Implantable Cardioverter-defibrillator For Secondary Prevention Research Articles

Defibrillation Threshold Testing and Long-term Follow-up in Chagas Disease.

Sudden cardiac death is the most common cause of death in chronic Chagas cardiomyopathy (CCC). Because most CCC patients who are candidates for implantable cardioverter-defibrillators (ICD) meet criteria for high defibrillation threshold values, a defibrillator threshold test (DTT) is suggested. We investigated the use of DTT in CCC patients, focusing on deaths related to ICD and arrhythmic events, as well as treatment during long-term follow-up. We retrospectively evaluated 133 CCC patients who received an ICD mainly for secondary prevention. Demographic, clinical, laboratory data, Rassi score, and DTT data were collected, with p < 0.05 considered significant. The mean patient age was 61 (SD, 13) years and 72% were men. The baseline left ventricular ejection fraction was 40 (SD, 15%) and the mean Rassi score was 10 (SD, 4). No deaths occurred during DTT and no ICD failures were documented. There was a relationship between higher baseline Rassi scores and higher DTT scores (ANOVA = 0.007). The mean time to first shock was 474 (SD, 628) days, although shock was only necessary for 28 (35%) patients with ventricular tachycardia, since most cases resolved spontaneously or through antitachycardia pacing. After a mean clinical follow-up of 1728 (SD, 1189) days, 43 deaths occurred, mainly related to progressive heart failure and sepsis. A routine DTT may not be necessary for CCC patients who receive an ICD for secondary prevention. High DTT values seem to be unusual and may be related to high Rassi scores.

Pacemaker implantation due to cardiac conduction disease in patients with subsequent cardiac sarcoidosis may be a marker of early disease and is associated with adverse 5-year clinical outcome

Abstract Background Sarcoidosis is a rare chronic granulomatous disease of unknown aetiology with potential multi-organ involvement and end-organ dysfunction. Cardiac sarcoidosis (CS) occurs in 5–10% of patients with sarcoidosis though an up to 25% prevalence has been reported by imaging and autopsy studies, suggesting undiagnosed silent disease. Progression of CS, especially if undiagnosed and untreated, may lead to heart failure, atrioventricular block (AVB), ventricular arrhythmias and sudden cardiac death. Aim We sought to determine whether signs of cardiac conduction disease (CCD) prior to the clinical diagnosis of sarcoidosis is associated with poor long-term prognosis in patients with imaging-confirmed cardiac involvement. Method All patients diagnosed with CS since January 1, 2000, at a tertiary centre (n=112) with either primary cardiac localisation (n=70) or cardiac involvement in otherwise primary non-cardiac sarcoidosis (n=42) as per imaging were included. Swedish pacemaker and ICD registry was used to identify patients who received cardiac implantable electronic device (CIED). CCD-related indications for CIED implant were defined as AVB, bi- or trifascicular block. Kaplan-Meier curve analysis and time-dependent Cox regression analysis were used for estimation of risk of death from any cause (primary endpoint), death or upgrade to cardiac resynchronization therapy (CRT, secondary endpoint) at 5 years after CS diagnosis, stratified for history of CIED implantation due to CCD. Hazard ratios were calculated in a univariate model and adjusted for age, gender and the use of implantable cardioverter-defibrillator (ICD). Results Mean age at CS diagnosis was 59±13 years (54% male). Forty-nine patients received CIED implant at a mean age of 54±13 years (14 pacemakers (29%), 14 primary prevention ICDs (29%), 13 secondary prevention ICDs (27%) and 8 CRT-D (16%)). The median time in years from CS diagnosis to CIED implant was for pacemaker −2.5 [IQR 8.5], primary ICD −0.3 [IQR 3.8], secondary ICD −4.0 [IQR 10.4] and CRT-D −0.03 [IQR 1.5]. CIED was implanted prior to CS diagnosis in 29 patients of whom 17 had CCD [MOU1] as the indication for implant. At 5-year follow-up in the CS cohort, 16 patients died and 2 underwent device upgrade to CRT (median 3.2 years [IQR 1.2]). CIED implant prior to CS diagnosis was associated with the primary (HRuni 3.5, 95% CI 1.2–10, p=0.021, Figure 1; HRadj 10.5, 95% CI 1.7–63, p=0.01) and the secondary (HR 3.5, 95% CI 1.2–10, p=0.019; HRadj 8.2, 95% CI 1.6–41.1, p=0.011) endpoints. Conclusion CIED implantation due to CCD can be an early manifestation of undiagnosed CS. It was observed in 15% of all patients with CS and was associated with adverse outcome. Identification of signs of CCD necessitating CIED implant in a middle-aged patient may motivate further diagnostic work-up aimed at timely detection of concealed CS. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Hjärt-Lung fondenAvtal om Läkarutbildning och Forskning

Posttraumatic stress disorder in pediatric patients with implantable cardioverter-defibrillators and their parents.

An implantable cardioverter-defibrillator (ICD) in the pediatric patient (and the precipitating events that led to ICD placement) can be traumatic for patients and their families and may lead to posttraumatic stress disorder (PTSD). This study aimed to estimate the prevalence of PTSD in pediatric patients with an ICD and their parents and identify the factors associated with PTSD incidence. Pediatric participants with an ICD aged 8-21 years and parents of children aged 0-21 years completed surveys that included demographic characteristics and PTSD measures. Pediatric participants completed additional psychosocial measures, such as anxiety and depression self-report questionnaires. Fifty youth (30% female) and 43 parents (70% female) completed the measures. Six of 50 youth (12%) met the screening criteria for a likely PTSD diagnosis, while 20 of 43 parents (47%) met the cutoff for PTSD on the screening measure. Children with PTSD were more likely to have had a secondary prevention ICD (83% vs 17%; P=.021), meet the clinical cutoff for depression (67% vs 16%; P= .005), and had higher shock anxiety scores (31.7 vs 17.9; P= .003) than children without PTSD. Female gender (57% vs 23%; P = .043) and patient depression (31% vs 5%; P = .042) were associated with PTSD in parents. Parents were found to be more likely to meet the criteria for PTSD than youth. In youth, PTSD was associated with medical and psychosocial factors, whereas PTSD in parents was associated with being female and child depression. Clinic-based screenings and management planning of emotional functioning are warranted to address psychological distress in patients and parents.

EP News: Allied Professionals

In this multcenter, international, randomized controlled trial, Tung et al (Circulation May 4, 2022; doi:10.1161/CIRCULATIONAHA.122.060039, PMID 35507499) sought to assess the efficacy of early catheter ablation of ventricular tachycardia (VT) at the time of implantable cardioverter-defibrillator (ICD) implantation as compared with conventional therapy. The Pan-Asia United States Prevention of Sudden Cardiac Death trial enrolled patients from centers in China, Japan, South Korea, and Taiwan who had structural heart disease (SHD) and an indication for secondary prevention ICD or who had VT inducible at the time of electrophysiology study (EPS) and met criteria for primary prevention ICD.

QRS fragmentation is associated with increased risk of ventricular arrhythmias in high-risk patients; Data from the SMASH 1 Study.

IntroductionQRS fragmentation (fQRS), defined as the presence of additional spikes within the QRS complex, has been associated with myocardial conduction abnormalities and arrhythmogenicity.ObjectiveWe aimed to assess whether fQRS is associated with incident ventricular arrhythmias (VA) in high‐risk patients treated with implantable cardioverter‐defibrillator (ICD) for primary and secondary prevention.MethodsIn a prospective observational multicenter study, we included 495 patients treated with ICD. fQRS was analyzed according to previously validated criteria, by two physicians blinded for outcome data. Incident VA were obtained from ICD recordings.ResultsECG recordings interpretable for fQRS were available in 459 patients (93%), aged 66 ± 12 years with left ventricular ejection fraction 40% ± 13%. fQRS was present in 52 patients (11%) with comparable baseline characteristics to patients without fQRS, except higher age, higher prevalence of coronary artery disease (CAD), lower prevalence of cardiomyopathy, and more frequently a secondary prevention ICD indication. Among patients with native QRS, those with fQRS had similar QRS duration and axis to those without fQRS. During 3.1 ± 0.7 years follow‐up, 126 patients (28%) had ≥1 VA . fQRS was associated with increased risk of VA (HR 3.41 [95% CI 2.27–5.13], p < .001), which persisted after adjusting for age, gender, sex, BMI, CAD, heart failure, renal function, ICD indication, QRS duration, QRS axis, Q waves, and bundle branch block. fQRS was more strongly associated with VA in patients with a primary (HR 6.05 [95% CI 3.16–11.60]) versus secondary (HR 2.39 [95% CI 1.41–4.04]) ICD indication (p‐for‐interaction = .047).ConclusionsfQRS is associated with threefold increased risk of VA in high‐risk patients, independent of established risk factors.

Implantable cardioverter-defibrillator therapy in the very young - Patient characteristics procedural outcome and one-year follow-up - A subgroup analysis of the german DEVICE registry

Abstract Funding Acknowledgements Type of funding sources: None. Background The implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy defibrillator (CRT-D) are well-established and essential therapeutic pillars for patients with heart failure and survivors of sudden cardiac death. The number of young patients receiving ICD or CRT-D has been increasing in the last decades. Understanding the key differences between the typically older ICD population and younger patients is paramount to optimized patient care. Methods The DEVICE registry prospectively enrolled patients undergoing ICD/CRT implantation or revision from 50 German centers between 2007–2014. Data on patient characteristics, procedural outcome, adverse events and mortality during the initial stay and follow-up was collected. All patients under the age of 45 years were identified and included into a comparative analysis with the remaining population. Results A total number of 4181 patients were enrolled into the registry, of which 236 patients (5.6%) were under the age of 45 years. Median age was 38.0 [31.0; 42.0] vs. 69.0 [60.0; 75.0] years, p&amp;lt;0.001), compared to older patients. Young patients were more likely to receive an ICD (91.5 vs. 69.4%, p&amp;lt;0.001), than CRT device and were less likely to suffer from non-cardiac comorbidities (20.3 vs. 67.4%, p&amp;lt;0.001). Coronary artery disease was less common in young patients (15.7 vs. 63.6%, p&amp;lt;0.001), whereas hypertrophic cardiomyopathy (11.0 vs. 2.5%, p&amp;lt;0.001) and primary cardiac electrical diseases (14.0 vs. 1.6%, p&amp;lt; 0.001) were encountered more often. Mean left-ventricular ejection fractions were 42.4±18.5 vs. 31.5±11.8%, respectively (p&amp;lt;0.001) with less young patients in NYHA functional class III/IV (19.5 vs. 45.3%, p&amp;lt;0.001). Primary symptom at presentation was chronic heart failure for older patients (19.5 vs. 34.8%, p&amp;lt;0.001) and survived sudden cardiac death (30.9 vs. 15.6%, p&amp;lt;0.001) for young patients. Thus, ICD for secondary prevention was more common in young patients (53.8 vs. 43.2%, p&amp;lt;0.001). There were no detectable differences in postoperative complications (3.0 vs. 4.1%, p=0.500) or in-hospital mortality (0.0 vs. 0.3%, p=1.000). Median follow-up time was 514 [398; 669] vs. 458 [391; 563] days (p=0.006). Device-associated complications requiring revision were more common in young patients (16.3 vs. 8.2%, p&amp;lt;0.001) and all-cause 1-year-mortality after implantation was lower (3.1 vs. 7.3%, p=0.029; HR 0.42, 95%CI: 0.19-0.94). Even though there was no difference in rates of rehospitalization between groups (32.1 vs. 32.4%, p=0.93), young patients were re-admitted more often for "cardiac" reasons (82.7 vs. 58.9%, p&amp;lt;0.001). Conclusion Rates for procedural complications and in-hospital mortality were very low and without differences between both age groups. However younger patients experienced a higher rate of postoperative complications requiring revision and had higher readmission rates for cardiac reasons, potentially due to a more active lifestyle.

Improved prediction of electrical storm in patients with prior myocardial infarction and implantaImproved prediction of electrical storm in patients with prior myocardiable cardioverter defibrillator

Abstract Funding Acknowledgements Type of funding sources: None. Aims To evaluate predictors of electrical storm (ES), including chronic total occlusion in an infarct-related coronary artery (infarct-related artery CTO, IRACTO), in a cohort of patients with prior myocardial infarction (MI) and implantable cardioverter-defibrillators (ICD). Methods Multicenter observational cohort study including 643 consecutive patients with prior MI and a first ICD implanted between 2005 and 2018 at three tertiary hospitals. All the patients included in the study had undergone a diagnostic coronary angiography before ICD implantation. The variable prior ventricular arrhythmias (VA+) was positive in patients with secondary prevention ICDs and in those with at least one appropriate ICD therapy after primary prevention implantation. Results During a median follow-up of 42 months 59 patients (9%) suffered ES. The presence of at least one IRACTO not revascularized (IRACTO-NR) was associated with a significantly higher cumulative incidence of ES (14.5% vs 4.8%, p&amp;lt;0.001). IRACTO-NR maintained a significant association with ES after adjustment for potential confounders (HR 2.3, p=0.005) and was an independent predictor of ES together with VA+ and LVEF. The best cut-off of LVEF to predict ES was ≤38%. A risk-prediction model based on IRACTO-NR, VA+ and LVEF≤38% identified three categories of ES risk (low, intermediate and high), with progressively increasing cumulative incidence of ES (2.2%, 9% and 20%). Conclusion In a cohort of patients with prior MI and ICD, IRACTO-NR is an independent predictor of ES. A new risk-prediction model allowed the identification of three categories of risk, with potentially important clinical implications.

Short-coupled ventricular ectopics leading to cardiac arrest in a young woman

BackgroundThis case report highlights the importance of recognizing that ventricular ectopy may be a cause for syncope and sudden cardiac death, through triggered disorganized arrhythmia. In the context of syncope, ventricular ectopy should be carefully assessed for coupling interval and morphology.Case presentationA 39-year-old woman, who had presented with recurrent syncope, had a cardiac arrest shortly after admission that required emergency defibrillation. Review of her cardiac monitoring revealed an episode of polymorphic ventricular tachycardia which had degenerated into ventricular fibrillation. The dysrhythmia had been initiated by a short-coupled (R-on-T) ventricular ectopic (VE) beat. Anti-arrhythmic therapy was initiated in the form of hydroquinidine, but the patient continued to have frequent VEs of right bundle branch block (RBBB) morphology with a relatively narrow QRS complex and a variation in frontal axis. A cardiac MRI revealed late gadolinium enhancement of the posterior papillary muscle (indicative of focal scarring). The patient underwent electrophysiological mapping and catheter ablation of her ectopy. The patient made a good recovery and was discharged from hospital with a secondary prevention implantable cardioverter-defibrillator (ICD) in situ.ConclusionsShort-couped VEs that are superimposed onto the preceding T wave (R-on-T) are indicative of electrical instability of the heart and should prompt urgent investigation. By studying the morphologies and axes of the QRS complexes produced by VEs, we can identify their likely origins and ascertain their clinical significance.

Association Of Myocardial Strain With Clinical Outcomes In Danon Disease

Background Ejection fraction (EF) has been the gold standard for assessing cardiac function, but does not directly measure myocardial contractility and has limited efficacy in predicting outcomes. Myocardial strain has become increasing used in identifying subclinical left ventricular dysfunction in various cardiac diseases. Therefore, we evaluated myocardial strain in a cohort of patients with Danon Disease (DD), a rare X-linked autophagic disorder that causes severe cardiac manifestations. Methods Echocardiograms were reviewed from a retrospective, international registry of DD patients. Traditional echo and myocardial strain parameters were obtained from images available. Regression analyses and receiver operating curve (ROC) were performed to evaluate for relationships between global longitudinal strain (GLS) and ejection fraction (EF) with the composite outcome (death, ventricular assist device, heart transplantation and implantable cardioverter-defibrillator for secondary prevention). Results Twenty-two patients with DD (male 14 [63.6%], median age 16.5 years) were included in the study. Notable echo and strain parameters included a median EF 60.0%, intraventricular septal diameter 12.8 mm, LV mass 228.3 g, LA volume index 21.2 mL/m2 and mean GLS of 12.2%. Univariate and multivariate logistic regression for GLS and composite outcome showed an odds ratio (OR) of 1.32 with p = 0.03 and OR 1.42 with p = 0.05, respectively. Mean GLS differed by presence of the composite outcome (8.43 vs 13.9%, p = 0.016). For ROC analysis, the area under the curve for GLS and EF with the composite outcome were 0.810 (p = 0.02) and 0.605 (p = 0.44), respectively. An absolute GLS cutoff of 10.0% yielded a true positive rate 85.7% and false positive rate of 13.3%. Conclusion In this cohort of DD patients, GLS may be superior to EF in predicting clinical outcomes. This study suggests that myocardial strain can be used to monitor disease progression and to predict clinical outcomes in DD and other genetic or acquired cardiomyopathies. Ejection fraction (EF) has been the gold standard for assessing cardiac function, but does not directly measure myocardial contractility and has limited efficacy in predicting outcomes. Myocardial strain has become increasing used in identifying subclinical left ventricular dysfunction in various cardiac diseases. Therefore, we evaluated myocardial strain in a cohort of patients with Danon Disease (DD), a rare X-linked autophagic disorder that causes severe cardiac manifestations. Echocardiograms were reviewed from a retrospective, international registry of DD patients. Traditional echo and myocardial strain parameters were obtained from images available. Regression analyses and receiver operating curve (ROC) were performed to evaluate for relationships between global longitudinal strain (GLS) and ejection fraction (EF) with the composite outcome (death, ventricular assist device, heart transplantation and implantable cardioverter-defibrillator for secondary prevention). Twenty-two patients with DD (male 14 [63.6%], median age 16.5 years) were included in the study. Notable echo and strain parameters included a median EF 60.0%, intraventricular septal diameter 12.8 mm, LV mass 228.3 g, LA volume index 21.2 mL/m2 and mean GLS of 12.2%. Univariate and multivariate logistic regression for GLS and composite outcome showed an odds ratio (OR) of 1.32 with p = 0.03 and OR 1.42 with p = 0.05, respectively. Mean GLS differed by presence of the composite outcome (8.43 vs 13.9%, p = 0.016). For ROC analysis, the area under the curve for GLS and EF with the composite outcome were 0.810 (p = 0.02) and 0.605 (p = 0.44), respectively. An absolute GLS cutoff of 10.0% yielded a true positive rate 85.7% and false positive rate of 13.3%. In this cohort of DD patients, GLS may be superior to EF in predicting clinical outcomes. This study suggests that myocardial strain can be used to monitor disease progression and to predict clinical outcomes in DD and other genetic or acquired cardiomyopathies.

Evaluating Common NOS1AP Variants in Patients with Implantable Cardioverter Defibrillators for Secondary Prevention : Evaluating SNPs in NOS1AP.

Recent research has found that single nucleotide polymorphisms (SNPs) in the nitric oxide synthase 1 adaptor protein (NOS1AP) gene are associated with altered QT intervals and sudden cardiac death (SCD). However, the clinical utility and implications of NOS1AP SNPs remain unclear. Thus, this study aimed to explore the influence of NOS1AP SNPs in patients with implantable cardioverter defibrillator (ICD) for secondary prevention. We conducted a case-control study to evaluate the most studied SNPs in NOS1AP (rs12143842, rs10494366, rs12567209, and rs16847548) in patients with ICD for secondary prevention. Patients were followed for up to 36months from the time of ICD implantation. ICD interrogation data at 3 and 12months, including rapid ventricular arrhythmia episodes and appropriate therapies, were then analyzed. RESULTS: A significant association was observed between rs10494366 and ICD recipients who experienced appropriate therapies. After a mean follow-up time of 31.70 ± 9.15months, we detected significant differences among the three rs10494366 genotype groups in the distribution of ICD shocks and appropriate therapies, as well as in the correlation of rs10494366 and ICD shocks. According to Kaplan-Meier and Cox regression analyses, patients with the TT genotype had a higher risk of SCD than those with the GG genotype. The present study revealed that NOS1AP SNP rs10494366 was associated with appropriate therapies. Specifically, the TT genotype increased ICD shocks and SCD risk in patients with ICD for secondary prevention for the first time.

Improved prediction of electrical storm in patients with prior myocardial infarction and implantable cardioverter defibrillator

AimsTo evaluate predictors of electrical storm (ES), including chronic total occlusion in an infarct-related coronary artery (infarct-related artery CTO, IRACTO), in a cohort of patients with prior myocardial infarction (MI) and implantable cardioverter-defibrillators (ICD). MethodsMulticenter observational cohort study including 643 consecutive patients with prior MI and a first ICD implanted between 2005 and 2018 at three tertiary hospitals. All the patients included in the study had undergone a diagnostic coronary angiography before ICD implantation. The variable prior ventricular arrhythmias (VA+) was positive in patients with secondary prevention ICDs and in those with at least one appropriate ICD therapy after primary prevention implantation. ResultsDuring a median follow-up of 42 months 59 patients (9%) suffered ES. The presence of at least one IRACTO not revascularized (IRACTO-NR) was associated with a significantly higher cumulative incidence of ES (14.5% vs 4.8%, p < 0.001). IRACTO-NR maintained a significant association with ES after adjustment for potential confounders (HR 2.3, p = 0.005) and was an independent predictor of ES together with VA+ and LVEF. The best cut-off of LVEF to predict ES was ≤38%. A risk-prediction model based on IRACTO-NR, VA+ and LVEF≤38% identified three categories of ES risk (low, intermediate and high), with progressively increasing cumulative incidence of ES (2.2%, 9% and 20%). ConclusionIn a cohort of patients with prior MI and ICD, IRACTO-NR is an independent predictor of ES. A new risk-prediction model allowed the identification of three categories of risk, with potentially important clinical implications.

Cardiovascular Characteristics of Patients with Genetic Variation in Desmoplakin (DSP).

Background:Variants in the desmoplakin (DSP) gene have been recognized in association with the pathogenesis of arrhythmogenic right ventricular cardiomyopathy (ARVC) for nearly 20 years. More recently, genetic variation in DSP has also been associated with left-dominant arrhythmogenic cardiomyopathy. Data regarding the cardiac phenotypes associated with genetic variation in DSP have been largely accumulated from phenotype-first studies of ARVC.Methods:We aimed to evaluate the clinical manifestations of cardiac disease associated with variants in DSP through a genotype-first approach employed in the University of Pennsylvania Center for Inherited Cardiovascular Disease registry. We performed a retrospective study of 19 individuals with “pathogenic” or “likely pathogenic” variants in DSP identified by clinical genetic testing. Demographics and clinical characteristics were collected.Results:Among individuals with disease-causing variants in DSP, nearly 40% had left ventricular enlargement at initial assessment. Malignant arrhythmias were prevalent in this cohort (42%) with a high proportion of individuals undergoing primary and secondary prevention implantable cardioverter defibrillator implantation (68%) and ablation of ventricular arrhythmias (16%). Probands also experienced end-stage heart failure requiring heart transplantation (11%).Conclusions:Our data suggest DSP cardiomyopathy may manifest with a high burden of heart failure and arrhythmic events, highlighting its importance in the pathogenesis of dilated and arrhythmogenic cardiomyopathies. Targeted strategies for diagnosis and risk stratification for DSP cardiomyopathy should be investigated.

DREAM-ICD-II Study.

Regulatory authorities of most industrialized countries recommend 6 months of private driving restriction after implantation of a secondary prevention implantable cardioverter-defibrillator (ICD). These driving restrictions result in significant inconvenience and social implications. This study aimed to assess the incidence rate of appropriate device therapies in contemporary recipients of a secondary prevention ICD. This retrospective study at 3 Canadian tertiary care centers enrolled consecutive patients with new secondary prevention ICD implants between 2016 and 2020. For a median of 760 days (324, 1190 days), 721 patients were followed up. The risk of recurrent ventricular arrhythmia was highest during the first 3 months after device insertion (34.4%) and decreased over time (10.6% between 3 and 6 months, 11.7% between 6 and 12 months). The corresponding incidence rate per 100 patient-days was 0.48 (95% CI, 0.35-0.64) at 90 days, 0.28 (95% CI, 0.17-0.45) at 180 days, and 0.21 (95% CI, 0.13-0.33) between 181 and 365 days after ICD insertion (P<0.001). The cumulative incidence of arrhythmic syncope resulting in sudden cardiac incapacitation was 1.8% within the first 90 days and subsequently dropped to 0.4% between 91 and 180 days (P<0.001) after ICD insertion. The incidence rate of appropriate therapies resulting in sudden cardiac incapacitation in contemporary recipients of a secondary prevention ICD is much lower than previously reported and declines significantly after the first 3 months. Lowering driving restrictions to 3 months after the index cardiac event seems safe, and revision of existing guidelines should be considered in countries still adhering to a 6-month period. Existing restrictions for private driving after implantation of a secondary prevention ICD should be reconsidered.

564 Controversial role of intracardiac eletrophysiology study in Brugada syndrome: analysis of a single-centre retrospective cohort study

Abstract Aims According to European guidelines, aborted sudden cardiac death (SCD) in Brugada syndrome (BrS) is regarded as a I class recommendation for secondary prevention implantable cardioverter defibrillator (ICD). However, the risk stratification of BrS patients for primary prevention ICD still represents a clinical conundrum. Although intracardiac electrophysiology (EP) study proved useful for the selection of high-risk patients in this setting. Therefore, aim of this study was to assess all clinical and EP variables associated with the induction of VA at EP study and the rate of appropriate/inappropriate ICD interventions and/or clinical SCD events in these patients occurring at follow-up. Methods and results From 2001 to 2021, all EP studies performed in symptomatic/asymptomatic patients (46 ± 14 years, M 88%) with/without family history of SCD spontaneous/drug-induced type I pattern (TIP) on ECG and no spontaneous ventricular arrhythmias were retrospectively considered at our study centre. Clinical variables, BrS pattern, EP study data (including right ventricular site and type of stimulation protocol), and ICD interventions (DC-shocks or Anti-Tachycardia Pacing events, ATP) and/or SCD events occurring at follow-up were all evaluated. EP study was deemed positive for any polymorphic VA induced during programmed ventricular stimulation; non-sustained episodes included. ICD was routinely implanted in all patients with a positive EP study. Follow-up data were detected by the collection of medical and home-monitoring recordings at study-site level. Follow-up data were available in 50 patients (9 ± 6 years on average). Patients were generally young with few cardiovascular comorbidities. SCD history was known in 21 (42%) with a significant number of asymptomatic patients (48%). Br patterns were equally distributed in the investigated population (spontaneous and drug-induced TIP in 52% and 48%, respectively) and AF history was fairly common (16%). In the study population, EP study tested positive in 30 patients (60%): spontaneous TIP (P = 0.0518), few extrastimuli during programmed ventricular stimulation (P = 0.0015), and right ventricular stimulation at the apical site (P ≤ 0.0001) were the only variables to be clearly associated with a positive EP study in the appraised patients. At follow-up, appropriate ICD shocks were documented in 4 out of 30 implanted patients (13%) at generally 5 ± 7 years from EP study evaluation. Although three ICD interventions (75%) occurred in patients with spontaneous TIP, one patient with drug-induced TIP pattern and positive EP study referred to Emergency Department for unrelenting VT storm after roughly 13 years from ICD implantation. Inappropriate ICD interventions for fast rate AF were detected in 10% of cases. Finally, no SCD events were documented at follow up in patients with a negative EP study. Conclusions In a retrospective analysis, EP study proved useful in the risk stratification of SCD in BrS patients. A few ventricular extrastimuli delivered at the right ventricular apex seem sufficient to prompt the induction of life-threatening VA in high-risk BrS patients during EP study. Moreover, in this setting, a negative EP study seems protective against the development of VA/SCD events at follow-up. However, not only is spontaneous TIP associated with an increased risk of arrhythmic death, but a drug-induced TIP, generally regarded as a low-risk condition, might also be associated with a long-term hazard of SCD in these patients.

Mode of death and outcomes of implantable cardioverter defibrillators in transthyretin amyloid cardiomyopathy

IntroductionTransthyretin cardiac amyloidosis (ATTR-CM) may associate with sudden cardiac death. We report on the mode of death and outcomes with implantable cardioverter defibrillators (ICDs) in a cohort with ATTR-CM. MethodsA single center observational cohort study of patients with ATTR-CM diagnosed between 2005 and 2019. ICD implant was at discretion of treating cardiologists. Medians are expressed with 25th,75th percentiles. ResultsEighty-four patients with ATTR-CM (age 73.5 ± 9.7 years, 94% male, median follow-up 21.1 months (11.4–38.1). Nineteen patients (23%) underwent ICD implantation – 18 for primary and 1 for secondary prevention. In the primary prevention ICD group, 1 patient had 2 inappropriate shocks, 1 patient had appropriate ATP on 3 occasions. One patient (mixed ischemic cardiomyopathy and ATTR-CM) with secondary prevention ICD had 15 appropriate shocks in 3 episodes of VT storm. In patients without ICD, ambulatory monitoring review (14,764 h) did not reveal sustained ventricular arrhythmia. Excluding the one patient with secondary prevention ICD, 5 (28%) in the primary prevention ICD group and 22 (34%) in the non-ICD group died, p = 0.14. Mode of death did not vary between both groups. ConclusionsPatients with ATTR-CM and primary prevention ICD infrequently receive appropriate device therapy without differing in mode of death, which was mainly related to progressive heart failure, compared to those without ICD.

Abstract 11665: Does the Benefit of Secondary Prevention Implantable Cardioverter-Defibrillators Vary Based on the Estimated Proportional Risk of Sudden Death?

Introduction: The Seattle Proportional Risk Model (SPRM) is a validated model developed in systolic heart failure patients without implantable cardioverter-defibrillators (ICDs) to estimate the proportion of all-cause mortality (ACM) due to sudden death. This study aims to ascertain if SPRM has utility in risk stratification for secondary prevention ICD. Methods: The AVID (Antiarrhythmics Versus Implantable Defibrillators) trial was a multicenter, randomized clinical trial in which 1,016 patients presenting with ventricular fibrillation or sustained, symptomatic ventricular tachycardia were randomized to ICD or antiarrhythmic (AA) drug therapy. Using routine clinical variables, we applied the SPRM to patient-level data (n=995 with complete data) and assessed if the ICD benefit for ACM varied with SPRM-predicted probability of sudden death. Results: SPRM was predictive of sudden death vs. non-sudden death in patients without an ICD (logistic regression p=0.005). The ICD hazard ratio for ACM was 0.59. ICD survival benefit varied with SPRM for ACM (p=0.013) with benefit (ICD HR≤0.80) seen in patients with SPRM&gt;40%. ICD benefit trended higher in patients with a history of heart failure (HF) vs no HF (HR=0.52 vs. 0.81, interaction p=0.13) (Figure 1). In comparison to the AA group, patients with either HF or SPRM&gt;51% (median) had a meaningful ICD benefit (HR=0.60, p=0.017), and patients with both HF and SPRM&gt;51% had the greatest ICD benefit (HR=0.38, p&lt;0.001). There was no ICD benefit if no HF and SPRM&lt;51% (HR=1.17). Conclusions: In a population of patients with VF or sustained VT, secondary prevention ICDs decreased ACM by 41%. ICD survival benefit varied with SPRM-predicted proportion of sudden death, and trended higher in patients with HF. SPRM may therefore provide a useful tool for risk stratifying patients for secondary prevention ICD. Figure 1: Survival benefit for ICD therapy varies with SPRM-estimated proportion of sudden death, and HF versus no HF.

Heart failure with recovered ejection fraction (HFrecEF): A new entity with improved cardiac outcome.

Aim of the study was a better characterization of heart failure (HF) with recovered ejection fraction (HFrecEF) and undulating EF (HFuEF) with regard to re-hospitalization due to congestive HF (CHF), adequate electric therapies (AETs) and mortality compared to HF with reduced EF (HFrEF), mid-range EF (HFmrEF) and preserved EF (pEF). Retrospective study of 342 participants with an implantable cardioverter defibrillator (ICD) for primary or secondary prevention. Type of HF was classified according to left ventricular EF with 4.7±3.1 investigations for each patient. Re-hospitalization due to CHF was similar in HFrecEF (7 (9.5%)), HFmrEF (2(9.0%)) and pEF (8(12.9%); p=n.s.) and significantly higher in HFrEF (62(38.0%)) and HFuEF (6(28.6%); p<.001 compared to HFrecEF and HFrEF). AETs were significantly lower in HFrecEF (13(17.6%)) compared to HFrEF (57(35.0%)), HFmrEF (7(31.8%)), pEF (18(29.0%)) and HFuEF (6(28.6%); each p<.01 compared to HFrecEF). Mortality was similar in HFrecEF (6(8.1%)) compared to HFuEF (0(0%)), pEF (4(6.5%)) and HFmrEF (2(9.0%), p=n.s.) and significantly lower compared to HFrEF (52(31.9%), p<.001). HFrEF was the strongest predictor for mortality besides age and chronic renal insufficiency according to Cox Regression (each p<.05) opposite to arterial hypertension, diabetes, type of cardiomyopathy and secondary prevention ICD indication (each p=n.s.). HFrecEF indicates as a new entity of HF with similar prognosis as pEF and HFmrEF with regard to re-hospitalization due to CHF and mortality and even better prognosis with regard to AETs. HFuEF showed similar rates of re-hospitalization due to CHF and AETs compared to HFrEF, but lower rates of mortality.

In-depth phenotypic characterisation of myocardial fibrosis by cardiovascular magnetic resonance predicts sudden cardiac death in coronary heart disease: a long-term prospective outcome study

Abstract Background Prospective studies harnessing late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) afford the potential to non-invasively characterise the phenotypic substrate for sudden cardiac death (SCD) and simultaneously interrogate its mechanistic drivers. Purpose To assess the utility of infarct characterisation by CMR, including scar microstructure analysis, to predict SCD in prospectively investigated patients with coronary heart disease (CHD). Methods Patients with stable CHD were prospectively recruited into a registry between August 2009 and January 2016. The primary outcome for this study was SCD or aborted SCD. Patients with a secondary prevention implantable cardioverter defibrillator (ICD) indication were excluded. All patients had CMR with LGE imaging. Infarct quantification (core scar and peri-infarct zone [PIZ]) was performed by an independent level 3 CMR reader. Outcome events were adjudicated by a panel of cardiologists blinded to the CMR data. To investigate fibrosis microstructure, bespoke computational image processing algorithms were applied to the LGE images in order to extract specific morphological and texture related features. Results Of 437 patients (mean age 64, mean left ventricular ejection fraction [LVEF] 47%, 91% with LGE) followed for a median of 6.3 years, 49 patients (11.2%) experienced the primary outcome. Patients with higher PIZ mass had an increased risk of the primary outcome (10-year risk 0.7%, 24.0% and 37.8% for patients with PIZ mass &amp;lt;5.66g, 5.66–12.28g and ≥12.29g respectively, P&amp;lt;0.001; figure 1a). On univariable analysis, an increase in PIZ mass and core infarct mass was associated with an increased risk of the primary outcome (per gram: HR 1.12, 95% CI 1.09–1.15, P&amp;lt;0.001 and HR 1.05, 95% CI 1.04–1.06, P&amp;lt;0.001 respectively). PIZ mass and core infarct mass remained independently associated with the primary outcome after adjustment for baseline predictors (per gram: HR 1.10, 95% CI 1.06–1.14, P&amp;lt;0.001 and HR 1.04, 95% CI 1.02–1.06, P&amp;lt;0.001 respectively) and together provided incremental value compared to conventional variables in predicting the endpoint (Harrell's C-statistic 0.76 to 0.82, figure 1b-c). Bespoke analysis of imaging data identified several shape-based scar metrics that associated with the primary outcome (figure 2). These included core infarct transmurality, radiality and interface length (the latter defining the core scar-PIZ boundary length), and the number of PIZ islets. Conclusions In this large prospective study of patients with stable CHD, both PIZ mass and core infarct mass independently predicted long-term SCD risk after adjusting for conventional predictors including LVEF. Reassuringly, minimal or absent LGE portended a comparatively low risk of SCD. Analysis of the scar microstructure identified several shape-based features that associated with SCD. These results highlight a potential avenue towards a more personalised approach to ICD implantation decisions. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Lung and Heart Institute, Imperial College London

Neurological outcome at 30-day as an estimator of 1-year functional status after out-of-hospital cardiac arrest with post-encephalopathy

Abstract Background Implantation of implantable cardioverter-defibrillators (ICD) for secondary prevention is fully recommended for those with an estimated survival over 1-year with a good functional status. However, we often face the difficulty to estimate the functional status and hesitate to implant ICD for patients with post-resuscitation encephalopathy. Methods There were 2391 out-of-hospital cardiac arrest (OHCA) patients transferred to 2 hospitals. We included 405 cardiovascular arrest patients, who got return of spontaneous circulation (ROSC) from January 2015 to December 2018. Among the patients, 343 patients could be considered to be implanted ICD for secondary prevention according to the initial waveform or the causes of OHCA. At 1-month later, 184 patients (54%) survived. To assess the association of functional status at 30-day and 1-year, we investigated patients' characteristics, pre-hospital information and clinical findings, and evaluated the neurological outcome according to the cerebral performance category (CPC) scale. Results At 1-month later, 145 patients (79%) survived with CPC≤2, and 39 patients (21%) survived with CPC&amp;gt;2. Bystander CPR (P=0.009), pre-hospital ROSC (P&amp;lt;0.001), low lactate level on admission (P=0.001), high geriatric nutritional risk index score (P&amp;lt;0.001) and without ECMO (P=0.002) were significantly associated with good neurological outcome at 30-day. The 1-year Kaplan-Meier event rate revealed significantly different survival rate (CPC&amp;gt;2 at 30-day:38.5%, vs CPC≤2 at 30-day:97.2%; P&amp;lt;0.001). In multivariate analysis, CPC scale at 30-day (OR 0.022; 95% CI 0.003–0.140; p&amp;lt;0.001) was the independent predictor of favorable neurological outcome at 1-year. Among the patients with CPC&amp;gt;2 at 30-day, only 3 patients (7.7%) of CPC=3 achieved the improvement of neurological outcome at 1-year (CPC≤2), while no patient of CPC=4 did. And one patient (2.5%) with CPC=3 was implanted ICD during the follow-up period. Twenty-five patients (64%) died of non-cardiovascular death with frailty of post-resuscitation encephalopathy after they were transferred to other hospital with the acceptation and intention of the do-not-attempt-resuscitation. Conclusions Neurological prognosis at 30-day after OHCA might be an estimator of 1-year functional status to guide us to implant ICD for secondary prevention. Funding Acknowledgement Type of funding sources: None.

Secondary prevention implantable cardioverter-defibrillator (ICD) therapy in octogenarians: effective and safe

Abstract Aims Implantable cardioverter-defibrillator is well established for secondary prevention, but there is a lack of studies showing efficacy and safety in the elderly. The current study compared the outcome of octogenarians after ICD implantation to other age groups. Methods Data was achieved from a local ICD registry. Patients who received ICD implantation for secondary prevention were included. All-cause mortality, appropriate ICD therapy and acute adverse events requiring surgical intervention were compared between different age groups. Results 519 patients were enrolled. 34 patients were ≥80 years. Over a median follow-up of 35 months after ICD implantation 129 patients (annual mortality rate 5.0%) died, including 16 patients in the age group ≥80 years (annual mortality rate 9.4%). Mortality rate in the age group ≥80 years was significantly higher than in the age groups ≤69 years (p&amp;lt;0.001) but no difference could be seen compared to age groups 70–79 y. Age at the time of ICD implantation was an independent predictor of all-cause mortality (p&amp;lt;0.001). 29.7% of patients had appropriate ICD therapy with no difference between age groups. Acute adverse events leading to surgical intervention were low (n=13) and not age-related. Conclusion Age is an independent predictor of mortality after ICD implantation for secondary prevention. No difference in mortality rate could be seen between octogenarians and other elderly from 70 – 79 years. Appropriate ICD therapy and acute adverse events leading to surgical intervention were not age-related. Implantable cardioverter-defibrillator for secondary prevention seems to be an effective and safe therapy in octogenarians. Funding Acknowledgement Type of funding sources: None.