Physical Activity and Sedentary Behaviour Thresholds for Secondary Prevention of Coronary Heart Disease: Morbidity Survival Tree Analysis.

BACKGROUND

There are no diagnosis-specific guidelines for moderate-to-vigorous physical activity (MVPA) and sedentary behaviour (SB) for coronary heart disease (CHD). This study aimed to identify thresholds of MVPA and SB associated with cardiovascular events.

METHODS

This cohort study included individuals with CHD. MVPA and SB were self-reported, and health registries identified cardiovascular events in the years 2006-2022. Survival tree analyses identified thresholds of time associated with the risk of cardiovascular events. Thresholds were explored with the use of Cox regression models.

RESULTS

There were 40,156 Australians, mean age 70 years, 62% men. Over a median 8.3 years, 3260 nonfatal cardiac events, 5161 total cardiac events, and 14,383 major adverse cardiovascular events (MACE) occurred. Thresholds for MVPA were 122 min/wk for nonfatal cardiac events and 94 min/wk for total cardiac events and MACE. Meeting MVPA thresholds was associated with an 18% lower risk for nonfatal cardiac events, 29% lower risk of total cardiac events, and 23% lower risk of MACE than not reaching the thresholds. Thresholds for SB were 4 and 10 h/d, respectively, for risk of total cardiac events and MACE. SB below thresholds was associated with a 14% lower risk of total cardiac events and an 18% lower risk of MACE. There were sex-specific thresholds for MVPA and SB.

CONCLUSIONS

To lower cardiovascular event risk, identified MVPA thresholds were lower (94-122 min/wk) than the public health guidelines (150 min/wk) in individuals with CHD. The SB thresholds associated with a lower risk of total cardiac events and MACE varied from 4 to 10 h/d.