Heart Care Info - Heart Disease Prevention & Treatment

Reduction of the Risk of Recurring Heart Failure Events With Cardiac Resynchronization Therapy:: MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial ...

I Goldenberg, WJ Hall, CA Beck, AJ Moss... - Journal of the American ..., 2011 - Elsevier OBJECTIVES: The evaluation of the risk of recurring heart failure events (HFEs) was a pre-specified substudy of MADIT-CRT (Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy). BACKGROUND: There are limited data regarding ...

Figure 1. Schematic Presentation of Efficacy Analysis: Follow-Up by Active Device Schematic diagram showing attribution of follow-up time to type of device active at the time, used in efficacy analyses presented in Table 2 and Table 3 and Figure 2 and Figure 3. This is in contrast to intention-to-treat (ITT) analyses, which categorize by randomized treatment assignment (presented in Table 2). Hence, efficacy analyses categorize follow-up time, whereas ITT analyses categorize patients. Patient #1: soon after enrollment, a cardiac resynchronization therapy with a defibrillator (CRT-D) device was successfully implanted; it remained active until the study ended (December 31, 2009). All follow-up was for a first heart failure event (HFE) and for death, most of it attributed to an active CRT-D device. Patient #2: After a short delay, a CRT-D device was implanted; it remained active for some while, except for a few days when lead repositioning due to diaphragmatic irritation (at which follow-up was censored in the modified efficacy analysis). A first HFE occurred while it was active, and some while later a second HFE occurred (considered to be the first event for the analysis of subsequent HF Es); the study terminated a short while later. In the full efficacy analysis, part of the follow-up for first HFE (and for death) is attributed to each device-type; follow-up for subsequent HF Es (and subsequent death) is attributed entirely to CRT-D. Patient #3: soon after enrollment, an implantable cardioverter-defibrillator (ICD)-only was inserted and remained active for some while. A first HFE was experienced, and soon thereafter CRT capability was added (at which time follow-up was censored in the modified efficacy analysis). While the CRT-D was active, 2 HF Es occurred (which were considered to be the initial events on CRT-D in the analysis for subsequent events). Shortly after the last one, the device was explanted, with death occurring a short while later. Follow-up for first HFE is attributed to no active device and to ICD-only; part of the follow-up for subsequent events in the full efficacy analysis is attributed to each of the 3 device-type categories. For analysis of subsequent events, Patient #1 is omitted; follow-up for Patient #2 is attributed to CRT-D, whereas parts of that for Patient #3 are attributed to each of the 3 device types.