"Cardiac-Resynchronization Therapy for the Prevention of Heart-Failure Events"

Voici un article scientifique sur la prévention de l'arrêt cardiaque. Rappelons qu'en France, depuis 2007, une situation d'arrêt cardiaque permet de prélever des organes (reins) : les prélèvements "à coeur arrêté" (plus exactement : les prélèvements de reins sur patients "décédés", c'est-à-dire en "arrêt cardio-respiratoire persistant"), ont repris en France depuis 2007.

Authors: Arthur J. Moss, M.D., W. Jackson Hall, Ph.D., David S. Cannom, M.D., Helmut Klein, M.D., Mary W. Brown, M.S., James P. Daubert, M.D., N.A. Mark Estes, III, M.D., Elyse Foster, M.D., Henry Greenberg, M.D., Steven L. Higgins, M.D., Marc A. Pfeffer, M.D., Ph.D., Scott D. Solomon, M.D., David Wilber, M.D., Wojciech Zareba, M.D., Ph.D., for the MADIT-CRT Trial Investigators

ABSTRACT

"Background: This trial was designed to determine whether cardiac-resynchronization therapy (CRT) with biventricular pacing would reduce the risk of death or heart-failure events in patients with mild cardiac symptoms, a reduced ejection fraction, and a wide QRS complex (1).

Methods During a 4.5-year period, we enrolled and followed 1820 patients with ischemic or nonischemic cardiomyopathy, an ejection fraction of 30 per cent or less, a QRS duration of 130 msec or more, and New York Heart Association class I or II symptoms. Patients were randomly assigned in a 3:2 ratio to receive CRT plus an implantable cardioverter–defibrillator (ICD) (1089 patients) or an ICD alone (731 patients). The primary end point was death from any cause or a nonfatal heart-failure event (whichever came first). Heart-failure events were diagnosed by physicians who were aware of the treatment assignments, but they were adjudicated by a committee that was unaware of assignments.

Results During an average follow-up of 2.4 years, the primary end point occurred in 187 of 1089 patients in the CRT–ICD group (17.2 per cent) and 185 of 731 patients in the ICD-only group (25.3 per cent) (hazard ratio in the CRT–ICD group, 0.66; 95 per cent confidence interval [CI], 0.52 to 0.84; P=0.001). The benefit did not differ significantly between patients with ischemic cardiomyopathy and those with nonischemic cardiomyopathy. The superiority of CRT was driven by a 41 per cent reduction in the risk of heart-failure events, a finding that was evident primarily in a prespecified subgroup of patients with a QRS duration of 150 msec or more. CRT was associated with a significant reduction in left ventricular volumes and improvement in the ejection fraction. There was no significant difference between the two groups in the overall risk of death, with a 3 per cent annual mortality rate in each treatment group. Serious adverse events were infrequent in the two groups.

Conclusions CRT combined with ICD decreased the risk of heart-failure events in relatively asymptomatic patients with a low ejection fraction and wide QRS complex. (ClinicalTrials.gov number, NCT00180271 [ClinicalTrials.gov].)"

Source Information

From the Departments of Medicine (A.J.M., H.K., M.W.B., W.Z.) and Biostatistics and Computational Biology (W.J.H.), University of Rochester Medical Center, Rochester, NY; Division of Cardiology, Hospital of the Good Samaritan, Los Angeles (D.S.C.); the Department of Medicine, Duke University Medical Center, Durham, NC (J.P.D.); New England Cardiac Arrhythmia Center, Tufts–New England Medical Center, Boston (N.A.M.E.); Cardiology Unit, University of California at San Francisco, San Francisco (E.F.); Cardiology Unit, St. Luke's–Roosevelt Hospital, New York (H.G.); the Department of Cardiology, Scripps Memorial Hospital, La Jolla, CA (S.L.H.); Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston (M.A.P., S.D.S.); and the Cardiovascular Institute, Loyola University Medical Center, Chicago (D.W.).

This article (10.1056/NEJMoa0906431) was published on September 1, 2009, at NEJM.org.

Address reprint requests to Dr. Moss at the Heart Research Follow-up Program, Box 653, University of Rochester Medical Center, Rochester, NY 14642, or at heartajm@heart.rochester.edu.

http://content.nejm.org

(1) QRS complex: The deflections in the tracing of the electrocardiogram (ECG or EKG), comprising the Q, R, and S waves, that represent the ventricular activity of the heart (the depolarization of the ventricles). (source)