Impact of Exercise on Cerebrovascular Physiology and Risk of Stroke

The structural and functional aspects of exercise-induced cardiac remodeling and the impact of exercise on cardiovascular outcomes

The relationship between exercise training and overall cardiovascular health is well defined, with associated reductions in incidence of cardiovascular disease and comorbidities such as hypertension, diabetes mellitus, cholesterol profile, body weight, and even some forms of cancer. In this regard, an exercise prescription is an effective tool to decrease all-cause mortality and improve overall health. As providers, properly educating patients on the type, amount, and intensity of exercise is important to ensure patients meet recommended exercise metrics to experience these health benefits. This review provides a concise, but comprehensive overview of the structural and functional aspects of exercise-induced cardiac remodeling, current recommended guidelines for exercise with supporting data, as well as the impact exercise has on various cardiovascular outcomes.

Physical activity, genetic predisposition, and incident cardiovascular disease: Prospective analyses of the UK Biobank

BACKGROUND

It is unclear whether physical activity can benefit participants with high genetic predisposition to cardiovascular disease. We examined the joint associations of intensity-specific physical activity and genetic predisposition (based on polygenetic risk score) with incident coronary heart disease (CHD), stroke, and atrial fibrillation (AF).

METHODS

This prospective cohort study included 303,950 adults (age = 56.4 ± 8.0 years, mean ± SD; 52.5% females) from the UK Biobank with physical activity and disease-related genotypes. Moderate-to-vigorous physical activity (MVPA) and intensity-specific activity was classified according to volume (e.g., MVPA was classified as none, low, medium, and high). Genetic predisposition for CHD, stroke, and AF were classified as low (Quintile 1), intermediate (Quintiles 2-4), and high (Quintile 5).

RESULTS

During 11.6 ± 2.1 years of follow-up: 19,865 CHD; 7907 stroke; and 16,688 AF events occurred. Compared to the no MVPA and high genetic risk group, we observed lower CHD risk for increasing levels of MVPA over and above genetic risk groupings. These associations were primarily driven by vigorous-intensity activity. For example, in the high genetic risk group, those with low vigorous-intensity activity levels (compared to none) had a hazard ratio (HR) of 0.78 (95% confidence interval (95%CI):0.72-0.86) compared to an HR of 0.90 (95%CI: 0.83-0.98) for low moderate-intensity activity levels. For stroke incidence, we observed a protective association for MVPA across genetic risk groups that was mostly driven by moderate-intensity activity volume. Among the high genetic risk group, low moderate-intensity had an HR of 0.77 (95%CI:0.66-0.90), whereas low vigorous-intensity had no association (HR = 0.95, 95%CI:0.82-1.09). We did not observe a consistent joint association of MVPA and AF genetic predisposition.

CONCLUSIONS

We observed lower CHD and stroke risk for low to high MVPA among participants with high genetic predisposition. The associations of moderate- and vigorous-intensity activity volume differed considerably across cardiovascular disease sub-types. Overall, our findings suggest vigorous intensity activity may mitigate genetic predisposition for CHD while moderate intensity activity may be associated with similar effects for stroke. Joint associations were less consistent across AF genetic predisposition groups. Our results inform precision medicine approaches and future lifestyle modification interventions by quantifying the potential benefits of physical activity among at-risk individuals.

Physical Activity Habits and Incident First-Ever Stroke in Middle-Aged Adults-A Prospective Cohort Study

BACKGROUND

Lifestyle affects the risk of cardiovascular events such as myocardial infarction and stroke. Several lifestyle factors, such as physical activity (PA), are modifiable, and in this study, we examined the association between leisure-time PA habits and the risk of a first-ever stroke.

METHODS

This prospective study included residents in Västerbotten, Sweden, who participated in the Västerbotten Intervention Programme at 40, 50, and 60 years of age. Altogether, 31,855 individuals (50.5% women, mean age: 42.6 [6.9] y at baseline) participated between 1989 and 2016. Leisure-time PA was categorized as irregular (never/now and then) or regular (once a week/2 or 3 times a week/more than 3 times a week). Changes in PA were compared between examinations (10 y apart). Cases of stroke were validated according to World Health Organization MONICA (Monitoring Trends and Determinants of Cardiovascular Disease) criteria. The risk related to changes in leisure-time PA was estimated using a multivariable Cox regression model.

RESULTS

During an average follow-up of 9.8 years (4.4), 609 incident first-ever stroke cases occurred (1.9%). A multivariable model showed that, compared with individuals with irregular PA at both examinations, those reporting regular PA over time had a lower risk of stroke (hazard ratio: 0.78, 95% CI, 0.61-0.99).

CONCLUSION

Middle-aged adults who maintained regular PA during their leisure time over 10 years had a lower risk of a first-ever stroke. This association is probably partly mediated by lower body mass index and a reduced risk of hypertension and diabetes.

Comparing the impact of cumulative insulin resistance surrogates exposure on stroke: optimizing prevention strategies

BACKGROUND

Insulin resistance (IR) plays a major role in increasing the risk of stroke. The objective of this research is to systematically evaluate and compare the impact of cumulative exposure over time to four commonly used IR surrogates-triglyceride-glucose (CumTyG) index, metabolic score for IR (CumMetS-IR), estimated glucose disposal rate (CumeGDR) and triglyceride to high-density lipoprotein cholesterol (CumTG/HDL-C) ratio-on stroke risk, providing insights for optimizing monitoring strategies for primary stroke prevention.

METHODS

The study population was sourced from the China Health and Retirement Longitudinal Study (CHARLS2011-2018). Cumulative exposure to IR (CumIR) surrogates was calculated as the mean value of IR surrogates measured in the first and third waves of CHARLS, multiplied by the total exposure duration. The primary endpoint was incident stroke, determined through questionnaires in the third and fourth waves of CHARLS. Multivariable Cox regression models were applied to estimate and compare HRs and 95% CIs for stroke across quartiles of CumIR surrogates.

RESULTS

A total of 4,669 participants with no history of stroke at baseline were included. During a median follow-up of 6 years, 347 new stroke events (7.43%) were recorded. The incidence rates of stroke in the highest quartiles of CumTyG index, CumTG/HDL-C ratio, and CumMetS-IR, as well as the lowest quartile of CumeGDR, were 9.67%, 9.93%, 10.45%, and 13.02%, respectively. In terms of risk assessment, the multivariable Cox regression analysis showed that the highest quartiles of CumTyG index, CumTG/HDL-C ratio, and CumMetS-IR and the lowest quartile of CumeGDR were associated with stroke risk, with corresponding HR (95% CI) of 1.48(1.05-2.10), 1.61(1.15-2.24), 1.72(1.21-2.43), and 3.57(2.25-5.68), respectively. In terms of event prediction, receiver operating characteristic analysis revealed that CumeGDR had the highest predictive accuracy for incident stroke compared with other common IR surrogates.

CONCLUSIONS

In assessing stroke risk and predicting events in middle-aged and elderly populations, cumulative exposure to eGDR demonstrates significant advantages over other common IR surrogates. Incorporating eGDR as an IR monitoring marker is recommended for primary stroke prevention.

Improving effect of physical exercise on heart failure: Reducing oxidative stress-induced inflammation by restoring Ca2+ homeostasis

Heart failure (HF) is associated with the occurrence of mitochondrial dysfunction. ATP produced by mitochondria through the tricarboxylic acid cycle is the main source of energy for the heart. Excessive release of Ca2+ from myocardial sarcoplasmic reticulum (SR) in HF leads to excessive Ca2+ entering mitochondria, which leads to mitochondrial dysfunction and REDOX imbalance. Excessive accumulation of ROS leads to mitochondrial structure damage, which cannot produce and provide energy. In addition, the accumulation of a large number of ROS can activate NF-κB, leading to myocardial inflammation. Energy deficit in the myocardium has long been considered to be the main mechanism connecting mitochondrial dysfunction and systolic failure. However, exercise can improve the Ca2+ imbalance in HF and restore the Ca2+ disorder in mitochondria. Similarly, exercise activates mitochondrial dynamics to improve mitochondrial function and reshape intact mitochondrial structure, rebalance mitochondrial REDOX, reduce excessive release of ROS, and rescue cardiomyocyte energy failure in HF. In this review, we summarize recent evidence that exercise can improve Ca2+ homeostasis in the SR and activate mitochondrial dynamics, improve mitochondrial function, and reduce oxidative stress levels in HF patients, thereby reducing chronic inflammation in HF patients. The improvement of mitochondrial dynamics is beneficial for ameliorating metabolic flow bottlenecks, REDOX imbalance, ROS balance, impaired mitochondrial Ca2+ homeostasis, and inflammation. Interpretation of these findings will lead to new approaches to disease mechanisms and treatment.

Clinical Considerations for Competitive Sports Participation for Athletes With Cardiovascular Abnormalities: A Scientific Statement From the American Heart Association and American College of Cardiology

COLLABORATORS

Larry A. Allen, MD, MHS, FAHA, FACC; Mats Börjesson, MD, PhD, FACC; Alan C. Braverman, MD, FACC; Julie A. Brothers, MD; Silvia Castelletti, MD, MSc, FESC; Eugene H. Chung, MD, MPH, FHRS, FAHA, FACC; Timothy W. Churchill, MD, FACC; Guido Claessen, MD, PhD; Flavio D'Ascenzi, MD, PhD; Douglas Darden, MD; Peter N. Dean, MD, FACC; Neal W. Dickert, MD, PhD, FACC; Jonathan A. Drezner, MD; Katherine E. Economy, MD, MPH; Thijs M.H. Eijsvogels, PhD; Michael S. Emery, MD, MS, FACC; Susan P. Etheridge, MD, FHRS, FAHA, FACC; Sabiha Gati, BSc (Hons), MBBS, PhD, MRCP, FESC; Belinda Gray, BSc (Med), MBBS, PhD; Martin Halle, MD; Kimberly G. Harmon, MD; Jeffrey J. Hsu, MD, PhD, FAHA, FACC; Richard J. Kovacs, MD, FAHA, MACC; Sheela Krishnan, MD, FACC; Mark S. Link, MD, FHRS, FAHA, FACC; Martin Maron, MD; Silvana Molossi, MD, PhD, FACC; Antonio Pelliccia, MD; Jack C. Salerno, MD, FACC, FHRS; Ankit B. Shah, MD, MPH, FACC; Sanjay Sharma, BSc (Hons), MBChB, MRCP (UK), MD; Tamanna K. Singh, MD, FACC; Katie M. Stewart, NP, MS; Paul D. Thompson, MD, FAHA, FACC; Meagan M. Wasfy, MD, MPH, FACC; Matthias Wilhelm, MD.

This American Heart Association/American College of Cardiology scientific statement on clinical considerations for competitive sports participation for athletes with cardiovascular abnormalities or diseases is organized into 11 distinct sections focused on sports-specific topics or disease processes that are relevant when considering the potential risks of adverse cardiovascular events, including sudden cardiac arrest, during competitive sports participation. Task forces comprising international experts in sports cardiology and the respective topics covered were assigned to each section and prepared specific clinical considerations tables for practitioners to reference. Comprehensive literature review and an emphasis on shared decision-making were integral in the writing of all clinical considerations presented.

Clinical Considerations for Competitive Sports Participation for Athletes With Cardiovascular Abnormalities: A Scientific Statement From the American Heart Association and American College of Cardiology

This American Heart Association/American College of Cardiology scientific statement on clinical considerations for competitive sports participation for athletes with cardiovascular abnormalities or diseases is organized into 11 distinct sections focused on sports-specific topics or disease processes that are relevant when considering the potential risks of adverse cardiovascular events, including sudden cardiac arrest, during competitive sports participation. Task forces comprising international experts in sports cardiology and the respective topics covered were assigned to each section and prepared specific clinical considerations tables for practitioners to reference. Comprehensive literature review and an emphasis on shared decision-making were integral in the writing of all clinical considerations presented.

Association Between Leisure-Time Physical Activity and All-Cause Mortality Among Stroke Survivors: Findings From National Health and Nutrition Examination Survey

BACKGROUND

Stroke is the second leading cause of death and the third leading cause of disability globally. But little is known about the optimal level of physical activity for stroke survivors. Therefore, we aimed to analyze the dose-response relationship between leisure-time physical activity (LTPA) and all-cause mortality in stroke survivors.

METHODS

One-thousand six hundred and sixty-four stroke survivors form from the 1999 to 2018 National Health and Nutrition Examination Surveys were classified into 6 groups: 0, 1 to 149, 150 to 299, 300 to 599, 600 to 899, and ≥900 minutes per week (based on the Global Physical Activity Questionnaire). Cox proportional hazards regression models with different adjustments of covariates were used to investigate the association between LTPA and all-cause mortality.

RESULTS

Except for stroke survivors with LTPA levels ranging from 600 to 899 minutes per week (P = .055), there was a significant difference in survival rates among stroke survivors with different levels of LTPA compared with those without LTPA. Stroke survivors engaging in LTPA levels exceeding 900 minutes per week exhibited the greatest benefit compared with stroke survivors who did not engage in LTPA (hazard ratio = 0.225; 95% confidence interval, 0.122-0.414).

CONCLUSIONS

Our research findings add to the expanding evidence base that highlights the favorable connection between LTPA and decreased risk of all-cause mortality among individuals who have survived a stroke. Our study emphasizes the significance of incorporating physical activity interventions into the poststroke care regimen and underscores the potential advantages of personalized activity guidance.

Exercise-Intervened Circulating Extracellular Vesicles Alleviate Oxidative Stress in Cerebral Microvascular Endothelial Cells Under Hypertensive Plus Hypoxic Conditions

Our group has recently demonstrated that exercise intervention affects the release and function of bone marrow endothelial progenitor cell-derived extracellular vesicles (EVs) in transgenic hypertensive mice. Whether such an exercise regimen can impact circulating EVs (cEVs) remains unknown. In this study, we investigated the influence of exercise on cEV level and function. Transgenic hypertensive mice (Alb1-Ren) underwent 8-week treadmill exercise (10 m/min for 1 h, 5 days per week). Age- and sex-matched sedentary Alb1-Ren mice served as controls. cEVs were isolated from the blood of exercised and sedentary mice and are denoted as ET-cEV and nET-cEV, respectively. cEVs were labeled to determine their uptake efficiency and pathways. The functions of cEVs were assessed in an Angiotensin II (Ang II) plus hypoxia-injured cerebral microvascular endothelial cell (mBMEC) injury model. Cellular migration ability and oxidative stress were evaluated. We found that treadmill exercise stimulated cEV release, and ET-cEVs were more prone to be internalized by mBMECs. The ET-cEV internalization was mediated by macropinocytosis and endocytosis pathways. Functional studies showed that ET-cEVs can improve the compromised migration capability of mBMECs challenged by Ang II plus hypoxia. Additionally, ET-cEV treatment upregulated the expression of p-Akt/Akt in mBMECs. Compared to nET-cEVs, ET-cEVs significantly reduced ROS overproduction in Ang II plus hypoxia-injured mBMECs, associated with decreased Nox2 expression. All these findings suggest that exercise-intervened cEVs can protect cerebral microvascular endothelial cells against hypertensive and hypoxic injury.

Exercise Testing in Elite Athletes

Exercise testing is frequently incorporated into management of patients with cardiovascular and/or pulmonary disease. A lifelong commitment to exercise promotes cardiac remodeling, leading to changes in structure and function of the atria and ventricles, commonly referred to as the "athletic heart." Stress testing is also incorporated into the management of athletes for a variety of reasons, such as identifying the cause of exertional symptoms, determining level of fitness and training zones, or assessing for acquired cardiomyopathies. Exercise testing should be tailored to the athlete, since performance may vary from other populations as a result of a commitment to exercise training.

Characteristics and Treatment of Exercise Intolerance in Patients With Long COVID

The post-acute sequalae of SARS-CoV-2, also known as "Long COVID," is characterized by profound fatigue, impaired functional capacity with post-exertional malaise, orthostatic intolerance, and tachycardia. At least 25-30% of individuals impacted by SARS-CoV-2 will go on to experience the Long COVID syndrome, underscoring the detrimental impact this condition has on society. Although efforts are underway to further understand risk factors for Long COVID and identify strategies to prevent disease development entirely, implementation of treatment strategies is warranted to alleviate symptom burden among those affected. This review provides a rationale for exercise prescriptions tailored to the Long COVID patient based on the pathophysiology underlying this syndrome, as well as the previously demonstrated benefits of exercise training in other similar populations whose clinical manifestations result from cardiac deconditioning. Herein, we discuss methods to tailor exercise protocols, accommodating exercise intolerance and post-exertional malaise that may otherwise limit the ability to participate in a training protocol, as well as data demonstrating that a focused exercise prescription may effectively alleviate symptom burden in these patients. Long COVID results, in large part, from deconditioning, which may result from as little as 20 hr of inactivity. Exercise prescriptions tailored to patients with Long COVID may effectively alleviate symptom burden associated with this condition and in the absence of overt contraindications should be considered in management.

Improved cardiorespiratory fitness is associated with lower incident ischemic stroke risk: Henry Ford FIT project

BACKGROUND

Change in cardiorespiratory fitness (CRF) modulates vascular disease risk; however, it's unclear if this adds further prognostic information, particularly for ischemic stroke. The objective of this analysis is to describe the association between the change in CRF over time and subsequent incident ischemic stroke.

METHODS

This is a retrospective, longitudinal, observational cohort study of 9,646 patients (age=55±11 years; 41% women; 25% black) who completed 2 clinically indicated exercise tests (> 12 months apart) and were free of any stroke at the time of test 2. CRF was expressed as metabolic-equivalents-of-task (METs). Incident ischemic stroke was identified using ICD codes. The adjusted hazard ratio (aHR) was determined for risk of ischemic stroke associated with change in CRF.

RESULTS

Mean time between tests was 3.7 years (IQR, 2.2, 6.0). During a median of 5.0 years (IQR, 2.7, 7.6 y) of follow-up, there were 873 (9.1%) ischemic stroke events. Each 1 MET increase between tests was associated with a 9% lower ischemic stroke risk (aHR 0.91 [0.88-0.94]; n = 9.646). There was an interaction effect by baseline CRF category, but not for sex or race. A sensitivity analysis which removed those who experienced an incident diagnosis known to be associated with an increased risk of ischemic vascular disease, validated our primary findings (aHR 0.91 [0.88, 0.95]; n= 6,943).

CONCLUSIONS

Improvement in CRF over time is independently and inversely associated with a lower risk of ischemic stroke. Encouragement of regular exercise focused on improving CRF may reduce ischemic stroke risk.

Emerging roles of ferroptosis in cardiovascular diseases

The mechanism of cardiovascular diseases (CVDs) is complex and threatens human health. Cardiomyocyte death is an important participant in the pathophysiological basis of CVDs. Ferroptosis is a new type of iron-dependent programmed cell death caused by excessive accumulation of iron-dependent lipid peroxides and reactive oxygen species (ROS) and abnormal iron metabolism. Ferroptosis differs from other known cell death pathways, such as apoptosis, necrosis, necroptosis, autophagy and pyroptosis. Several compounds have been shown to induce or inhibit ferroptosis by regulating related key factors or signalling pathways. Recent studies have confirmed that ferroptosis is associated with the development of diverse CVDs and may be a potential therapeutic drug target for CVDs. In this review, we summarize the characteristics and related mechanisms of ferroptosis and focus on its role in CVDs, with the goal of inspiring novel treatment strategies.