Optimal treatment of atrial fibrillation in patients with cardiac dysfunction and scar

Dr Louise Segan, Baker Heart and Diabetes Institute

2020 Health Professional Scholarship

Years funded: 2021-2024

Atrial fibrillation (AF) is an irregular heart rhythm commonly seen in patients with heart failure. Heart failure often occurs due a weakened heart muscle resulting in breathlessness, fatigue and fluid retention. AF can cause or worsen heart failure. Some patients experience improvement in symptoms and heart function if the rhythm is restored to a regular rhythm (sinus rhythm), achieved through a minimally invasive procedure 'Catheter Ablation'. Previous studies suggest catheter ablation is beneficial where AF is thought to contribute to weakening of the heart muscle.

The CAMERA-MRI II study will assess whether catheter ablation is able to achieve better improvements in heart function, symptoms and survival compared to medical therapy in those with AF and heart failure who have established structural changes (scarring on MRI). This study will involve MRI and other assessments before the treatments and during follow up at specific time intervals.

This study will also evaluate changes in the heart chambers using ultrasound and MRI and determine whether these changes correlate to improvements in patient outcomes. Moreover, we hope this study will help to better predict which patients with AF and heart failure will benefit most from catheter ablation to inform future directions in heart failure management beyond medical therapy.

The study focuses on the role of cardiac MRI as a potential risk stratification tool in identifying which patients with AF and heart failure will benefit most from catheter ablation beyond existing clinical and investigational tools. It will also, for the first time, evaluate the degree to which scarring (known as 'myocardial fibrosis') may impact on clinical outcomes, including mortality and heart failure hospitalisations in patients with AF and heart failure undergoing catheter ablation.