RISK Stratification Using a Combination of Cardiac Troponin T and Brain Natriuretic Peptide in Patients Receiving CRT-D

Primary Endpoint The primary endpoint is the occurrence of either death or first HF hospitalization. HF hospitalizations must satisfy both of the following criteria: 1. Admission to hospital for \>24 hours with at least one of the following HF worsening symptoms: * Increased CHF class * Orthopnea * Paroxysmal nocturnal dyspnea * Edema * Dyspnea on exertion, or * Gastrointestinal (GI) symptoms attributable to HF * Placement on the Status I heart transplant list AND 2. One or more of the following intensive treatment(s) for HF within 24 hours of admission: * Intravenous (IV) diuresis * IV inotropic medications prescribed during the hospitalization, or * Increasing frequency of dialysis for patients with chronic renal failure 2.3 Secondary Endpoints Secondary endpoints include: * Cause of death * Change in NYHA functional class * Number of HF related hospitalizations * Performance on a standard 6-minute hall walk test * Quality of Life as measured by the Minnesota Living with Heart Failure (MLWHFQ) questionnaire * Patient global clinical assessment * Left ventricular ejection fraction (LVEF) measured by echocardiography * LV volume measured by echocardiography * LV lead placement position * QRS duration at baseline and with CRT * Number of AT/AF, VT/VF episodes * Frequency of appropriate/inappropriate ICD therapy * % Atrial and Ventricular Pacing * Antiarrhythmic drug utilization * Study related complications 2.3.1 Response to CRT 1. A positive response to CRT is defined by the following: Improvement in NYHA functional class by at least one grade 2. Improvement in echocardiographic LVEF \& left ventricular end diastolic index (LVEDI) 3. Improvement in patient global clinical assessment 4. Improvement in 6-minute hall walk by 10%