Medtronic
 
 

Heart Failure

Multicenter InSync Randomized Clinical Evaluation (MIRACLE)

Multicenter InSync Randomized Clinical Evaluation (MIRACLE)

Purpose:

To evaluate the efficacy and safety of combined cardiac resynchronization therapy (CRT) for patients with heart failure.

Primary endpoints:

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

Main secondary endpoints:

  • Peak VO 2 and exercise time during cardiopulmonary exercise
  • Left ventricular ejection fraction (LVEF), left ventricular end diastolic dimension (LVEDD), mitral regurgitation
  • QRS duration

Status:

Enrollment period: November 1998 to
December 2000
- Follow-up: 6 months
- Sample size: 453 implanted patients (92.4% implant success rate)

Results:

In NYHA Classes III and IV systolic heart failure patients with intraventricular conduction delays, CRT significantly improved:

  • Quality of life, functional class, and exercise capacity
  • Cardiac function and structure

68% of CRT patients improved by one or more functional classes compared with 38% of control patients (p< 0.001)

Reference:
  1. Abraham WT, Fischer WG, Smith AL, et al, for the MIRACLE Study Group. Cardiac resynchronization in chronic heart failure. N Engl J Med. 2002;346:1845-1853.

Additional Information