(P23-080-23) Impact of an Intensive Lifestyle Program on Low Attenuation Plaque and Myocardial Perfusion in Coronary Heart Disease: A Randomised Clinical Trial Protocol

Objectives: To conduct a randomised controlled trial (RCT) to determine the impact of a 12-month intensive lifestyle intervention program (ILIP) versus a standard clinical recommendations program (SCRP) on low-attenuation plaque (LAP) volume and structure, stress myocardial perfusion, and diastolic function (LIVEPLUS trial).

Methods: This is a single-centre, parallel-group, RCT (Trials Registry: ACTRN12620001151921) of individuals with stable coronary heart disease, who have LAP based on a coronary computed tomography angiography (CCTA). The ILIP group (n = 75) will follow a 5:2 pesco-vegetarian diet, individualised exercise training, and mindfulness-based stress reduction, whereas the SCRP group (n = 75) will follow American Heart Association guidelines for diet and exercise and World Health Organization guidelines for stress reduction. The co-primary endpoints are: 1- LAP volume (mm3), and 2-Adenosine stress myocardial blood flow (stress MBF, mL/min/g). Other key measurements include body weight, liver steatosis, subclinical abnormalities, arterial stiffness, endothelial function, genomic, metabolomic, and gut microbiome-related adaptations to these structural changes. An intention-to-treat principle will be used for all analyses.

Results: To demonstrate the feasibility of our interventions, body weight was used as a secondary compliance indicator of the intervention. Ten participants were recruited by Feb 2023: five randomised to ILIP, three to SCRP, and two awaiting randomisation. Four individuals (three in ILIP, one in SCRP) followed our interventions for more than 6 months, with those following ILIP achieving an average of 9.4kg (9.5%) and those following SCRP achieving an average of 3.5kg (4.4%) body weight reduction.

Conclusions: This trial will represent the single most detailed and integrated analysis of the effects of a comprehensive lifestyle intervention targeting multiple metabolic pathways, on coronary macro- and microcirculation, heart physiology, and cardiometabolic risk. It will provide a new framework for allowing clinicians and individuals to optimise metabolic health for the prevention and management of atherosclerotic cardiovascular diseases.

Funding Sources: The Australian NHMRC Investigator Grant (APP1177797), Australian Youth and Health Foundation and Philip Bushell Foundation.