Physical activity levels and predictors in patients following percutaneous coronary intervention: a cross-sectional study

Physical inactivity is common worldwide, especially among people with chronic diseases or disabilities who have fewer opportunities to be active.¹ In 2018, the World Health Organization (WHO) endorsed a global action plan on physical activity (PA) and agreed to a target of 15% relative reduction in the prevalence of insufficient PA by 2030.² Many advances have been made to increase PA worldwide, but there is still insufficient activity in people following percutaneous coronary intervention (PCI).

PCI has been firmly established as the most important procedure used for an invasive treatment in ischemic heart disease. It has rapidly evolved, and its utilization rate has increased dramatically over the past years.³ However, the PCI procedure and drug therapy alone cannot effectively improve the prognosis of patients. PCI can neither reverse or slow down the biological process of atherosclerosis nor eliminate the risk factors of heart disease.^4,5 Stent thrombosis (ST) and in-stent restenosis are two major problems following the PCI procedure, which present as recurrent angina, acute myocardial infarction, or sudden death. Approximately 10% of patients have repeat percutaneous revascularization.^6,7 In addition, decreased exercise tolerance, anxiety, and depression after the PCI procedure seriously affect the quality of life of patients. The American Heart Association (AHA) guidelines recommend PA-based cardiac rehabilitation for secondary prevention after PCI.⁸

In China, exercise rehabilitation after coronary intervention is in its infancy. Health workers still focus on rescue and treatment in the acute stage of the disease, and there is a lack of understanding and practice of exercise rehabilitation. PA in post-PCI patients causes a high risk of cardiovascular disease recurrence and brings a huge economic burden and labor loss to the family and the country. Therefore, it is imperative to carry out exercise rehabilitation in China. First, the current situation within the population should be understood. However, data on PA in post-PCI patients are insufficient. Some results are not comparable due to different data collection or analysis formats, making it difficult to judge the quality of the PA. Moreover, the priorities and preference for domain-specific PA in post-PCI patients remain unknown. In addition, the factors that influence PA in post-PCI patients are not completely understood. Hence, the objective of the present study was to examine PA of post-PCI patients and explore the socio-demographic, clinical, and social psychological characteristics associated with PA levels.

The present study was one of the first to investigate the levels of PA and associated socio-demographic, medical, and psychological factors among post-PCI patients in China using the IPAQ. Our study indicated that 20% of people have insufficient PA, and the most popular PA activities were walking and leisure PA. Motivation, self-efficacy, occupational status, and monthly income were predictors of high PA. This finding provides a basis for medical workers to carry out health education and PA intervention and lays a foundation for the development of exercise rehabilitation in post-PCI patients.

We observed that 20% of PCI patients had insufficient PA, which is relatively high compared to the general population²². When compared with other types of cardiovascular disease, such as acute coronary syndrome and CHD, the percentage of PA was relatively low.^23,24 Therefore, insufficient PA observed in PCI patients was lower than in patients with other types of cardiovascular disease, but inferior to the general population. The high-level PA participation rate was lower than the PA of the general population²⁵ and other types of cardiovascular patient population,²³ indicating that high level of PA was insufficient. PA has been well established by the 2020 WHO guidelines to be a health benefit in adults with chronic conditions. Therefore, improving the high-level of PA participation in PCI patients is a problem that needs to be solved.

For the domain-specific PA, several surveys on the general population and people with diabetes have shown that PA was mainly based on work, housework, or transportation.^26–28 Unlike previous reports, our study found that leisure-time PA accounted for the majority of PA, with a participation rate of 80%. This rate was higher than that from a recent survey involving a large Chinese sample population.²⁹ This result may be ideal because the benefit of leisure-time PA has been well established and might be more amendable to change during cardiac rehabilitation. In future studies, health care workers could provide scientific guidance for patients to carry out leisure-time PA.

Higher motivation, self-efficacy, unemployment, and lower monthly income predicted higher PA levels. Previous studies have comprehensively explored the factors that influence PA within the general population and cardiovascular patients, but the findings have been inconsistent, except for self-efficacy and motivation.^30,31 Similar results were obtained in the present study that showed motivation and self-efficacy were predictors of high-level PA in post-PCI patients.

The influence of occupational status on PA has been extensively studied in the cardiovascular disease population.³² Whether patients return to work after a major event, like surgery or a heart attack, and its impact on their life and behavior after returning to work are a matter of concern. The present study showed that unemployed patients have a higher level of PA, which may be related to sufficient time and less work pressure.

The high-income population was more likely to have insufficient PA. Previous studies have suggested that high-income countries had a transition toward more sedentary occupations and personal motorized transportation; conversely, in lower-income countries, more activity is undertaken at work, transport, and housework, which provides some insight into the interpretation of our results.²² Further analysis in our research showed that transport PA levels with a monthly income below 3000 RMB, 3000-5000 RMB, and above 5000 RMB were 420.5, 286.5, and 224.7 MET-min/week, respectively, and the housework PA levels were 290.5, 226.2, and 177.2 MET-min/week, respectively. This indicates that with the increase in income, transport and housework PA levels tend to decrease; however, work-related and leisure-time PA levels did not increase correspondingly. Therefore, more attention should be paid to high-income patients.

The effect of social support on PA is uncertain. From the current research, social support was found to be more effective for promoting PA in people with cardiovascular disease than in the general population.^30,31 However, the present study showed that social support had a non-significant impact on PA. These results may be partly attributed to gender as the majority of the participants in the current study were male. By contrast, previous studies have shown that women generally had a wider network of relationships than men and were more vulnerable to social support.³³ Similarly, social support may have had an indirect effect on PA.³⁴ Thus, a PA-specified social support questionnaire may be needed in future studies.

In the present study, symptoms did not influence PA, which is contrary to the findings from previous studies.³⁵ First, the reason for this difference could be because of the subjective nature of the survey questions, affecting the accuracy of the results. Second, studies have shown that symptoms may affect the confidence and self-efficacy of certain behaviors by influencing anxiety and depression; therefore, it is necessary to explore the influence of mediating variables.³⁶ There are a few studies on the effect of the number of stents on PA. With the continuous development and improvement of the PCI technology, the scope of application has been broadened, and the proportion of blockage treatment for complex coronary lesions has been increasing. Therefore, the number and total length of stents are also increasing. The correlation between the number of stents and cardiovascular adverse events has been confirmed.³⁷ However, whether the number of stents is related to PA and the mechanism of action needs to be further confirmed by more studies. In addition, the small sample size may also be the reason why these two factors are not significant.

The present study had some limitations. The data collection of the IPAQ was self-reported, and we expect selected memory bias and exaggeration, which could reduce the reliability of the results. However, the use of a questionnaire was still the most convenient and economical way to collect information. In addition, selfefficacy and social support questions focused on PA may be more helpful for further analysis.

The present study aimed to understand the PA of post-PCI patients in China. The results showed that the overall level of PA in post-PCI patients was not optimal, with the highest participation observed in leisuretime PA. Motivation, self-efficacy, monthly income, and occupational status influenced PA levels. In future studies, PCI patients in different regions should be investigated, and ecological models should be introduced to explore the influencing factors of PCI patients more comprehensively.