Publications by authors named "Alan H Kadish"

Objectives: This study sought to determine the absolute and relative associations of diabetes mellitus (DM) and hemoglobin A (HbA) with sudden and/or arrhythmic death (SAD) versus other modes of death in patients with coronary artery disease (CAD) who do not qualify for implantable cardioverter-defibrillators.

Background: Patients with CAD and DM are at elevated risk for SAD; however, it is unclear whether these patients would benefit from implantable cardioverter-defibrillators given competing causes of death and/or whether HbA might augment SAD risk stratification.

Methods: In the PRE-DETERMINE study of 5,764 patients with CAD with left ventricular ejection fraction (LVEF) of >30% to 35%, competing risk analyses were used to compare the absolute and relative risks of SAD versus non-SAD by DM status and HbA level and to identify risk factors for SAD among 1,782 patients with DM.

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Background: Eleven criteria correlating electrocardiogram (ECG) findings with reduced left ventricular ejection fraction (LVEF) have been previously published. These have not been compared head-to-head in a single study. We studied their value as a screening test to identify patients with reduced LVEF estimated by cardiac magnetic resonance (CMR) imaging.

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Background Myocardial infarction (MI) size is a key predictor of prognosis in post-MI patients. Cardiovascular magnetic resonance (CMR) is the gold standard test for MI quantification, but the ECG is less expensive and more widely available. We sought to quantify the relationship between ECG markers and cardiovascular magnetic resonance infarct size.

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Aim: There is limited information on the outcomes after primary prevention implantable cardioverter-defibrillator (ICD) implantation in patients with heart failure (HF) and diabetes. This analysis evaluates the effectiveness of a strategy of ICD plus medical therapy vs. medical therapy alone among patients with HF and diabetes.

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Background: Primary prevention implantable cardioverter defibrillator (ICD) reduce all-cause mortality by reducing sudden cardiac death. There are conflicting data regarding whether patients with more advanced heart failure derive ICD benefit owing to the competing risk of nonsudden death.

Methods: We performed a patient-level meta-analysis of New York Heart Association (NYHA) class II/III heart failure patients (left ventricular ejection fraction ≤35%) from 4 primary prevention ICD trials (MADIT-I, MADIT-II, DEFINITE, SCD-HeFT).

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Background: No precise tools exist to predict appropriate shocks in patients with a primary prevention ICD. We sought to identify characteristics predictive of appropriate shocks in patients with a primary prevention implantable cardioverter defibrillator (ICD).

Methods: Using patient-level data from the Multicenter Automatic Defibrillator Implantation Trial II (MADIT II) and the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT), we identified patients with any appropriate shock.

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Gender differences in J point height exist. Previous studies suggest male sex hormones mediate effects on cardiovascular disease through myocardial repolarization. Our objective was to assess whether male and female sex hormones are associated with J point amplitude in healthy subjects.

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Background: Left ventricular size and shape are important for quantifying cardiac remodeling in response to cardiovascular disease. Geometric remodeling indices have been shown to have prognostic value in predicting adverse events in the clinical literature, but these often describe interrelated shape changes. We developed a novel method for deriving orthogonal remodeling components directly from any (moderately independent) set of clinical remodeling indices.

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Background: Although adverse left ventricular shape changes (remodeling) after myocardial infarction (MI) are predictive of morbidity and mortality, current clinical assessment is limited to simple mass and volume measures, or dimension ratios such as length to width ratio. We hypothesized that information maximizing component analysis (IMCA), a supervised feature extraction method, can provide more efficient and sensitive indices of overall remodeling.

Methods: IMCA was compared to linear discriminant analysis (LDA), both supervised methods, to extract the most discriminatory global shape changes associated with remodeling after MI.

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Article Synopsis
  • The study merged data from 5 major trials to assess how patient age impacts death and rehospitalization risks after receiving an implantable cardioverter-defibrillator (ICD).
  • Older patients had more health issues compared to younger patients, but ICD recipients had a lower risk of death across all age groups, with varying levels of benefit as age increased.
  • The findings indicate that while ICDs provide survival benefits, this effectiveness diminishes with age, and there was no significant relationship between age and rehospitalization rates.
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Myocardial infarction leads to changes in the geometry (remodeling) of the left ventricle (LV) of the heart. The degree and type of remodeling provides important diagnostic information for the therapeutic management of ischemic heart disease. In this paper, we present a novel analysis framework for characterizing remodeling after myocardial infarction, using LV shape descriptors derived from atlas-based shape models.

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Objectives: The aim of this study was to determine if the benefit of implantable cardioverter-defibrillators (ICDs) is modulated by medical comorbidity.

Background: Primary prevention ICDs improve survival in patients at risk for sudden cardiac death. Their benefit in patients with significant comorbid illness has not been demonstrated.

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Article Synopsis
  • The study investigates the effectiveness of implantable cardioverter-defibrillators (ICDs) for patients with chronic kidney disease and heart failure, using a meta-analysis from several trials.
  • Approximately 36.3% of the 2,867 patients included had reduced kidney function (eGFR < 60 mL/min/1.73 m²), with results showing that ICDs significantly reduced mortality only in patients with better kidney function (eGFR ≥ 60), while showing no benefit for those with lower kidney function.
  • Limitations included the small sample size of patients with very low eGFR and potential inconsistencies in trial measurement methods that could affect results.
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Objectives: The purpose of this study was to provide a meta-analysis to estimate the performance of 12 commonly reported risk stratification tests as predictors of arrhythmic events in patients with nonischemic dilated cardiomyopathy.

Background: Multiple techniques have been assessed as predictors of death due to ventricular tachyarrhythmias/sudden death in patients with nonischemic dilated cardiomyopathy.

Methods: Forty-five studies enrolling 6,088 patients evaluating the association between arrhythmic events and predictive tests (baroreflex sensitivity, heart rate turbulence, heart rate variability, left ventricular end-diastolic dimension, left ventricular ejection fraction, electrophysiology study, nonsustained ventricular tachycardia, left bundle branch block, signal-averaged electrocardiogram, fragmented QRS, QRS-T angle, and T-wave alternans) were included.

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A collaborative framework was initiated to establish a community resource of ground truth segmentations from cardiac MRI. Multi-site, multi-vendor cardiac MRI datasets comprising 95 patients (73 men, 22 women; mean age 62.73±11.

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Background: Cardiovascular imaging studies generate a wealth of data which is typically used only for individual study endpoints. By pooling data from multiple sources, quantitative comparisons can be made of regional wall motion abnormalities between different cohorts, enabling reuse of valuable data. Atlas-based analysis provides precise quantification of shape and motion differences between disease groups and normal subjects.

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Background: Peri-infarct border zone (BZ) as quantified by late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (MRI) has been proposed as a risk stratification tool, and is associated with increased mortality. BZ has been measured by various methods in the literature. We assessed which BZ analysis best predicts inducible arrhythmia during electrophysiological study (EPS).

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Article Synopsis
  • Left ventricular ejection fraction (LVEF) can change over time, impacting patients' health outcomes in nonischemic cardiomyopathy.
  • The DEFINITE trial assessed how changes in LVEF influenced survival and arrhythmias in patients enrolled, with follow-up LVEF data collected for only 17% of participants.
  • Results showed that patients with improved LVEF had significantly lower mortality rates compared to those whose LVEF worsened, but improved LVEF did not correlate with reduced instances of appropriate shocks, indicating caution in assuming LVEF improvement will lead to fewer arrhythmic events.
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Article Synopsis
  • The study investigates the best timing for placing implantable cardioverter-defibrillators (ICDs) in patients post-myocardial infarction (MI) and whether this timing affects outcomes such as mortality and complications.
  • Analysis of data from nine clinical trials shows that patients receiving ICDs had lower mortality rates compared to those who did not, regardless of the timing of the implant after MI.
  • The research concludes that the timing of ICD implantation beyond 40 days after MI does not significantly influence its effectiveness or the occurrence of rehospitalizations and complications.
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Article Synopsis
  • ICDs are recommended for preventing sudden cardiac death in patients with left ventricular dysfunction, but their effectiveness in patients with very low baseline LVEF (<25%) or prolonged QRS duration (>120 ms) is uncertain.
  • A meta-analysis was conducted to examine how very low LVEF and prolonged QRS duration impact the mortality benefits of ICD therapy, using data from various randomized controlled trials.
  • The results indicated that LVEF and QRS duration do not significantly alter the survival benefits of ICDs in patients with LVEF<35%, though those recently experiencing a myocardial infarction show no benefit, particularly if they have LVEF<25% or wide QRS duration.
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