: (1) HF requiring an ICD is profoundly disruptive to patients' lives; (2) patients had positive, yet unrealistic opinions of ICDs; or (3) Patients had negative/ambivalent opinions of ICDs; (4) medical decision-making included aspects of shared decision-making and informed consent.

CONCLUSIONS

Patients without ICDs perceived less benefit from ICDs and had less decision support. Participants viewed conversations with providers as insufficient. Needed interventions include the development and validation of processes for informed decisions about ICDs.