Effects of acute exercise on hemorheological, endothelial, and platelet markers in patients with chronic heart failure in sinus rhythm

Intravascular cells and circulating microparticles induce procoagulant activity via phosphatidylserine exposure in heart failure

Relatively little information is known about the definitive role of phosphatidylserine (PS) in the hypercoagulability of heart failure (HF). Our objectives were to assess the levels of PS exposure on microparticles (MPs) and blood cells (BCs) in each group of HF patients and to evaluate their procoagulant activity (PCA). HF patients in each NYHA functional class II-IV (II n = 30, III n = 30, IV n = 30) and healthy controls (n = 25) were enrolled in the present study. PS exposure on MPs, BCs was analyzed with flow cytometry. MPs were classified based on their cellular origin: platelets (CD41a⁺), neutrophils (CD66b⁺), endothelial cells (CD31⁺CD41a^-), erythrocytes (CD235a⁺), monocytes (CD14⁺), T lymphocytes (CD3⁺), and B lymphocytes (CD19⁺). PCA was evaluated by clotting time, extrinsic/intrinsic FXa and prothrombinase production assays, as well as fibrin formation assays. Inhibition assays of PCA of PS⁺ BCs and MPs were performed by lactadherin. There was no significant difference in MP cellular origin between healthy and HF subjects. However, the total number of PS⁺ MPs was significantly increased in HF patients compared with healthy controls. In addition, circulating PS⁺ BCs cooperated with PS⁺ MPs to markedly shorten coagulation time and dramatically increase FXa/thrombin generation and fibrin formation in each HF group. Moreover, blockade of exposed PS on BCs and MPs with lactadherin inhibited PCA by approximately 80%. Our results lead us to believe that exposing PS on the injured BCs and MPs played a pivotal role in the hypercoagulability state in HF patients.

Effects of Physical (In)activity on Platelet Function

As platelet activation is closely related to the liberation of growth factors and inflammatory mediators, platelets play a central role in the development of CVD. Virtually all cardiovascular risk factors favor platelet hyperreactivity and, accordingly, also physical (in)activity affects platelet function. Within this paper, we will summarize and discuss the current knowledge on the impact of acute and habitual exercise on platelet function. Although there are apparent discrepancies regarding the reported effects of acute, strenuous exercise on platelet activation, a deeper analysis of the available literature reveals that the applied exercise intensity and the subjects' cardiorespiratory fitness represent critical determinants for the observed effects. Consideration of these factors leads to the summary that (i) acute, strenuous exercise can lead to platelet activation, (ii) regular physical activity and/or physical fitness diminish or prevent platelet activation in response to acute exercise, and (iii) habitual physical activity and/or physical fitness also favorably modulate platelet function at physical rest. Notably, these effects of exercise on platelet function show obvious similarities to the well-recognized relation between exercise and the risk for cardiovascular events where vigorous exercise transiently increases the risk for myocardial infarction and a physically active lifestyle dramatically reduces cardiovascular mortality.

Effects of acute and chronic exercise in patients with essential hypertension: benefits and risks

The importance of regular physical activity in essential hypertension has been extensively investigated over the last decades and has emerged as a major modifiable factor contributing to optimal blood pressure control. Aerobic exercise exerts its beneficial effects on the cardiovascular system by promoting traditional cardiovascular risk factor regulation, as well as by favorably regulating sympathetic nervous system (SNS) activity, molecular effects, cardiac, and vascular function. Benefits of resistance exercise need further validation. On the other hand, acute exercise is now an established trigger of acute cardiac events. A number of possible pathophysiological links have been proposed, including SNS, vascular function, coagulation, fibrinolysis, and platelet function. In order to fully interpret this knowledge into clinical practice, we need to better understand the role of exercise intensity and duration in this pathophysiological cascade and in special populations. Further studies in hypertensive patients are also warranted in order to clarify the possibly favorable effect of antihypertensive treatment on exercise-induced effects.

Platelet activation in essential hypertension during exercise: pre- and post-treatment changes with an angiotensin II receptor blocker

BACKGROUND

Acute exercise may exert deleterious effects on the cardiovascular system through a variety of pathophysiological mechanisms, including increased platelet activation. However, the degree of exercise-induced platelet activation in untreated hypertensive (UH) individuals as compared with normotensive (NT) individuals has yet to be established. Furthermore, the effect of antihypertensive treatment on exercise-induced platelet activation in essential hypertension (EH) remains unknown.

METHODS

Study 1 consisted of 30 UH and 15 NT subjects. UH subjects who received treatment were included in study 2 and were followed-up after a 3-month treatment period with an angiotensin II receptor blocker (ARB; valsartan). Circulating monocyte-platelet aggregates (MPA) and platelet P-selectin were measured as platelet activation markers at baseline, immediately after a treadmill exercise test, and 10, 30, and 90 minutes later.

RESULTS

Maximal platelet activation was observed at 10 minutes after peak exercise in both groups. In UH subjects, MPA levels remained increased at 30 minutes after peak exercise, despite BP fall to baseline levels. MPA levels were significantly higher in UH subjects than NT subjects at maximal exercise and at 10 and 30 minutes of recovery. Post-treatment MPA levels increased significantly only at 10 minutes into recovery and were similar to those of NT subjects.

CONCLUSIONS

Acute high-intensity exercise exaggerates platelet activation in untreated patients with EH compared with NT individuals. Angiotensin II receptor blockade with adequate BP control greatly improves exercise-induced platelet activation in EH. Further studies are needed to clarify whether this phenomenon depends purely on BP lowering or benefits also from the pleiotropic effects of ARBs.

Effects of high-amount-high-intensity exercise on in vivo platelet activation: modulation by lipid peroxidation and AGE/RAGE axis

Physical activity is associated with cardiovascular risk reduction, but the effects of exercise on platelet activation remain controversial. We investigated the effects of regular high-amount, high intensity aerobic exercise on in vivo thromboxane (TX)-dependent platelet activation and plasma levels of platelet-derived proteins, CD40L and P-selectin, and whether platelet variables changes may be related to changes in high-density lipoprotein (HDL) and in the extent of oxidative stress and oxidative stress-related inflammation, as reflected by urinary isoprostane excretion and endogenous soluble receptor for advanced glycation end-products (esRAGE), respectively. Urinary excretion of 11-dehydro-TXB₂ and 8-iso-prostaglandin (PG)F(2α) and plasma levels of P-selectin, CD40L and esRAGE were measured before and after a eight-week standardised aerobic high-amount-high-intensity training program in 22 sedentary subjects with low-to-intermediate risk. Exercise training had a clear beneficial effect on HDL cholesterol (+10%, p=0.027) and triglyceride (-27%, p=0.008) concentration. In addition, a significant (p<0.0001) decrease in urinary 11-dehydro-TXB₂ (26%), 8-iso-PGF(2α) (21%), plasma P-selectin (27%), CD40L (35%) and a 61% increase in esRAGE were observed. Multiple regression analysis revealed that urinary 8-iso-PGF(2α) [beta=0.33, SEM=0.116, p=0.027] and esRAGE (beta=-0.30, SEM=31.3, p=0.046) were the only significant predictors of urinary 11-dehydro-TXB₂ excretion rate over the training period. In conclusion, regular high-amount-high-intensity exercise training has broad beneficial effects on platelet activation markers, paralleled and possibly associated with changes in the lipoprotein profile and in markers of lipid peroxidation and AGE/RAGE axis. Our findings may help explaining why a similar amount of exercise exerts significant benefits in preventing cardiovascular events.

Altered arterial stiffness and subendocardial viability ratio in young healthy light smokers after acute exercise

BACKGROUND

Studies showed that long-standing smokers have stiffer arteries at rest. However, the effect of smoking on the ability of the vascular system to respond to increased demands (physical stress) has not been studied. The purpose of this study was to estimate the effect of smoking on arterial stiffness and subendocardial viability ratio, at rest and after acute exercise in young healthy individuals.

METHODS/RESULTS

Healthy light smokers (n = 24, pack-years = 2.9) and non-smokers (n = 53) underwent pulse wave analysis and carotid-femoral pulse wave velocity measurements at rest, and 2, 5, 10, and 15 minutes following an exercise test to exhaustion. Smokers were tested, 1) after 12h abstinence from smoking (chronic condition) and 2) immediately after smoking one cigarette (acute condition). At rest, chronic smokers had higher augmentation index and lower aortic pulse pressure than non-smokers, while subendocardial viability ratio was not significantly different. Acute smoking increased resting augmentation index and decreased subendocardial viability ratio compared with non-smokers, and decreased subendocardial viability ratio compared with the chronic condition. After exercise, subendocardial viability ratio was lower, and augmentation index and aortic pulse pressure were higher in non-smokers than smokers in the chronic and acute conditions. cfPWV rate of recovery of was greater in non-smokers than chronic smokers after exercise. Non-smokers were also able to achieve higher workloads than smokers in both conditions.

CONCLUSION

Chronic and acute smoking appears to diminish the vascular response to physical stress. This can be seen as an impaired 'vascular reserve' or a blunted ability of the blood vessels to accommodate the changes required to achieve higher workloads. These changes were noted before changes in arterial stiffness or subendocardial viability ratio occurred at rest. Even light smoking in young healthy individuals appears to have harmful effects on vascular function, affecting the ability of the vascular bed to respond to increased demands.

The effects of maximal treadmill graded exercise testing on haemorheological, haemodynamic and flow cytometry platelet markers in patients with systolic or diastolic heart failure

BACKGROUND

Acute exercise has been associated with activation of thrombosis, and this risk may be accentuated in patients with heart failure. Given the relation of platelets to atherothrombosis, we tested the hypothesis that acute exercise would adversely affect platelet indices and platelet activation markers in patients with systolic and diastolic heart failure.

MATERIALS AND METHODS

We studied 20 patients with systolic heart failure (17 men, 3 women; mean age 64 +/- 10 years, all with ejection fraction (EF) < or = 40%) and 20 patients with diastolic heart failure (14 men, 6 women; mean age 64 +/- 8 years, mean EF = 66%) who were exercised to maximal intensity, who were compared to 13 healthy controls (6 men, 7 women; mean age 60 +/- 4 years, mean EF = 73%). We measured platelet indices (platelet volume, mass and component) and platelet activation markers (platelet-bound CD62P%G, CD63%G and CD40L%G using flow cytometry, as well as plasma sCD40L and soluble P-selectin (sP-sel) levels).

RESULTS

Baseline Mean Platelet Volume (MPV), sP-sel, CD40L%G and CD63%G levels were significantly higher in patients with systolic and diastolic heart failure, when compared with controls. The mean exercise duration and VO(2 )peak in patients with systolic and diastolic heart failure were not significantly different, but lower than that seen in healthy controls. Following exercise, mean haematocrit, CD62P%G, and CD63%G significantly increased in all three subject groups (all P < 0.05). The proportional change in CD62P%G and CD63%G were not significantly different between healthy controls and heart failure patients (P > 0.05).

CONCLUSION

Acute maximal graded exercise increases platelet activation markers, with no disproportionate differences between heart failure patients and healthy controls, despite the former group having a lower exercise tolerance and VO2 peak.

Exercise induced von Willebrand Factor release -- new model for routine endothelial testing

Endothelial dysfunction (ED) is actively involved in the mechanism of occurrence, development and progression of all the degrees of atherosclerosis. The established impact of ED on the progress and outcome of cardiovascular diseases, together with convincing indications of a possible successful therapeutic modification, necessitate the changeover of ED assessment from experimental to a routine practice. As there is no appropriate method for a clinical practice, scientists anticipate significant research efforts in the further development. Among numerous methods already available, von Willebrand Factor (vWF) stands out significantly. In accordance with the accepted leading diagnostic role of vWF baseline levels in the group of peripheral endothelial markers, and earlier scientific observations on the absence of its expected reactivation during physical exercise, we hypothesised this promising theory. We believe that a constant stronger release of vWF in endothelial cell injury leads to the exhaustion of its stores in Weibel-Palade bodies with the consequent absence of the expected rise of concentration during the exercise. Therefore, we hypothesised that ED could be exhaustible vWF endothelopathy and the exercise induced release of vWF a new, simple, safe and reliable test for the detection of ED and monitoring of the expected therapeutic effect. In order to have a final clinical usability of the proposed diagnostic model, it is necessary to test its reliability in different pathological and risk states, and establish susceptibility in therapeutic procedures. The correlation with invasive functional angiographic tests and the flow mediated dilatation test of peripheral arteries also needs to be validated. We expect the proposed test of vWF inducibility to find its place in clinical practice, i.e. in prevention, prediction and therapy of cardiovascular diseases.

A systematic review of the effects of acute psychological stress and physical activity on haemorheology, coagulation, fibrinolysis and platelet reactivity: Implications for the pathogenesis of acute coronary syndromes

Physical activity and psychological stress are two potential triggers for the onset of acute coronary syndromes (ACS). To examine the mechanisms underlying this association, we systematically reviewed the literature to determine the effects of acute psychological stress and physical activity on haemorheology and haemostasis. Studies examining the haemorheological and haemostatic response to an acute bout of physical activity (i.e. <60 min) or laboratory psychological stress task were eligible for inclusion. The experimental evidence, although compromised by various methodological weaknesses, suggests that low and moderate intensity physical activity may be cardio-protective through beneficial effects on fibrinolytic system. High levels of physical activity, and psychological to a lesser extent, have been consistently associated with robust changes in haemorheology and haemostasis. Such findings imply that such activities may have the potential to trigger the onset of ACS, although in reality this may be limited sedentary individual and/or those with pre-existing vascular disease. In addition, the data also suggest that individuals may be at a greatest risk of stress-induced thrombogenesis in the period immediately following physical activity or psychological stress, rather than during the activity per se. In conclusion, psychological stress and physical activity may act as potential triggers for the onset of ACS via effects on haemostasis and haemorheology.

Role of clotting factors and fibrin structure in predisposition to atherothrombotic disease

Atherothrombotic disease is a multifactorial disorder that develops secondary to a complex gene-environment interaction. The formation of an obstructive thrombus represents the final stage of the atherothrombotic process, and understanding the mechanisms involved in clot formation is essential in order to develop new preventive and therapeutic strategies aimed at decreasing mortality and morbidity from the disease. Studies have demonstrated an important correlation between final clot structure and predisposition to atherothrombotic disease. Both genetic and environmental factors contribute to the final ultrastructure of the clot, which, in turn, influences an individual's risk of the disease. This paper reviews the factors involved in determining clot structure. The role of commonly used therapeutic agents in modulating clot structure will also be discussed.

Exercise and the endothelial cell

Regular exercise is known to be effective in the prevention and treatment of cardiovascular disease. Among the cardioprotectant mechanisms influenced by exercise, the endothelium is becoming recognised as a major target. Preservation of endothelial cell structure is vital for frictionless blood flow, prevention of macrophage and lipid infiltration and, ultimately, optimal vascular function. Exercise causes various kinds of mechanical, chemical and thermal stresses, and repeated exposure to these stresses may precondition the endothelial cell to future stresses through a number of different mechanisms. This review discusses stress-induced changes in endothelial cell morphology, biochemistry and components of platelet activation and cell adhesion that impact on endothelial cell structure. An enhanced understanding of the effects of exercise on the endothelial cell will assist in directing future research into the prevention of cardiovascular disease.

Aggregation and Activation of Blood Platelets in Exercise and Training

This article presents an overview of the progress that has been made in recent years in our understanding of the interaction between exercise and platelets in health and disease. Although platelets are important in normal haemostasis, recent evidence emphasises the pivotal role of abnormal platelet function in acute coronary artery diseases, myocardial infarction, unstable angina and stroke. In light of the positive health benefits of exercise, interest has been heightened on the association between exercise and platelet aggregation and function, not only in normal healthy subjects but also in patients. However, the study of exercise effects on blood platelets are highly contentious because of the fact that the analytical methods employed to study platelets are bedevilled by numerous methodological problems. While exercise effects on platelet aggregation and function in healthy individuals have been extensively examined, the evidence reported has been conflicting. Somewhat less contradictory are the results generated from studies in patients with coronary heart disease, as the preponderance of evidence available would strongly suggest that platelet aggregation and function are increased with exercise. Several drugs are known to influence platelet aggregation and function, the most examined among these medications is aspirin (acetylsalicylic acid). However, aspirin appears to be ineffective to attenuate exercise-induced increases in platelet aggregation and activation. Few studies are available on the effect of training on blood platelets and the exact effects of exercise training on platelet activation and function is not as yet known. This lack of information makes further studies particularly important, in order to clarify whether there are favourable effects of exercise training on platelet aggregation and function in health and disease.

Endothelial markers in chronic heart failure: training normalizes exercise-induced vWF release

BACKGROUND

Chronic heart failure (CHF) is characterized by endothelial dysfunction. Vascular endothelium is important for control of haemostasis and vasoregulation. The aim of the present study was to investigate plasma levels of several endothelial markers and the exercise-induced changes on these plasma levels in CHF patients. Subsequently, the effect of a 6-month training programme on these markers is described.

MATERIALS AND METHODS

Twenty-nine male CHF patients (NYHA II/III, age 60 +/- 8 year, body mass index 26.7 +/- 2.3 kg m(-2), left ventricular ejection fraction 26.3-7.2%; mean +/- SD) participated. Patients were randomly assigned to a training or control group. Training (26 weeks; combined strength and endurance exercises) was four sessions/week: two sessions supervised and two sessions at home. Before and after intervention, anthropometry, endothelial markers (haemostasis and vasoregulation), maximal workload and peak oxygen uptake were assessed.

RESULTS

Physical training positively affected maximal workload. Plasma levels of endothelial markers were not affected by physical training and not related to exercise tolerance. After training, stimulated (maximal exercise) plasma von Willebrand Factor (vWF) release was present, whereas at baseline this release was absent.

CONCLUSION

Physical training led to normalization of the stimulated plasma vWF release. Plasma levels of other endothelial markers were not affected by physical training either at rest or under stimulated (maximal exercise) conditions.

Exercise and Training Effects on Blood Haemostasis in Health and Disease

In recent years, the dysfunction of the haemostatic system in relation to the clinical complications from arterioscleroses and cardiovascular diseases has become more recognised. Blood coagulation and fibrinolysis comprise two important physiological systems, which are regulated by a balance between activators and inhibitors. Activation of blood coagulation is associated with accelerated clot formation, whereas activation of blood fibrinolysis enhances the breakdown of the blood clot. Available evidence suggests that strenuous exercise induces activation of blood coagulation with simultaneous enhancement of blood fibrinolysis. Although the responses of blood coagulation and fibrinolysis appear to be related to the exercise intensity and its duration, recent reports suggest that moderate exercise intensity is followed by activation of blood fibrinolysis without concomitant hyper-coagulability, while very intense exercise is associated with concurrent activation of blood coagulation and fibrinolysis. Similar to blood coagulation and fibrinolysis, systemic platelet-related thrombogenic factors have been shown to be involved in the initiation and progression of atherogenesis and plaque growth. Although exercise effects on platelet aggregation and function in healthy individuals have been examined, the results reported have been conflicting. However, for patients with coronary heart disease, the balance of evidence available would strongly suggest that platelet aggregation and functions are increased with exercise. Few studies are available concerning the influence of training on blood coagulation and fibrinolysis and the exact effects of exercise training on the equilibrium between blood coagulation and fibrinolysis is not as yet known. Although the effects of physical training on platelets have been briefly investigated, available meagre evidence suggests that exercise training is associated with favourable effects on platelet aggregation and activation in both men and women.