Implantable Cardioverter Defibrillator Indication Research Articles

Global Longitudinal Strain May Be the One that Appropriately Identifies Candidates of ICD Implantation.

Hypertrophic cardiomyopathy (HCM) significantly contributes to an elevated risk of sudden cardiac death. Primary prevention is implemented by using an implantable cardioverter defibrillator (ICD). However, all of the HCM patients do not really need ICD therapy. Providing a superior index for ICD indication compared with the current indices like ejection fraction is essential to differentiate high-risk patients efficiently. The present study assessed the potential of global longitudinal strain (GLS) for the differentiation of HCM patients based on their need for ICD shocks. Patients with HCM were considered in four defined centers between March and June 2021. Those with previous ICD implantation or current candidates for ICD therapy were included in the study. Participants were subjected to speckle-tracking echocardiography, and GLS as well as some other echocardiographic parameters were recorded. Afterwards, data from implanted ICDs were extracted. Patients who received ICD shocks (appropriate) due to ventricular tachycardia (VT)/ventricular fibrillation (VF) were categorized in group A. The remaining patients were constituted group B who received inappropriate shocks, i.e., other than VT/VF. Overall, 34 patients were found eligible to participate with a mean age of 62 ± 16.1 years including 64.7% of males. Among a variety of echocardiographic parameters, GLS was the sole one that was significantly higher in group A compared with that in group B. Our findings revealed that only GLS could predict fatal arrhythmias. To substantiate, the odds of VT were raised by 43% with a single increase in GLS unit. GLS showed the highest accuracy for ICD indication among HCM patients and, therefore, could be a solid and early criterion to predict the incidence of life-threatening arrhythmias. In this regard, identifying appropriate HCM patients with respect to their need for ICD therapy is feasible.

Sex-Related Differences in Ventricular Tachyarrhythmia Events in Patients With Implantable Cardioverter-Defibrillator and Prior Ventricular Tachyarrhythmias

BackgroundData on the risk of ventricular tachycardia (VT), ventricular fibrillation (VF), and death by sex in patients with prior VT/VF are limited. ObjectivesThis study aimed to assess sex-related differences in implantable cardioverter-defibrillator (ICD)-treated VT/VF events and death in patients implanted for secondary prevention or primary prevention ICD indications who experienced VT/VF before enrollment in the RAID (Ranolazine Implantable Cardioverter-Defibrillator) trial. MethodsSex-related differences in the first and recurrent VT/VF requiring antitachycardia pacing or ICD shock and death were evaluated in 714 patients. ResultsThere were 124 women (17%) and 590 men observed during a mean follow-up of 26.81 ± 14.52 months. Compared to men, women were at a significantly lower risk of VT/VF/death (HR: 0.67; P = 0.029), VT/VF (HR: 0.68; P = 0.049), VT/VF treated with antitachycardia pacing (HR: 0.59; P = 0.019), and VT/VF treated with ICD shock (HR: 0.54; P = 0.035). The risk of recurrent VT/VF was also significantly lower in women (HR: 0.35; P < 0.001). HR for death was similar to the other endpoints (HR: 0.61; P = 0.162). In comparison to men, women presented with faster VT rates (196 ± 32 beats/min vs 177 ± 30 beats/min, respectively; P = 0.002), and faster shock-requiring VT/VF rates (258 ± 56 beats/min vs 227 ± 57 beats/min, respectively; P = 0.30). There was a significant interaction for the risk of VT/VF by race (P = 0.013) with White women having significantly lower risk than White men (HR: 0.36; P < 0.001), whereas Black women had a similar risk to Black men (HR: 1.06; P = 0.851). ConclusionsWomen with a history of prior VT/VF experienced a lower risk recurrent VT/VF requiring ICD therapy when compared to men. Black Women had a risk similar to men, whereas the lower risk for VT/VF in women was observed primarily in White women. (Ranolazine Implantable Cardioverter-Defibrillator Trial; NCT01215253)

Temporal trends in baseline characteristics of implantable cardioverter defibrillator recipients for primary prevention of sudden cardiac death- The DAIPP program

Abstract Introduction Since expanding the indication for implantable cardioverter defibrillators (ICD) to primary prevention, the patient population of ICD carriers continues to evolve over time. In pursuit of progressively decreasing the burden of sudden cardiac death, improved patient selection and risk-benefit assessment demand, among others, awareness of these temporal changes in clinical baseline characteristics of the ICD population. Purpose The aim was to explore the temporal differences in baseline characteristics of ICD recipients implanted for primary prevention of sudden cardiac death (SCD), and perioperative complications, to improve understanding of ICD population selection over the last two decades in a real-world setting. Methods The Primary Prevention ICD French Registry (DAI-PP program) was initiated in 2002 with an overall aim to assess the risk-benefit ratio of the introduction of ICD for primary prevention over a 20-year period, including a pilot evaluation that finished in 2012. The pilot study laid ground for the ongoing prospective DAIPP Consortium that started in 2018 and is aiming to follow 10000 patients under remote monitoring, using a specific integrational research platform. The two cohorts are in this study compared with regards to baseline characteristics as well as perioperative outcomes, i.e., early mortality and procedural complications. Results This study included 8432 participants, 5521 from the pilot study and 2211 from the prospective trial, with a median follow up of 2.36 (IQR 1.25-3.75) years. Median age was 64 (IQR 56-71) years, 17% female and 61% had ischemic heart disease. Baseline characteristics that remained stable over time were age, cancer burden. Compared to the 2002-2012 period, recent findings found a significant increase in the proportion of females (15 vs 20%, p &amp;lt;0.001), pauci-symptomatic patients (New York Heart Association Functional class-NYHA II, 41 vs. 57%, p &amp;lt;0.001), narrow QRS patients (31 vs. 43%, p&amp;lt;0.001), use of subcutaneous ICD (0 vs. 14%, P&amp;lt;0.001) and more comorbidities including an increase in diabetes, and slight increase in stroke. Regarding pharmacological treatment, there was an increase in use of 2 or 3 medications (2: 6.5% to 16% p&amp;lt;0.001; 3: 20% to 33%, p&amp;lt;0.001) where more received beta blockers and amiodarone in the contemporary study. Perioperative complications decreased over time (13% to 7.9% p&amp;lt;0.001) with a decrease in early reinterventions (1.3% to 0.1% p&amp;lt;0.001) and discrete fall in number of infections (0.7% to 0.1%, p&amp;lt;0.001) and pocket hematoma (4.4% to 3.0% p&amp;lt;0.001). A slight upward trend in number of lead dislodgements was seen over time (1.3% to 1.7% p&amp;lt;0.001). See Table 1 for perioperative complications. Conclusion The primary prevention ICD population has significantly changed over time. An increase in women, comorbidities, and use of 2-3 medications was seen, coupled with more participants receiving a subcutaneous ICD. Perioperative complications decreased over time.

Effect of ICD on patients with improved EF in idiopathic dilated cardiomyopathy

Abstract Background The efficacy of implantable cardioverter defibrillator (ICD) therapy in patients who had heart failure with improved ejection fraction (HFimpEF) above guidelines indication for ICD (&amp;gt;35%) during generator change is still controversial. This meta-analysis assesses the impact of ICD therapy in patients with HFimpEF with EF &amp;gt;35% and patient with NICM. Methods Databases were searched for studies reporting the association between ICD in patients with NICM and HFimpEF and ventricular arrhythmias (VA) and sudden cardiac death (SCD); including Ovid MEDLINE, EMBASE, Web of Science, and Google Scholar. The search was not restricted to time or publication status. The minimal follow up duration was one year. Results A total of 38 studies and 13,538 patients (5,829 with improved EF vs 7,709 with EF &amp;lt;35% during follow up) were included; mean follow up was 43 months (ranging between 12 to 74 months). Mean age was 63.5 and 75% were males. Patients with HFimpEF with ICD, wither alone or as part of CRT therapy, was associated with lower risk of VA and SCD (OR 0.39, 95% CI 0.32-0.47; P&amp;lt;0.01; annual rate 4.1 vs. 8%). Sub-analysis for patients with ICD for patient with NICM was associated with lower risk of VA and SCD (OR 0.25, 95% CI 0.1-0.62; P&amp;lt;0.01; annual rate 2.9 vs. 10.2%). (Figure) Conclusion Improved EF is associated with reduced VA but with still elevated risk in HFimpEF especially in NICM.

Neurohormonal status is associated with long-term appropriate implantable cardioverter defibrillator therapy for life-threatening ventricular arrhythmia

Abstract Background Neurohormonal status is associated with the risk of life-threatening ventricular arrhythmia. Purpose We aimed to assess whether neurohormonal status in patients with an implantable cardioverter defibrillator (ICD) is correlated with the risk of long-term appropriate shock or overdrive delivered by the ICD for life-threatening arrhythmia. Methods A total of 331 clinically stable patients with ICD without any past history of shock or overdrive for life-threatening ventricular arrhythmia were enrolled in a two-center prospective cohort and followed up for a median time of 7.9 years. At enrolment, patients’ medical history, treatment, clinical and imaging data were recorded and, blood and, blood samples were drawn for the assessment of standard biological parameters as well as 3 neurohormones (aldosterone, A type NT-pro-Atrial natriuretic peptide (ANP) and MR-pro-Adrenomedullin (ADM). The primary endpoint of the study was the occurrence of appropriate shock or overdrive delivered by the ICD (ICD therapy). A multivariable cox model adjusted on age, gender, primary or secondary prevention ICD as well as all baseline variables unequally distributed between groups with or without ICD therapy was used for the assessment of the relationship between the 3 neurohormones and the primary endpoint. Results The population consisted of patients with a mean age of 60±15 years, among which 59(18%) women and 160(48%) with a secondary prevention indication for ICD. At baseline all data were similar between patients with or without ICD therapy with the exception of weight, systolic blood pressure, left ventricular ejection fraction (LVEF) and serum potassium and creatinine levels. No other variable, including MADIT and SHOCKED score were significantly associated with the risk of ICD therapy. Death was recorded in 114(34%) patients and a total of 78(24%), 76(23%) and 106(33%) patients had appropriate shock, overdrive and ICD therapy respectively during the follow-up. On multivariable analysis, highest levels of ANP and lowest levels of ADM but not aldosterone were independently associated with life-threatening ventricular arrhythmia requiring ICD therapy (table). Other correlates of ICD therapy were lower LVEF and, higher weight, serum potassium and creatinine concentrations. ANP and ADM had a stepwise additive impact on the risk of ICD therapy. (Figure 1) Conclusions In a stable all comer population with ICD and no history of ICD therapy, blood levels of neurohormones ANP and ADM are associated with the risk of life-threatening ventricular arrhythmia requiring ICD-delivered shock or overdrive independent of other correlates. ANP and ADM concentrations may be useful in identifying patients at high risk of such arrhythmia and who may most benefit from ICD implantation.

N-terminal pro-B-type natriuretic peptide for prediction of ventricular arrhythmias: data from the SMASH Study

Abstract Background Elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations predict heart failure (HF) and mortality, but whether NT-proBNP predicts ventricular arrhythmias (VA) is not clear. Purpose We hypothesize that high NT-proBNP concentrations associate with the risk of incident VA, defined as adjudicated ventricular fibrillation or sustained ventricular tachycardia. Methods In a prospective, observational study of patients treated with implantable cardioverter defibrillator (ICD), we analyzed NT-proBNP concentrations at baseline and after mean 1.4 years in association to incident VA. Results We included 491 patients (age 66±12 years, 83% men) out of whom 51% had a primary prevention ICD indication. The median NT-proBNP concentration was 567 (25-75 percentile 203-1480) ng/L, and patients with higher concentrations were older with more HF and ICD for primary prevention. During mean 3.1±0.7 years, 136 patients (28%) had ≥1 VA. Baseline NT-proBNP concentrations were associated with risk of incident VA (HR 1.39 [95%CI 1.22-1.58], p&amp;lt;0.001) (Figure1), HF hospitalizations (HR 3.38 [95%CI 2.69-4.25], p&amp;lt;0.001) and all-cause mortality (HR 2.49 [2.05-3.04], p&amp;lt;0.001) (Figure2), which persisted after adjusting for age, sex, BMI, CAD, HF, renal function, and LVEF. The association with VA was stronger in secondary vs primary prevention ICD indication: HR 1.59 (95% CI 1.34-1.88 C-statistics 0.71) vs HR 1.25 (1.02-1.52, C-statistics 0.55), p-for-interaction=0.06. Changes in NT-proBNP during the first 1.4 years did not associate with subsequent VA. Conclusions NT-proBNP concentrations are associated with the risk of incident VA after adjustment for established risk factors, with the strongest association in patients with a secondary prevention ICD indication.

Abstract 13746: Mental Health and Implantable Cardioverter Defibrillator Implantation in Black Patients at Risk for Sudden Cardiac Death

Introduction: Black patients with guideline indications for implantable cardioverter defibrillators (ICD) have lower rates of implantation compared to White patients. The Educational Videos to Address Racial Disparities in ICD Therapy Via Innovative Designs (VIVID) trial enrolled self-identified Black individuals with chronic systolic heart failure and studied the impact of a video-based decision-support tool on decisional quality and ICD implantation. Hypothesis: We hypothesized that depressive symptoms are associated with greater decisional conflict and lower rates of ICD implantation among study participants. Methods: Participants were administered the Patient Health Questionnaire-2 (PHQ-2) depression screen; and the 12-Item Short-Form Health Survey, from which we derived the Mental Component Summary-12 (MCS-12). A decisional conflict scale (DCS) adapted from the Ottawa framework for shared decision-making was used to assess decisional conflict associated with the decision for ICD implantation. An analysis of covariance was used to assess differences in DCS scores. Multivariable logistic regression was used to examine the association between mental health scores and ICD implantation at 90 days. Results: Among 306 included participants, 60 (19.6%) reported depressed mood and 142 (46.4%) reported anhedonia. Participants with the lowest MCS-12 scores (poorer mental health) had greater decisional conflict regarding ICD assent compared to those with the highest MCS-12 scores (adjusted mean difference in DCS score = 3.05 [95% CI: 0.32, 5.78]). By 90-day follow-up, 204 participants (66.6%) underwent ICD implantation. There was no significant association between either PHQ-2 score or MCS-12 score and ICD implantation. Conclusions: Depressed mood and anhedonia were prevalent among Black patients considering primary prevention ICD. Poorer mental health did not impact the likelihood of ICD implantation in this population.

Abstract 15634: Primary Prevention Defibrillator Use in a Safety-Net Setting

Introduction: Disparities in use of implantable cardioverter-defibrillators (ICD) for primary prevention have been documented; however, whether ICDs may be underutilized within a safety-net healthcare system has not been studied. Methods: Using an electronic health record cohort of all patients with heart failure (HF) who received care within the public safety-net system in San Francisco from 2001-2018 linked to device implantation records from two health systems, we identified all patients with ICD implantation (adjudicated with manual chart review) and primary prevention ICD-eligible with no indication for secondary prevention ICD, EF&lt;35% on 2 echocardiograms at least 90 days apart, HF hospitalization (to increase specificity for symptomatic HF), and prescribed beta blocker and ACEi/ARB. For exploratory survival analysis, eligibility and follow up started at the second echocardiogram. Results: Out of 14,230 patients with HF, at least 384 patients were potentially eligible for primary prevention ICD, but only 9 (2.3%) had an ICD implanted (2 CRT-D, 7 ICD). Of these 6 were nonischemic, and 3 had revascularized ischemic cardiomyopathy. Those who received ICD were younger (47 years vs 55 years; p=0.05), with lower rates of substance use (Table). Among 4 patients who died after ICD, median survival after device placement was 2.8 years (range 0.73 to 7.3); among 5 still alive, median follow up is 6.2 years (range 5.5 to 7.0). In an exploratory analysis, survival did not greatly differ by ICD placement (logrank p=0.53; age-adjusted HR 1.55; 95%CI 0.57-4.24). Conclusion: Among individuals receiving care at a safety-net system in San Francisco, even acknowledging that not all barriers to ICD placement are measured, very few guideline-eligible patients received primary prevention ICD. Additional studies are needed to identify patient-level and systems-level barriers to referral and implantation specific to a diverse, publicly insured patient population.

Outcomes Following Implantable Cardioverter-Defibrillator Insertion in Patients 80 Years of Age or Older: A Statewide Population Cohort Study

BackgroundPatients ≥ 80 years of age are underrepresented in major implantable cardioverter-defibrillator (ICD) trials, and real-world data are lacking. In this study, we sought to assess ICD utilisation, outcomes, and their predictors, in an unselected statewide population including patients ≥ 80 years old. MethodsWe extracted details of ICDs implanted from 2009 to 2018 in New South Wales (NSW), Australia from the Centre for Health Record Linkage administrative data sets. Analysis was stratified into age groups of < 60 years, 60-79 years, and ≥ 80 years. ResultsA total of 9304 patients (mean age 66.1 ± 13.1 years; 12.1% ≥ 80 years) had de novo ICD placement at an average rate of 1163 ± 122 patients per annum, with more implants in men in all age groups. After adjusting for NSW population size by sex, age group, and calendar year, mean implantation rates were 5.5 ± 0.6, 63.2 ± 8.6, and 52.7 ± 10.8 per 100,000 persons per annum in patients aged < 60 years, 60-79 years, and ≥ 80 years, respectively. In-hospital mortality was 0.4% and did not differ among age groups. However, 1-year mortality was 2.1%, 5.9%, and 10.7%, in those < 60 years, 60-79 years, and ≥ 80 years of age, respectively (P < 0.001), with hazard ratios for those aged ≥ 80 years of 4.3 (95% confidence interval [CI] 3.1-6.0) and those aged 60-79 years of 2.6 (95% CI 1.9-3.5) relative to those aged < 60 years (both P < 0.001) after adjusting for ICD indications, sex, implantation year, referral source, and comorbidities. In those aged ≥ 80 years, age > 83 years, congestive cardiac failure, chronic renal failure, neurodegenerative disease, and a higher Charlson comorbidity index score were each independent predictors of 1-year mortality. ConclusionsICD use in patients aged ≥ 80 years and 60-79 years was 10-fold that in patients aged < 60 years, and perioperative outcomes were good in all ages, but there was substantially increased 1-year mortality in those aged ≥ 80 years. Careful selection based on age and comorbidity may further reduce 1-year mortality in patients ≥ 80 years old receiving ICDs.

Effectiveness of the risk stratification proposed by the 2022 European Heart Rhythm Association Expert Consensus statement on arrhythmic mitral valve prolapse

Recently, an expert consensus statement proposed indications where implantation of a primary prevention implantable cardioverter-defibrillator (ICD) may be reasonable in patients with mitral valve prolapse (MVP). The objective was to evaluate the proposed risk stratification by the expert consensus statement. Consecutive patients with MVP without alternative arrhythmic substrates with cardiac magnetic resonance imaging (CMR) were included in a single-center retrospective registry. Arrhythmic MVP (AMVP) was defined as a total premature ventricular complex burden ≥5%, non-sustained ventricular tachycardia (VT), VT, or ventricular fibrillation. The end point was a composite of SCD, VT, inducible VT, and appropriate ICD shocks. In total, 169 patients (52.1% male, median age 51.4 years) were included and 99 (58.6%) were classified as AMVP. Multivariate logistic regression identified the presence of late gadolinium enhancement (OR 2.82, 95%CI 1.45-5.50) and mitral annular disjunction (OR 1.98, 95%CI 1.02-3.86) as only predictors of AMVP. According to the EHRA risk stratification, 5 patients with AMVP (5.1%) had a secondary prevention ICD indication, while in 69 patients (69.7%) the implantation of an ICD may be reasonable. During a median follow-up of 8.0 years (IQR 5.0-15.6), the incidence rate for the composite arrhythmic end point was 0.3%/year (95%CI 0.1-0.8). More than half of MVP patients referred for CMR met the AMVP diagnostic criteria. Despite low long-term event rates, in 70% of patients with AMVP the implantation of an ICD may be reasonable. Risk stratification of SCD in MVP remains an important knowledge gap and requires urgent investigation.

Outcomes in Dutch DPP6 risk haplotype for familial idiopathic ventricular fibrillation: afocused update.

The genetic risk haplotype DPP6 has been linked to familial idiopathic ventricular fibrillation (IVF), but the associated long-term outcomes are unknown. DPP6 risk haplotype-positive family members (DPP6cases) and their risk haplotype-negative relatives (DPP6 controls) were included. Clinical follow-up data were collected through March 2023. Implantable cardioverter-defibrillator (ICD) indication was divided in primary or secondary prevention. Cumulative survival and event rates were calculated. We included 327 DPP6cases and 315 DPP6 controls. Median follow-up time was 9years (interquartile range: 4-12). Of the DPP6cases, 129 (39%) reached the composite endpoint of appropriate ICD shock, sudden cardiac arrest or death, at amedian age of 45years (range: 15-97). Median overall survival was 83years and 87years for DPP6cases and DPP6 controls, respectively (p < 0.001). In DPP6cases, median overall survival was shorter for males (74years) than females (85years) (p < 0.001). Of the DPP6cases, 97 (30%) died, at amedian age of 50years. With aprophylactic ICD implantation advise based on risk haplotype, sex and age, 137 (42%) of DPP6cases received an ICD, for primary prevention (n = 109) or secondary prevention (n = 28). In the primary prevention subgroup, 10patients experienced atotal of 34 appropriate ICD shocks, and there were no deaths during follow-up. DPP6cases with asecondary prevention ICD experienced atotal of 231 appropriate ICD shocks. Patients with the DPP6 risk haplotype, particularly males, are at an increased risk of IVF and sudden cardiac death. Using arisk stratification approach based on risk haplotype, sex and age, asubstantial proportion of patients with aprimary prevention ICD experienced appropriate ICD shocks, showing the benefit of prophylactic ICD implantation with this strategy.

Adverse Outcomes With Cardiac Sarcoid: New Zealand Experience in the Modern Era

Diagnosis of cardiac sarcoidosis (CS) has increased with availability of multi-modal imaging yet presenting phenotype and natural history of the disease remain highly variable. This study evaluated experience in the Auckland/Northland regions between 2004 and 2022. A retrospective observational study of patients with CS defined according to Heart Rhythm Society (HRS) criteria. Demographics, diagnostic presentation, and adverse clinical outcomes were evaluated, including heart failure, ventricular arrhythmia (VA), device therapy, transplant, and death. Ninety-nine patients met diagnostic criteria for CS; median age was 55±11 years and 52% were male. Clinical presentations included symptomatic conduction disease in 53%, new heart failure in 24%, in VA 16%, and incidental in 6%. Diagnosis was confirmed by imaging studies: cardiac MRI in 85 patients (86%) and/or positive computed tomography-positron emission tomography (CT-PET) in 47 (47%), and positive cardiac biopsy in 24 (24%). Devices were implanted in 84 (85%) patients, with defibrillator capability in 67 (80%). Seventy (71%) patients experienced 158 adverse events: death in 13%, heart failure in 28%, VA in 27%, device therapies in 21%, progressive conduction disease in 7%, atrial arrhythmias in 3%, stroke in 1%, and transplant in 6%. Twenty-two patients (26%) did not meet Class I indications for implantable cardioverter defibrillator, but more than one-third required device therapy. A regimen of high-dose steroid (>30 mg prednisone) with a tapering regimen was used in 65% of patients, with additional steroid sparing agents in 55%. Complete disease suppression was assessed by repeat PET at 3 months was observed in 55%. Adverse cardiovascular events are common with CS. Over 50% of patients experience cardiac arrhythmia and consideration of appropriate device therapy is important at diagnosis.

PM and ICD trends during COVID-19 pandemic in Italy. A global analysis of the national hospital discharge database

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Italian Minister of Health. Background At the beginning of the COVID-19 emergency, important restrictions in hospital admissions for non-urgent procedures, to reduce the spread of the epidemic and to direct resources for the management of patients affected by the SARS-COV2 virus were required. Furthermore, in the same period there was a significant reduction of admissions for cardiological emergencies, too. The nationwide impact of COVID-19 pandemic on invasive procedures, such Pacemakers (PM) and Implantable Cardioverter-Defibrillators (ICD) interventions, is unknown. Purpose To evaluate the trend of PM and ICD procedures performed in Italy in the last 10 years and particularly in the pandemic period. Methods All the Italian Hospital Discharge Records (Schede di Dimissione Ospedaliera – SDO) from 2012 to 2021, sent by the Italian Ministry of Health to the National Institute of Health (NIH, Istituto Superiore di Sanità-ISS) were reviewed. Among these, only records including ICD or PM procedures, either primary or secondary, and correctly reporting patient’s age and gender, were selected. The ICD9-CM codes, single and combined, relating to PM and ICD procedures were selected a taxonomy arranged into 16 groups of procedures was defined. PM procedures were also divided in 1°implant and replacement, while ICD could be considered as total procedures only. Results From 2012 to 2019 the yearly number of total PM procedures was quite stable, ranging from 63.498 (1.069/million inhabitants) to 68.807 (1.150/million). In 2020, a reduction of total procedures (38.411, 1078/million, -11% towards 2019) and 1st implant of PM (from 52.216 to 43.962, -16%), but not PM replacement, (from 16.591 to 17.331, +4%) was observed; at beginning of pandemic period (April 2020), the drop in total PM procedures in comparison to the 2018 and 2019 average value was 49%. In 2021, an increase to values exceeding the pre-pandemic numbers, was observed (total procedures 69.330, 1170/million, 49.555 1° implants, 19.775 replacements). For ICD, a slow increase of the procedure rate was observed from 2012 (20.774, 350/million) to 2017, 24.255, 400/million); afterwards, a small reduction of implants was observed in 2018 (22.616, 378/million) and 2020 (22.355, 375/million). The drop in ICD procedures observed in April 2020, compared to the 2018 and 2019 average value, was 46%. In 2021 the rate of ICD procedures (25.384, 429/million) increased more than to the pre-pandemic values. No significant changes in PM and ICD indications were observed during the study interval. Conclusions During the first year of COVID-19 pandemic, a reduction of PM and ICD procedures was observed, especially in the first period (April 2020); for PM, no reduction of replacements was observed in 2020, while the reduction of 1° PM implant and ICD procedures was compensated by an increase of activity in 2021.

Ventricular tachycardia as presenting arrhythmia as a determinant of appropriate implantable cardioverter-defibrillator therapy in secondary prevention

Abstract Funding Acknowledgements Type of funding sources: None. Background Sudden cardiac death (SCD) is a leading cause of death. The implantable cardioverter-defibrillator (ICD) is an established therapy to prevent SCD in patients with prior ventricular tachycardia (VT) or ventricular fibrillation (VF). Determination of patient characteristics related to ICD therapies may provide targets for more intensive monitoring or management of ventricular arrhythmias. Therefore, we aimed to find determinants of appropriate ICD therapy. Methods In this retrospective, single-centre study, 223 consecutive secondary prevention ICD recipients were included. Data was obtained on medical history, laboratory measurements, electrocardiography and echocardiography. The primary outcome was appropriate ICD therapy, which included shock and antitachycardia pacing (ATP) given for VF or VT. Backward stepwise Cox regression analysis was performed to find determinants of appropriate therapy. Results The median age of the study population was 65.3 years (interquartile range (IQR) 55.4 – 72.0 years). 188 (84.3%) patients were male. 153 (68.6%) patients had ischemic heart disease. During a median follow-up duration of 6.00 years (interquartile range (IQR) 4.85 – 7.70 years), appropriate ICD therapy occurred in 89 (39.9%) patients, appropriate ICD shock in 65 (29.1%) patients, death in 55 (24.7%), inappropriate shock in 11 (4.9%) and device-related complications in 18 (8.1%). VT as index arrhythmia, QRS fragmentation and diminished right ventricular function were determinants of appropriate device therapy. Interestingly, whereas the majority of patients (141 (63.2%)) had an ICD implanted for initial presentation with VF, the first occurrence of appropriate therapy during follow-up was for monomorphic VT in the majority of patients (84 (94.4%)). Conclusion In patients with a secondary prevention ICD indication, VT as presenting arrhythmia is a determinant of appropriate ICD therapy during follow-up. Most ICD therapies during follow-up were applied for monomorphic VT.

Optimizing diastolic filling by pacing in nonobstructive hypertrophic cardiomyopathy

Treatment options for symptomatic patients with nonobstructive hypertrophic cardiomyopathy (nHCM) are limited. The purpose of this study was to determine the effect of sequential atrioventricular (AV) pacing, from different right ventricular (RV) sites with varying AV delays, on the diastolic function and functional capacity of patients with nHCM. Twenty-one patients with symptomatic nHCM and normal left ventricular (LV) systolic function were prospectively enrolled. Inclusion criteria included PR interval >150 ms, E/e' ≥15, and an indication for implantable cardioverter-defibrillator (ICD) implantation. Doppler echocardiographic study was performed during dual-chamber pacing at various AV intervals. Pacing was performed at 3 RV sites: RV apex (RVA), RV midseptum (RVS), and RV outflow tract (RVO). The site and sensed AV delay (SAVD) at which optimal diastolic filling occurred were chosen based on diastolic filling period and E/e'. During ICD implantation, the RV lead was implanted at the site identified by the pacing study. Devices were programmed in DDD mode at the optimal SAVD. During follow-up, diastolic function and functional capacity were assessed. Among the 21 patients (age 47.8 ± 7.7 years; 81.0% male), baseline E/A and E/e' were 2.4 ± 0.6 and 17.2 ± 2.2, respectively. There was an improvement in diastolic function (E/e') in 18 patients (responders) when pacing from the RVA (12.9 ± 3.4; P <.001) than from the RVS (16.6 ± 2.3) and RVO (16.9 ± 2.2). Among responders, optimal diastolic filling occurred at SAVD of 130-160 ms with RVA pacing. Nonresponders had longer duration of symptoms (P = .006), lower LV ejection fraction (P = .037), and higher late gadolinium enhancement burden (P <.001). During 13.5 ± 1.5 months of follow-up, there was an improvement (Δ) in diastolic function (E/e' -4.1 ± 0.5), functional capacity (New York Heart Association functional class -1.5 ± 0.3), and reduction in N-terminal pro-brain natriuretic peptide level (-55.6 ± 12.3 pg/mL) compared to baseline. Pacing at an optimized AV delay from the RVA improves diastolic function and functional capacity in a subset of patients with nHCM.

Clinical, electrocardiographic, and echocardiographic parameters associated with the development of pacing and implantable cardioverter-defibrillator indication in patients with transthyretin amyloid cardiomyopathy.

This study aimed to identify factors for attention leading to future pacing device implantation (PDI) and reveal the necessity of prophylactic PDI or implantable cardioverter-defibrillator (ICD) implantation in transthyretin amyloid cardiomyopathy (ATTR-CM) patients. This retrospective single-center observational study included consecutive 114 wild-type ATTR-CM (ATTRwt-CM) and 50 hereditary ATTR-CM (ATTRv-CM) patients, neither implanted with a pacing device nor fulfilling indications for PDI at diagnosis. As a study outcome, patient backgrounds were compared with and without future PDI, and the incidence of PDI in each conduction disturbance was examined. Furthermore, appropriate ICD therapies were investigated in all 19 patients with ICD implantation. PR-interval ≥220 msec, interventricular septum (IVS) thickness ≥16.9 mm, and bifascicular block were significantly associated with future PDI in ATTRwt-CM patients, and brain natriuretic peptide ≥35.7 pg/mL, IVS thickness ≥11.3 mm, and bifascicular block in ATTRv-CM patients. The incidence of subsequent PDI in patients with bifascicular block at diagnosis was significantly higher than that of normal atrioventricular (AV) conduction in both ATTRwt-CM [hazard ratio (HR): 13.70, P = 0.019] and ATTRv-CM (HR: 12.94, P = 0.002), whereas that of patients with first-degree AV block was neither (ATTRwt-CM: HR: 2.14, P = 0.511, ATTRv-CM: HR: 1.57, P = 0.701). Regarding ICD, only 2 of 16 ATTRwt-CM and 1 of 3 ATTRv-CM patients received appropriate anti-tachycardia pacing or shock therapy, under the number of intervals to detect for ventricular tachycardia of 16-32. According to our retrospective single-center observational study, prophylactic PDI did not require first-degree AV block in both ATTRwt-CM and ATTRv-CM patients, and prophylactic ICD implantation was also controversial in both ATTR-CM. Larger prospective, multi-center studies are necessary to confirm these results.

Ability to remotely monitor atrial high-rate episodes using a single-chamber implantable cardioverter-defibrillator with a floating atrial sensing dipole.

To allow timely initiation of anticoagulation therapy for the prevention of stroke, the European guidelines on atrial fibrillation (AF) recommend remote monitoring (RM) of device-detected atrial high-rate episodes (AHREs) and progression of arrhythmia duration along pre-specified strata (6 min…<1 h, 1 h…<24 h, ≥ 24 h). We used the MATRIX registry data to assess the capability of a single-lead implantable cardioverter-defibrillator (ICD) with atrial sensing dipole (DX ICD system) to follow this recommendation in patients with standard indication for single-chamber ICD. In 1841 DX ICD patients with daily automatic RM transmissions, electrograms of first device-detected AHREs per patient in each duration stratum were adjudicated, and the corresponding positive predictive values (PPVs) for the detections to be true atrial arrhythmia were calculated. Moreover, the incidence and progression of new-onset AF was assessed in 1451 patients with no AF history. A total of 610 AHREs ≥6 min were adjudicated. The PPV was 95.1% (271 of 285) for episodes 6min…<1 h, 99.6% (253/254) for episodes 1 h…<24 h, 100% (71/71) for episodes ≥24 h, or 97.5% for all episodes (595/610). The incidence of new-onset AF was 8.2% (119/1451), and in 31.1% of them (37/119), new-onset AF progressed to a higher duration stratum. Nearly 80% of new-onset AF patients had high CHA2DS2-VASc stroke risk, and 70% were not on anticoagulation therapy. Age was the only significant predictor of new-onset AF. A 99.7% detection accuracy for AHRE ≥1 h in patients with DX ICD systems in combination with daily RM allows a reliable guideline-recommended screening for subclinical AF and monitoring of AF-duration progression.

Left Bundle Branch Area Defibrillator (LBBAD): A First-in-Human Feasibility Study

BackgroundLeft bundle branch area (LBBA) pacing is a promising pacing technique. LBBA implantable cardioverter-defibrillator (ICD) lead implantation reduces the number of leads in patients with both pacing and ICD indications, reducing cost and potentially increasing safety. LBBA positioning of ICD leads has not previously been described. ObjectivesThe goal of this study was to evaluate the safety and feasibility of implanting an LBBA ICD lead. MethodsThis prospective, single-center, feasibility study was conducted in patients with an ICD indication. LBBA ICD lead implantation was attempted. Acute pacing parameters and paced electrocardiography data were collected, and defibrillation testing was performed. ResultsLBBA defibrillator (LBBAD) implantation was attempted in 5 patients (mean age 57 ± 16.5 years; 20% female) and achieved in 3 (60%). Mean procedural and fluoroscopy duration were 170.0 ± 17.3 minutes and 28.8 ± 16.1 minutes, respectively. Left bundle capture was achieved in 2 patients (66%) and left septal capture in 1 patient. LBBA pacing exhibited a mean QRS duration and V6 R-wave peak time of 121.3 ± 8.3 milliseconds and 86.1 ± 10.0 milliseconds. In all 3 patients, defibrillation testing was successful with mean time to adequate shock delivery of 8.6 ± 2.6 seconds. Acute LBBA pacing threshold and R-wave amplitudes were 0.80 ± 0.60 V at 0.4 milliseconds and 7.0 ± 2.7 mV. No LBBA lead-related complications occurred. ConclusionsThis first-in-human evaluation showed the feasibility of LBBAD implantation in a small cohort of patients. With current tools, implantation remains complex and time-consuming. Considering the feasibility reported and the potential benefits, further technological development in this field is warranted with evaluation of long-term safety and performance.

Annals for Educators - March 2023.

Annals for Educators - March 2023.

Cardioverter-defibrillator reduces mortality risk in eligible ischemic and non-ischemic cardiomyopathy patients: Sub-analysis of the multi-center Improve SCA study

Background & ObjectiveDespite the burden of sudden cardiac arrest (SCA) worldwide, implantable cardioverter-defibrillators (ICDs) are underutilized, particularly in Asia, Latin America, Eastern Europe, the Middle East, and Africa. The Improve SCA trial demonstrated that primary prevention (PP) patients in these regions benefit from an ICD or a cardiac resynchronization therapy defibrillator (CRT-D). We aimed to compare the rate of device therapy and mortality among ischemic and non-ischemic cardiomyopathy (ICM and NICM) PP patients who met guideline indications for ICD therapy and had an ICD/CRT-D implanted. MethodsImprove SCA was a prospective, non-randomized, non-blinded multicenter trial that enrolled patients from the above-mentioned regions. All-cause mortality and device therapy were examined by cardiomyopathy (ICM vs NICM) and implantation status. Cox proportional hazards methods were used, adjusting for factors affecting mortality risk. ResultsOf 1848 PP NICM patients, 1007 (54.5%) received ICD/CRT-D, while 303 of 581 (52.1%) PP ICM patients received an ICD/CRT-D. The all-cause mortality rate at 3 years for NICM patients with and without an ICD/CRT-D was 13.1% and 18.3%, respectively (HR 0.51, 95% CI 0.38–0.68, p < 0.001). Similarly, all-cause mortality at 3 years in ICM patients was 13.8% in those with a device and 19.9% in those without an ICD/CRT-D (HR 0.54, 95% CI 0.33–.0.88, p = 0.011). The time to first device therapy, time to first shock, and time to first antitachycardia pacing (ATP) therapy were not significantly different between groups (p ≥ 0.263). ConclusionsIn this large data set of patients with a guideline-based PP ICD indication, defibrillator device implantation conferred a significant mortality benefit in both NICM and ICM patients. The rate of appropriate device therapy was also similar in both groups. Clinical trial registrationClinicalTrials.gov ID: NCT02099721.