Cardiac rehabilitation-mediated molecular mechanisms of cardiovascular protection

Endothelial glycocalyx damage as a systemic inflammatory microvascular endotheliopathy in COVID-19

In atherosclerosis patients, vascular endothelial dysfunction is commonly observed alongside damage of the vascular endothelial glycocalyx, an extracellular matrix bound to and encapsulating the endothelial cells lining the blood vessel wall. Although atherosclerotic risk factors have been reported in severe patients with coronavirus disease 2019 (COVID-19), the exact mechanisms are unclear. The mortality associated with the COVID-19 outbreak is increased by comorbidities, including hypertension, diabetes, obesity, chronic obstructive pulmonary disease (COPD), and cardiovascular disease. Besides, older individuals and smokers have significantly worse outcomes. Interestingly, these comorbidities and risk factors are consistent with the pathophysiology that causes vascular endothelial glycocalyx damage. Moreover, vascular glycocalyx dysfunction causes microvascular leakage, which results in interstitial pulmonary abnormal shadows (multiple patchy shadows with a ground glass inter-pneumonic appearance). This is frequently followed by severe acute respiratory distress syndrome (ARDS), closely related to coagulo-fibrinolytic changes contributing to disseminated intravascular coagulation (DIC) and Kawasaki disease shock syndrome, as well as inducing activation of the coagulation cascade, leading to thromboembolism and multiple organ failure. Notably, SARS-CoV-2, the causative virus of COVID-19, binds to ACE2, which is abundantly present not only in human epithelia of the lung and the small intestine, but also in vascular endothelial cells and arterial smooth muscle cells. Moreover, COVID-19 can induce severe septic shock, and sepsis can easily lead to systemic degradation of the vascular endothelial glycocalyx. In the current review, we propose new concepts and therapeutic goals for COVID-19-related vascular endothelial glycocalyx damage, based on previous vascular endothelial medicine research.

Cardiac rehabilitation in patients with peripheral arterial disease after revascularization

OBJECTIVES

To evaluate safety, feasibility, and benefit of cardiac rehabilitation (CR) in patients with peripheral arterial disease (PAD) who undergo revascularization.

METHODS

We conducted a prospective, non-randomized, pilot study to assess the feasibility, safety, and benefit of CR in PAD patients after revascularization compared to standard of care (controls). CR feasibility was assessed by the ability to complete 36 sessions. Safety was defined as the absence of adverse cardiovascular events during CR. Quality of life (QoL) assessment was performed using SF-36 form (Medical Outcomes Study 36-Item Short-Form Health Survey) and PAD-specific quality of life questionnaire (VascuQOL6). Other endpoints included incidence of claudication during 6-minute walk test (6MWT), mean distance, and number of laps walked. All outcome data were collected before and after CR completion. Standard statistical tests were used for comparisons.

RESULTS

This study enrolled 20 subjects (CR group = 10). Mean age was 60.70 (±7.13) and 63.1 (±9.17) years in CR and controls, respectively (p-value > 0.05). Fifty percent and 60% were female in CR and control group, respectively. All subjects completed 36 CR sessions without adverse events. The increase in mean distance walked during 6MWT was higher in the CR group compared to control group (63.7 m vs. 10.5 m, p = 0.043). Change in mean number of laps walked was higher in the CR group (3.5 vs. -1.1; p < 0.01). Scores on 6 of 8 scales of SF-36 and VascuQOL6 were higher in the CR group, though not statistically significant.

CONCLUSION

CR is safe, feasible, and improves walking ability in ambulatory patients with PAD after arterial revascularization.