MRI in Randomised Cohorts of Asymptomatic AS

Ongoing randomised control trials (RCT) are testing the strategy of early AVR in asymptomatic severe AS ('The Early surgery in severe ASYmptomatic Aortic Stenosis': EASY-AS and 'Early Valve Replacement guided by Biomarkers of Left Ventricular Decompensation in Asymptomatic Patients with Severe Aortic Stenosis': EVOLVED), and if positive, have the potential to shift the timing of intervention to earlier disease. With TAVR recently being shown to be non-inferior to SAVR in low risk, mostly symptomatic patients, this also has the potential to be extended to asymptomatic patients.

MRI studies have shown that up to 50% of those with asymptomatic AS already have scarring (LGE), which is only partially reversible even after AVE, and remains a marker of mortality. It is not known if earlier valve replacement will lead to less scar burden within the myocardium.

Patient reported outcome measures (PROM) are increasingly recognised as an important outcome measure of surgery, especially in an elderly population, for whom a significant increase in survival may be neither possible, nor sought by the patient. World Health Organisation Disability Assessment Schedule-2 (WHODAS-2) is a standardised cross-cultural measurement of health status assessing functioning and disability in major life domains, that has been shown to be a valid and reliable instrument for assessment of disability. A comprehensive formal review of PROMS instruments in patients receiving medical treatment for heart failure concluded that the Euroqol (EQ5D) and Minnesota Living with Heart Failure Questionnaire (MLHFQ) were the most appropriate to measure quality of life in this group. Euroqol is the most commonly used generic instrument in Europe, and showed improvement at 1 year post-AVR for severe AS. MLHFQ is a cardiovascular disease-specific tool that has been shown to be reliable, valid and responsive to therapeutic intervention in patients undergoing valve surgery. Understanding the effect of intervention on PROMs can aid shared decision-making and help shape future individualised recommendations.

This prospective, observational mechanistic study will maximise the opportunity offered by ongoing RCTs, to try and establish the effect of the two treatment strategies (early vs late AVR) on cardiac reverse remodelling (in particular fibrosis burden), PROMs and peri-operative recovery.

Inclusion criteria

• Willing to and able to consent
• Participant in an RCT randomising patients with asymptomatic severe AS to early AVR vs standard care
• Severe aortic stenosis, as defined by original trial's inclusion criteria
• Asymptomatic at the time of randomisation in the RCT
• Willingness to have 1-2 cardiac MRI scan(s)

Exclusion criteria

• Contra-indication to MRI.
• eGFR <30.
• Severe claustrophobia (precluding MRI).