Healthy grocery delivery in the usual care for adults recovering from an acute coronary event: protocol for a three-arm randomised controlled trial

Introduction Coronary heart disease is a major contributor to the global burden of disease. Appropriate nutrition is a cornerstone of the prevention and treatment of coronary heart disease; however, barriers including cost and access to recommended foods limits long-term adherence for many. We are conducting, in adults with coronary heart disease, a randomised controlled trial comparing usual care with two dietary interventions in which usual care is augmented by 12 weeks free delivered groceries.

Methods and analysis Three hundred adults recovering from an acute coronary event will be recruited from outpatient cardiovascular services in three regions of Aotearoa New Zealand. Participants will be randomly allocated to three arms: usual care (control group), usual care and the free delivery of foods high in dietary fibre or usual care and the free delivery of foods high in unsaturated fats. Interventions duration is 12 weeks, with a further 12 months follow-up.

The primary outcome measures are change in low-density lipoprotein (LDL) cholesterol concentration following the intervention, and a cost-effectiveness analysis of healthcare access and social costs in the year after the intervention. A broad range of secondary outcome measures include other blood lipids, anthropometry, glycaemia, inflammatory markers, gut microbiome, dietary biomarkers, food acceptability, dietary change and the facilitators and barriers to dietary change. The trial will determine whether the free provision of groceries known to reduce cardiovascular risk within usual care will be clinically beneficial and justify the cost of doing so. Results may also provide an indication of the relative benefit of foods rich in dietary fibre or unsaturated fats in coronary heart disease management.

Ethics and dissemination This trial, The Healthy Heart Study, has Health and Disability Ethics Committee approval (20/NTB/121), underwent Māori consultation, and has locality authority to be conducted in Canterbury, Otago and Southland.

Trial registration number ACTRN12620000689976, U1111-1250-1499.