The AUStralian MEDiterranean Diet Heart Trial (AUSMED Heart Trial): A randomized clinical trial in secondary prevention of coronary heart disease in a multiethnic Australian population: Study protocol

The Mediterranean diet was first characterized as a heart-protective diet in the 1960s. The significant cardioprotective effects of the Mediterranean diet in comparison to the standard-care low-fat diet have been established in the primary prevention of cardiovascular disease (CVD); however, there is insufficient evidence in secondary prevention research to influence the current standard of care. Opportunity exists to assess the Mediterranean diet as a therapeutic target for secondary CVD prevention within Australia's ethnoculturally diverse communities. The AUSMED Heart Trial is a multisite randomized controlled trial that will evaluate the efficacy of the Mediterranean diet for secondary prevention of CVD in the Australian health care setting. This trial aims to evaluate the effect of a 6-month Mediterranean diet intervention (delivered by dietitians) versus a “standard-care” low-fat diet in reducing the composite incidence of cardiovascular events at 12 months and at trial end in participants with documented evidence of a previous acute myocardial infarction at trial entry. The quality of the diet at baseline and follow-up will be assessed using comprehensive dietary questionnaires and diaries as well as relevant dietary biomarkers (such as urinary polyphenols and erythrocyte fatty acids). Cardiovascular risk markers, including novel measures of immune and inflammatory status, endothelial function, vascular compliance, platelet activity, and body composition, will be collected to explore possible mechanisms for treatment effect. Cost-effectiveness will also be estimated to support policy translation. We plan to recruit 1,032 participants (516 per arm) from cardiology clinics in major Australian hospitals in Melbourne, Adelaide, and Brisbane.