Associations between change in moderate-to-vigorous physical activity and sedentary behaviour with risk of recurrent cardiovascular events among individuals with coronary heart disease: A prospective cohort study

BACKGROUND: Moderate-to-vigorous physical activity (MVPA) and limiting time in sedentary behaviour (SB) are recommended for the secondary prevention of coronary heart disease (CHD). Little is known about MVPA and SB changes and recurrent cardiovascular events. This study explores the associations between changes in MVPA and SB for recurrent cardiovascular events among individuals with CHD. METHODS: Prospective cohort study based on individuals with CHD. MVPA and SB were self-reported, and recurrent cardiovascular events were identified using health registers (2006-2022). Changes in MVPA and SB were categorized as remaining high, decreasing, increasing, and remaining low. Associations were explored using Cox proportional regression models. RESULTS: There were 9430 Australians, 62 % males with a mean age of 70 (SD = 10) years. During the follow-up, with a median time of 4.9 (IQR = 6.1) years, 508 non-fatal cardiac events, 951 total cardiac events, and 2481 major adverse cardiovascular events (MACE) occurred. The risk of recurrent cardiovascular events was 32-39 % lower when MVPA remained high compared to remaining low. An increase in MVPA was associated with a 30 % lower risk of total cardiac events and a 26 % lower risk of MACE, while a decrease was associated with a 16 % lower risk of MACE. Keeping low SB was associated with a 25-29 % lower risk of total cardiac events and MACE than SB remained high. A decrease in SB was associated with a 25 % lower risk of MACE. CONCLUSION: Supporting individuals with CHD to remain high or improve levels of MVPA and low levels of SB is important in secondary prevention.