A prospective study examining the role of myocardial Fibrosis in outcome following mitral valve repair IN DEgenerative mitral Regurgitation: rationale and design of the mitral FINDER study

BMC Cardiovascular Disorders

Study Protocol

Christopher Weston¹  Gerard Nash¹  Nicolas Nikolaidis²  Moninder Bhabra³  Desley A. H. Neal³  Nicola C. Edwards⁴  Boyang Liu⁴  Richard P. Steeds⁴  Thomas Barker⁵  Ramesh Patel⁵ 

[1] Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK;The Royal Wolverhampton NHS Trust, Wolverhampton, UK;University Hospital Birmingham NHS Foundation Trust, Birmingham, UK;University Hospital Birmingham NHS Foundation Trust, Birmingham, UK;Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK;University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK;

关键词: Primary mitral regurgitation;    Timing of surgery;    Myocardial fibrosis;    Cardiac MRI;    Ventricular reverse remodelling;    Extracellular volume;    Arrhythmia risk;    Exercise capacity;   

DOI  :  10.1186/s12872-017-0715-y

 received in 2017-09-08, accepted in 2017-11-12,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundThe optimal management of chronic severe primary degenerative mitral regurgitation (MR) is to repair the valve but identification of the optimal timing of surgery remains challenging. Current guidelines suggest ‘watchful waiting’ until the onset of symptoms or left ventricular (LV) dysfunction but these have been challenged as promoting ‘rescue surgery’. Better predictors are required to inform decision-making in relation to the necessity and timing of surgery. Chronic volume overload is a stimulus for adverse adaptive LV remodelling. Subclinical reduction in LV strain before mitral repair predicts a fall in LV ejection fraction following surgery and is thought to reflect the development of myocardial fibrosis in response to chronic volume overload. Myocardial fibrosis can be detected non-invasively using cardiac magnetic resonance (CMR) imaging techniques as an expansion of the extracellular volume (ECV).Methods/designThis study investigates whether: 1) patients with above median ECV will have smaller reduction in end-systolic volume index (as a measure of the degree of reverse LV remodelling) on CMR following mitral valve repair, compared to those with below median ECV; and 2) higher ECV on CMR, validated through histology, adversely impacts upon post-operative complications and symptomatic improvement following surgery.This is a multi-centre, prospective, cross-sectional comparison of patients prior to and 9 months following surgery for chronic severe primary degenerative MR. To establish the natural history of ECV in MR, an additional cohort of patients with asymptomatic MR who do not wish to consider early repair will be followed. Investigations include CMR, cardiopulmonary exercise test, stress echocardiography, signal-averaged electrocardiogram, 24-h electrocardiogram monitoring, laboratory tests and patient-reported outcome measures. Patients undergoing surgery will have cardiac biopsies performed at the time of mitral valve repair for histological quantification of fibrosis.DiscussionThis study will advance our understanding of ventricular remodelling in MR, its impact on patient symptoms and ventricular response following surgery. Establishing the link between myocardial fibrosis (measured on CMR and validated through histology), with early ventricular dysfunction, will offer physicians a novel non-invasive biomarker that can further inform the timing of surgery.Trial registrationThis trial was registered at ClinicalTrials.gov (NCT02355418) on 30th November 2015.

【 授权许可】

CC BY   
© The Author(s). 2017