For Whom the Bell Tolls : Refining Risk Assessment for Sudden Cardiac Death.

Sudden cardiac death is one of the most important causes of death worldwide. Advancements in medical treatment, percutaneous interventions, and device therapy (ICD and CRTD) showed consistent reduction in mortality, mainly in survivors of SCD and in patients with ischemic cardiomyopathy and depressed left ventricular function. Patients with non-ischemic cardiomyopathies, mildly reduced LV function, and channelopathies have increased risk for SCD.

Predictors and Risk of Ventricular Tachyarrhythmias or Death in Black and White Cardiac Patients: A MADIT-CRT Trial Substudy.

Objectives: The study sought to analyze the risk of ventricular tachyarrhythmia (VTA) or death in black and white subjects implanted with implantable cardioverter-defibrillators (ICDs) or defibrillator and combined cardiac resynchronization therapy (CRT-D) in the MADIT-CRT (Multicenter Automatic Defibrillator Implantation with Cardiac Resynchronization Therapy) trial.

Background: There are limited data on ethnic differences in the risk for VTA in mildly symptomatic heart failure patients with left ventricular dysfunction.

Methods: The risk for first VTA (≥180 beats/min) or death was evaluated in black (n = 139) versus white (n = 1,638) patients enrolled in the MADIT-CRT trial using Kaplan-Meier survival analyses and Cox proportional hazards regression models after adjustment for relevant clinical covariates.

Relation of QRS Duration to Clinical Benefit of Cardiac Resynchronization Therapy in Mild Heart Failure Patients Without Left Bundle Branch Block: The Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy Substudy.

Background: There are conflicting data regarding the efficacy of cardiac resynchronization therapy (CRT) in patients with heart failure (HF) and without left bundle branch block.

Methods And Results: We evaluated the long-term clinical outcomes of 537 non-left bundle branch block patients with mild HF enrolled in the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT) study by QRS duration or morphology further stratified by PR interval. At 7 years of follow-up, the cumulative probability of HF hospitalization or death was 45% versus 56% among patients randomized to implantable cardioverter-defibrillator and CRT with defibrillator (CRT-D), respectively (P=0.

Relative Wall Thickness and the Risk for Ventricular Tachyarrhythmias in Patients With Left Ventricular Dysfunction.

Background: Relative wall thickness (RWT), defined as 2 times posterior wall thickness divided by the left ventricular (LV) diastolic diameter, is a measure of LV geometry and may be a marker for adverse events in patients with LV dysfunction.

Objectives: The aim of this study was to investigate the relationship between RWT and the risk for ventricular tachyarrhythmia (VA) in patients enrolled in the MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy) study.

Methods: The study population comprised 1,260 patients with mild heart failure and left bundle branch block.

Relationship between age and inappropriate implantable cardioverter-defibrillator therapy in MADIT-RIT (Multicenter Automatic Defibrillator Implantation Trial-Reduce Inappropriate Therapy).

Background: There is limited data regarding the relationship between age and inappropriate therapy among patients with an implantable cardioverter-defibrillator (ICD) and resynchronization therapy.

Objectives: We aimed to investigate this relationship and the effect of ICD programming on inappropriate therapy by age.

Methods: In the Multicenter Automatic Defibrillator Implantation Trial-Reduce Inappropriate Therapy (MADIT-RIT) 1500 patients were randomized to 3 ICD programming arms: (A) conventional with ventricular tachycardia (VT) therapy ≥170; (B) high-rate cutoff with VT therapy ≥200, and (C) prolonged 60-second delay for VT therapy ≥170.