45 research outputs found
Development and external validation of prediction models to predict implantable cardioverter-defibrillator efficacy in primary prevention of sudden cardiac death
No full textAbstract Aims This study was performed to develop and externally validate prediction models for appropriate implantable cardioverter-defibrillator (ICD) shock and mortality to identify subgroups with insufficient benefit from ICD implantation. Methods and results We recruited patients scheduled for primary prevention ICD implantation and reduced left ventricular function. Bootstrapping-based Cox proportional hazards and Fine and Gray competing risk models with likely candidate predictors were developed for all-cause mortality and appropriate ICD shock, respectively. Between 2014 and 2018, we included 1441 consecutive patients in the development and 1450 patients in the validation cohort. During a median follow-up of 2.4 (IQR 2.1–2.8) years, 109 (7.6%) patients received appropriate ICD shock and 193 (13.4%) died in the development cohort. During a median follow-up of 2.7 (IQR 2.0–3.4) years, 105 (7.2%) received appropriate ICD shock and 223 (15.4%) died in the validation cohort. Selected predictors of appropriate ICD shock were gender, NSVT, ACE/ARB use, atrial fibrillation history, Aldosterone-antagonist use, Digoxin use, eGFR, (N)OAC use, and peripheral vascular disease. Selected predictors of all-cause mortality were age, diuretic use, sodium, NT-pro-BNP, and ACE/ARB use. C-statistic was 0.61 and 0.60 at respectively internal and external validation for appropriate ICD shock and 0.74 at both internal and external validation for mortality. Conclusion Although this cohort study was specifically designed to develop prediction models, risk stratification still remains challenging and no large group with insufficient benefit of ICD implantation was found. However, the prediction models have some clinical utility as we present several scenarios where ICD implantation might be postponed
Critical appraisal of technologies to assess electrical activity during atrial fibrillation: a position paper from the European Heart Rhythm Association and European Society of Cardiology Working Group on eCardiology in collaboration with the Heart Rhythm Society, Asia Pacific Heart Rhythm Society, Latin American Heart Rhythm Society and Computing in Cardiology
No full textWe aim to provide a critical appraisal of basic concepts underlying signal recording and processing technologies applied for (i) atrial fibrillation (AF) mapping to unravel AF mechanisms and/or identifying target sites for AF therapy and (ii) AF detection, to optimize usage of technologies, stimulate research aimed at closing knowledge gaps, and developing ideal AF recording and processing technologies. Recording and processing techniques for assessment of electrical activity during AF essential for diagnosis and guiding ablative therapy including body surface electrocardiograms (ECG) and endo- or epicardial electrograms (EGM) are evaluated. Discussion of (i) differences in uni-, bi-, and multi-polar (omnipolar/Laplacian) recording modes, (ii) impact of recording technologies on EGM morphology, (iii) global or local mapping using various types of EGM involving signal processing techniques including isochronal-, voltage- fractionation-, dipole density-, and rotor mapping, enabling derivation of parameters like atrial rate, entropy, conduction velocity/direction, (iv) value of epicardial and optical mapping, (v) AF detection by cardiac implantable electronic devices containing various detection algorithms applicable to stored EGMs, (vi) contribution of machine learning (ML) to further improvement of signals processing technologies. Recording and processing of EGM (or ECG) are the cornerstones of (body surface) mapping of AF. Currently available AF recording and processing technologies are mainly restricted to specific applications or have technological limitations. Improvements in AF mapping by obtaining highest fidelity source signals (e.g. catheter-electrode combinations) for signal processing (e.g. filtering, digitization, and noise elimination) is of utmost importance. Novel acquisition instruments (multi-polar catheters combined with improved physical modelling and ML techniques) will enable enhanced and automated interpretation of EGM recordings in the near future.Signal Processing SystemsBiomechanical Engineerin
ECG Quantification of Myocardial Scar Does Not Differ between Primary and Secondary Prevention ICD Recipients with Ischemic Heart Disease
No full textBackground: Myocardial scar is an anatomic substrate for potentially lethal arrhythmias. Recent study showed that higher QRS-estimated scar size using the Selvester QRS score was associated with increased arrhythmogenesis during electrophysiologic testing. Therefore, QRS scoring might play a potential role in risk stratification before implantable cardioverter defibrillator (ICD) implantation. In this study, we tested the hypothesis that QRS scores among ICD recipients for secondary prevention are higher than QRS scores in primary prevention patients. Methods and Results: From the hospital database, 100 consecutive patients with ischemic heart disease and prior ICD implantation were selected. Twelve-lead electrocardiograms (ECGs) had been obtained before implantation. ECGs were scored following the 32-points Selvester QRS scoring system and corrected for underlying conduction defects and/or hypertrophy. Ninety-three ECGs were suitable for scoring; seven ECGs were rejected because of noise, missing leads, excessive ventricular extrasystoles, or ventricular pacing. No statistically significant difference in QRS score was found between the primary [6.90 (standard deviation [SD] 3.94), n = 63] and secondary prevention group [6.17 (SD 4.50) (P = 0.260), n = 30]. Left ventricular ejection fraction (LVEF) was significantly higher in the secondary prevention group [31% (SD 13.5) vs 24% (SD 11.7) (P = 0.015)]. When patients with LVEF ≥35% were excluded, QRS scores were still comparable, namely 7.02 (SD 4.04) in the primary prevention group (n = 52) and 6.28 (SD 4.24) in the secondary (P = 0.510) (n = 18). Conclusion: We found no significant difference in QRS score between the ischemic primary and secondary prevention groups. Therefore, a role of the Selvester QRS score as a risk stratifier remains unlikely. (PACE 2010; 33:192–197
Properties of unipolar electrograms recorded with a multielectrode basket catheter
No full textIn the past few years, clinical trials with multielectrocle "basket" catheters have provided unique recordings from the endocardium of intact in-situ human hearts. Analysis of these recordings is difficult because unipolar electrograms obtained from a basket catheter in the blood-filled cavity differ from those obtained by other mapping techniques such as endocardial balloons used during antiarrhythmic surgery. We investigated these differences using basket catheter recordings obtained in isolated porcine and canine hearts that could be filled with perfusion fluid and evacuated at will. The results indicated that the differences between basket and balloon recordings are largely attributable to the presence and absence of blood. Activation maps obtained in the presence and absence of blood were usually similar and only differed in a minority of cases at sites in which electrograms revealed multiple deflections. In conclusion, unipolar mapping using a basket catheter can be used with confidence for the creation of activation maps if appropriate care is taken in the interpretation of fractionated electrogram
Diagnostic yield in sudden unexplained death and aborted cardiac arrest in the young: The experience of a tertiary referral center in The Netherlands
No full textBACKGROUND In sudden unexplained death (SUD) in the young (age 1-50 years), cardiologic and genetic examination in surviving relatives may unmask the cause of death in a significant proportion. The causes of aborted cardiac arrest (ACA) in this age group likely are similar to those in sudden cardiac death. However, there is a paucity of recent data on this topic. OBJECTIVE The purpose of this study was to gain insight into the yield of current diagnostic strategies used in relatives of SUD victims and in ACA victims aged 1-50 years in our dedicated tertiary referral center. METHODS We studied (1) all consecutive families who presented to the cardiology department for examination because of >= 1 first-degree related SUD victim aged 1-50 years and (2) all consecutive ACA victims aged 1-50 years who presented to the cardiology department from 1996 to 2009. Comprehensive cardiologic and genetic examination was performed in both populations. RESULTS A certain or probable diagnosis was made in 47 (33%) of 140 SUD families, including 45 (96%) cases of inherited cardiac diseases. Long QT syndrome (19%) was the most prevalent diagnosis. In 42 (61%) of 69 ACA victims, the cause of the event was determined (inherited in 31 [74%]). Hypertrophic cardiomyopathy was most prevalent (17%). CONCLUSION The yield of the current diagnostic workup in relatives of young SUD victims is 33% and is almost twice as high in young ACA victims. Inherited cardiac diseases are predominantly causative in both groups
131-03: Comparison of Complications and Shocks in Pediatric and Young Subcutaneous and Transvenous Implantable Cardioverter Defibrillator Patients
No full textThe cost-effectiveness of primary prophylactic implantable defibrillator therapy in patients with ischaemic or non-ischaemic heart disease: a European analysis
No full textIt remains unclear whether primary prophylactic implantable cardioverter-defibrillator (ICD) therapy is cost-effective compared with a ono ICD strategy' in the European health care setting. We performed a cost-effectiveness analysis for a cohort of patients with a left ventricular ejection fraction 40 and ischaemic or non-ischaemic heart disease.
A Markov decision analytic model was used to evaluate long-term survival, quality-adjusted life years (QALYs), and lifetime costs for a cohort of patients with a reduced left ventricular function without previous arrhythmias, managed with a prophylactic ICD. Input data on effectiveness were derived from a meta-analysis of primary prophylactic ICD-only therapy randomized trials, from a prospective cohort study of ICD patients, from a health care utilization survey, and from the literature. Input data on costs were derived from a micro-cost analysis. Data on quality-of-life were derived from the literature. Deterministic and probabilistic sensitivity analysis was performed to assess the uncertainty. Probabilistic sensitivity analysis demonstrated a mean lifetime cost of Euro50 685 Euro4604 and 6.26 0.64 QALYs for patients in the ono ICD strategy'. Patients in the oICD strategy' accumulated Euro86 759 Euro3343 and an effectiveness of 7.08 0.71 QALYs yielding an incremental cost-effectiveness ratio of Euro43 993/QALY gained compared with the ono ICD strategy'. The probability that ICD therapy is cost-effective was 65 at a willingness-to-pay threshold of Euro80 000/QALY.
Our results suggest that primary prophylactic ICD therapy in patients with a left ventricular ejection fraction 40 and ischaemic or non-ischaemic heart disease is cost-effective in the European setting
Early mortality in prophylactic implantable cardioverter-defibrillator recipients: development and validation of a clinical risk score
No full textAims: To reduce sudden cardiac death, implantable cardioverter-defibrillators (ICDs) are indicated in patients with ischaemic and non-ischaemic dilated cardiomyopathy and a left ventricular ejection fraction (LVEF) <= 35%. Current guidelines do not recommend device therapy in patients with a life expectancy <1 year since benefit in these patients is low. In this study, we evaluated the incidence and predictors of early mortality (<1 year after implantation) in a consecutive primary prevention population.
Methods and results: Analysis was performed on a prediction and validation cohort. The primary endpoint was all-cause mortality at 1 year. The prediction cohort comprised 861 prophylactic ICD recipients with ischaemic cardiomyopathy or dilated cardiomyopathy from the Academic Medical Center (Amsterdam) and Thorax Center Twente (Enschede). Detailed clinical data were collected. After multivariate analysis, a risk score was developed based on age >= 75 years, LVEF = 3 factors) risk group could be identified with 1-year mortality of, respectively, 3.4, 10.9, and 38.9% (P < 0.01). Afterwards, the risk score was validated in 706 primary prevention patients from the Erasmus Medical Center (Rotterdam). One-year mortality was, respectively, 2.5, 13.2, and 46.3% (all P < 0.01).
Conclusion: A simple risk score based on age, LVEF, eGFR, and atrial fibrillation can identify patients at low, intermediate, and high risk for early mortality after ICD implantation. This may be helpful in the risk assessment of ICD candidates
Microvolt T-wave alternans during exercise and pacing are not comparable
No full textThe absence of microvolt T-wave alternans (MTWA) identifies a group of patients who are at low risk for ventricular arrhythmia or sudden cardiac death. However, in exercised assessed MTWA, 20-40% of all test results are indeterminate. We hypothesised that MTWA during pacing would yield less indeterminate results. Thirty patients with ischaemic cardiomyopathy and prior dual chamber implantable cardioverter defibrillator implantation were enrolled. All patients underwent sequential MTWA testing using an exercise (E), atrial-paced (A), and atrioventricular-paced (AV) protocol. The number of indeterminate tests was lower during pacing (A: 17%; AV: 3%) compared with exercise (37%) (E vs. A: P = 0.015, E vs. AV: P = <0.001). When positive and indeterminate test results were grouped as non-negative, the concordance rates between E and A, E and AV, and A and AV were 60% (kappa = 0.17), 57% (kappa = 0.058), and 70% (kappa = 0.348), respectively. If indeterminate results were excluded, agreements were 60% (kappa = 0.19), 50% (kappa = 0.129) and 67% (kappa = 0.33), respectively. Indeterminate test results are less common during pacing. However, there is a low concordance rate between test results using different protocols. This necessitates further study to determine the predictive value of each method in high risk patients with ischaemic cardiomyopath
Contribution of body surface mapping to clinical outcome after surgical ablation of postinfarction ventricular tachycardia
No full textThis article investigates the influence of body surface mapping on outcome of ventricular antiarrhythmic surgery. Preoperative mapping is advocated to optimize map-guided antiarrhythmic surgery of postinfarction ventricular tachycardia. We sequentially analyzed the results of catheter activation sequence mapping, body surface mapping, and intraoperative multielectrode mapping in 54 patients and made a comparison with 30 control patients (group B) in whom catheter activation sequence mapping was omitted. Endpoints were actuarial survival, freedom of arrhythmia, and comparability of the localisation of sites of ventricular tachycardia origin. A total of 128 morphologically different monomorphic sustained ventricular tachycardias were mapped in group A. In group A, 87 ventricular tachycardias were mapped preoperatively with body surface mapping and 30 ventricular tachycardias with catheter activation sequence mapping. In 19 of 24 ventricular tachycardias (79%) that were localized with both mapping methods the ventricular tachycardia exit site was similar. In-hospital death was 1 of 85 (1.2%). Actuarial freedom from ventricular arrhythmias at 4-year follow-up was 74.1 +/- 6.0% in group A vs. 90.0+/-5.5% in group B (P =.10). In group A 14 of 54 patients died (29.6%), whereas 4 of 30 patients (13.3%) died in group B (P =.09). Arrhythmia freedom and survival is as good in patients mapped with body surface mapping only as in patients mapped with body surface mapping and catheter activation sequence mappin
