Medtronic
 
 

Heart Failure

Multicenter InSync Randomized Clinical Evaluation (MIRACLE) ICD Study-US

Multicenter InSync Randomized Clinical Evaluation (MIRACLE) ICD Study-US

Purpose:

To examine the safety and efficacy of combined CRT and ICD therapies in patients with NYHA class III or IV congestive heart failure despite optimal medical therapy.

Hypothesis:

The MIRACLE ICD trail hypothesized that patients with HF symptoms, a wide QRS interval, LV systolic dysfunction, and an established indication for an ICD would benefit from CRT, and that CRT would not be proarrhythmic or compromise ICD therapy.

Primary endpoints:

  • Changes in NYHA Functional Class
  • Quality of Life: Minnesota Living with Heart Failure Questionnaire
  • 6-minute walk distance

Main secondary endpoints:

  • Cardiopulmonary exercise
  • Left ventricular ejection fraction (LVEF), left ventricular end diastolic dimension (LVEDD) and volumes, and degree of mitral regurgitation

Status:

Enrollment period: October 1999 to August 2001
Follow-up: 6 months
Sample size: 369 implanted patients (89% implant success rate)

Results:

CRT improves quality of life, functional status, and exercise capacity in patients with moderate to severe heart failure, a wide QRS interval, and life-threatening arrhythmias.

These improvements occurred in the context of underlying appropriate medical management without proarrhythmia or compromised ICD function.

References:
  1. Young JB, Abraham WT, Smith AL, et al, for The Multicenter InSync ICD Randomized Clinical Evaluation (MIRACLE ICD) Trial Investigators. Combined cardiac resynchronization and implantable cardioversion defibrillation in advanced chronic heart failure: The MIRACLE ICD Trial. JAMA. 2003;289:2685-2694.
  2. Bradley, DJ. Combining resynchronization and defibrillation therapies for heart failure. JAMA. 2003:289:2719-2121,

 

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