The potential of cardiac rehabilitation as a method of suppressing abdominal aortic aneurysm expansion: a pilot study

The Impact of Physical Activity on Abdominal Aortic Aneurysm: A Scoping Review

BACKGROUND

Abdominal aortic aneurysm (AAA), a condition primarily affecting older men, is often asymptomatic but becomes life-threatening if rupture occurs. While AAA risk factors such as age, gender, and smoking are well-studied, physical activity (PA) may also play a critical role in managing AAA progression, though this relationship remains understudied. This scoping review aims to synthesize current knowledge on the impact of PA on AAA, examining safety, physiological effects, and potential protective effects against AAA progression.

METHODS

A comprehensive scoping review methodology was applied, covering databases from their inception to October 2024, including MEDLINE, CINAHL, Scopus, and Web of Science. Seven studies meeting the inclusion criteria were analyzed, with intervention designs ranging from cross-sectional to longitudinal studies.

RESULTS

After full-text review of 44 articles, 38 were excluded due to focus on surgical intervention or flow models. The manual screening adding one study, resulting in 7 articles included in this review. PA appears generally safe for individuals with small AAAs, with minimal adverse events reported in most studies, though one study noted a cardiac incident during exercise. PA interventions often improved cardiovascular metrics, including ventilatory threshold and inflammatory markers, yet demonstrated mixed effects on AAA growth. Notably, the protective effect of PA against AAA progression remains inconclusive, requiring further investigation.

CONCLUSIONS

This review indicates that moderate PA is generally safe and may provide health benefits for individuals with small AAAs. However, significant knowledge gaps remain, especially regarding the optimal frequency, intensity, and duration of PA, as well as its long-term impact on aneurysm progression. All these issues require objective measurement of PA to develop targeted physical activity guidelines for this population.

A Multifaceted Approach to Abdominal Aortic Aneurysm

The underlying mechanisms of abdominal aortic aneurysms (AAAs) are not fully understood. Given the multifactorial nature of AAA development and progression, a comprehensive approach is essential. Throughout my academic career, I conducted various studies on AAA. To better understand this mechanism, I initially developed an elastase-infused rat AAA model and applied it to nanoparticle drug delivery systems. While open surgery has traditionally been the standard treatment for AAA, endovascular aneurysm repair (EVAR) has seen significant advancements over the past 25 years. However, insufficient evidence exists regarding this novel treatment, particularly in Japan. To address this issue, we analyzed extensive datasets on EVAR using various registries, including the Japanese Committee for Stent Graft Management. Furthermore, through medical-engineering collaboration, simulation methods were utilized to generate evidence addressing clinical questions encountered in practice.

Exercise, Sports, and Cardiac Rehabilitation Recommendations in Patients with Aortic Aneurysms and Post-Aortic Repair: A Review of the Literature

INTRODUCTION

Balancing the well-documented benefits of regular exercise, particularly its positive impact on cardiovascular risk factors like hypertension, with the potential risks for patients with aortic aneurysms presents a significant challenge. This narrative review aims to summarize the current evidence and guidelines to assist clinicians in making informed exercise and sports recommendations for patients with aortic aneurysms or post-aortic repair.

METHODS

Nine clinical trials on the effect of exercise on abdominal aortic aneurysms (AAAs) were identified, including one study on cardiopulmonary exercise testing (CPET) in AAA patients. As no clinical trials on exercise in thoracic aortic aneurysms (TAAs) were found, we extrapolated data from other studies on exercise in aortic diseases, including data from patients who have had an aortic dissection, as well as three studies on cardiac rehabilitation (CR) and one study on CPET after proximal aortic repair. Review articles and guidelines were also incorporated to ensure a comprehensive overview of the topic.

RESULTS

Currently, no clear correlation exists between intense sports activities and the development of aortic aneurysms or dissections.

CONCLUSIONS

Light to moderate physical activity appears safe and beneficial for patients with aortic aneurysms and post-aortic repair. Given the lack of evidence linking athletic activity to aortic complications, caution is warranted in restricting such activities for athletes, underscoring the importance of shared decision-making. Regular follow-up and optimal management of cardiovascular risk factors are essential.

The effect of exercise training intervention for patients with abdominal aortic aneurysm on cardiovascular and cardiorespiratory variables: an updated meta-analysis of randomized controlled trials

OBJECTIVE

The purpose of this meta-analysis was to evaluate the effect of exercise training intervention in patients with abdominal aortic aneurysm (AAA).

METHODS

Eight randomized controlled trials (RCTs) that recruited 588 AAA patients were extracted using 4 databases (PubMed, Embase, Wanfang Data, and Cochrane Library). Physiological and biochemistry parameters that included in this study are high-sensitivity C-reactive protein (hs-CRP), respiratory peak oxygen uptake rate (VO2peak), triglyceride (TG), total cholesterol (TC), anaerobic threshold (AT), the diameter of AAA, high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), and matrix metalloproteinase-9 (MMP-9). Standard mean difference (SMD) was used to assess the between group effect.

RESULTS

This meta-analysis was synthesized with findings from RCTs and found that hs-CRP (SMD, - 0.56 mg/dL; 95% CI: - 0.90 to 0.22; P = 0.001), VO2peak (SMD, 0.4 mL/kg/min; 95% CI, 0.21 to 0.60; P < 0.001), TG (SMD, - 0.39 mg/dL; 95% CI: - 0.02 to 0.77; P = 0.04), and AT (SMD, 0.75 mL/kg/min; 95% CI, 0.54 to 0.96; P < 0.001) were significantly improved in the exercise groups, while the size of AAA (SMD, - 0.15; 95% CI: - 0.36 to 0.06; P = 0.15), TC (SMD, 0.16 mg/dL; 95% CI: - 0.10 to 0.42; P = 0.23), HDL/LDL ratio (SMD, - 0.06; 95% CI: - 0.32 to 0.20; P = 0.64), HDL (SMD, - 0.09; 95% CI: - 0.39 to 0.20; P = 0.54), LDL (SMD, 0.08; 95% CI: - 0.21 to 0.38; P = 0.59), and MMP-9 (SMD, - 0.23 mg/dL; 95% CI: - 0.53 to 0.06; P = 0.12) did not differ in the exercise groups compared with the controls.

CONCLUSION

Exercise intervention improved some of the CVD risk factors but not all, hs-CRP, VO2peak and AT were significantly improved after exercise intervention, while, changes of MMP-9, the size of AAA, and the overall lipids profile were not. Exercise intervention provides an additional solution for improving cardiorespiratory capacity and health status among AAA patients, and might lead to a delay of AAA progression.

Effects of cardiac rehabilitation on inflammatory biomarkers in unstable ischemic heart disease patients following percutaneous coronary intervention: a randomized controlled study

INTRODUCTION

Several blood inflammatory markers, such as high-sensitivity C-reactive protein (hs-CRP), neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR), are linked to increased risk for cardiovascular diseases. This study aimed to evaluate these inflammatory markers after cardiac rehabilitation (CR) in patients with unstable ischemic heart disease (UIHD) who underwent successful percutaneous coronary intervention (PCI).

METHODS

A cohort of 115 patients with successful PCI due to UIHD enrolled in the study from January 2018 to March 2021. We used a permuted block stratified randomization technique (2 : 1 ratio). Seventy-seven patients were randomized to the CR group and 38 patients to the control group. The CR group underwent a 12-week pre-specified CR regimen. Blood samples were taken at baseline and follow-up at 12 weeks for both groups.

RESULT

Among the 115 patients, 33 patients were female. The mean age was (53 ± 5.55 years) in the control and (53 ± 6.09 years) in the CR group. The two groups were comparable regarding their baseline characteristics and the values of the inflammatory markers. By contrast, at 12 weeks, the inflammatory marker values were significantly lower in the CR group compared to the control group; hs-CRP: 0.11 [0.08-0.14] vs. 0.21 [0.19-0.21], P -value <0.001; NLR: 2.17 [1.42-2.43] vs. 2.26 [2.07-2.6], P -value: 0.016; PLR: 91.2821 [63.3333-103.2000] vs. 92.600 [84.6154-110.0000], P -value: 0.027.

CONCLUSION

CR after PCI in UIHD patients may attenuate some inflammatory markers, which might benefit cardiovascular health. Further studies are required to evaluate these findings with longer follow-up and the powered to measure major cardiovascular event rates.

Comprehensive Cardiac Rehabilitation as a Therapeutic Strategy for Abdominal Aortic Aneurysm

Abdominal aortic aneurysms (AAA) are referred to as “time bombs”. The only way to prevent AAA rupture is elective repair beforehand using surgical replacement or an endovascular procedure. Non-surgical strategies to prevent AAA expansion are under intense investigation. At each AAA stage, that is, occurrence, expansion, and rupture, the mechanisms and risk factors are different, as discussed in this review. Based on the mechanism and risk factors for AAA expansion, the most effective strategy against AAA expansion need to be identified, but so far none has. Exercise is known to be essential for preventing atherosclerosis related to the coexistence of AAA and CAD, but some doctors are hesitant to prescribe exercise programs to AAA patients given that BP elevation during exercise can cause AAA expansion or rupture. In our retrospective study and prospective study on the safety and effectiveness of exercise for AAA patients, the protective role of mild-moderate exercise against expansion of small AAA was clearly shown. The stability of AAA on exercise might be related to reduced inflammatory activity in the aortic wall, stabilized elevation in BP during exercise, increased aortic blood flow, upregulation of transforming growth factor-β1, moderated BMI and/or fat, or improved endothelial function. Until a revolutionary drug emerges that can regress AAA, cardiac rehabilitation remains the best strategy for preventing AAA expansion and rupture.