Authors' objectives:

The objectives of this review were to determine the efficacy, safety, and cost-effectiveness of cardiac resynchronization therapy (CRT) in adults with symptomatic congestive heart failure (CHF).

Authors' results and conclusions: In nine RCTs (3216 patients, 85% with NYHA Class III or IV symptoms and 100% with prolonged QRS duration), CRT improved peak oxygen consumption (WMD 0.65 ml/kg/min, 95% CI 0.27 to 1.04 ml/kg/min), left ventricular ejection fraction (WMD 3.35%, 95% CI 1.22% to 5.48%), six-minute walk distance (WMD 23 meters, 95% CI 9 m to 38 m), quality of life (WMD reduction of 5.5 points, 95% CI 2 to 9 points on the Minnesota Living with Heart Failure Questionnaire), and functional class (57% improved at least one NYHA class compared to 34% of controls). Heart failure hospitalizations decreased by 32% (RR 0.68, 95% CI 0.41 to 1.12), especially in patients with NYHA III/IV symptoms (RR 0.65, 95% CI 0.48 to 0.88; number needed to treat [NNT]=12). All-cause mortality was reduced by 25% (RR 0.75, 95% CI 0.60 to 0.93, NNT=27), mainly due to 40% fewer progressive heart failure deaths (RR 0.60, 95% CI 0.36 to 1.01). Kaplan Meier curves separated at 3 months, and the risk of death was reduced 41% after the first 3 months (hazard ratio 0.59, 95% CI 0.43 to 0.81). No significant differences were seen in sudden cardiac deaths or non-cardiac deaths. Safety: In 17 prospective studies (3512 patients with CRT devices), the implant success rate was 89.9% (88.8% to 90.9%) and peri-implant death risk was 0.4% (95% CI 0.2% to 0.7%). Over a median 6 months of followup, lead dislodgement occurred in 8.5% (7.4% to 9.9%), mechanical malfunctions in 6.7% (5.4% to 8.2%), arrhythmias in 1.7% (0.8% to 3.4%), and site infections in 1.4% (0.8% to 2.3%) of patients.

Authors' recommendations: In patients with NYHA Class III or IV CHF despite medical management, reduced ejection fractions, and prolonged QRS duration, CRT improves functional and hemodynamic markers and reduces morbidity/mortality. Given the moderate implantation success rates, biventricular pacemaker insertions should only be done by experienced providers. The cost-effectiveness of CRT remains uncertain; additional effectiveness and cost data surrounding peri-implantation complications are required to determine whether CRT is sufficient value to be widely adopted.

Authors' methods: Systematic review

Project Status: Completed

URL for project: http://www.ahrq.gov/clinic/tp/resyntp.htm

Year Published: 2004

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: United States

Organisation Name: Agency for Healthcare Research and Quality

Contact Address: Center for Outcomes and Evidence Technology Assessment Program, 540 Gaither Road, Rockville, MD 20850, USA. Tel: +1 301 427 1610; Fax: +1 301 427 1639;

Contact Name: martin.erlichman@ahrq.hhs.gov

Contact Email: martin.erlichman@ahrq.hhs.gov

Copyright: Agency for Healthcare Research and Quality (AHRQ)