Effects of Physical Prehabilitation on the Dynamics of the Markers of Endothelial Function in Patients Undergoing Elective Coronary Bypass Surgery

Transient changes in L-arginine, asymmetric and symmetric dimethyl arginine in triathletes following Norseman Xtreme Triathlon

Arterial vasodilation is dependent on nitric oxide synthesized from L-arginine by endothelial nitric oxide synthase. Triathletes are reported to display altered serum concentrations of nitric oxide metabolites such as L-arginine, asymmetric dimethyl arginine (ADMA) and symmetric dimethyl arginine (SDMA) shortly after completing long-distance triathlon races. In other populations, similar changes to nitric oxide metabolites are established risk markers of cardiovascular disease. The objective of this study was to assess serum concentrations of metabolites for endothelial nitric oxide synthesis in triathletes one week following a long-distance triathlon race. In this prospective observational study, we used high-performance liquid chromatography to measure circulating concentrations of L-arginine, ADMA, and SDMA in triathletes. Venous blood samples were collected before, immediately after, day one, and one week following the triathlon race. Serum concentrations and L-arginine/ADMA ratio were determined for each time-point and compared to baseline. L-arginine/ADMA ratio was reduced on day one (147 ± 32 vs 163 ± 40, p < 0.02). ADMA was reduced immediately after and increased at day one and remained elevated at one week (0.29 ± 0.05 μM, p < 0.001, 0.44 ± 0.08 μM, p < 0.001 and 0.42 ± 0.07 μM, p = 0.04, respectively vs 0.40 ± 0.05 μM). SDMA was increased at all time-points when compared to baseline (0.48 ± 0.10 μM, p < 0.001, 0.53 ± 0.11 μM, p < 0.001 and 0.42 ± 0.08 μM, p = 0.048 vs 0.38 ± 0.05 μM). L-arginine was only decreased immediately after (46.0 ± 9.3 μM vs. 64.6 ± 16.1 μM, p < 0.001). Long-distance triathlon racing induces altered levels of metabolites for endothelial nitric oxide production that mostly normalizes within one week following racing. The clinical relevance of these transient changes has yet to be elucidated in the athletic population.

Role of Angiopoietic Coronary Endothelial Dysfunction in the Pathogenesis of Ischemic Cardiomyopathy

BACKGROUND

The angiopoietic endothelial dysfunction in ischemic cardiomyopathy (ICMP) remains unexplored.

AIM

The identification of the imbalance of endothelial dysfunction mediators and the number of endothelial progenitor (EPC) and desquamated (EDC) cells in patients with coronary heart disease (CHD) with and without ICMP.

METHODS

A total of 87 patients (47 with ICMP and 40 without ICMP) were observed. The content of EPCs (CD14⁺CD34⁺VEGFR2⁺) in vein blood and EDCs (CD45^-CD146⁺) in the blood from the coronary sinus and cubital vein was determined by flow cytometry. The contents of HIF-1α and HIF-2α in vein blood as well as that of ADMA and endothelin-1 in sinus plasma and angiopoietin-2, MMP-9 and galectin-3 in both samples were assessed using ELISA, and VEGF, PDGF, SDF-1 and MCP-1 contents using immunofluorescence.

RESULTS

ADMA and endothelin-1 levels in the sinus blood were comparable between the patient groups; a deficiency of HIF-1α and excess of HIF-2α were detected in the vein blood of ICMP patients. The EDC content in the vein blood increased in CHD patients regardless of ICMP, and the concentrations of VEGF-A, VEGF-B, PDGF, MCP-1, angiopoietin-2, and MMP-9 were normal. In ICMP patients, vein blood was characterized by an excess of galectin-3 and sinus blood by an excess of EDCs, angiopoietin-2, MMP-9 and galectin-3.

CONCLUSION

ICMP is accompanied by angiopoietic endothelial dysfunction.

Prehabilitation in elective patients undergoing cardiac surgery: a randomised control trial (THE PrEPS TRIAL) - a study protocol

INTRODUCTION

Prehabilitation prior to surgery has been shown to reduce postoperative complications, reduce length of hospital stay and improve quality of life after cancer and limb reconstruction surgery. However, there are minimal data on the impact of prehabilitation in patients undergoing cardiac surgery, despite the fact these patients are generally older and have more comorbidities and frailty. This trial will assess the feasibility and impact of a prehabilitation intervention consisting of exercise and inspiratory muscle training on preoperative functional exercise capacity in adult patients awaiting elective cardiac surgery, and determine any impact on clinical outcomes after surgery.

METHODS AND ANALYSIS

PrEPS is a randomised controlled single-centre trial recruiting 180 participants undergoing elective cardiac surgery. Participants will be randomised in a 1:1 ratio to standard presurgical care or standard care plus a prehabilitation intervention. The primary outcome will be change in functional exercise capacity measured as change in the 6 min walk test distance from baseline. Secondary outcomes will evaluate the impact of prehabilitation on preoperative and postoperative outcomes including; respiratory function, health-related quality of life, anxiety and depression, frailty, and postoperative complications and resource use. This trial will evaluate if a prehabilitation intervention can improve preoperative physical function, inspiratory muscle function, frailty and quality of life prior to surgery in elective patients awaiting cardiac surgery, and impact postoperative outcomes.

ETHICS AND DISSEMINATION

A favourable opinion was given by the Sheffield Research Ethics Committee in 2019. Trial findings will be disseminated to patients, clinicians, commissioning groups and through peer-reviewed publication.

TRIAL REGISTRATION NUMBER

ISRCTN13860094.