"Cardiac-Resynchronization Therapy in Heart Failure with QRS Complex".The New England Journal of Medicine. 2010. 363(25):2385-2395.PubMed•Full text•PDF

Clinical Question

In patients with NYHA class II or III heart failure, left ventricular systolic dysfunction, and a wide QRS complex, does the addition of CRT to an ICD and optimal medical therapy improve outcomes?

Bottom Line

In patients with NYHA class II or III heart failure, adding CRT to an ICD and optimal medical therapy reduced rates of death and hospitalization for heart failure but was accompanied by more adverse events.

Major Points

Guidelines

As of 2010, there were no established guidelines reflecting the results of this trial. It is likely subsequent guidelines will incorporate these findings.

Design

Multicenter, double-blind, randomized, controlled trial.

Population

Inclusion Criteria:
- NYHA class II or III heart failure
- Left ventricular ejection fraction ≤30%
- Intrinsic QRS duration ≥120 msec or paced QRS duration ≥200 msec

Exclusion Criteria:
- Major coexisting illness or recent cardiovascular event

Interventions

- ICD alone (n=904)
- ICD with CRT (n=894)

Outcomes

Primary Outcome: Death from any cause or hospitalization for heart failure.
Secondary Outcomes: Death from any cause at any time, death from cardiovascular cause, hospitalization for heart failure, subgroup analyses based on NYHA class.

Criticisms

- Higher rate of adverse events associated with device implantation in the CRT group suggests that implantation and follow-up care require careful consideration.

Funding

Canadian Institutes of Health Research and Medtronic of Canada. Medtronic provided funding and CRT components but was not involved in trial conduct or reporting.

Further Reading

Detailed protocol and statistical analysis plan can be found by visiting NEJM.org and searching for the article or its ClinicalTrials.gov number, NCT00251251.