Dose–Response Independent and Joint Associations of Physical Activity and Sedentary Behavior With Mortality Risk in 40 156 Australian Adults With Coronary Heart Disease

BACKGROUND: Little is known about the relationship between physical activity (PA) and sedentary behavior (SB) with death in people with coronary heart disease. The aim was to examine the independent and joint associations of PA and SB with death. METHODS AND RESULTS: This is a prospective cohort study including Australian participants aged ≥45 years with self-reported coronary heart disease (2006-2020). Self-reported PA (min/wk) and SB (h/d) were the exposures. Cardiac and all-cause death were the main outcomes. The cohort included 40 156 participants (mean age, 70.3 (SD, 10.3) years; 15 278 women [38%]). During a median follow-up of 11.1 (interquartile range, 6.2-14.4) years, 2497 cardiac and 12 240 all-cause deaths were recorded. Compared with no PA, a 20% to 30% lower risk of cardiac and all-cause death was associated with any level of PA. Walking and moderate to vigorous PA at 150 to 300 min/wk was associated with a 43% to 44% lower risk of cardiac death and 35% to 40% lower risk of all-cause death. Compared with ≥10.5 h/d of SB, participants who were sedentary for 7 to 10.4 h/d experienced an ≈25% reduced associated risk of cardiac and all-cause death. A 56% associated reduction in all-cause mortality risk was found if SB was limited to <3.4 h/d. If participants completed >150 min/wk moderate to vigorous PA and spent <7 h/d in SB, the associated risk of cardiac and all-cause death was reduced by ≈70%. CONCLUSIONS: All people with coronary heart disease should be encouraged to meet the PA guidelines and limit SB to <7 h/d, noting any increase in physical activity and decrease in SB is better than none to prevent premature death.