Objectives To evaluate the clinical response to cardiac resynchronisation therapy (CRT) in patients with heart failure and a normal QRS duration (<120 ms).
Setting Single centre.
Patients 60 patients with heart failure and a normal QRS duration receiving optimal pharmacological treatment (OPT).
Interventions Patients were randomly assigned to CRT (n=29) or to a control group (OPT, n=31). Cardiovascular magnetic resonance was used in order to avoid scar at the site of left ventricular (LV) lead deployment.
Main outcome measures The primary end point was a change in 6 min walking distance (6-MWD). Other measures included a change in quality of life scores (Minnesota Living with Heart Failure questionnaire) and New York Heart Association class.
Results In 93% of implantations, the LV lead was deployed over non-scarred myocardium. At 6 months, the 6-MWD increased with CRT compared with OPT (p<0.0001), with more patients reaching a ≥25% increase (51.7% vs 12.9%, p=0.0019). Compared with OPT, CRT led to an improvement in quality-of-life scores (p=0.0265) and a reduction in NYHA class (p<0.0001). The composite clinical score (survival for 6 months free of heart failure hospitalisations plus improvement by one or more NYHA class or by ≥25% in 6-MWD) was better in CRT than in OPT (83% vs 23%, respectively; p<0.0001). Although no differences in total or cardiovascular mortality emerged between OPT and CRT, patients receiving OPT had a higher risk of death from pump failure than patients assigned to CRT (HR=8.41, p=0.0447) after a median follow-up of 677.5 days.
Conclusions CRT leads to an improvement in symptoms, exercise capacity and quality of life in patients with heart failure and a normal QRS duration.
(ClinicalTrials.gov number, NCT00480051.)
- Cardiac resynchronisation therapy
- heart failure
- normal QRS duration
- cardiac remodelling
- cardiomyopathy dilated
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.
See Editorial, p 1029
Funding Medtronic Inc. Bakken Research Centre, The Netherlands.
Competing interests PWXF held a research fellowship sponsored by Medtronic Inc. BS is an employee of Medtronic Inc. REAS and FL have received sponsorship from Medtronic Inc. MPF has received a grant in aid funding for investigator-led studies from Medtronic Inc and is on the End Points Committee for a study funded by Biotronik.
Ethics approval This study was conducted with the approval of the North Birmigham Ethics Committee.
Provenance and peer review Not commissioned; externally peer reviewed.