"Cardiac-Resynchronization Therapy for the Prevention of Heart-Failure Events".
Links to original sources: Wiki Journal Post Full Journal Article
The New England Journal of Medicine. 2009. 361(14):1329-1338. PubMed•Full text•PDF
Contents 1 Clinical Question 2 Bottom Line 3 Major Points 4 Guidelines 5 Design 6 Population 6.1 Inclusion Criteria 6.2 Exclusion Criteria 6.3 Baseline Characteristics 7 Interventions 8 Outcomes 8.1 Primary Outcome 8.2 Secondary Outcomes 9 Funding 10 Further Reading
Does cardiac-resynchronization therapy (CRT) with biventricular pacing reduce the risk of death or heart-failure events in patients with mild cardiac symptoms, a reduced ejection fraction, and a wide QRS complex?
CRT combined with an implantable cardioverter–defibrillator (ICD) decreased the risk of heart-failure events in relatively asymptomatic patients with a low ejection fraction and wide QRS complex.
CRT has demonstrated benefits in reducing symptoms, hospitalization rates, and mortality in patients with advanced heart failure. The MADIT-CRT trial showed that CRT, when combined with ICD therapy, reduces the risk of death or nonfatal heart-failure events in patients with mild heart failure symptoms, reduced ejection fraction, wide QRS complex, and sinus rhythm.
The 2008 guidelines for implantation of cardiac devices recommend CRT as a class I indication for patients with a left ventricular ejection fraction of 35% or less, a QRS duration of 120 msec or more, and sinus rhythm who have NYHA functional class III or ambulatory class IV heart-failure symptoms.
Multicenter, randomized, controlled trial N=1,820 CRT-ICD (n=1,089) ICD alone (n=731) Setting: 110 hospital centers Enrollment: 2004-2008 Mean follow-up: 2.4 years Analysis: Intention-to-treat Primary outcome: Death from any cause or a nonfatal heart-failure event
Inclusion Criteria: NYHA class I (ischemic cardiomyopathy) or class II (ischemic or nonischemic cardiomyopathy), ejection fraction of ≤30%, QRS duration ≥130 msec, sinus rhythm. Exclusion Criteria: Existing or planned CRT, recent MI or cardiac intervention, atrial fibrillation, and other criteria. Baseline Characteristics: Similar across groups.
Patients were randomly assigned to receive CRT with an ICD (CRT-ICD group) or an ICD alone (ICD-only group).
Primary Outcome: Risk reduction of 34% for death or nonfatal heart-failure events in the CRT-ICD group compared to the ICD-only group (hazard ratio, 0.66; 95% confidence interval, 0.52 to 0.84; P=0.001). Secondary Outcomes: Significant reduction in left ventricular volumes and improvement in ejection fraction in the CRT-ICD group.
Supported by a research grant from Boston Scientific to the University of Rochester.
Full text available on the New England Journal of Medicine website.