Title: HESTER study: Has electrical sinus translated into effective remodelling?
Funder: Department of Health (England)

Abstract: DESIGN: Matched cohort study to compare atrial transport function in patients who reverted to sinus rhythm following the maze procedure with those who have never been in atrial fibrillation and are in normal sinus rhythm before and after cardiac surgery.SETTING: Multi-centre study (Papworth Hospital Cambridge and Glenfield Hospital Leicester)TARGET POPULATION: Patients who are in sinus rhythm after participating in the Amaze trial will constitute the study group. The study patients be targeted at least 1 year after their adjunct maze cardiac procedure. We shall then compare atrial transport function in this group with that in a closely matched group of controls who also had similar cardiac procedures but were not in the Amaze trial and who were in sinus rhythm before and after surgery. Patients will be matched for age sex type of surgery left ventricular function predicted risk as calculated by the logistic Euroscore and approximate time since their procedure. STUDY ASSESSMENTS: Atrial transport function will be assessed using echocardiographic measures supplemented by cardiac magnetic resonance imaging (Mr.I) to evaluate the effectiveness of the maze procedure in restoring atrial transport function.MEASUREMENT OF COST AND OUTCOME: The primary outcome measure is left atrial function generally and specifically left atrial ejection fraction.The HESTER study will determine if sinus rhythm restoration after operative intervention is associated with recovery of atrial function and the extent of any recovery. It will also provide the criteria to measure the risk of stroke identify patients who have atrial recovery and allow in appropriately identified patients the potential withdrawal of long-term anticoagulation with its inherent lifestyle limitations and risk of haemorrhagic complications. These are important to the individual patient and to the NHS as a whole.SAMPLE SIZE: Sample size was estimated on the basis of active left atrial ejection fraction which is calculated as:100 x (pre-atrial contraction volume - atrial end-distole volume)/pre-atrial contraction volume. According to the study by Anwar et al the mean LAEF when in SR is 43% with standard deviation of 18.2%. Aiming to show that the Maze patients return to this level (equivalence trial) we will assume equivalence if the mean difference is within one standard deviation. With a SD at 18.2% for both groups and using 95% CIs and 80% power a sample size of 22 is required in each group.PROJECT TIMETABlE: Study set up will require 3 months with an additional month for screening for control patients at both sites. We envisage recruitment rate to be 4-6/month and will be completed between 4-15months. Data cleaning and preparation will take two months with primary outcome analysis and report writing a futher three months.EXPERTISE:Mr. Sam Nashef (Consultant Cardiac Surgeon) is the CI for the Amaze trial and has extensive surgical and research experience. Dr Linda Sharples is a highly experienced Mr.C statistician working on various NIHR grants (Aster C-CAT Amaze). Mr. Yasir Abu-Omar is a Consultant Cardiothoracic Surgeon Dr Deepa Gopalan is a Consultant Radiologist and Dr Bushra Rana is a Consultant Cardiologist. Dr Victoria Stoneman (Research Officer) is the current Amaze Trial Manager and Mr.s Christine Mills is the current Amaze Trial Co-ordinator - both both members of the Papworth R&D Unit with expertise in research project management and trial co-ordination.Anwar et al 2007 Am J Cardiol 2008;102:847–853


Research activity codes: 7.3 MANAGEMENT AND DECISION MAKING
Health categories: CARDIOVASCULAR