Implantable Cardiac Defibrillator For Primary Prevention Research Articles

Evaluation of MADIT-II Risk Stratification Score Among Nationwide Registry of Heart Failure Patients With Primary Prevention Implantable Cardiac Defibrillators or Resynchronization Therapy Devices

Current guidelines advocate prophylactic Implantable Cardioverter Defibrillator (ICD) for all symptomatic heart failure (HF) patients with low LVEF. Since many patients will never use their device, a score delineating subgroups with differential ICD benefit is crucial. We aimed to Evaluate MADIT II-based Risk Stratification Score (MRSS) feasibility to delineate ICD survival benefit among nationwide registry of HF patients with prophylactic ICDs. Accordingly, all Israeli HF patients with prophylactic ICD/CRTDs were categorized into MRSS-based risk-subgroups. Study endpoints included overall mortality, sustained ventricular arrhythmia (VA), and a competing risk of VA (potential preventable arrhythmic death, where ICD could benefit survival) versus non-arrhythmic death. Potential ICD survival benefit was estimated by the area between these cumulative incidence curves. Among 2,177 HF patients implanted prophylactic device, 189 patients (8.7%) had VA and 316 (14.5%) died during median Follow-up (F/U) of 2.9 years. MRSS risk-subgroups were significantly associated with overall mortality (p < 0.001) and weakly with VA (p 0.3). Competing risk analysis of VA versus non-arrhythmic death revealed significantly shorter duration (p < 0.001) and smaller magnitude of ICD survival benefit with increased risk subgroups, yielding estimated 76, 60, 38, and 0 life-days gained from prophylactic ICD implant during 5-year F/U for the MRSS low, intermediate, high, and very-high risk subgroups, respectively (p for trend< 0.05). In conclusion, MRSS use among nationwide registry of ischemic and non-ischemic cardiomyopathy patients, revealed subgroups with differing ICD survival benefit, suggesting it could help evaluate prophylactic ICD survival benefit.

Left cardiac sympathetic denervation in children. A matter of facts

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Cardiac sympathectomy (CS) is a second-line treatment for drug-refractory adrenalin-sensitive channelopathies. We present our series of paediatric sympathectomies for long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT) as adjunctive treatment. Methods Between 2011 and 2021, 30 CS (28 left, 2 right) were performed by videothoracoscopy in 28 patients (21 LQTS and 7 CPVT), aged 8 days to 21 years. The mean follow-up was 29 months. All patients were treated pharmacologically before surgery, three had an implantable cardiac defibrillator (ICD). Indications for CS in patients with CPVT included previous cardiac arrest (3/7) and sustained VT induced by emotion/stress despite medication (4/7). In LQTS, indications included syncope (4/21), VT despite medication (7/21) and high risk of malignant arrhythmias (10/21). Results There were no intraoperative complications or deaths. Four patients had transient palpebral ptosis with mild miosis, 23/28 patients were monitored by ICD or subcutaneous holter. After sympathectomy, 24/28 remain asymptomatic; three patients experienced syncope and one received appropriate discharge. Seven patients experienced VT (3/7 due to pharmacological non-compliance) of which three required ICD and four improved with medication. During follow-up, five high-risk patients received ICDs for primary prevention. Conclusion CS is an effective and safe technique in children as an adjunctive treatment for severe arrhythmias due to channelopathies. After CS, 85% remained asymptomatic. Medication non-compliance is an important cause of VT after CS, although ICD was occasionally required. In our experience, long-term remote monitoring is key to effective follow-up.

Validation of CalECG software for primary prevention heart failure patients: Reducing inter-observer measurement variability

BackgroundIn primary prevention heart failure patients the 12‑lead electrocardiogram (ECG) may be useful for the prediction of ventricular arrhythmias. However, inter-observer measurement variability first needs to be identified and any software used, validated. ObjectiveTo compare manual ECG measures with CalECG software and to assess the reliability of visual recognition of fragmented QRS (fQRS) by advanced cardiology trainees. Methods30 pre-implant ECGs were assessed on patients who met guidelines for primary prevention Implantable Cardiac Defibrillator. Parameters included RR, PR, QT, QRS duration, axis location, fQRS and T wave peak to T wave end (TpTe). ECGs were analyzed by members of the cardiology department with different levels of experience, and compared to CalECG software. Interobserver agreement was assessed using Fleiss' Kappa (κ) and intraclass correlation coefficients (ICC). Pearson correlation coefficient (r) was used to compare human and software measures. ResultsStrong/very strong correlation was recorded across manual ECG measures (ICC = 0.749–0.979, p ≤ 0.0001) with moderate/strong correlation for TpTe (ICC = 0.547–0.765, p ≤ 0.001). Advanced cardiology trainees demonstrated substantial agreement on ECG interpretation (κ = 0.788, p ≤ 0.0001), however, reliability of fQRS assessment was only moderate for identification (κ = 0.5, p ≤ 0.0001) and fair for location (κ = 0.295, p = 0.001). CalECG software showed strong/very strong correlation with manual measurement for standard measures (r = 0.756–0.977, p ≤ 0.001). Concordance between human and software TpTe measurements varied between leads, with V5 showing a non-significant weak correlation (r = 0.197). ConclusionCalECG software showed strong/very strong correlation with standard manual measures which affirms its use in ECG analysis. Advanced cardiology trainees showed greater variability in the identification and location of fQRS.

PO-632-02 GUIDELINE DIRECTED MEDICAL THERAPY AND THE RISK OF DEATH IN PRIMARY PREVENTION DEFIBRILLATOR RECIPIENTS

Primary prevention implantable cardiac defibrillators (ICD) are indicated in patients with heart failure and severely reduced ejection fraction (EF). Quadruple guideline-directed medical therapy (GDMT) with ACE inhibitors/ARB/ARNI, beta-blockers, aldosterone antagonists, and SGLT-2 inhibitors is indicated in this population.

The Evolving Evidence Base of Implantable Cardiac defribrillators: Past, Present, and Future

This review describes the evidence that forms the foundation for the use of an implantable cardiac defibrillator (ICD). The authors present the current guidelines for the implantation of ICDs and describe the most important historic and latest clinical trials that have been conducted to examine the role of ICDs for primary and secondary prevention of a cardiac arrest. Finally, the authors discuss new technologies that have been developed to improve outcomes and reduce adverse events associated with these types of cardiac implantable electronic devices.

Clinical characteristics and natural history of pre-adolescent non-syndromic hypertrophic cardiomyopathy

Abstract Background The clinical presentation and natural history of pre-adolescent sarcomeric hypertrophic cardiomyopathy (HCM) has not been systematically characterised. The aim of this study was to describe the clinical characteristics and outcomes of a large, international, multicentre cohort of children diagnosed with non-syndromic HCM below the age of 12. Methods Data from the International Paediatric Hypertrophic Cardiomyopathy Consortium on 639 children meeting diagnostic criteria for HCM below 12 years of age (pre-adolescent) were collected and compared with 568 diagnosed aged 12–16 years. Patients with syndromic and metabolic HCM were excluded. Results Of 639 (male n=417, 65.3%) children with pre-adolescent HCM, 339 (53.1%) had a family history of HCM and 57 (8.9%) a family history of sudden cardiac death (SCD). At the time of baseline assessment; 132 (20.7%) had heart failure symptoms and 39 (6.1%) reported unexplained syncope. Median maximal left ventricular wall thickness on echocardiogram was 13.6mm (IQR 10–19) with a corresponding median z-score of 8.7 (5.3–14.4). 145 (22.7%) had left ventricular outflow tract obstruction (LVOTO) (maximal LVOT gradient≥30mmHg) and 35 (5.5%) had severe LVOTO (gradient≥90mmHg). Over a median follow up 5.6 years (IQR 2.3–10), 10.5% underwent a myectomy and 23.2% implantable cardiac defibrillator (ICD) implantation for primary (81.8%) or secondary (14.2%) prevention. 42 (6.7%) patients died [SCD 4.9%, heart failure death 0.8%, other 1%] and 21 (3.3%) underwent cardiac transplantation. 69 (10.8%) patients had an arrhythmic event (SCD n=31, resuscitated cardiac arrest n=17, appropriate ICD therapy n=14, sustained VT with haemodynamic compromise n=7). Compared to those presenting after 12 years, those under 12 were less likely to have a family history of SCD (8.9% vs 13%, p:0.047) or report unexplained syncope (6.1% vs 12.3%, p&amp;lt;0.00). The degree of hypertrophy did not differ but a higher proportion of pre-adolescent patients had LVOTO (22.7% vs 14.4%, p&amp;lt;0.00). A higher proportion of pre-adolescent underwent a myectomy (10.5% vs 7.2%, p:0.045) but a lower proportion received a primary prevention ICD (18.9% vs 30.1%, p:0.041). The overall proportion of patients reaching the mortality or arrhythmic end-points did not differ, but SCD and resuscitated cardiac arrest events were more frequent in pre-adolescent patients (4.9% vs 3.9% and 2.7 vs 1.6% respectively). Conclusion Pre-adolescent HCM is associated with a high symptom burden and variable cardiac phenotype, comparable to those presenting later in childhood. Despite baseline similarities and equal overall survival, younger patients were less likely to receive a primary prevention ICD despite being more likely to experience a SCD or resuscitated cardiac arrest. This study suggests that younger patients should not be considered a distinct entity for risk stratification and that similar management strategies to older HCM patients should be employed. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): BHF (British Heart Foudnation) MRC (Medical Research Council)

Association of Guideline-Based Medical Therapy with Malignant Arrhythmias and Mortality among Heart Failure Patients Implanted with Cardioverter Defibrillator (ICD) or Cardiac Resynchronization-Defibrillator Device (CRTD).

Aim: Evaluate prevalence of heart failure (HF) medications and their association with ventricular arrhythmia (VA) and survival among patients implanted with primary prevention implantable cardiac defibrillator (ICD)/cardiac resynchronization therapy + defibrillator (CRTD) devices. Methods: Association of treatment and dose (% guideline recommended target) of beta-adrenergic receptor antagonist (BB), angiotensin-antagonists (AngA), and mineralocorticoid-antagonists (MRA), after ICD/CRTD implant with VA and mortality was retrospectively analyzed. Results: Study included 186 HF patients; 42.5% and 57.5% implanted with ICD and CRTD, respectively. During 3.8 (2.1;6.7) years; 52 (28%) had VA and 77 (41.4%) died. Treatment (% of patients) included: BB (83%), AngA (87%), and MRA (59%). Median doses were 25(12.5;50)% of target for all medications. BB treatment >25% target dose was associated with reduced VA incidence. In the multivariable model including age, gender, diabetes, heart rate, and medication doses, increased BB dose was associated with reduced VA (hazard ratio (HR) 0.443 95% CI 0.222–0.885; p = 0.021). In the multivariable model for overall mortality including age, gender, renal disease, VA, and medical treatment, VA was associated with increased mortality (HR 2.672; 95% CI 1.429–4.999; p = 0.002) and AngA treatment was associated with reduced mortality (HR 0.515; 95% CI 0.285–0.929; p = 0.028). Conclusions: In this cohort of real-life HF patients discharged after ICD/CRTD implant, prevalence of guideline-based HF medications was high, albeit with low doses. Higher BB dose was associated with reduced VA, while AngA was associated with improved survival.

Real-world evaluation of followup strategies after ICD therapies in patients with VT (REFINE-VT).

Implantable cardiac defibrillators (ICDs) can prevent sudden cardiac death, but the risk of recurrent ventricular arrhythmia (VA) and ICD shocks persist. Strategies to minimise such risks include medication optimisation, device programming and ventricular tachycardia (VT) ablation. Whether the choice of these interventions at follow-up are influenced by factors such as the type of arrhythmia or ICD therapy remains unclear. To investigate this, we evaluated ICD follow-up strategies in a real-world population with primary and secondary prevention ICDs. REFINE-VT (Real-world Evaluation of Follow-up strategies after Implantable cardiac-defibrillator therapies in patients with Ventricular Tachycardia) is an observational study of 514 ICD recipients recruited between 2018 and 2019. We found that 77 patients (15%) suffered significant VA and/or ICD therapies, of whom 26% experienced a second event; 31% received no intervention. We observed an inconsistent approach to the choice of strategies across different types of arrhythmias and ICD therapies. Odds of intervening were significantly higher if ICD shock was detected compared with anti-tachycardia pacing (odds ratio [OR] 8.4, 95% confidence interval [CI] 1.7 to 39.6, p=0.007). Even in patients with two events, the rate of escalation of antiarrhythmics or referral for VT ablation were as low as patients with single events. This is the first contemporary study evaluating how strategies that reduce the risk of recurrent ICD events are executed in a real-world population. Significant inconsistencies in the choice of interventions exist, supporting the need for a multi-disciplinary approach to provide evidence-based care to this population.

Primary Prevention Implantable Cardiac Defibrillators: A Townsville District Perspective.

Background: Despite major advances in treating patients with severe heart failure, deciding who should receive an implantable cardiac defibrillator (ICD) remains challenging.Objective: To study the risk factors and mortality in patients after receiving an ICD (January 2008–December 2015) in a regional hospital in Australia.Methods: Eighty-two primary prevention patients received an ICD for ischemic cardiomyopathy (ICM, n = 41) and non-ischemic cardiomyopathy (NICM, n = 40) with 4.8-yrs follow-up. One patient had mixed ICM/NICM indications. Ventricular arrhythmias were assessed using intracardiac electrograms. Statistical analysis compared the total population and ICM and NICM groups using Kaplan-Meier for survival, Cox regression for mortality predictors, and binary logistic regression for predictors of ventricular arrhythmias (p < 0.05).Results: Major risk factors were hypercholesterolemia (70.7%), hypertension (47.6%), and obesity (41.5%). Severe obstructive sleep apnea (OSA) was found exclusively in NICM patients (23.7%, p = 0.001). Mortality was 30.5% after 4.8-yrs. The majority of patients (n=67) had no sustained ventricular arrhythmias yet 28% received therapy (n = 23), 18.51% were appropriate (n = 15), and 13.9% inappropriate (n = 11). Patients receiving ≥2 incidences of inappropriate shocks were 18-times more likely to die (p = 0.013). Three sudden cardiac deaths (SCD) (3.7%) were prevented by the ICD.Conclusion: Patients implanted with an ICD in Townsville had 30.5% all-cause mortality after 4.8-yrs. Only 28% of patients received ICD therapy and 13.9% were inappropriate. OSA may have contributed to the fourfold increase in inappropriate therapy in NICM patients. Our study raises important efficacy, ethical and healthcare cost questions about who should receive an ICD, and possible regional and urban center disparities.

P1658Pharmacological treatment of patients with HFrEF: is it really optimized in case of CRT and/or ICD implantation?

Abstract Background Cardiac resynchronization (CRT) as well as implantable cardiac defibrillator (ICD) in primary prevention should be considered in patients with heart failure and reduced ejection fraction (HFrEF) only when pharmacological treatment has been optimized. Purpose we sought to analyze pharmacological treatments according to the presence or not of CRT-P, CRT-D or ICD in real life HFrEF patients by using a multicenter survey. Methods the survey (NCT01956539) was carried out between 2015 and 2018 in 32 hospitals and included 2735 patients with HF who gave their consent during consultation or hospitalization. In this study, we analyzed only outpatients with chronic HFrEF treated for more than 6 months. Results among 1061 patients studied, 138 had CRT-P or CRT-D and 215 had ICD for primary prevention. The main clinical characteristics were: age 65±13 years, ischemic heart disease in, NYHA classes 1, 2, 3 and 4 in 15%, 52%, 23% and 10% cases respectively, systolic blood pressure 115mmHg [IQR 104–129], heart rate 70bpm [IQR 60–80], eGFR 64ml/min/1.73m2 [IQR 46–83]and LVEF was 30% [IQR 24–34]. The table shows the rate of use of evidence-based drugs and the dose for ACEi/ARB and betablockers, according to the presence of ICD or CRT. HFrEF CRT-P or D ICD (primary prevention) n=1061 n=138 n=215 Loop diuretics 78.2% 79.7% 74.9% ACEi or ARB 65.2% 75.4% 67.3% Sacubitril/valsartan 5.9% 8.5% 9.5% Betablockers 72.3% 83.9% 76.8% Mineralocorticoid antagonists 45.7% 63.6% 60.2% ACEi/ARB mean % maxi dose 77 81 83 Beta-blockers mean % maxi dose 74 63 79 Conclusion these results suggest that pharmacological treatment remains poorly optimized in a number of patients with HFrEF who received ICD or CRT

To Exchange or Not: Defibrillators, Ventricular Assist Devices and Hematomas

Purpose To assess peri-procedural complications in left ventricular assist device (LVAD) patients undergoing implantable cardiac defibrillator (ICD) generator exchange for primary prevention of sudden cardiac death. Methods In this single-center study, we retrospectively analyzed all current patients with a durable LVAD (n=39) who underwent ICD generator exchange between January 2014 and August 2018. Data was collected from electronic medical records and clinical outcomes analyzed included death, stroke, infection, any hematoma formation, need for blood products transfusion and hospital admission for above reasons within 30 days of ICD generator exchange. Results Of 39 current LVAD patients 15 (38%) underwent an ICD generator exchange. 14/15 (93%) patients were male and mean age was 73 ± 8.2 years. 11/15 patients (73.3%) had the ICD implanted for primary prevention vs. 4/15 (26.7%) had the ICD for secondary prevention. In the primary prevention ICD cohort, none of the patients received a defibrillator shock during the time course of having the device. Mean follow-up from the date of ICD generator exchange was 2.2 patient years. Pocket hematoma was noted in 3/11 (27.2%) primary prevention patients who underwent ICD generator exchange, of which 1 patient was hospitalized for observation of the hematoma. No patients required blood products. All 3 patients who developed pocket hematoma were on antiplatelet therapy with aspirin as well as warfarin with INRs ranging from 2.2-3.5. There were no infections as a result of ICD generator exchange. Conclusion In this single center study, pocket hematoma formation was noted in 27% of the primary prevention cohort who underwent ICD generator exchange. No patients required a blood product transfusion or developed an infection. Of note, no patients received an ICD shock during the course of follow-up. This raises a clinically relevant central question on indication of ICDs and generator exchange in patients with LVADs and no prior history of arrhythmia.

Abstract 076: Modeling Heterogeneity of Benefit in Patients Eligible for Implantable Cardiac Defibrillators: Insights From the SCD-HeFT Registry

Background: Guidelines recommend that patients with heart failure and reduced ejection fraction (&lt;35%; HFrEF), on goal-directed medical therapy be considered for placement of an implantable cardiac defibrillator (ICD) for primary prevention of sudden cardiac death. This recommendation arose from the results of the SCD-HeFT trial, where there was a 7% absolute mortality reduction at 5 years in those who got an ICD. However, the application of these guidelines has been suboptimal and it is unknown if particular patient characteristics drive this benefit. Methods: We used patient-level data from the multi-center SCD-HeFT trial to examine the heterogeneity of the primary outcome (5-year all-cause mortality) in 1676 patients randomized to placebo or ICD (excluding those randomized to amiodarone). We used step-wise variable selection to select the variables for the final model. A cox proportional hazards model was then applied to develop a prediction tool to estimate patient benefit with ICD. Results: After variable selection, the following variables were found to be significantly associated with an increased risk of mortality over 5 years: older age, male sex, ischemic heart disease, diabetes, higher NYHA class, lower LVEF, diuretic use, lower mean blood pressure, higher blood urea nitrogen, and randomization to placebo (see Figure 1). There was a significant interaction of treatment allocation with diabetes, where the benefit of ICDs was greatest amongst those without diabetes (HR placebo vs. ICD amongst diabetics, 6.33, 95% CI 2.40-20.91; p &lt; 0.001). Conversely, among diabetics ICD therapy was associated with an increased risk of mortality when compared to medical therapy (HR 6.39, 95% CI 2.51-15.95; p &lt; 0.001). The c-statistic for the model was 0.73. Conclusion: There is substantial heterogeneity of treatment benefit from an ICD for primary prevention of 5-year all-cause mortality. If validated in a distinct and more contemporary dataset, this model may have an important role in patient selection and shared decision-making.

Cardiovascular magnetic resonance‐GUIDEd management of mild to moderate left ventricular systolic dysfunction (CMR GUIDE): Study protocol for a randomized controlled trial

The majority of sudden cardiac death (SCD) in patients with heart failure occurs in those with mild-moderate left ventricular (LV) systolic dysfunction (LVEF 36-50%) who under current guidelines are ineligible for primary prevention implantable cardiac defibrillator (ICD) therapy. Recent data suggest that cardiac magnetic resonance (CMR) evidence of replacement fibrosis forms a substrate for malignant arrhythmia and therefore potentially identifies a subgroup at increased risk of SCD. Our hypothesis is that among patients with mild-moderate LV systolic dysfunction, a CMR-guided management strategy for ICD insertion based on the presence of scar or fibrosis is superior to a current strategy of standard care. CMR GUIDE is a prospective, multicenter randomized control trial enrolling patients with mild-moderate LV systolic dysfunction and CMR evidence of fibrosis on optimal heart failure therapy. Participants will be randomized to receive either a primary prevention ICD or an implantable loop recorder (ILR). The primary endpoint is the time to SCD or hemodynamically significant ventricular arrhythmia (VF or VT) during an average 4-year follow-up. Secondary endpoints include quality of life assessed by Minnesota Living with Heart Failure Questionnaire, heart failure related hospitalizations, and a cost-utility analysis. Clinical trials.gov identifier NCT01918215. CMR GUIDE trial will add substantially to our understanding of the role of myocardial fibrosis and the risk of developing life-threatening ventricular arrhythmias. If the superiority of a CMR-guided approach over standard care is proven, it may change international clinical guidelines, with the potential to considerably increase survival in this growing patient population.

The prognostic value of discordant T waves in lead aVR: A simple risk marker of sudden cardiac arrest in ischemic cardiomyopathy

BackgroundSimple and reliable ECG marker(s) for sudden cardiac arrest (SCA) could be very useful in assessing high-risk populations. Since ischemic repolarization abnormalities in the left ventricular (LV) apex are strongly correlated with discordant T waves in lead aVR, we sought to evaluate the clinical and prognostic significance of this feature in ischemic cardiomyopathy. MethodsThe PAREPET trial enrolled patients with ischemic cardiomyopathy eligible for a primary prevention implantable cardiac defibrillator (ICD). Those with persistent pacing or left bundle branch block were excluded. Amplitudes of T/aVR were automatically computed from median ECG beats at enrollment and endpoints were blindly adjudicated. ResultsThe sample was mainly composed of older men (n=138, age 65±12, 91% male, EF 29±9%). At enrollment, amplitude of T/aVR significantly correlated with EF, indexed LV end-diastolic volume, B-type natriuretic peptide (BNP), regional scar volume, and PET-quantified denervated myocardium. After a median follow up of 4.2years, there were 23 (17%) adjudicated SCA. In multivariate analysis, the presence of discordant T/aVR (>0mm, n=42, 30%) was a significant and independent predictor of SCA (hazard ratio 2.0 [95% CI 1.0–4.9]) and cardiac death (hazard ratio 1.9 [95% CI 1.0–3.7]). ConclusionsIn subjects with ischemic cardiomyopathy, discordant T waves in lead aVR are associated with high-risk clinical parameters including lower ejection fraction, greater ventricular volume, higher BNP, and more denervated myocardium. Furthermore, discordant T/aVR remained an independent predictor of SCA and cardiovascular mortality even after accounting for these prognostic factors.

30 Primary Prevention ICD post-STEMI: Impact of Adoption of Nice vs ESC Guidelines

<h3>Background</h3> It has been demonstrated that implantable cardiac defibrillators (ICD) can be effective in the primary prevention of sudden cardiac death in patients with severe left ventricular systolic dysfunction (LVSD). However, studies have been unable to elucidate any benefit from ICD implantation prior to 40 days post-infarct. Therefore, ESC guidelines recommend ICD implantation in patients with a persistent ejection fraction (EF) &lt;/=40% on repeat LV assessment taken at least 40 days post-STEMI. The NICE guidelines are more restrictive, recommending ICD implantation in patients with EF &lt;/=35% and QRS duration &gt;120 ms. The extent to which these guidelines are followed in clinical practice is unclear. <h3>Aims</h3> To evaluate in a primary percutaneous coronary intervention (PPCI) cohort: Whether patients with LVSD are receiving a re-assessment of their EF at least 40 days post-STEMI. The impact of adoption of ESC versus NICE guidelines on ICD implantation rates for primary prevention. <h3>Methods</h3> This was a retrospective observational study carried out at a tertiary referral centre in South West England. Data was collected from consecutive patients referred for PPCI with a diagnosis of STEMI (January to December 2013). LVSD was defined as an EF &lt;/=40% according to echocardiography or cardiac MRI. ECG changes were preferentially sourced from the date closest to the follow-up LV assessment. <h3>Results</h3> 573 patients were included, of which, 74% were male and the median age was 64 years. 214 patients had LVSD on initial assessment and were alive after 40 days. 29% (62/214) of patients were followed up elsewhere (echo data not available) and hence excluded from further analysis. 76% (115/152) had a repeat assessment of their EF; however, only 70% (80/115) of reassessments were carried out at least 40 days after the acute event. Of these, 41% (33/80) had persistent LVSD. Thus, 28% (33/115) patients qualified for an ICD under ESC guidelines. On the contrary, 3% qualified under the NICE guidelines, as 17/80 had an EF &lt;/=35% at repeat echo and only 3 of these had a QRS duration &gt; 120 ms. <h3>Conclusion</h3> In a UK PPCI population, significantly more patients would be eligible for an ICD based on ESC compared to NICE guidelines (28% vs. 3%). This would have significant cost implications. The requirement for repeat echocardiography and ECG least 40 days after the STEMI emphasises the need for appropriate linking of care between the PPCI centre and those hospitals undertaking subsequent follow-up. This remains a challenge to the NHS but we need to find ways to achieve it!

Shock therapy: psychological impact and patient support

Patients with a history of coronary artery disease, myocardial infarction and poor ventricular function are at high risk of sudden cardiac death and, as such, are candidates for a primary-prevention implantable cardiac defibrillator. The evidence for the use of implantable cardiac defibrillators in the prevention of sudden cardiac death is irrefutable. However, the impact of the implantable cardiac defibrillator on the psychological functioning of a patient is still being investigated. Shock therapy is recognised as being a potent predictor of both mortality and psychological functioning in defibrillator recipients; it is questionable whether patients with implantable cardiac defibrillators are receiving the support they need from current service provision.

Predictors of new onset atrial fibrillation in patients with heart failure

IntroductionStroke associated with atrial fibrillation (AF) is more frequent in heart failure. It is unknown what variables predict future AF in these patients and how AF might evolve over time. We investigated this in patients with implantable cardiac defibrillators (ICD) where AF detection is optimal. MethodsSingle centre, retrospective, observational cohort study. All ischaemic cardiomyopathy patients with dual chamber, primary prevention ICD implants between Aug 2003 and Dec 2009 were screened and included if at implant, they had no known AF history. Nine variables were analysed. AF was defined as any atrial tachyarrhythmia ≥180bpm and ≥30s. Multivariable, binary logistic regression models were built by adding variables significant in the univariate models. Variables were retained in the final multivariate models if p<0.05. Resultsn=197 met the inclusion criteria (85.8% male, median age: 66.8years). After median follow-up for 2.8years, 44.2% developed AF. After univariate analysis, the baseline variables associated with AF after implant were age, NYHA class and renal impairment (RI, defined eGFR<60ml/min/1.73m2) (p<0.05). After multivariable analysis, the only variable which was associated with AF was RI (HR: 2.04 (CI: 1.10–3.79)). Two baseline variables were independently associated with all-cause mortality: RI (HR: 2.42 (1.14–5.12)) and non-white ethnicity. ConclusionRI at time of implant was independently associated with both future AF and all-cause mortality during long-term follow-up. RI was a stronger predictor of AF than age. Those patients with heart failure and RI should be regularly screened for asymptomatic AF, regardless of age, to ensure that stroke prophylaxis may be initiated.

What to Do About Primary-Prevention Implantable Cardiac Defibrillators in Patients with Improved Ejection Fraction

Approximately 20-40% of heart failure patients with reduced ejection fraction (EF) demonstrate substantial improvements in their EF during follow-up. A subset of these patients who had originally received implantable cardioverter defibrillators (ICD) for the primary prevention of sudden cardiac death (i.e., patients with EF < 35%) pose a challenge to cardiologists when they present with improvements in EF to above 35% at the time of their battery depletion. Little is known about the risk of sudden cardiac death in these patients. Is the risk high enough to warrant the replacement of the ICD generator? In the following article, we review the available data on the risk of sudden cardiac death in these patients, and aim to assist the clinician and the patient in making informed decisions about whether the ICD therapy should be continued.

Can We Predict Sudden Cardiac Death in Long-term Survivors of Atrial Switch Surgery for Transposition of the Great Arteries?

This study aims to identify predictors of sudden cardiac death (SCD) in patients with transposition of the great arteries (TGA) who have undergone atrial baffle surgery with the Mustard or Senning operation. Patients with TGA and previous atrial baffle surgery are known to be at increased risk of SCD. Despite this, indications for insertion of an implantable cardiac defibrillator for primary prevention have not been established. Eighty-nine patients with a diagnosis of TGA and previous Mustard or Senning repair were identified. Medical records were reviewed for SCD, aborted SCD, implantation of cardiac defibrillator (ICD), and use of cardiac medications. Clinically significant events (heart failure admissions, documented arrhythmias, and insertion of a pacemaker) were ascertained, and results of echocardiograms were explored. There were five SCDs in our population, and five patients underwent a primary prevention ICD insertion, with no subsequent sustained ventricular arrhythmia or aborted SCD. Patients who suffered SCD had undergone surgery at an older age (median 53 months vs. 14 months) in a slightly earlier era (median year of operation 1971 vs. 1975). Atrial arrhythmias requiring treatment were documented in 100% of the SCD and in 29% of the no SCD patients. Criteria for insertion of primary prevention implantable cardiac defibrillators postatrial baffle surgery remain to be established. In the SCD subgroup, surgery at an older age, earlier era of surgical repair, and history of atrial arrhythmia appear to convey an increased risk of sudden death.

Regional Myocardial Sympathetic Denervation Predicts the Risk of Sudden Cardiac Arrest in Ischemic Cardiomyopathy

The PAREPET (Prediction of ARrhythmic Events with Positron Emission Tomography) study sought to test the hypothesis that quantifying inhomogeneity in myocardial sympathetic innervation could identify patients at highest risk for sudden cardiac arrest (SCA). Left ventricular ejection fraction (LVEF) is the only parameter identifying patients at risk of SCA who benefit from an implantable cardiac defibrillator (ICD). We prospectively enrolled 204 subjects with ischemic cardiomyopathy (LVEF ≤35%) eligible for primary prevention ICDs. Positron emission tomography (PET) was used to quantify myocardial sympathetic denervation ((11)C-meta-hydroxyephedrine [(11)C-HED]), perfusion ((13)N-ammonia) and viability (insulin-stimulated (18)F-2-deoxyglucose). The primary endpoint was SCA defined as arrhythmic death or ICD discharge for ventricular fibrillation or ventricular tachycardia >240 beats/min. After 4.1 years follow-up, cause-specific SCA was 16.2%. Infarct volume (22 ± 7% vs. 19 ± 9% of left ventricle [LV]) and LVEF (24 ± 8% vs. 28 ± 9%) were not predictors of SCA. In contrast, patients developing SCA had greater amounts of sympathetic denervation (33 ± 10% vs. 26 ± 11% of LV; p = 0.001) reflecting viable, denervated myocardium. The lower tertiles of sympathetic denervation had SCA rates of 1.2%/year and 2.2%/year, whereas the highest tertile had a rate of 6.7%/year. Multivariate predictors of SCA were PET sympathetic denervation, left ventricular end-diastolic volume index, creatinine, and no angiotensin inhibition. With optimized cut-points, the absence of all 4 risk factors identified low risk (44% of cohort; SCA <1%/year); whereas ≥2 factors identified high risk (20% of cohort; SCA ∼12%/year). In ischemic cardiomyopathy, sympathetic denervation assessed using (11)C-HED PET predicts cause-specific mortality from SCA independently of LVEF and infarct volume. This may provide an improved approach for the identification of patients most likely to benefit from an ICD. (Prediction of ARrhythmic Events With Positron Emission Tomography [PAREPET]; NCT01400334).