Walking as a viable alternative to moderate-to-vigorous physical activity for improving cardiovascular outcomes in coronary artery disease patients

Background: Home-based cardiac rehabilitation is recommended for coronary artery disease (CAD) patients, while exercise is the most important component. There is lack of evidence on whether walking alone can improve cardiovascular prognosis in CAD patients, particularly those unable to tolerate moderate-to-vigorous physical activity (MVPA). Methods: Participants with diagnosed CAD from the UK Biobank with baseline PA assessment were included. PA data, including total PA, MVPA, and walking, were collected using the International Physical Activity Questionnaire, and expressed as the total metabolic equivalent of tasks minutes per week. We accessed the association between PA and cardiovascular composite outcome (cardiac death, heart failure hospitalization, non-fatal myocardial infarction, percutaneous coronary intervention, coronary artery bypass grafting) and all-cause mortality. Result: Over a median follow-up of 13.5 years, incidence of all-cause mortality (21.6, 16.7, 15.9, 15.6 per 1000 person-years) and cardiovascular composite events (20.6, 17.8, 17.8, 17.2 per 1000 person-years) decreased with increasing time of total PA in 19,074 patients. Notably, for patients who did not meet AHA/ESC/WHO recommendations, achieving an adequate amount of walking (100 min/week) reduced risk of cardiovascular composite outcome (HR = 0.84, 95 %CI [0.71-0.99], p = 0.038) and all-cause mortality (HR = 0.84, 95 %CI [0.77-0.91], p < 0.001). In patients with lower levels of PA, replacing 30 min per day of sedentary behavior with walking or MVPA reduced all-cause mortality risk. Conclusion: In this large cohort, prolonged exercise duration, including total PA, MVPA and walking, may reduce the cardiovascular risks for CAD patients. For patients unable to tolerate MVPA, walking may serve as a suitable alternative.