Decrease in accelerometer assessed physical activity during the first-year post-myocardial infarction: a prospective cohort study

To elucidate physical activity in the first year after myocardial infarction (MI), and to explore differences in various subgroups, delineated by age, participation in exercise-based cardiac rehabilitation (exCR), or restrictions due to the covid-19 pandemic. Secondly, to explore associations between changes in physical activity variables with blood pressure and lipid levels.
A longitudinal study in 2017-2023. Physical activity variables were assessed via accelerometers at two- and twelve months post-MI. The intensity was divided into, sedentary, light, moderate, and vigorous-intensity physical activity, according to established cut-offs. Blood pressure and lipids were measured by standardized procedures at the same time points.
There were 178 patients included at baseline, 81% male, mean age of 64 (9 SD) years. Patients spent 72% of their time sedentary, followed by light (19%), moderate (8%), and vigorous physical activity (1%). Patients included during covid-19 restrictions and younger patients had a higher level of moderate-intensity physical activity compared to patients included during non-pandemic restrictions and older patients. At 12-month follow-up, patients overall increased time (1%) in sedentary behavior (p = 0.03) and decreased time (0.6%) in moderate-intensity physical activity (p = 0.04), regardless of participation in exCR or age. There was a positive association between the change in mean physical activity intensity and HDL-cholesterol (p = 0.047).
Participants had a low fraction of time in moderate-to-vigorous-intensity physical activity two months post-MI, which deteriorated during the first year. This emphasizes the need for improved implementation of evidence-based interventions to support and motivate patients to perform regular physical activity.

为阐明心肌梗死（myocardial infarction, MI）后第一年的身体活动状况，并探索按年龄、是否参与运动心脏康复（exercise-based cardiac rehabilitation, exCR）或是否受新冠疫情相关限制措施划分的各亚组间的差异。其次，探讨身体活动变量的变化与血压、血脂水平的关联。
本研究为2017-2023年开展的一项纵向研究。于心肌梗死后2个月和12个月时，通过加速度计（accelerometers）评估身体活动变量。依据既定截断阈值（cut-offs），将运动强度划分为久坐、轻强度、中等强度及高强度身体活动。同时在相同时间点采用标准化流程测量血压与血脂水平。
本研究基线共纳入178例患者，其中81%为男性，平均年龄为64（标准差9）岁。患者每日72%的时间处于久坐状态，其次为轻强度活动（19%）、中等强度活动（8%）及高强度活动（1%）。相较于非新冠疫情限制期间纳入的患者与老年患者，新冠疫情限制期间纳入的患者及年轻患者的中等强度身体活动水平更高。在12个月随访时，无论是否参与运动心脏康复或年龄如何，全体患者的久坐时间整体增加1%（p=0.03），中等强度身体活动时间减少0.6%（p=0.04）。平均身体活动强度的变化与高密度脂蛋白胆固醇（HDL-cholesterol）水平呈正相关（p=0.047）。
心肌梗死后2个月时，受试者的中等至高强度身体活动占比偏低，且该状况在术后第一年进一步恶化。这凸显了优化循证干预措施实施的必要性，以支持并激励患者坚持规律身体活动。