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Entropy of cardiac repolarization predicts ventricular arrhythmias and mortality in patients receiving an implantable cardioverter-defibrillator for primary prevention of sudden death.

ABSTRACT: The need for a readily available, inexpensive, non-invasive method for improved risk stratification of heart failure (HF) patients is paramount. Prior studies have proposed that distinct fluctuation patterns underlying the variability of physiological signals have unique prognostic value. We tested this hypothesis in an extensively phenotyped cohort of HF patients using EntropyXQT, a novel non-linear measure of cardiac repolarization dynamics.In a prospective, multicentre, observational study of 852 patients in sinus rhythm undergoing clinically indicated primary prevention implantable cardioverter-defibrillator (ICD) implantation (2003-10), exposures included demographics, history, physical examination, medications, laboratory results, serum biomarkers, ejection fraction, conventional electrocardiographic (ECG) analyses of heart rate and QT variability, and EntropyXQT. The primary outcome was first 'appropriate' ICD shock for ventricular arrhythmias. The secondary outcome was composite events (appropriate ICD shock and all-cause mortality). After exclusions, the cohort (n = 816) had a mean age of 60 ± 13 years, 28% women, 36% African Americans, 56% ischaemic cardiomyopathy, and 29 ± 16% Seattle HF risk score (SHFS) 5-year predicted mortality. Over 45 ± 24 months, there were 134 appropriate shocks and 166 deaths. After adjusting for 30 exposures, the hazard ratios (comparing the 5th to 1st quintile of EntropyXQT) for primary and secondary outcomes were 3.29 (95% CI 1.74-6.21) and 2.28 (1.53-3.41), respectively. Addition of EntropyXQT to a model comprised of the exposures or SHFS significantly increased net reclassification and the ROC curve area.EntropyXQT measured during ICD implantation strongly and independently predicts appropriate shock and all-cause mortality over follow-up. EntropyXQT complements conventional risk predictors and has the potential for broad clinical application.

SUBMITTER: DeMazumder D

PROVIDER: S-EPMC5291192 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature

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Entropy of cardiac repolarization predicts ventricular arrhythmias and mortality in patients receiving an implantable cardioverter-defibrillator for primary prevention of sudden death.

DeMazumder Deeptankar D Limpitikul Worawan B WB Dorante Miguel M Dey Swati S Mukhopadhyay Bhasha B Zhang Yiyi Y Moorman J Randall JR Cheng Alan A Berger Ronald D RD Guallar Eliseo E Jones Steven R SR Tomaselli Gordon F GF

Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology 20160404 12

<h4>Aims</h4>The need for a readily available, inexpensive, non-invasive method for improved risk stratification of heart failure (HF) patients is paramount. Prior studies have proposed that distinct fluctuation patterns underlying the variability of physiological signals have unique prognostic value. We tested this hypothesis in an extensively phenotyped cohort of HF patients using EntropyX<sub>QT</sub>, a novel non-linear measure of cardiac repolarization dynamics.<h4>Methods and results</h4>I ...[more]

PMID: 27044982

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Project description:ImportanceCardiac resynchronization therapy (CRT) reduces the risk for mortality and heart failure-related events in select patients. Little is known about the use of CRT in combination with an implantable cardioverter defibrillator (ICD) in patients who are eligible for this therapy in clinical practice.ObjectiveTo (1) identify patient, clinician, and hospital characteristics associated with CRT defibrillator (CRT-D) use and (2) determine the extent of hospital-level variation in the use of CRT-D among guideline-eligible patients undergoing ICD placement.Design, setting, and participantsMulticenter retrospective cohort from 1428 hospitals participating in the National Cardiovascular Data Registry ICD Registry between April 1, 2010, and June 30, 2014. Adult patients meeting class I or IIa guideline recommendations for CRT at the time of device implantation were included in this study.Main outcomes and measuresImplantation of an ICD with or without CRT.ResultsA total of 63 506 eligible patients (88.6%) received CRT-D at the time of device implantation. The mean (SD) ages of those in the ICD and CRT-D groups were 67.9 (12.2) years and 68.4 (11.5) years, respectively. In hierarchical multivariable models, black race was independently associated with lower use of CRT-D (odds ratio [OR], 0.77; 95% CI, 0.71-0.83) as was nonprivate insurance (OR, 0.90; 95% CI, 0.85-0.95 for Medicare and OR, 0.73; 95% CI, 0.65-0.82 for Medicaid). Clinician factors associated with greater CRT-D use included clinician implantation volume (OR, 1.01 per 10 additional devices implanted; 95% CI, 1.01-1.01) and electrophysiology training (OR, 3.13 as compared with surgery-boarded clinicians; 95% CI, 2.50-3.85). At the hospital level, the overall median risk-standardized rate of CRT-D use was 79.9% (range, 26.7%-100%; median OR, 2.08; 95% CI, 1.99-2.18).Conclusions and relevanceIn a national cohort of patients eligible for CRT-D at the time of device implantation, nearly 90% received a CRT-D device. However, use of CRT-D differed by race and implanting operator characteristics. After accounting for these factors, the use of CRT-D continued to vary widely by hospital. Addressing disparities and variation in CRT-D use among guideline-eligible patients may improve patient outcomes.

Project description:BackgroundThere are conflicting data on the impact of implantable cardioverter-defibrillator (ICD) shocks on subsequent mortality.ObjectivesThe aim of this study was to determine whether the arrhythmic substrate leading to ICD therapy or the therapy itself increases mortality.MethodsThe study cohort included 5,516 ICD recipients who were enrolled in 5 landmark ICD trials (MADIT-II, MADIT-RISK, MADIT-CRT, MADIT-RIT, RAID). The authors evaluated the association of device therapy with subsequent mortality in 4 separate time-dependent models: model I, type of ICD therapy; model II, type of arrhythmia for which ICD therapy was delivered; model III, combined assessment of all arrhythmia and therapy types during follow-up; and model IV, incremental risk associated with repeated ICD shocks.ResultsWhen analyzed by the type of ICD therapy (model I), a first appropriate ICD shock was associated with increased risk of subsequent mortality with or without concomitant occurrence of inappropriate shock during follow-up (hazard ratio [HR]: 2.78 and 2.31; p < 0.001 and p = 0.12), whereas inappropriate shock alone was not associated with mortality risk (HR: 1.23; p = 0.42). Similarly, ICD therapy for ventricular tachycardia (VT) ≥200 beats/min or ventricular fibrillation (VF) (model II) was associated with increased risk of death with or without concomitant therapy for VT <200 beats/min (HRs: 2.25 and 2.62; both p < 0.001), whereas appropriate therapy for VT <200 beats/min or inappropriate therapy (regardless of etiology) did not reach statistical significance (all p > 0.10). Combined assessment of all therapy and arrhythmia types during follow-up (model III) showed that appropriate ICD shocks for VF, shocks for fast VT (≥200 beats/min) without prior antitachycardia pacing (ATP), as well as shocks for fast VT delivered after failed ATP, were associated with the highest risk of subsequent death (HR: all >2.8; p < 0.001). Finally, 2 or more ICD appropriate shocks were not associated with incremental risk to the first appropriate ICD shock (model IV).ConclusionThe combined data from 5 landmark ICD trials suggest that the underlying arrhythmic substrate rather than the ICD therapy is the more important determinant of mortality in ICD recipients.

Project description:BackgroundCardiac sarcoidosis (CS) predisposes to sudden cardiac death (SCD). Guidelines for implantable cardioverter defibrillators (ICDs) in CS have been issued by the Heart Rhythm Society in 2014 and the American College of Cardiology/American Heart Association/Heart Rhythm Society consortium in 2017. How well they discriminate high from low risk remains unknown.MethodsWe analyzed the data of 398 patients with CS detected in Finland from 1988 through 2017. All had clinical cardiac manifestations. Histological diagnosis was myocardial in 193 patients (definite CS) and extracardiac in 205 (probable CS). Patients with and without Class I or IIa ICD indications at presentation were identified, and subsequent occurrences of SCD (fatal or aborted) and sustained ventricular tachycardia were recorded, as were ICD indications emerging first on follow-up.ResultsOver a median of 4.8 years, 41 patients (10.3%) had fatal (n=8) or aborted (n=33) SCD, and 98 (24.6%) experienced SCD or sustained ventricular tachycardia as the first event. By the Heart Rhythm Society guideline, Class I or IIa ICD indications were present in 339 patients (85%) and absent in 59 (15%), of whom 264 (78%) and 30 (51%), respectively, received an ICD. Cumulative 5-year incidence of SCD was 10.7% (95% CI, 7.4%-15.4%) in patients with ICD indications versus 4.8% (95% CI, 1.2%-19.1%) in those without (χ2=1.834, P=0.176). The corresponding rates of SCD were 13.8% (95% CI, 9.1%-21.0%) versus 6.3% (95% CI, 0.7%-54.0%; χ2=0.814, P=0.367) in definite CS and 7.6% (95% CI, 3.8%-15.1%) versus 3.3% (95% CI, 0.5%-22.9%; χ2=0.680, P=0.410) in probable CS. In multivariable regression analysis, SCD was predicted by definite histological diagnosis (P=0.033) but not by Class I or IIa ICD indications (P=0.210). In patients without ICD indications at presentation, 5-year incidence of SCD, sustained ventricular tachycardia, and emerging Class I or IIa indications was 53% (95% CI, 40%-71%). By the American College of Cardiology/American Heart Association/Heart Rhythm Society guideline, all patients with complete data (n=245) had Class I or IIa indications for ICD implantation.ConclusionsCurrent ICD guidelines fail to distinguish a truly low-risk group of patients with clinically manifest CS, the 5-year risk of SCD approaching 5% despite absent ICD indications. Further research is needed on prognostic factors, including the role of diagnostic histology. Meanwhile, all patients with CS presenting with clinical cardiac manifestations should be considered for an ICD implantation.

Project description:Background One third of primary prevention implantable cardioverter-defibrillator patients receive appropriate therapy, but all remain at risk of defibrillator complications. Information on these complications in contemporary cohorts is limited. This study assessed complications and their risk factors after defibrillator implantation in a Dutch nationwide prospective registry cohort and forecasts the potential reduction in complications under distinct scenarios of updated indication criteria. Methods and Results Complications in a prospective multicenter registry cohort of 1442 primary implantable cardioverter-defibrillator implant patients were classified as major or minor. The potential for reducing complications was derived from a newly developed prediction model of appropriate therapy to identify patients with a low probability of benefitting from the implantable cardioverter-defibrillator. During a follow-up of 2.2 years (interquartile range, 2.0-2.6 years), 228 complications occurred in 195 patients (13.6%), with 113 patients (7.8%) experiencing at least one major complication. Most common ones were lead related (n=93) and infection (n=18). Minor complications occurred in 6.8% of patients, with lead-related (n=47) and pocket-related (n=40) complications as the most prevailing ones. A surgical reintervention or additional hospitalization was required in 53% or 61% of complications, respectively. Complications were strongly associated with device type. Application of stricter implant indication results in a comparable proportional reduction of (major) complications. Conclusions One in 13 patients experiences at least one major implantable cardioverter-defibrillator-related complication, and many patients undergo a surgical reintervention. Complications are related to defibrillator implantations, and these should be discussed with the patient. Stricter implant indication criteria and careful selection of device type implanted may have significant clinical and financial benefits.

Dataset Information

Entropy of cardiac repolarization predicts ventricular arrhythmias and mortality in patients receiving an implantable cardioverter-defibrillator for primary prevention of sudden death.

Publications

Entropy of cardiac repolarization predicts ventricular arrhythmias and mortality in patients receiving an implantable cardioverter-defibrillator for primary prevention of sudden death.

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