A multiparametric heart failure score at baseline is associated with long-term outcome in patients with remotely monitored implantable cardioverter-defibrillators: A pooled analysis of nine clinical trials.

BACKGROUND: To predict worsening heart failure hospitalizations (WHFHs), the HeartInsight multiparametric algorithm calculates a Heart Failure (HF) Score based on temporal trends of physiologic parameters obtained through automatic daily remote monitoring of implantable cardioverter-defibrillators (ICDs). OBJECTIVE: We studied the association of the baseline HF Score (BHFScore), determined at algorithm activation, with long-term patient outcomes. METHODS: Data from nine clinical trials were pooled, including 1,841 ICD patients with a pre-implant ejection fraction ≤35%, NYHA class II/III, and no long-standing atrial fibrillation. Primary endpoint was a composite of death or WHFH. RESULTS: After a median follow-up of 631 days (interquartile range, 385-865), there were 243 WHFHs in 173 patients (9.4%) and 122 deaths (6.6%), 52 of which (42.6%) were cardiovascular. Primary endpoint occurred in 265 patients (14.4%). A multivariable time-to-first event analysis showed that a high BHFScore (>23, as determined by a time-dependent receiver operating characteristics curve analysis) was significantly associated with the occurrence of primary endpoint (adjusted hazard ratio [HR], 2.05; 95%-confidence interval [CI], 1.54-2.71; p<0.0001), all-cause death (HR, 2.37; CI, 1.56-3.58; p<0.0001), cardiovascular death (HR, 2.19; CI, 1.14-4.22; p=0.019), and WHFH (HR, 1.91; CI, 1.35-2.71; p=0.0003). In a hierarchical event analysis of all-cause death as the outcome with highest priority and WHFHs as repeated-event outcomes, the win-ratio was 2.47 (CI, 1.89-3.24; p<0.0001). CONCLUSIONS: Based on a retrospective analysis of clinical trial data with adjudicated events, baseline HF Score derived from device-monitored variables was able to stratify patients at higher long-term risk of death or WHFH.

The arrhythmic substrate of hypertrophic cardiomyopathy using ECG imaging.

Introduction: Patients with hypertrophic cardiomyopathy (HCM) are at risk for lethal ventricular arrhythmia, but the electrophysiological substrate behind this is not well-understood. We used non-invasive electrocardiographic imaging to characterize patients with HCM, including cardiac arrest survivors. Methods: HCM patients surviving ventricular fibrillation or hemodynamically unstable ventricular tachycardia (n = 17) were compared to HCM patients without a personal history of potentially lethal arrhythmia (n = 20) and a pooled control group with structurally normal hearts. Subjects underwent exercise testing by non-invasive electrocardiographic imaging to estimate epicardial electrophysiology. Results: Visual inspection of reconstructed epicardial HCM maps revealed isolated patches of late activation time (AT), prolonged activation-recovery intervals (ARIs), as well as reversal of apico-basal trends in T-wave inversion and ARI compared to controls (p < 0.005 for all). AT and ARI were compared between groups. The pooled HCM group had longer mean AT (60.1 ms vs. 52.2 ms, p < 0.001), activation dispersion (55.2 ms vs. 48.6 ms, p = 0.026), and mean ARI (227 ms vs. 217 ms, p = 0.016) than structurally normal heart controls. HCM ventricular arrhythmia survivors could be differentiated from HCM patients without a personal history of life-threatening arrhythmia by longer mean AT (63.2 ms vs. 57.4 ms, p = 0.007), steeper activation gradients (0.45 ms/mm vs. 0.36 ms/mm, p = 0.011), and longer mean ARI (234.0 ms vs. 221.4 ms, p = 0.026). A logistic regression model including whole heart mean activation time and activation recovery interval could identify ventricular arrhythmia survivors from the HCM cohort, producing a C statistic of 0.76 (95% confidence interval 0.72-0.81), with an optimal sensitivity of 78.6% and a specificity of 79.8%. Discussion: The HCM epicardial electrotype is characterized by delayed, dispersed conduction and prolonged, dispersed activation-recovery intervals. Combination of electrophysiologic measures with logistic regression can improve differentiation over single variables. Future studies could test such models prospectively for risk stratification of sudden death due to HCM.

Identifying genomic variant associated with long QT syndrome type 2 in an ecuadorian mestizo individual: a case report.

Introduction: Long QT syndrome (LQTS) is an autosomal dominant inherited cardiac condition characterized by a QT interval prolongation and risk of sudden death. There are 17 subtypes of this syndrome associated with genetic variants in 11 genes. The second most common is type 2, caused by a mutation in the KCNH2 gene, which is part of the potassium channel and influences the final repolarization of the ventricular action potential. This case report presents an Ecuadorian teen with congenital Long QT Syndrome type 2 (OMIM ID: 613688), from a family without cardiac diseases or sudden cardiac death backgrounds. Case presentation: A 14-year-old girl with syncope, normal echocardiogram, and an irregular electrocardiogram was diagnosed with LQTS. Moreover, by performing Next-Generation Sequencing, a pathogenic variant in the KCNH2 gene p.(Ala614Val) (ClinVar ID: VCV000029777.14) associated with LQTS type 2, and two variants of uncertain significance in the AKAP9 p.(Arg1654GlyfsTer23) (rs779447911), and TTN p. (Arg34653Cys) (ClinVar ID: VCV001475968.4) genes were identified. Furthermore, ancestry analysis showed a mainly Native American proportion. Conclusion: Based on the genomic results, the patient was identified to have a high-risk profile, and an implantable cardioverter defibrillator was selected as the best treatment option, highlighting the importance of including both the clinical and genomics aspects for an integral diagnosis.

Device programing and SMART pass algorithm activation in subcutaneous implantable defibrillator patients: Data from a remote monitoring database.

BACKGROUND: The programing of subcutaneous implantable cardioverter-defibrillators (S-ICD) in clinical practice has been little studied, as the activation status of the SMART Pass filter, which was implemented to reduce inappropriate shocks. PURPOSE: We assessed device programing during follow-up and the rate of detected arrhythmias in consecutive S-ICD recipients. METHODS: We analyzed data from 670 S-ICD patients followed on the remote network at 17 Italian centers for a median of 31 months (25th-75th percentile: 16-51). The enhanced SMART Pass version, introduced in October 2022, was expected to reduce the unintentional deactivation rate. RESULTS: At the latest remote data transmission, the median conditional zone cut-off was set to 210 bpm (25th-75th percentile: 200-220), the shock zone cutoff was 250 bpm (25th-75th percentile: 240-250), and the SMART Pass was enabled in 586 (87%) patients. During follow-up, 194 automatic deactivation events were reported in 118 (18%) patients. Shocks were delivered in 129 (19%) patients, and untreated arrhythmias were recorded in 136 (20%) patients. The rate of shocks was lower when SMART Pass was enabled -0.12/patient-year (95% CI: 0.10-0.14) versus 0.20 (95% CI: 0.15-0.26) (p = .002), as it was the rate of untreated arrhythmias -0.12/patient-year (95% CI: 0.11-0.14) versus 0.23 (95% CI: 0.18-0.30) (p = .001). The enhanced SMART Pass version was associated with a lower rate of deactivations -0.04/patient-year (95% CI: 0.02-0.05) versus 0.14 (95% CI: 0.12-0.16) (p < .001), and with a reduction in treated and untreated arrhythmias (Incidence rate ratios: 0.40 (95% CI: 0.28-0.53) and 0.40 (95% CI: 0.30-0.55), respectively (p < .001)). CONCLUSIONS: Centers tend to program devices to detect high ventricular rates for arrhythmia detection, to minimize inappropriate shock occurrences. SMART Pass activation is associated with lower rates of detected and treated arrhythmias. The enhanced SMART Pass version seems associated with a lower deactivation rate and with a further decrease in treated arrhythmias.

Inflammatory biomarkers as predictors of systemic vs isolated pocket infection in patients undergoing transvenous lead extraction.

Background: Cardiovascular implantable electronic device (CIED) infections are a common indication for device extraction. Early diagnosis and complete system removal are crucial to reduce morbidity and mortality. The lack of clear infectious symptoms makes the diagnosis of pocket infections challenging and may delay referral for extraction. Objective: We aimed to determine if inflammatory biomarkers can help diagnose CIED isolated pocket infection. Methods: We performed a retrospective analysis of all patients undergoing transvenous lead extraction for CIED infection at the University of California San Diego from 2012 to 2022 (N = 156). Patients were classified as systemic infection (n = 88) or isolated pocket infection (n = 68). Prospectively collected preoperative procalcitonin (PCT), C-reactive protein, and white blood cell count were compared between groups. Results: Pairwise comparisons revealed that the systemic infection group had a higher PCT than the control group (P < .001) and the pocket infection group (P = .009). However, there was no significant difference in PCT value between control subjects and isolated pocket infection subjects. Higher white blood cell count was only associated with systemic infection when compared with our control group (P = .018). Conclusion: In patients diagnosed with CIED infections requiring extraction, inflammatory biomarkers were not elevated in isolated pocket infection. Inflammatory markers are not predictive of the diagnosis of pocket infections, which ultimately requires a high level of clinical suspicion.

Failure to defibrillate or cardiovert due to premature truncation of biphasic shocks from implantable defibrillators.

BACKGROUND: In 2022 and 2023, Medtronic recalled implantable defibrillators because they may deliver less than full-energy shocks. The 2022 problem truncates the second phase of the waveform (SCP-T2), resulting in ∼32-J shocks, and is mitigated by downloadable software. The 2023 malfunction truncates the first phase of the waveform, resulting in 0- to 12-J shocks due to a glassed feedthrough problem (GFT-T1) that might be avoided by programming B>AX shock polarity. OBJECTIVE: The purpose of this study was to assess the consequences of GFT-T1 and SCP-T2 shocks in the Food and Drug Administration's Manufacturers and User Facility Device Experience (MAUDE) database and to estimate the incidences of GFT-T1 and SCP-T2. METHODS: We analyzed MAUDE reports supplemented by Medtronic data; lead failures were excluded. The incidences of SCP-T2 and GFT-T1 were estimated using USA volumes for devices with glassed feedthroughs. RESULTS: One hundred thirty-two devices delivered truncated shocks: 27 (20.5%) were GFT-T1; 103 (78.0%) were SCP-T2; and 2 (1.5%) truncated both phases (BOTH-T1&2). Of 54 ventricular fibrillation (VF) patients, 21 (38.9%) were not defibrillated by truncated shocks: 8 (38.1%) received GFT-T1 shocks, 12 (57.1%) received SCP-T2 shocks, and 1 received a BOTH-T1&2 shock; 2 patients suffered unrelated deaths; 1 was externally rescued; 1 outcome was unknown; the others were defibrillated by subsequent shocks or terminated spontaneously. The majority of patients (79.1%) shocked for ventricular tachycardia (VT) were converted, primarily (94.1%) by SCP-T2 shocks. Estimated incidences of GFT-T1 and SCP-T2 were 0.0078%-0.0088% and 0.1062%-0.1110%. CONCLUSION: GFT-T1 and SCP-T2 shocks can result in failure to terminate VF/VT, but they may be preventable. Although the incidences of these truncated shocks are very low, heightened surveillance is warranted.

DOACs vs Vitamin K Antagonists During Cardiac Rhythm Device Surgery: A Multicenter Propensity-Matched Study.

BACKGROUND: There is a paucity of data comparing vitamin K antagonists (VKAs) to direct oral anticoagulants (DOACs) at the time of cardiac implantable electronic device (CIED) surgery. Furthermore, the best management of DOACs (interruption vs continuation) is yet to be determined. OBJECTIVES: This study aimed to compare the incidence of device-related bleeds and thrombotic events based on anticoagulant type (DOAC vs VKA) and regimen (interrupted vs uninterrupted). METHODS: This was an observational multicenter study. We included patients on chronic oral anticoagulation undergoing CIED surgery. Patients were matched using propensity scoring. RESULTS: We included 1,975 patients (age 73.8 ± 12.4 years). Among 1,326 patients on DOAC, this was interrupted presurgery in 78.2% (n = 1,039) and continued in 21.8% (n = 287). There were 649 patients on continued VKA. The matched population included 861 patients. The rate of any major bleeding was higher with continued DOAC (5.2%) compared to interrupted DOAC (1.7%) and continued VKA (2.1%) (P = 0.03). The rate of perioperative thromboembolism was 1.4% with interrupted DOAC, whereas no thromboembolic events occurred with DOAC or VKA continuation (P = 0.04). The use of dual antiplatelet therapy, DOAC continuation, and male sex were independent predictors of major bleeding on a multivariable analysis. CONCLUSIONS: In this large real-world cohort, a continued DOAC strategy was associated with a higher bleeding risk compared to DOAC interruption or VKA continuation in patients undergoing CIED surgery. However, DOAC interruption was associated with increased thromboembolic risk. Concomitant dual antiplatelet therapy should be avoided whenever clinically possible. A bespoke approach is necessary, with a strategy of minimal DOAC interruption likely to represent the best compromise.

Validity and reliability of the Brazilian Portuguese version of the Florida Patient Acceptance Survey for patients with implantable cardioverter defibrillators.

Device acceptance is a crucial factor in identifying implantable cardioverter defibrillator (ICD) patients at risk for psychosocial distress and unfavorable quality of life outcomes. The purpose of this study was to examine the evidence of the validity of internal structure (construct) and reliability of the Florida Patient Acceptance Survey (FPAS) in a sample of ICD patients, comparing the psychometric indicators of the complete (FPAS-18 item) and abbreviated (FPAS-12 item) versions. The sample included 151 participants (97 males, mean age of 55.7 ± 14.1 years) who completed the cross-culturally adapted version of the FPAS instrument for the Brazilian context. The psychometric properties of both versions of the FPAS instrument were evaluated by two distinct approaches:•Exploratory and confirmatory factor analysis: used to test the internal structure of the instrument•Cronbach's Alpha and McDonald's Omega: used to determine the reliability of the instrument The two versions of the FPAS-Br instrument showed consistent evidence of internal structure validity and reliability. However, the FPAS-Br 12-item showed a better psychometric adjustment, confirmed by the analysis of the quality indicators of the models.

Simultaneous subcutaneous implantable cardioverter-defibrillator and leadless pacemaker implantation for patients at high risk of infection: a retrospective case series report.

BACKGROUND: The subcutaneous implantable cardioverter defibrillator (S-ICD) and leadless pacemaker (LP) are alternative options for patients at high risk of infection requiring ICD and pacing therapy. In this analysis, we described the simultaneous implantation of S-ICD and LP in patients with high infectious risk. METHODS: The study cohort comprised patients referred to our institution for ICD implantation due to high-risk factors of infection. RESULTS: Between 2018 and 2022, 13 patients were referred, including 11 with infected ICD and 2 for first ICD implantation in the presence of high-risk factors. In cases of infected ICD, successful extraction was performed using a mechanical dilatation technique. Reimplantation was delayed until resolution of infection with antibiotic therapy. The devices were implanted during a single procedure, with S-ICD implantation following LP placement for verification of sensing adequacy through surface ECG screening. Suitable vectors for sensing during inhibited and ventricular pacing were identified in all patients. Defibrillation testing was effective, and no issues with double counting or undersensing were observed. The postoperative period was uneventful, and during a median follow-up of 35 months, no complications or infections were reported. The median ventricular pacing percentage was 5%, and a single inappropriate shock episode due to myopotential interference was reported and resolved by reprogramming the sensing vector. CONCLUSION: Simultaneous implantation of S-ICD and LP is feasible and safe in patients at high risk of infection requiring both ICD and pacing therapy. This combined approach provides an effective solution for these patients.

Length of hospital stay for elective electrophysiological procedures: a survey from the European Heart Rhythm Association.

AIMS: Electrophysiological (EP) operations that have traditionally involved long hospital lengths of stay (LOS) are now being undertaken as day case procedures. The coronavirus disease-19 pandemic served as an impetus for many centres to shorten LOS for EP procedures. This survey explores LOS for elective EP procedures in the modern era. METHODS AND RESULTS: An online survey consisting of 27 multiple-choice questions was completed by 245 respondents from 35 countries. With respect to de novo cardiac implantable electronic device (CIED) implantations, day case procedures were reported for 79.5% of implantable loop recorders, 13.3% of pacemakers (PMs), 10.4% of implantable cardioverter defibrillators (ICDs), and 10.2% of cardiac resynchronization therapy (CRT) devices. With respect to CIED generator replacements, day case procedures were reported for 61.7% of PMs, 49.2% of ICDs, and 48.2% of CRT devices. With regard to ablations, day case procedures were reported for 5.7% of atrial fibrillation (AF) ablations, 10.7% of left-sided ablations, and 17.5% of right-sided ablations. A LOS ≥ 2 days for CIED implantation was reported for 47.7% of PM, 54.5% of ICDs, and 56.9% of CRT devices and for 54.5% of AF ablations, 42.2% of right-sided ablations, and 46.1% of left-sided ablations. Reimbursement (43-56%) and bed availability (20-47%) were reported to have no consistent impact on the organization of elective procedures. CONCLUSION: There is a wide variation in the LOS for elective EP procedures. The LOS for some procedures appears disproportionate to their complexity. Neither reimbursement nor bed availability consistently influenced LOS.

Modern subcutaneous implantable defibrillator therapy in patients with cardiomyopathies and channelopathies: data from a large multicentre registry.

AIMS: Patients with cardiomyopathies and channelopathies are usually younger and have a predominantly arrhythmia-related prognosis; they have nearly normal life expectancy thanks to the protection against sudden cardiac death provided by the implantable cardioverter defibrillator (ICD). The subcutaneous ICD (S-ICD) is an effective alternative to the transvenous ICD and has evolved over the years. This study aimed to evaluate the rate of inappropriate shocks (IS), appropriate therapies, and device-related complications in patients with cardiomyopathies and channelopathies who underwent modern S-ICD implantation. METHODS AND RESULTS: We enrolled consecutive patients with cardiomyopathies and channelopathies who had undergone implantation of a modern S-ICD from January 2016 to December 2020 and who were followed up until December 2022. A total of 1338 S-ICD implantations were performed within the observation period. Of these patients, 628 had cardiomyopathies or channelopathies. The rate of IS at 12 months was 4.6% [95% confidence interval (CI): 2.8-6.9] in patients with cardiomyopathies and 1.1% (95% CI: 0.1-3.8) in patients with channelopathies (P = 0.032). No significant differences were noted over a median follow-up of 43 months [hazard ratio (HR): 0.76; 95% CI: 0.45-1.31; P = 0.351]. The rate of appropriate shocks at 12 months was 2.3% (95% CI: 1.1-4.1) in patients with cardiomyopathies and 2.1% (95% CI: 0.6-5.3) in patients with channelopathies (P = 1.0). The rate of device-related complications was 0.9% (95% CI: 0.3-2.3) and 3.2% (95% CI: 1.2-6.8), respectively (P = 0.074). No significant differences were noted over the entire follow-up. The need for pacing was low, occurring in 0.8% of patients. CONCLUSION: Modern S-ICDs may be a valuable alternative to transvenous ICDs in patients with cardiomyopathies and channelopathies. Our findings suggest that modern S-ICD therapy carries a low rate of IS. CLINICAL TRIAL REGISTRATION: URL: http://clinicaltrials.gov/Identifier: NCT02275637.

Cardiac device-related infective endocarditis need for lead extraction whatever the device according to the ESC EORP EURO-ENDO registry.

Aims: Cardiac device-related infective endocarditis (CDRIE) is a severe complication of cardiac device (CD) implantation and is usually treated by antibiotic therapy and percutaneous device extraction. Few studies report the management and prognosis of CDRIE in real life. In particular, the rate of device extraction in clinical practice and the management of patients with left heart infective endocarditis (LHIE) and an apparently non-infected CD (LHIE+CDRIE-) are not well described. Methods and results: We sought to study in EURO-ENDO, the characteristics, prognosis, and management of 483 patients with a CD included in the European Society of Cardiology EurObservational Research Programme EURO-ENDO registry. Three populations were compared: 280 isolated CDRIE (66.7 ± 14.3 years), 157 patients with LHIE and an apparently non-infected CD (LHIE+CDRIE-) (71.1 ± 13.6), and 46 patients with both LHIE and CDRIE (LHIE+CDRIE+) (70.2 ± 10.1). Echocardiography was not always transoesophageal echography (TOE); it was transthoracic echography (TTE) for isolated CDRIE in 88.4% (TOE = 67.6%), for LHIE+CDRIE- TTE = 93.0% (TOE = 58.6%), and for CDRIE+LHIE+ TTE = 87.0% (TOE = 63.0%). Nuclear imaging was performed in 135 patients (positive for 75.6%). In-hospital mortality was lower in isolated CDRIE 13.2% vs. 22.3% and 30.4% for LHIE+CDRIE- and LHIE+CDRIE+ (P = 0004). Device extraction was performed in 62.1% patients with isolated CDRIE, 10.2% of LHIE+CDRIE- patients, and 45.7% of CDRIE+LHIE+ patients. Device extraction was associated with a better prognosis [hazard ratio 0.59 (0.40-0.87), P = 0.0068] even in the LHIE+CDRIE- group (P = 0.047). Conclusion: Prognosis of endocarditis in patients with a CD remains poor, particularly in the presence of an associated LHIE. Although recommended by guidelines, device extraction is not always performed. Device removal was associated with better prognosis, even in the LHIE+CDRIE- group.

Risk of occurrence of electromagnetic interference from the application of transcutaneous electrical nerve stimulation on the sensing function of implantable defibrillators.

BACKGROUND: Transcutaneous electrical nerve stimulation (TENS) is an established method for pain relief. But electrical TENS currents are also a source of electromagnetic interference (EMI). Thus, TENS is considered to be contraindicated in implantable cardioverter-defibrillator (ICD) patients. However, data might be outdated due to considerable advances in ICD and cardiac resynchronization therapy (CRT) filtering and noise protection algorithm technologies. The aim of this pilot safety study was to re-evaluate the safety of TENS in patients with modern ICDs. METHODS AND RESULTS: One hundred and seven patients equipped with 55 different models of ICD/CRT with defibrillators from 4 manufacturers underwent a standardized test protocol including TENS at the cervical spine and the thorax, at 2 stimulation modes-high-frequency TENS (80 Hz) and burst-mode TENS (2 Hz). Potential interference monitoring included continuous documentation of ECG Lead II, intracardiac electrograms and the marker channel. Electromagnetic interference was detected in 17 of 107 patients (15.9%). Most frequent were: interpretations as a premature ventricular beats (VS/S) in 15 patients (14%), noise reversion in 5 (4.6%) which resulted in temporary asynchronous pacing in 3 (2.8%), interpretation as ventricular tachycardia/ventricular fibrillation in 2 (1.9%), and premature atrial beat in 2 (1.9%) patients. Electromagnetic interference occurrence was influenced by position (chest, P < 0.01), higher current intensity (P < 0.01), and manufacturer (P = 0.012). CONCLUSION: Overall, only intermittent and minor EMI were detected. Prior to the use of TENS in patients with ICDs, they should undergo testing under the supervision of a cardiac device specialist.

Deactivation of implantable defibrillators at the end of life - A register-based study of ICD-deactivation at home and the impact of palliative care.

BACKGROUND: The Implantable Cardioverter-Defibrillator (ICD) is a well-established life-saving therapy for heart failure patients, but due to the risk for unnecessary shocks, deactivation of ICD:s is recommended at the end of life. We aimed to identify i) how many people with HF and an ICD who died in Sweden in 2018 received Specialized Palliative Care (SPC), ii) of those dying outside of hospital, the proportion with deactivated ICDs prior to death for the group as a whole and by SPC access. METHODS AND RESULTS: We analyzed data from i) the Swedish ICD and Pacemaker Registry to find all who died with an ICD in Sweden in 2018, ii) the Swedish Register of Palliative Care and, iii) the Swedish Causes of Death Certificate Register to find those who died outside of hospital. Clinical records were obtained to assess if ICDs were deactivated before death. Descriptive statistics, t-tests and chi-squared tests were applied. 46/406 (11%) of those who died with an ICD in Sweden in 2018 had SPC access, of whom 50% also had cancer. 86/164 (52%) ICDs were deactivated prior to death in people dying outside of hospital; higher in those accessing SPC (36/46, (78%) SPC access versus 151/360, (42%) no SPC access; p < 0.05). CONCLUSIONS: Half of those with HF and an ICD dying outside of hospital had ICD deactivation prior to death. Those accessing SPC were more likely to have their ICD deactivated but few received SPC, without a comorbid cancer diagnosis.