British randomised controlled trial of AV and VV optimization ("BRAVO") study: rationale, design, and endpoints

Zachary I Whinnett, S M Afzal Sohaib, Siana Jones, Andreas Kyriacou, Katherine March, Emma Coady, Jamil Mayet, Alun D Hughes, Michael Frenneaux, Darrel P Francis, BRAVO Investigators

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Echocardiographic optimization of pacemaker settings is the current standard of care for patients treated with cardiac resynchronization therapy. However, the process requires considerable time of expert staff. The BRAVO study is a non-inferiority trial comparing echocardiographic optimization of atrioventricular (AV) and interventricular (VV) delay with an alternative method using non-invasive blood pressure monitoring that can be automated to consume less staff resources.

BRAVO is a multi-centre, randomized, cross-over, non-inferiority trial of 400 patients with a previously implanted cardiac resynchronization device. Patients are randomly allocated to six months in each arm. In the echocardiographic arm, AV delay is optimized using the iterative method and VV delay by maximizing LVOT VTI. In the haemodynamic arm AV and VV delay are optimized using non-invasive blood pressure measured using finger photoplethysmography. At the end of each six month arm, patients undergo the primary outcome measure of objective exercise capacity, quantified as peak oxygen uptake (VO2) on a cardiopulmonary exercise test. Secondary outcome measures are echocardiographic measurement of left ventricular remodelling, quality of life score and N-terminal pro B-type Natriuretic Peptide (NT-pro BNP). The study is scheduled to complete recruitment in December 2013 and to complete follow up in December 2014.

If exercise capacity is non-inferior with haemodynamic optimization compared with echocardiographic optimization, it would be proof of concept that haemodynamic optimization is an acceptable alternative which has the potential to be more easily implemented.
Original languageEnglish
Article number42
JournalBMC Cardiovascular Disorders
Publication statusPublished - 3 Apr 2014


  • Biological Markers
  • Blood Pressure Determination
  • Cardiac Resynchronization Therapy
  • Cardiac Resynchronization Therapy Devices
  • Clinical Protocols
  • Cross-Over Studies
  • Echocardiography, Doppler
  • Exercise Test
  • Exercise Tolerance
  • Great Britain
  • Heart Failure
  • Hemodynamics
  • Humans
  • Natriuretic Peptide, Brain
  • Peptide Fragments
  • Photoplethysmography
  • Predictive Value of Tests
  • Quality of Life
  • Questionnaires
  • Recovery of Function
  • Research Design
  • Time Factors
  • Treatment Outcome
  • Ventricular Function, Left
  • Ventricular Remodeling

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