- Question
- Does cardiac-resynchronization therapy (CRT) with biventricular pacing reduce the risk of death or heart-failure events in patients with mild symptoms, a reduced ejection fraction and a wide QRS complex?
- Design
- Randomized, multicenter, open-label trial (heart-failure events were adjudicated by a blinded committee) with 1820 patients assigned 3:2 and an average follow-up of 2.4 years.
- Population
- Patients with ischemic or nonischemic cardiomyopathy, ejection fraction of 30% or less, QRS duration of 130 msec or more and NYHA class I or II symptoms.
- Intervention
- CRT plus an implantable cardioverter-defibrillator (ICD), with 1089 patients in this group.
- Control
- ICD alone, with 731 patients in this group.
- Primary outcome
- Death from any cause or a first nonfatal heart-failure event, whichever came first.
- Results
- The primary end point occurred in 187 of 1089 patients (17.2%) in the CRT-ICD group and 185 of 731 (25.3%) in the ICD-only group (HR 0.66; 95% CI 0.52 to 0.84; P=0.001). The benefit was driven by a 41% reduction in heart-failure events, mainly in the prespecified subgroup with QRS duration of 150 msec or more.
- Safety
- Serious adverse events were infrequent in both groups. There was no significant difference in overall mortality between groups, with a 3% annual mortality rate in each.
- Conclusion
- CRT combined with an ICD reduced the risk of heart-failure events in relatively asymptomatic patients with a low ejection fraction and a wide QRS complex.
- Why it matters
- It broadened the indication for cardiac resynchronization to patients with mildly symptomatic heart failure, showing that it can prevent disease progression and not only improve those who are already symptomatic.
Card generated automatically with AI from the abstract of the original publication and the trial registry; every figure was checked against those sources. It may contain errors: verify the data at the source before using it for clinical decisions.
Generated on October 10, 2026