A randomised trial investigating therapies needed to maintain remission in dilated cardiomyopathy

INTERVENTION: We will do a randomised controlled trial of SGLT2i and MRA withdrawal between the point of randomisation and 16 weeks, with a follow‐on phase between 16‐32 weeks that will include a single‐arm cross‐over for those initially randomised to the control arm. Patients will be randomised using an online tool to two arms in a 1:1 ratio using random permuted blocks, stratified by three groups of NT‐pro‐BNP: 1) <50ng/l, 2) 50‐125ng/l, 3) >125ng/L. Patients randomised to Arm B will stop SGLT2i at baseline, followed by MRA at 8 weeks. In the follow‐on phase, they will continue follow‐up off these medications between 16‐32 weeks. Patients randomised to Arm A will continue current therapy between baseline and 16 weeks. After 16 weeks, patients who have continued therapy in Arm A will have the opportunity to enter a single arm cross‐over phase and stop MRA followed by SGLT2i at 24 weeks (the reverse order to Arm B in the randomised phase). CONDITION: Patients with a previous diagnosis of dilated cardiomyopathy who have improved cardiac function and who are asymptomatic ; Circulatory System PRIMARY OUTCOME: Relapse of DCM defined by any one of the following:; 1. A reduction in LVEF>10% and to below 50%; 2. A two‐fold rise in NT‐pro‐BNP and to >400ng/L or; 3. Clinical features of heart failure as determined by the research team.; This is a composite of prognostically important variables supported by the findings of TRED‐HF, taking into account changes in markers of cardiac function and congestion. The primary analysis will take place after 16 weeks of the randomised phase. There will also be a follow‐on phase. The incidence of the primary end‐point will also be assessed between 16‐32 weeks. SECONDARY OUTCOME: At baseline, 16 weeks and 32 weeks:; 1. Left ventricular ejection fraction (%) (cardiovascular magnetic resonance [CMR]); 2. Left ventricular end‐diastolic volume indexed to body surface area (ml/m²) (CMR); 3. Left ventricular global longitudinal strain (LV GLS) (CMR); 4. Left ventricular mass inde X(LVMi; g/m²) (CMR); 5. Left atrial volume inde X(LAVi; ml/m²) (CMR); 6. Left atrial strain (LAS) (CMR); 7. Right ventricular ejection fraction (RVEF; %) (CMR); 8. NT‐pro‐BNP (ng/L) (plasma concentration from peripheral blood sampling); 9. Quality of life: EQ‐5D‐5L score; 10. Treatment Burden Questionnaire score INCLUSION CRITERIA: 1. A diagnosis of DCM 2. Previous LVEF <40% (on echocardiography or cardiovascular magnetic resonance [CMR]) 3. Current LVEF >50% for at least 6 months duration with normal left ventricular end‐diastolic volume (LVEDV) at inclusion 4. Plasma NT‐pro‐BNP<250ng/L 5. New York Heart Association (NYHA) class I 6. Sinus rhythm 7. Taking a beta‐blocker and an ACEi, ARB or sacubitril‐valsartan, along with at least one of an MRA or SGLT2i.