Physical activity and physiological cardiac remodelling in a community setting: the Multi-Ethnic Study of Atherosclerosis (MESA)

Associations Between Sedentary Time, Physical Activity, and Cardiovascular Health in 6-Year-Old Children Born to Mothers With Increased Cardiometabolic Risk

PURPOSE

To assess associations between sedentary time (ST), physical activity (PA), and cardiovascular health in early childhood.

METHOD

Cross-sectional study including 160 children (age 6.1 y [SD 0.5], 86 boys, 93 maternal body mass index ≥ 30 kg/m2, and 73 gestational diabetes) assessed for pulse wave velocity, echocardiography, ultra-high frequency 48-70 MHz vascular ultrasound, and accelerometery.

RESULTS

Boys had 385 (SD 53) minutes per day ST, 305 (SD 44) minutes per day light PA, and 81 (SD 22) minutes per day moderate to vigorous PA (MVPA). Girls had 415 (SD 50) minutes per day ST, 283 (SD 40) minutes per day light PA, and 66 (SD 19) minutes per day MVPA. In adjusted analyses, MVPA was inversely associated with resting heart rate (β = -6.6; 95% confidence interval, -12.5 to -0.7) and positively associated with left ventricular mass (β = 6.8; 1.4-12.3), radial intima-media thickness (β = 11.4; 5.4-17.5), brachial intima-media thickness (β = 8.0; 2.0-14.0), and femoral intima-media thickness (β = 1.3; 0.2-2.3). MVPA was inversely associated with body fat percentage (β = -3.4; -6.6 to -0.2), diastolic blood pressure (β = -0.05; -0.8 to -0.1), and femoral (β = -18.1; -32.4 to -0.8) and radial (β = -13.4; -24.0 to -2.9) circumferential wall stress in boys only. ST and pulse wave velocity showed no significant associations.

CONCLUSIONS

In young at-risk children, MVPA is associated with cardiovascular remodeling, partly in a sex-dependant way, likely representing physiological adaptation, but ST shows no association with cardiovascular health in early childhood.

Association between intensity of physical activity and cognitive function in hypertensive patients: a case-control study

Previous studies have shown that a higher intensity of physical activity (PA) is associated with a lower risk of cognitive impairment (CI), whereas hypertension is associated with higher CI. However, there are few studies on the association between PA intensity and cognitive function in hypertensive patients. This study investigated the association between PA intensity and cognitive function in hypertensive patients. A total of 2035 hypertensive patients were included in this study, including 407 hypertensive patients with CI and 1628 hypertensive patients with normal cognitive function matched 1:4 by age and sex. The International Physical Activity Questionnaire-Long Form and the Mini-mental State Examination were used to evaluate PA intensity, total metabolic equivalents, and cognitive function in patients with hypertension. Multivariate logistic regression was used to analyze the correlation between PA intensity and CI in hypertensive patients. The Spearman correlation coefficient was used to analyze the correlation between PA intensity and the total score of each component of the MMSE and the correlation between PA total metabolic equivalents and cardiac structure in hypertensive patients. After adjusting for all confounding factors, PA intensity was negatively associated with CI in hypertensive patients (OR = 0.608, 95% CI: 0.447-0.776, P < 0.001), and this association was also observed in hypertensive patients with education level of primary school and below and junior high school and above (OR = 0.732, 95% CI: 0.539-0.995, P = 0.047; OR = 0.412, 95% CI: 0.272-0.626, P < 0.001). The intensity of PA in hypertensive patients was positively correlated with orientation (r = 0.125, P < 0.001), memory (r = 0.052, P = 0.020), attention and numeracy (r = 0.151, P < 0.001), recall ability (r = 0.110, P < 0.001), and language ability (r = 0.144, P < 0.001). PA total metabolic equivalents in hypertensive patients were negatively correlated with RVEDD and LAD (r = - 0.048, P = 0.030; r = - 0.051, P = 0.020) and uncorrelated with LVEDD (r = 0.026, P = 0.233). Higher PA intensity reduced the incidence of CI in hypertensive patients. Therefore, hypertensive patients were advised to moderate their PA according to their circumstances.

Accumulating Sedentary Time and Physical Activity From Childhood to Adolescence and Cardiac Function in Adolescence

BACKGROUND

Increased physical activity (PA) may mitigate the negative cardiovascular health effects of sedentary behavior in adolescents. However, the relationship of PA and sedentary time from childhood with cardiac function in adolescence remains underexplored. Therefore, we investigated the associations of cumulative sedentary time and PA from childhood to adolescence with cardiac function in adolescence.

METHODS AND RESULTS

Participants were 153 adolescents (69 girls) who were aged 6 to 8 years at baseline, 8 to 10 years at 2-year follow-up, and 15 to 17 years at 8-year follow-up. Cumulative sedentary time and PA exposure between baseline and 2-year follow-up and between baseline and 8-year follow-up were measured using a combined accelerometer and heart rate monitor. Cardiac function was assessed using impedance cardiography at 8-year follow-up. The data were analyzed using linear regression analyses adjusted for age and sex. Cumulative moderate to vigorous PA (standardized regression coefficient [β]=-0.323 [95% CI, -0.527 to -0.119]) and vigorous PA (β=-0.295 [95% CI, -0.508 to -0.083]) from baseline to 8-year follow-up were inversely associated with cardiac work at 8-year follow-up. Conversely, cumulative sedentary time had a positive association (β=0.245 [95% CI, 0.092-0.398]). Cumulative vigorous PA from baseline to 8-year follow-up was inversely associated with cardiac work index at 8-year follow-up (β=-0.218 [95% CI, -0.436 to 0.000]).

CONCLUSIONS

Higher levels of sedentary time and lower levels of PA during childhood were associated with higher cardiac work in adolescence, highlighting the importance of increasing PA and reducing sedentary time from childhood.

Atrial septal defect closure in children at young age is beneficial for left ventricular function

Aims

Atrial septal defects (ASDs) lead to volume-loaded right ventricles (RVs). ASD closure does not always alleviate symptoms or improve exercise capacity, which is possibly explained by impaired left ventricular (LV) haemodynamics. This study evaluated the effect of ASD closure in children using non-invasive LV pressure-volume (PV) loops derived from cardiac magnetic resonance (CMR) imaging and brachial blood pressure, compared with controls.

Methods and results

Twenty-three children with ASD underwent CMR, and 17 of them were re-examined 7 (6-9) months after ASD closure. Twelve controls were included. Haemodynamic variables were derived from PV loops by time-resolved LV volumes and brachial blood pressure. After ASD closure, LV volume increased [76 (70-86) vs. 63 (57-70) mL/m2, P = 0.0001]; however, it was still smaller than in controls [76 (70-86) vs. 82 (78-89) mL/m2, P = 0.048]. Compared with controls, children with ASD had higher contractility [2.6 (2.1-3.3) vs. 1.7 (1.5-2.2) mmHg/mL, P = 0.0076] and arterial elastance [2.1 (1.4-3.1) vs. 1.4 (1.2-2.0) mmHg/mL, P = 0.034]. After ASD closure, both contractility [2.0 (1.4-2.5) mmHg/mL, P = 0.0001] and arterial elastance [1.4 (1.3-2.0) mmHg/mL, P = 0.0002] decreased.

Conclusion

Despite the left-to-right atrial shunt that leads to low LV filling and RV enlargement, the LV remains efficient and there is no evidence of impaired LV haemodynamics in children. Closure of ASD at young age while the ventricle is compliant is thus beneficial for LV function. LV volumes, however, remain small after ASD closure, which may impact long-term cardiovascular risk and exercise performance.

Characterizing Decision-Making Surrounding Exercise in ARVC: Analysis of Decisional Conflict, Decisional Regret, and Shared Decision-Making

BACKGROUND

Limiting high-intensity exercise is recommended for patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) due to its association with penetrance, arrhythmias, and structural progression. Guidelines recommend shared decision-making (SDM) for exercise level, but there is little evidence regarding its impact. Therefore, we sought to evaluate the extent and implications of SDM for exercise, decisional conflict, and decisional regret in patients with ARVC and at-risk relatives.

METHODS

Adults diagnosed with ARVC or with positive genetic testing enrolled in the Johns Hopkins ARVC Registry were invited to complete a questionnaire that included exercise history and current exercise, SDM (SDM-Q-9), decisional conflict, and decisional regret.

RESULTS

The response rate was 64.8%. Two-thirds of participants (68.0%, n=121) reported clinically significant decisional conflict regarding exercise at diagnosis/genetic testing (DCS [decisional conflict scale]≥25), and half (55.1%, n=98) in the past year. Prevalence of decisional regret was also high with 55.3% (n=99) reporting moderate to severe decisional regret (DRS [decisional regret scale]≥25). The extent of SDM was highly variable ranging from no (0) to perfect (100) SDM (mean, 59.6±25.0). Those diagnosed in adolescence (≤age 21) reported significantly more SDM (P=0.013). Importantly, SDM was associated with less decisional conflict (ß=-0.66, R2=0.567, P<0.01) and decisional regret (ß=-0.37, R2=0.180, P<0.001) and no difference in vigorous intensity aerobic exercise in the 6 months after diagnosis/genetic testing or the past year (P=0.56; P=0.34, respectively).

CONCLUSIONS

SDM is associated with lower decisional conflict and decisional regret; and no difference in postdiagnosis exercise. Our data thus support SDM as the preferred model for exercise discussions for ARVC.

Preventing new-onset heart failure: Intervening at stage A

Heart failure (HF) prevention is an urgent public health need with national and global implications. Stage A HF patients do not show HF symptoms or structural heart disease but are at risk of HF development. There are no unique recommendations on detecting Stage A patients. Patients in Stage A are heterogeneous; many patients have different combinations of risk factors and, therefore, have markedly different absolute risks for HF. Comprehensive strategies to prevent HF at Stage A include intensive blood pressure lowering, adequate glycemic and lipid management, and heart-healthy behaviors (adopting Life's Essential 8). First and foremost, it is imperative to improve public awareness of HF risk factors and implement healthy lifestyle choices very early. In addition, recognize the HF risk-enhancing factors, which are nontraditional cardiovascular (CV) risk factors that identify individuals at high risk for HF (genetic susceptibility for HF, atrial fibrillation, chronic kidney disease, chronic liver disease, chronic inflammatory disease, sleep-disordered breathing, adverse pregnancy outcomes, radiation therapy, a history of cardiotoxic chemotherapy exposure, and COVID-19). Early use of biomarkers, imaging markers, and echocardiography (noninvasive measures of subclinical systolic and diastolic dysfunction) may enhance risk prediction among individuals without established CV disease and prevent chemotherapy-induced cardiomyopathy. Efforts are needed to address social determinants of HF risk for primordial HF prevention.Central illustrationPolicies developed by organizations such as the American Heart Association, American College of Cardiology, and the American Diabetes Association to reduce CV disease events must go beyond secondary prevention and encompass primordial and primary prevention.

Understanding Exercise Capacity: From Elite Athlete to HFpEF

Exercise capacity is a spectrum that reflects an individual's functional capacity and the dynamic nature of cardiac remodelling along with respiratory and skeletal muscle systems. The relationship of increasing physical activity, increased cardiac mass and volumes, and improved cardiorespiratory fitness (CRF) is well established in the endurance athlete. However, less emphasis has been placed on the other end of the spectrum, which includes individuals with a more sedentary lifestyle and small hearts who are at increased risk of functional disability and poor clinical outcomes. Reduced CRF is an independent predictor of all-cause mortality and cardiovascular events determined by multiple inter-related exogenous and endogenous factors. In this review, we explore the relationship of physical activity, cardiac remodelling, and CRF across the exercise spectrum, emphasising the critical role of cardiac size in determining exercise capacity. In contrast to the large compliant left ventricle of the endurance athlete, an individual with a lifetime of physical inactivity is likely to have a small, stiff heart with reduced cardiac reserve. We propose that this might contribute to the development of heart failure with preserved ejection fraction in certain individuals, and is key to understanding the link between low CRF and increased risk of heart failure.

Clinical and Echocardiographic Diversity Associated With Physical Fitness in the Project Baseline Health Study: Implications for Heart Failure Staging

BACKGROUND

Clinical and echocardiographic features may carry diverse information about the development of heart failure (HF). Therefore, we determined heterogeneity in clinical and echocardiographic phenotypes and its association with exercise capacity.

METHODS

In 2036 community-dwelling individuals, we defined echocardiographic profiles of left and right heart remodeling and dysfunction. We subdivided the cohort based on presence (+) or absence (-) of HF risk factors (RFs) and echocardiographic abnormalities (RF-/Echo-, RF-/Echo+, RF+/Echo-, RF+/Echo+). Multivariable-adjusted associations between subgroups and physical performance metrics from 6-minute walk and treadmill exercise testing were assessed.

RESULTS

The prevalence was 35.3% for RF-/Echo-, 4.7% for RF-/Echo+, 39.3% for RF+/Echo-, and 20.6% for RF+/Echo+. We observed large diversity in echocardiographic profiles in the Echo+ group. Participants with RF-/Echo+ (18.6% of Echo+) had predominantly echocardiographic abnormalities other than left ventricular (LV) diastolic dysfunction, hypertrophy and reduced ejection fraction, whereas their physical performance was similar to RF-/Echo-. In contrast, participants with RF+/Echo+ presented primarily with LV hypertrophy or dysfunction, features that related to lower 6-minute walking distance and lower exercise capacity.

CONCLUSIONS

Subclinical echocardiographic abnormalities suggest HF pathogenesis, but the presence of HF risk factors and type of echo abnormality should be considered so as to distinguish adverse from benign adaptation and to stratify HF risk.

Too Little of a Good Thing: Strong Associations Between Cardiac Size and Fitness Among Women

BACKGROUND

Cardiorespiratory fitness (CRF) is associated with functional impairment and cardiac events, particularly heart failure (HF). However, the factors predisposing women to low CRF and HF remain unclear.

OBJECTIVES

This study sought to evaluate the association between CRF and measures of ventricular size and function and to examine the potential mechanism linking these factors.

METHODS

A total of 185 healthy women aged >30 years (51 ± 9 years) underwent assessment of CRF (peak volume of oxygen uptake [Vo2peak]) and biventricular volumes at rest and during exercise by using cardiac magnetic resonance (CMR). The relationships among Vo2peak, cardiac volumes, and echocardiographic measures of systolic and diastolic function were assessed using linear regression. The effect of cardiac size on cardiac reserve (change in cardiac function during exercise) was assessed by comparing quartiles of resting left ventricular end-diastolic volume (LVEDV).

RESULTS

Vo2peak was strongly associated with resting measures of LVEDV and right ventricular end-diastolic volume (R2 = 0.58-0.63; P < 0.0001), but weakly associated with measures of resting left ventricular (LV) systolic and diastolic function (R2 = 0.01-0.06; P < 0.05). Increasing LVEDV quartiles were positively associated with cardiac reserve, with the smallest quartile showing the smallest reduction in LV end-systolic volume (quartile [Q]1: -4 mL vs Q4: -12 mL), smallest augmentation in LV stroke volume (Q1: +11 mL vs Q4: +20 mL) and cardiac output (Q1: +6.6 L/min vs Q4: +10.3 L/min) during exercise (interaction P < 0.001 for all).

CONCLUSIONS

A small ventricle is strongly associated with low CRF because of the combined effect of a smaller resting stroke volume and an attenuated capacity to increase with exercise. The prognostic implications of low CRF in midlife highlight the need for further longitudinal studies to determine whether women with small ventricles are predisposed to functional impairment, exertional intolerance, and HF later in life.

Association between physical activity and major adverse cardiovascular events in northwest China: A cross-sectional analysis from the Regional Ethnic Cohort Study

Background

To examine the association between daily physical activity (PA) and major adverse cardiovascular events (MACEs) in northwest China.

Methods

The data in this analysis were part of the baseline survey of the Regional Ethnic Cohort Study in Northwest China from June 2018 to May 2019 in Shaanxi Province. This study used standardized self-reported total physical activity (continuous and categorical variables) and self-reported outcomes of MACEs. All analyses were conducted using the logistic regression model and stratified by age, sex, body mass index (BMI), and region. The dose-response relationships were assessed with a restricted cubic spline.

Results

The average level of total PA was 17.60 MET hours per day (MET-h/d). Every increase of four MET-h/d of total PA was associated with a lower risk of MACEs [adjusted OR = 0.95 (95% CI, 0.93~0.98)]. Compared with participants in the bottom quartile of total PA, a lower risk of MACEs was observed in the top quartile group [≥23.3 MET-h/d, 0.68 (0.55~0.83)]. Stratified analyses showed similar results in males, females, participants over 45 years old, participants in the rural region, and normal weight range participants (BMI < 24 kg/m²). Total participants also observed a dose-response relationship after adjusting for socioeconomic and lifestyle factors.

Conclusions

A higher level of PA was associated with a lower MACE risk. Future research should examine the longitudinal association of prospectively measured PA and the risk of MACEs.

Heart Failure With Preserved Ejection Fraction as an Exercise Deficiency Syndrome: JACC Focus Seminar 2/4

Across differing spectrums of cardiac function and cardiac pathologies, there are strong associations between measures of cardiorespiratory fitness and burden of symptoms, quality of life, and prognosis. In this part 2 of a 4-part series, we contend that there is a strong association among physical activity, cardiorespiratory fitness, and cardiac function. We argue that a chronic lack of exercise is a major risk factor for heart failure with preserved ejection fraction in some patients. In support of this hypothesis, increasing physical activity is associated with greater cardiac mass, greater stroke volumes, greater cardiac output and peak oxygen consumption, and fewer clinical events. Conversely, physical inactivity results in cardiac atrophy, reduced output, reduced chamber size, and decreased ability to augment cardiac performance with exercise. Moreover, physical inactivity is a strong predictor of heart failure risk and death. In sum, exercise deficiency should be considered part of the broad heart failure with preserved ejection fraction phenotype.

Density and Fat Fraction of the Psoas, Paraspinal, and Oblique Muscle Groups Are Associated With Lumbar Vertebral Bone Mineral Density in a Multi-Ethnic Community-Living Population: The Multi-Ethnic Study of Atherosclerosis

Low vertebral bone mass is a major risk factor for vertebral compression fractures. Although sarcopenia has been shown to be associated with low bone mineral density (BMD), it is not known whether trunk musculature is directly associated with lumbar BMD, and whether exercise modifies this association. Using data from the Multi-Ethnic Study of Atherosclerosis (MESA), we sought to determine the association of muscle density and fat fraction of the psoas, paraspinal, and oblique muscle groups with L₃ lumbar volumetric BMD, and whether these associations were modified by exercise. We obtained L₃ vBMD measurements, and fat and muscle measurements (in Hounsfield units [HU]) from abdominal computed tomography (CT) scans spanning the L₂ -L₄ intervertebral disc spaces. Muscle density was defined as the mean HU value for a muscle group area. Fat fraction was calculated as the mean HU value for the muscle group fat area/total muscle group area (cm² ). Exercise data were self-reported (MET-minute/week). We utilized multivariable linear regression to evaluate these associations, stratified by gender, and adjusting for demographics, body mass index (BMI), smoking status, impaired fasting glucose, and corticosteroid and anti-resorptive medication use. Among 1923 MESA participants, mean ± standard deviation (SD) age was 62 ± 10 years, 49% were female, 40% white, 21% black, 26% Hispanic/Latino, and 13% Chinese. In fully adjusted analysis, for every 1-SD higher psoas fat fraction, there was a 3.19-SD lower L₃ vBMD in men and 4.3-SD lower L₃ vBMD in women (p < 0.001). For every 1-SD higher psoas density, there was a 0.2-SD higher L₃ vBMD (p < 0.001) in men and 0.19-SD higher L₃ vBMD (p < 0.001) in women. Findings were similar for paraspinal and oblique muscles. Intentional exercise did not modify these associations. In men and women, trunk muscle density was positively associated with higher lumbar BMD, suggesting a local association. Future studies are warranted to determine the temporality of this association. © 2022 American Society for Bone and Mineral Research (ASBMR).

Low cardiopulmonary fitness is associated with higher liver fat content and higher gamma-glutamyltransferase concentrations in the general population - "The Sedentary's Liver"

BACKGROUND

We investigated the association between low cardiorespiratory fitness and liver fat content (LFC) in the general population.

MATERIALS AND METHODS

We evaluated data from 2151 adults (51.1% women) from two population-based cohorts of the Study of Health in Pomerania (SHIP-2 and SHIP-TREND-0). We analysed the cross-sectional associations of peak oxygen uptake (VO_2peak ) with LFC, assessed by magnetic resonance imaging proton density fat fraction, as well as serum gamma-glutamyltransferase (GGT) and aminotransferase concentrations by multivariable regression models.

RESULTS

We observed significant inverse associations of VO_2peak with LFC and serum GGT, but not with serum aminotransferase levels. Specifically, a 1 L/min lower VO_2peak was associated with a 1.09% (95% confidence interval [CI]: 0.45-1.73; P = .002) higher LFC and a 0.18 μkatal/L (95% CI: 0.09-0.26; P < .001) higher GGT levels. The adjusted odds ratio (OR) for the risk of prevalent hepatic steatosis (HS) by a 1 L/min decrease in VO_2peak was 1.61 (95% CI: 1.22-2.13; P = .001). Compared to subjects with high VO_2peak , obese and overweight individuals with low VO_2peak had 1.78% (95% CI: 0.32-3.25; P = .017) and 0.94% (95% CI: 0.15-1.74; P = .021) higher mean LFC, respectively. Compared to those with high VO_2peak , low VO_2peak was independently associated with a higher risk of prevalent HS in the obese (adjusted-OR 2.29, 95% CI=1.48-3.56; P < .001) and overweight (adjusted OR 1.57, 95% CI=1.16-2.14; P = .04) groups.

CONCLUSIONS

Lower VO_2peak was significantly associated with greater LFC and higher serum GGT levels in a population-based cohort of adult individuals. Our results suggest that low VO_2peak might be a risk factor for HS.

What Is Normal for an Aging Heart?: A Prospective CMR Cohort Study

BACKGROUND

This study aims to investigate normal changes throughout aging of the heart in cardiac magnetic resonance (CMR) imaging in healthy volunteers. While type 2 diabetes mellitus is a frequent finding in the elderly population, also the influence of this circumstance in otherwise healthy persons is part of our study.

METHODS

In this prospective single-center trial, 75 healthy subjects in distinct age groups and 10 otherwise healthy diabetics were enrolled. All subjects underwent functional, flow sensitive, native T2- and T1-mapping in a 1.5T CMR scanner.

RESULTS

No differences in right and left ventricular ejection fractions were observed between aging healthy groups. Bi-ventricular volumes lowered significantly (p<0.001) between the age groups. There was also a significant decrease in myocardial T1 values, aortic distensibility, and left ventricular peak diastolic strain rates. There were no differences in T2 mapping and the other deformation parameters. Patients with type 2 diabetes mellitus had lower end-diastolic volume indexes; all the other measurements were comparable.

CONCLUSIONS

Aging processes in the healthy heart involve a decrease in ventricular volumes, with ejection fractions remaining normal. Stiffening of the myocardium and aorta and a decrease in T1 values are potential indications of age-related remodeling. Type 2 diabetes mellitus seems to have no major influence on aging processes of the heart.

Trial Registration

EudraCT Identifier: EudraCT 2017-000045-42

Lower Cardiorespiratory Fitness Is Associated With Right Ventricular Geometry and Function - The Sedentary's Heart: SHIP

Background

Lower cardiorespiratory fitness (CRF) is associated with an increased risk for cardiovascular disease. However, very little information is available about the association between lower CRF and right ventricular (RV) remodeling. We investigated the relationship between CRF and RV structure and function in a large, aging, and largely sedentary adult population–based cohort.

Methods and Results

We used cross‐sectional data of 2844 subjects (1486 women; median age, 51 years; interquartile range, 40–62 years) from the population‐based cohort SHIP (Study of Health in Pomerania) with echocardiography, of which 941 also had cardiac magnetic resonance imaging. We analyzed the associations of peak oxygen uptake with RV parameters determined by both imaging techniques using multivariable‐adjusted linear regression models. In echocardiography, a 1 L/min lower peak oxygen uptake was associated with a 1.18 mm (95% CI, 0.66–1.71; P<0.001) smaller RV end‐diastolic diameter and a 1.41 mm (95% CI, 0.90–1.92; P<0.001) narrower RV end‐diastolic outflow tract diameter. Similarly, using cardiac magnetic resonance imaging measurements, a 1 L/min lower peak oxygen uptake was associated with a 23.5 mL (95% CI, 18.7–28.4; P<0.001) smaller RV end‐diastolic volume, a 13.0 mL (95% CI, 9.81–16.2; P<0.001) lower RV end‐systolic volume, and a 10.7 mL/beat (95% CI, 8.10–13.3; P<0.001) lower RV stroke volume.

Conclusions

Our results indicate a significant association between CRF and RV remodeling. Lower CRF was associated with smaller RV chamber and lower RV systolic function, stroke volume, and cardiac output.

Lower muscular strength is associated with smaller left and right chambers and lower cardiac mass in the general population - The Sedentary's Heart

BACKGROUND

The cardiac muscle has the ability to adapt to different loading conditions. We analyzed the associations of the age-related decreasing handgrip strength (HGS), a marker of muscular fitness, on cardiac structure and function in a community-based sample.

METHODS

We performed cross-sectional analyses of 4646 subjects (2554 women; 55.0%) aged 20 to 93 years from two independent cohorts of the Study of Health in Pomerania (SHIP-2 and SHIP-TREND-0). We analyzed the associations of HGS with structural and functional left and right ventricular (LV and RV) and left atrial (LA) parameters as determined by echocardiography and magnetic resonance imaging (MRI) as well with log-transformed NT-proBNP values using multivariable-adjusted linear regression models.

RESULTS

MRI data showed that a 1 kg lower HGS was associated with a 0.40 mL (95% confidence interval: 0.26 to 0.54; p < 0.001) lower LV end-diastolic volume, a 0.011 mm (0.005 to 0.018; p = 0.001) lower LV wall-thickness, a 0.59 g (0.43 to 0.75; p < 0.001) lower LV mass, a 0.58 mL/beat (0.43 to 0.74; p < 0.001) lower LV stroke volume, a 0.03 L/min (0.02 to 0.04; p < 0.001) lower LV cardiac output, a 0.48 mL (0.27 to 0.68; p < 0.001) lower LA end-diastolic volume, and a 1.02 mL (0.71 to 1.32) lower RV end-diastolic volume. Similar findings were observed for echocardiographic parameters. Moreover, lower HGS was associated with higher echocardiographic LV diastolic stiffness and NT-proBNP levels.

CONCLUSIONS

In this large population-based sample, lower muscular fitness as assessed by HGS was associated with lower LV wall thickness and mass as well as with smaller chamber size, stroke volume and cardiac output of the LV, LA and RV. Moreover, HGS was inversely related to LV diastolic stiffness and NT-proBNP values. These outcomes might demonstrate the effects of an aging-related decrease in physical activity and lower muscular fitness on the heart - "the sedentary's heart".

Cardiac MRI shows an association of lower cardiorespiratory fitness with decreased myocardial mass and higher cardiac stiffness in the general population - The Sedentary's Heart

BACKGROUND

The heart has the capacity to adapt to different demands. The pathophysiological mechanisms involved with sedentarism are not fundamentally the opposite of those related with physical activity and regular exercise. We investigated the impact of lower cardiorespiratory fitness (CRF) on heart's plasticity and function in a population-based setting.

METHODS

We used data from 1165 participants (539 women; 46.3%) aged 21-81 years from two independent cohorts of the Study of Health in Pomerania (SHIP-2 and SHIP-TREND-0). We analyzed the cross-sectional associations of peak oxygen uptake (VO_2peak), determined by symptom-limited cardiopulmonary exercise testing, with structural and functional left ventricular (LV) and left atrial (LA) parameters determined by magnetic resonance imaging (MRI) using multivariable- adjusted linear regression models.

RESULTS

A 1 L/min lower VO_2peak was associated with a 10.5 g (95% confidence interval: 8.00 to 12.9; p < 0.001) lower LV mass, a 14.8 mL (10.9 to 18.6; p < 0.001) lower LV end-diastolic volume, a 0.29 mm (0.19 to 0.40; p < 0.001) lower LV wall-thickness, a 8.85 mL/beat (6.53 to 11.2; p < 0.001) lower LV stroke volume, a 0.42 L/min (0.25 to 0.60; p < 0.001) lower LV cardiac output and a 7.51 mL (3.88 to 11.1; p < 0.001) lower LA end-diastolic volume. Moreover, there were no associations with a concentric or eccentric remodeling and LV and LA ejection fraction.

CONCLUSIONS

Lower CRF was associated with a smaller heart, LV wall-thickness and mass, LV and LA stroke volume and cardiac output. Conversely, there was no association with LA and LV ejection fraction. Our cross-sectional observations are consistent with cardiac adaptations reflecting reduced volume loading demands of a sedentary lifestyle - "the sedentary's heart".

Sex-Specific Impacts of Exercise on Cardiovascular Remodeling

Cardiovascular diseases (CVD) remain the leading cause of death in men and women. Biological sex plays a major role in cardiovascular physiology and pathological cardiovascular remodeling. Traditionally, pathological remodeling of cardiovascular system refers to the molecular, cellular, and morphological changes that result from insults, such as myocardial infarction or hypertension. Regular exercise training is known to induce physiological cardiovascular remodeling and beneficial functional adaptation of the cardiovascular apparatus. However, impact of exercise-induced cardiovascular remodeling and functional adaptation varies between males and females. This review aims to compare and contrast sex-specific manifestations of exercise-induced cardiovascular remodeling and functional adaptation. Specifically, we review (1) sex disparities in cardiovascular function, (2) influence of biological sex on exercise-induced cardiovascular remodeling and functional adaptation, and (3) sex-specific impacts of various types, intensities, and durations of exercise training on cardiovascular apparatus. The review highlights both animal and human studies in order to give an all-encompassing view of the exercise-induced sex differences in cardiovascular system and addresses the gaps in knowledge in the field.

Associations between physical activity, sedentary behaviour and left ventricular structure and function from the Echocardiographic Study of Latinos (ECHO-SOL)

OBJECTIVE

The cross-sectional association between accelerometer-measured physical activity (PA), sedentary behaviour (SB) and cardiac structure and function is less well described. This study's primary aim was to compare echocardiographic measures of cardiac structure and function with accelerometer measured PA and SB.

METHODS

Participants included 1206 self-identified Hispanic/Latino men and women, age 45-74 years, from the Echocardiographic Study of Latinos. Standard echocardiographic measures included M-mode, two-dimensional, spectral, tissue Doppler and myocardial strain. Participants wore an Actical accelerometer at the hip for 1 week.

RESULTS

The mean±SE age for the cohort was 56±0.4 years, 57% were women. Average moderate to vigorous PA (MVPA) was 21±1.1 min/day, light PA was 217±4.2 min/day and SB was 737±8.1 min/day. Both higher levels of light PA and MVPA (min/day) were associated with lower left ventricular (LV) mass index (LVMI)/end-diastolic volume and a lower E/e' ratio. Higher levels of MVPA (min/day) were associated with better right ventricular systolic function. Higher levels of SB were associated with increased LVMI. In a multivariable linear regression model adjusted for demographics and cardiovascular disease modifiable factors, every 10 additional min/day of light PA was associated with a 0.03 mL/m2 increase in left atrial volume index (LAVI) (p<0.01) and a 0.004 cm increase in tricuspid annular plane systolic excursion (p<0.01); every 10 additional min/day of MVPA was associated with a 0.18 mL/m2 increase in LAVI (p<0.01) and a 0.24% improvement in global circumferential strain (p<0.01).

CONCLUSIONS

Our findings highlight the potential positive association between the MVPA and light PA on cardiac structure and function.

Cross-Sectional Associations of Objectively Measured Sedentary Time, Physical Activity, and Fitness With Cardiac Structure and Function: Findings From the Dallas Heart Study

Background

Physical inactivity and low cardiorespiratory fitness (CRF) are associated with higher risk of heart failure. However, the independent contributions of objectively measured sedentary time, physical activity, and CRF toward left ventricular (LV) structure and function are not well established.

Methods and Results

We included 1368 participants from the DHS (Dallas Heart Study) (age, 49 years; 40% men) free of cardiovascular disease who had physical activity and sedentary time measured by accelerometer, CRF estimated from submaximal treadmill test, and cardiac magnetic resonance imaging performed using 3‐T magnetic resonance imaging. A series of linear regression models were constructed to evaluate the associations of sedentary time, moderate physical activity, vigorous physical activity, and CRF with LV parameters after adjustment for established cardiovascular risk factors. We observed a modest correlation between CRF levels and objectively measured moderate (correlation coefficient, 0.17; P<0.001) and vigorous physical activity (correlation coefficient, 0.25; P<0.001) levels. In contrast, sedentary time was not associated with CRF. In adjusted analysis, both vigorous physical activity and higher CRF were significantly associated with greater stroke volume, LV mass, LV end‐diastolic volume, and lower arterial elastance, independent of other confounders. Sedentary time and moderate physical activity levels were not associated with LV parameters.

Conclusions

Vigorous physical activity and CRF are significantly associated with cardiac structure and function parameters. Future studies are needed to determine if interventions aimed at improving CRF levels may favorably modify cardiac structure and function.

Exercise restriction is protective for genotype-positive family members of arrhythmogenic right ventricular cardiomyopathy patients

Aims

In arrhythmogenic right ventricular cardiomyopathy (ARVC) patients, exercise worsens disease course, so exercise restriction is recommended. However, recommendations for genotype-positive ARVC family members is incompletely resolved. We aimed to provide evidence for exercise recommendations for genotype-positive ARVC family members.

Methods and results

Arrhythmogenic right ventricular cardiomyopathy family members inheriting a pathogenic desmosomal variant were interviewed about exercise history from age 10. Exercise was characterized by duration, intensity, and dose (duration*intensity). Associations between exercise and (i) diagnosis by 2010 Task Force Criteria and (ii) development of sustained ventricular arrhythmias were examined. The study included 101 family members (age: 40.5 ± 19.3 years, male: 41%, Plakophilin-2 variant: 81%). Forty-four individuals (44%) met diagnostic criteria and 16 (16%) experienced sustained ventricular arrhythmia. Individuals who met diagnostic criteria had significantly higher average exercise duration and dose, but not peak intensity than those who did not. Only one individual who exercised below the American Heart Association recommended minimum (650 metabolic equivalent of task-hours/year) met diagnostic criteria or experienced sustained ventricular arrhythmia as opposed to 50% of individuals who exceeded it (adjusted odds ratio = 0.03, 95% confidence interval 0.003–0.26). The difference in exercise exposure between affected and unaffected individuals was more striking in females than in males. Females who had done high-dose exercise in adolescence had the worst survival free from diagnosis (P &lt; 0.01).

Conclusions

In phenotype-negative ARVC family members with a pathogenic desmosomal variant, athletic activities should be limited, particularly exercise dose. Exercise may play a greater role in promoting disease in female family members.

Association of Heart Rate Variability With Cognitive Performance: The Multi-Ethnic Study of Atherosclerosis

Background Heart rate variability (HRV) is associated with vascular risk factors for dementia, but whether HRV is associated with specific domains of cognitive performance is unclear. Methods and Results In the Multi-Ethnic Study of Atherosclerosis (N=3018; mean age 59.3±9.2 years), we assessed the relationship of 10-second HRV to scores on tests of global cognitive performance (Cognitive Abilities Screening Instrument), processing speed (Digit Symbol Coding), and working memory (Digit Span). HRV was computed as the SD of normal-normal intervals (SDNN) and root mean square of successive differences (RMSSD) at Exam 1 (2000-2002) and Exam 5 (2010-2012). Cognitive tests were administered at Exam 5. We report regression coefficients (β [95% CI]) representing cognitive test score change per 2-fold increase in HRV. After adjustment for age, race/ethnicity, sex, education, apolipoprotein E genotype, and cardiovascular risk factors and incident disease, higher Exam 1 (β=0.37 [0.06, 0.67]) and Exam 5 (β=0.31 [0.04, 0.59]) SDNN were associated with better Cognitive Abilities Screening Instrument performance. Higher Exam 1 (β=0.80 [0.17, 1.43]) and Exam 5 (β=0.63 [0.06, 1.20]) SDNN, and Exam 5 RMSSD (β=0.54 [0.01, 1.08]) were associated with better Digit Symbol Coding performance. Finally, higher Exam 5 SDNN was associated with better Digit Span performance (β=0.17 [0.01, 0.33]). Associations were attenuated after adjustment for resting heart rate. Conclusions Higher HRV is generally associated with better cognitive performance in this multi-ethnic cohort of aging adults, and further study of the relationship of autonomic function to cognition is warranted.

Clinical characteristics and determinants of the phenotype in TMEM43 arrhythmogenic right ventricular cardiomyopathy type 5

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy type V (ARVC-5) is the most aggressive heterozygous form of ARVC. It is predominantly caused by a fully penetrant mutation (p.S358L) in the nondesmosomal gene TMEM43-endemic to Newfoundland, Canada. To date, all familial cases reported worldwide share a common ancestral haplotype. It is unknown whether the p.S358L mutation by itself causes ARVC-5 or whether the disease is influenced by genetic or environmental factors.

OBJECTIVE

The purpose of this study was to examine the phenotype, clinical course, and the impact of exercise on patients with p.S358L ARVC-5 without the Newfoundland genetic background.

METHODS

We studied 62 affected individuals and 73 noncarriers from 3 TMEM43-p.S358L Spanish families. The impact of physical activity on the phenotype was also evaluated.

RESULTS

Haplotype analysis revealed that the 3 Spanish families were unrelated to patients with ARVC-5 with the Newfoundland genetic background. Two families shared 10 microsatellite markers in a 4.9 cM region surrounding TMEM43; the third family had a distinct haplotype. The affected individuals showed a 38.7% incidence of sudden cardiac death, which was higher in men. Left ventricular involvement was common, with 40% of mutation carriers showing a left ventricular ejection fraction of <50%. Compared with noncarriers, the R-wave voltage in lead V₃ was lower (3.2 ± 2.8 mV vs 7.5 ± 3.6 mV; P < .001) and QRS complex in right precordial leads wider (104.7 ± 24.0 ms vs 88.2 ± 7.7 ms; P = .001). A history of vigorous exercise showed a trend toward more ventricular arrhythmias only in women (P = .053).

CONCLUSION

ARVC-5 is associated with a high risk of sudden cardiac death and characteristic clinical and electrocardiographic features irrespective of geographical origin and genetic background. Our data suggest that, as in desmosomal ARVC, vigorous physical activity could aggravate the phenotype of TMEM43 mutation carriers.

Change in Physical Activity and Cardiac Structure over 10 Years: The Multi-Ethnic Study of Atherosclerosis

INTRODUCTION

Physical activity (PA) is inversely associated with risk of heart failure and cardiovascular disease (CVD), whereas increased left ventricular (LV) mass and mass to volume (m:v) ratio are unfavorable CVD risk factors. We assessed whether changes in leisure time PA were associated with longitudinal changes in cardiac structure in a community-based population.

METHODS

We included 2779 Multi-Ethnic Study of Atherosclerosis participants, free of baseline CVD, who had available data on PA and cardiac magnetic resonance imaging at examinations 1 (2000-2002) and 5 (2010-2012). Physical activity was measured by a Typical Week PA Survey and converted to MET-minutes per week of moderate+vigorous activity. We used linear mixed effect models to estimate the associations of baseline and change in PA with baseline and change in cardiac structure, adjusting for CVD risk factors and body size.

RESULTS

At baseline, the mean age was 59 yr, 53% were women, and 58% of nonwhite race/ethnicity. During average 10-yr follow-up, and after accounting for baseline PA levels, the highest quintiles of PA increase were significantly associated with increases in LV mass (2.3 g; 95% confidence interval [CI], 0.4-4.2), LV end-diastolic volume (4.7 mL; 95% CI, 2.4-7.0), and stroke volume (3.3 mL; 95% CI, 1.6-5.1), but lower M:V ratio (-2.9; 95% CI, -5.0 to -0.8) compared with the lowest quintiles. Increasing exercise PA was associated with increases in LV diameter and reductions in M:V ratio, whereas occupational PA was associated with increases in m:v ratio. Increasing PA over 10 yr was also associated with greater risk of eccentric dilated LV hypertrophy at examination 5.

CONCLUSIONS

After accounting for baseline PA, greater positive changes in leisure-time PA levels were associated with a more eccentric-type of LV remodeling pattern over 10 yr. The clinical implications of such findings remain to be determined.

Physical activity and left ventricular trabeculation in the UK Biobank community-based cohort study

OBJECTIVE

Vigorous physical activity (PA) in highly trained athletes has been associated with heightened left ventricular (LV) trabeculation extent. It has therefore been hypothesised that LV trabeculation extent may participate in exercise-induced physiological cardiac remodelling. Our cross-sectional observational study aimed to ascertain whether there is a 'dose-response' relationship between PA and LV trabeculation extent and whether this could be identified at opposite PA extremes.

METHODS

In a cohort of 1030 individuals from the community-based UK Biobank study (male/female ratio: 0.84, mean age: 61 years), PA was measured via total metabolic equivalent of task (MET) min/week and 7-day average acceleration, and trabeculation extent via maximal non-compaction/compaction ratio (NC/C) in long-axis images of cardiovascular magnetic resonance studies. The relationship between PA and NC/C was assessed by multivariate regression (adjusting for potential confounders) as well as between demographic, anthropometric and LV phenotypic parameters and NC/C.

RESULTS

There was no significant linear relationship between PA and NC/C (full adjustment, total MET-min/week: ß=-0.0008, 95% CI -0.039 to -0.037, p=0.97; 7-day average acceleration: ß=-0.047, 95% CI -0.110 to -0.115, p=0.13, per IQR increment in PA), or between extreme PA quintiles (full adjustment, total MET-min/week: ß=-0.026, 95% CI -0.146 to -0.094, p=0.67; 7-day average acceleration: ß=-0.129, 95% CI -0.299 to -0.040, p=0.49), across all adjustment levels. A negative relationship was identified between left ventricular ejection fraction and NC/C, significantly modified by PA (ß difference=-0.006, p=0.03).

CONCLUSIONS

In a community-based general population cohort, there was no relationship at, or between, extremes, between PA and NC/C, suggesting that at typical general population PA levels, trabeculation extent is not influenced by PA changes.

Athletic Remodeling in Female College Athletes: The "Morganroth Hypothesis" Revisited

BACKGROUND

There is limited data regarding ventricular remodeling in college female athletes, especially when appropriate scaling of cardiac dimensions to lean body mass (LBM) is considered. Moreover, it is not well established whether cardiac remodeling in female athletes is a balanced process with proportional increase in left ventricular (LV) mass and volume or the right and LV size.

METHODS

During the preparticipation competitive screening, 72 female college athletes volunteered to undergo dual energy x-ray absorptiometry scan for quantification of LBM and comprehensive 2D echocardiography including assessment of longitudinal myocardial strain. The athletes were divided in 2 groups according to the intensity of the dynamic and static components of their sport categories, ie, a higher intensity dynamic and resistive group (n = 37 participating in rowing, water polo and lacrosse) and a lower intensity group (n = 35, participating in short distance running, sailing, synchronized swimming, and softball). In addition, we recruited a group of 31 age-matched nonathlete controls.

RESULTS

The mean age of the study population was 18.7 ± 1.0 years. When scaled to body surface area, the higher intensity group had 17.1 ± 3.6% (P < 0.001) greater LV mass when compared with the lower intensity group and 21.7 ± 4.0% (P < 0.001) greater LV mass than the control group. The differences persisted after scaling to LBM with 14.2 ± 3.2% (P < 0.001) greater LV mass in the higher intensity group. By contrast, there was no difference in any of the relative remodeling indices including the LV mass to volume ratio, right to LV area ratio, or left atrial to LV volume ratio (P > 0.50 for all). In addition, no significant difference was noted among the 3 groups in LV ejection fraction (P = 0.22), LV global longitudinal strain (P = 0.55), LV systolic strain rate (P = 0.62), or right ventricular global longitudinal strain (P = 0.61).

CONCLUSION

Female collegiate athletes participating in higher intensity dynamic and resistive sports have higher indexed LV mass even when scaled to LBM. The remodeling process does however appear to be a balanced process not only at the intraventricular level but also at the interventricular and atrioventricular levels.

Athlete's Heart: Diagnostic Challenges and Future Perspectives

Distinguishing between adaptive and maladaptive cardiovascular response to exercise is crucial to prevent the unnecessary termination of an athlete's career and to minimize the risk of sudden death. This is a challenging task essentially due to the substantial phenotypic overlap between electrical and structural changes seen in the physiological athletic heart remodeling and pathological changes seen in inherited or acquired cardiomyopathies. Stress testing is an ideal tool to discriminate normal from abnormal cardiovascular response by unmasking subtle pathologic responses otherwise undetectable at rest. Treadmill or bicycle electrocardiography, transthoracic echocardiography, and cardiopulmonary exercise testing are common clinical investigations used in sports cardiology, specifically among participants presenting with resting electrocardiographic abnormalities, frequent premature ventricular beats, or non-sustained ventricular arrhythmias. In this setting, as well as in cases of left ventricular hypertrophy or asymptomatic left ventricular dysfunction, stress imaging and myocardial tissue characterization by cardiovascular magnetic resonance show promise. In this review, we aimed to reappraise current diagnostic schemes, screening strategies and novel approaches that may be used to distinguish adaptive remodeling patterns to physical exercise from early phenotypes of inherited or acquired pathological conditions commanding prompt intervention.

Impact of Exercise Restriction on Arrhythmic Risk Among Patients With Arrhythmogenic Right Ventricular Cardiomyopathy

BACKGROUND

Prior studies have shown a close link between exercise and development of arrhythmogenic right ventricular cardiomyopathy. How much exercise restriction reduces ventricular arrhythmia (VA), how genotype modifies its benefit, and whether it reduces risk sufficiently to defer implantable cardioverter-defibrillator (ICD) placement in arrhythmogenic right ventricular cardiomyopathy are unknown.

METHODS AND RESULTS

We interviewed 129 arrhythmogenic right ventricular cardiomyopathy patients (age: 34.0±14.8 years; male: 60%) with ICDs (36% primary prevention) about exercise participation. Exercise change was defined as annual exercise duration and dose in the 3 years before clinical presentation minus that after presentation. The primary outcome was appropriate ICD therapy for VA. During the 5.1 years (interquartile range: 2.7-10.8 years) after presentation, 74% (95/129) patients reduced exercise dose and 85 (66%) patients experienced the primary outcome. In multivariate analyses, top tertile reduction in exercise duration and dose were both associated with less VA (duration: hazard ratio: 0.23 [95% confidence interval, 0.07-0.81]; dose: hazard ratio: 0.14 [95% confidence interval, 0.04-0.44]). Greater reduction in exercise dose conferred greater reduction in VA (P=0.01 for trend). Patients without desmosomal mutations and those with primary-prevention ICDs benefited more from exercise reduction (P=0.16 and P=0.06 for interaction); however, 58% (18/31) of athletes who reduced exercise dose by >80% still experienced VA.

CONCLUSIONS

Exercise restriction should be recommended to all arrhythmogenic right ventricular cardiomyopathy patients with ICDs. Patients who are "gene-elusive" and those with primary-prevention devices may particularly benefit. Exercise reduction is unlikely to reduce arrhythmia sufficiently in high-risk patients to alter decision-making regarding ICD implantation.

Cardiovascular magnetic resonance in an adult human population: serial observations from the multi-ethnic study of atherosclerosis

The Multi-Ethnic Study of Atherosclerosis (MESA) is the first large-scale multi-ethnic population study in the U.S. to use advanced cardiovascular magnetic resonance (CMR) imaging. MESA participants were free of cardiovascular disease at baseline between 2000 and 2002, and were followed up between 2009 and 2011 with repeated CMR examinations as part of MESA. CMR allows the clinician to visualize and accurately quantify volume and dimensions of all four cardiac chambers; measure systolic and diastolic ventricular function; assess myocardial fibrosis; assess vessel lumen size, vessel wall morphology, and vessel stiffness. CMR has a number of advantages over other imaging modalities such as echocardiography, computed tomography, and invasive angiography, and has been proposed as a diagnostic strategy for high-risk populations. MESA has been extensively evaluating CMR imaging biomarkers, as markers of subclinical disease, in the last 15 years for low-risk populations. On a more practical level, some of the imaging biomarkers developed and studied are translatable to at-risk populations. In this review, we discuss the progression of subclinical cardiovascular disease and the mechanisms responsible for the transition to symptomatic clinical outcomes based on our findings from MESA.

Moderate Physical Activity in Healthy Adults Is Associated With Cardiac Remodeling

Supplemental Digital Content is available in the text.

Background—

Cardiac mass and volumes are often elevated in athletes, but it is not known whether moderate physical activity is also associated with cardiac dilatation and hypertrophy in a healthy adult population.

Methods and Results—

In total, 1096 adults (54% female, median age 39 years) without cardiovascular disease or cardiomyopathy-associated genetic variants underwent cardiac magnetic resonance imaging to determine biventricular volumes and function. Physical activity was assessed using a validated activity questionnaire. The relationship between cardiac parameters and activity was assessed using multiple linear regression adjusting for age, sex, race, and systolic blood pressure. Logistic regression was performed to determine the effect of activity on the likelihood of subjects having cardiac dilatation or hypertrophy according to standard cardiac magnetic resonance normal ranges. Increasing physical activity was associated with greater left ventricular (LV) mass (β=0.23; P<0.0001) and elevated LV and right ventricular volumes (LV: β=0.26, P<0.0001; right ventricular: β=0.26, P<0.0001). Physical activity had a larger effect on cardiac parameters than systolic blood pressure (0.06≤β≤0.21) and a similar effect to age (−0.20≤β≤−0.31). Increasing physical activity was a risk factor for meeting imaging criteria for LV hypertrophy (adjusted odds ratio 2.1; P<0.0001), LV dilatation (adjusted odds ratio 2.2; P<0.0001), and right ventricular dilatation (adjusted odds ratio 2.2; P<0.0001).

Conclusions—

Exercise-related cardiac remodeling is not confined to athletes, and there is a risk of overdiagnosing cardiac dilatation or hypertrophy in a proportion of active, healthy adults.

Sedentary screen time and left ventricular structure and function: the CARDIA study

INTRODUCTION

Sedentary screen time (watching TV or using a computer) predicts cardiovascular outcomes independently from moderate and vigorous physical activity and could affect left ventricular structure and function through the adverse consequences of sedentary behavior.

PURPOSE

This study aimed to determine whether sedentary screen time is associated with measures of left ventricular structure and function.

METHODS

The Coronary Artery Risk Development in Young Adults Study measured screen time by questionnaire and left ventricular structure and function by echocardiography in 2854 black and white participants, age 43-55 yr, in 2010-2011. Generalized linear models evaluated cross-sectional trends for echocardiography measures across higher categories of screen time and adjusting for demographics, smoking, alcohol, and physical activity. Further models adjusted for potential intermediate factors (blood pressure, antihypertensive medication use, diabetes, and body mass index).

RESULTS

The relationship between screen time and left ventricular mass (LVM) differed in blacks versus whites. Among whites, higher screen time was associated with larger LVM (P < 0.001), after adjustment for height, demographics, and lifestyle variables. Associations between screen time and LVM persisted when adjusting for blood pressure, antihypertensive medication use, and diabetes (P = 0.008) but not with additional adjustment for body mass index (P = 0.503). Similar relationships were observed for screen time with LVM indexed to height, relative wall thickness, and mass-to-volume ratio. Screen time was not associated with left ventricular structure among blacks or left ventricular function in either race group.

CONCLUSIONS

Sedentary screen time is associated with greater LVM in white adults, and this relationship was largely explained by higher overall adiposity. The lack of association in blacks supports a potential qualitative difference in the cardiovascular consequences of sedentary screen-based behavior.

Mediterranean diet score and left ventricular structure and function: the Multi-Ethnic Study of Atherosclerosis

BACKGROUND

Data are limited on the relation between dietary patterns and left ventricular (LV) structure and function.

OBJECTIVE

We examined cross-sectional associations of a diet-score assessment of a Mediterranean dietary pattern with LV mass, volume, mass-to-volume ratio, stroke volume, and ejection fraction.

DESIGN

We measured LV variables with the use of cardiac MRI in 4497 participants in the Multi-Ethnic Study of Atherosclerosis study who were aged 45-84 y and without clinical cardiovascular disease. We calculated a Mediterranean diet score from intakes of fruit, vegetables, nuts, legumes, whole grains, fish, red meat, the monounsaturated fat:saturated fat ratio, and alcohol that were self-reported with the use of a food-frequency questionnaire. We used linear regression with adjustment for body size, physical activity, and cardiovascular disease risk factors to model associations and assess the shape of these associations (linear or quadratic).

RESULTS

The Mediterranean diet score had a slight U-shaped association with LV mass (adjusted means: 146, 145, 146, and 147 g across quartiles of diet score, respectively; P-quadratic trend = 0.04). The score was linearly associated with LV volume, stroke volume, and ejection fraction: for each +1-U difference in score, LV volume was 0.4 mL higher (95% CI: 0.0, 0.8 mL higher), the stroke volume was 0.5 mL higher (95% CI: 0.2, 0.8 mL higher), and the ejection fraction was 0.2 percentage points higher (95% CI: 0.1, 0.3 percentage points higher). The score was not associated with the mass-to-volume ratio.

CONCLUSIONS

A higher Mediterranean diet score is cross-sectionally associated with a higher LV mass, which is balanced by a higher LV volume as well as a higher ejection fraction and stroke volume. Participants in this healthy, multiethnic sample whose dietary patterns most closely conformed to a Mediterranean-type pattern had a modestly better LV structure and function than did participants with less-Mediterranean-like dietary patterns. This trial was registered at clinicaltrials.gov as NCT00005487.

Preventing heart failure: the role of physical activity

PURPOSE OF REVIEW

Heart failure prevention is an important public health goal. Increased physical activity and exercise may help to prevent heart failure, as they are associated with reduced heart failure incidence and potentially act through a variety of mechanisms to slow disease progression.

RECENT FINDINGS

Increased physical activity, higher cardiorespiratory fitness, and lower sedentary time are associated with reduced heart failure incidence. These associations are consistent for occurrence of heart failure with both preserved and reduced ejection fraction, the common subphenotypes of the condition. Physiologic cardiac and vascular remodeling occurs across the normal range of physical activity in the community, and regular exercise (four to five sessions per week) is necessary to mitigate age-associated reductions in ventricular compliance and cardiac mass.

SUMMARY

Greater physical activity, less sedentary time, and improved cardiorespiratory fitness are associated with reductions in heart failure risk. Various mechanisms may explain these findings, including: reducing the prevalence of standard and novel cardiovascular risk factors, inhibiting pathologic cardiovascular remodeling, promoting physiologic remodeling, and improving cardiac, neurohormonal, skeletal muscle, pulmonary, renal, and vascular performance. Future research is needed to elucidate the optimal timing, duration, and modality of physical activity and exercise training necessary to prevent the development of heart failure.

25(OH)D3 Levels Relative to Muscle Strength and Maximum Oxygen Uptake in Athletes

Vitamin D is mainly known for its effects on the bone and calcium metabolism. The discovery of Vitamin D receptors in many extraskeletal cells suggests that it may also play a significant role in other organs and systems. The aim of our study was to assess the relationship between 25(OH)D₃ levels, lower limb isokinetic strength and maximum oxygen uptake in well-trained professional football players. We enrolled 43 Polish premier league soccer players. The mean age was 22.7±5.3 years. Our study showed decreased serum 25(OH)D₃ levels in 74.4% of the professional players. The results also demonstrated a lack of statistically significant correlation between 25(OH)D₃ levels and lower limb muscle strength with the exception of peak torque of the left knee extensors at an angular velocity of 150°/s (r=0.41). No significant correlations were found between hand grip strength and maximum oxygen uptake. Based on our study we concluded that in well-trained professional soccer players, there was no correlation between serum levels of 25(OH)D₃ and muscle strength or maximum oxygen uptake.

Exercise has a disproportionate role in the pathogenesis of arrhythmogenic right ventricular dysplasia/cardiomyopathy in patients without desmosomal mutations

Background

Exercise is associated with age‐related penetrance and arrhythmic risk in carriers of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C)‐associated desmosomal mutations; however, its role in patients without desmosomal mutations (gene‐elusive) is uncertain. This study investigates whether exercise is (1) associated with onset of gene‐elusive ARVD/C and (2) has a differential impact in desmosomal and gene‐elusive patients.

Methods and Results

Eighty‐two ARVD/C patients (39 desmosomal, all probands) were interviewed about regular physical activity from age 10. Participation in endurance athletics, duration (hours/year), and intensity (MET‐Hours/year) of exercise prior to clinical presentation were compared between patients with desmosomal and gene‐elusive ARVD/C. All gene‐elusive patients were endurance athletes. Gene‐elusive patients were more likely to be endurance athletes (P<0.001) and had done significantly more intense (MET‐Hrs/year) exercise prior to presentation (P<0.001), particularly among cases presenting < age 25 (P=0.027). Family history was less prevalent among gene‐elusive patients (9% versus 40% desmosomal, P<0.001), suggesting a greater environmental influence. Gene‐elusive patients without family history did considerably more intense exercise than other ARVD/C patients (P=0.004). Gene‐elusive patients who had done the most intense (top quartile MET‐Hrs/year) exercise prior to presentation had a younger age of presentation (P=0.025), greater likelihood of meeting ARVD/C structural Task Force Criteria (100% versus 43%, P=0.02), and shorter survival free from a ventricular arrhythmia in follow‐up (P=0.002).

Conclusions

Gene‐elusive, non‐familial ARVD/C is associated with very high intensity exercise suggesting exercise has a disproportionate role in the pathogenesis of these cases. As exercise negatively modifies cardiac structure and promotes arrhythmias, exercise restriction is warranted.

Relation of Physical Activity and Incident Atrial Fibrillation (from the Multi-Ethnic Study of Atherosclerosis)

Previous studies have raised the question of whether an association exists between physical activity and atrial fibrillation (AF). We used the Multi-Ethnic Study of Atherosclerosis (MESA) database to examine the association between physical activity and AF in a diverse population without clinically recognized cardiovascular disease (CVD). MESA participants (n = 5,793) with complete baseline physical activity and covariate data were included. Cox proportional hazards models were used to calculate hazard ratios (HRs) for incident AF by levels of total intentional exercise and vigorous physical activity, independently and in combination. Multivariate models were adjusted for demographics and CVD risk factors. During a mean follow-up of 7.7 ± 1.9 years, 199 AF cases occurred. In the overall MESA population, neither vigorous physical activity nor total intentional exercise was independently associated with incident AF after adjusting for covariates. However, within the group that reported any vigorous physical activity, there was a statistically significant inverse association between total intentional exercise (modeled as a continuous variable) and incident AF. In those who reported any vigorous physical activity, the top tertile of total intentional exercise was associated with a significantly lower risk of incident AF compared with the group with no total intentional exercise in the fully adjusted model (HR 0.46, 95% confidence interval 0.22 to 0.98). In conclusion, neither total intentional exercise nor vigorous physical activity alone was associated with incident AF, but greater total intentional exercise was associated with a lower risk of incident AF in those who participated in any vigorous physical activity. As importantly, no subgroup of participants demonstrated an increased risk of incident AF with greater physical activity. The results re-emphasize the beneficial role of physical activity for cardiovascular health.

The combined effect of physical activity and sedentary behaviors on a clustered cardio-metabolic risk score: The Helena study

BACKGROUND/OBJECTIVE

Increased physical activity (PA) and decreased sedentary behaviors (SBs) may have beneficial effects on cardio-metabolic risk in adolescents. The aim of this study was to examine the associations between independent/combined effects of PA and SB with individual/clustered cardio-metabolic risk factors.

METHODS

A sample of 769 adolescents (12.5-17.5 years) from the HELENA cross-sectional study (Healthy Lifestyle in Europe by Nutrition in Adolescence) and with valid data on metabolic risk factors were included.

RESULTS

Concerning moderate-to-vigorous-PA (MVPA) and vigorous-PA (VPA), measured with accelerometers, girls tended to do more MVPA (36%) and VPA (114%) than boys. Unadjusted analyses show a positive association between "PA ≥ 60 min/d; SB ≥ 2 h" and the ratio TC/HDL-c (β = 0.27; 95%CI 0.01 to 0.52; p < 0.05), and a negative association between "MVPA ≥ 60 min/d; SB < 2h" with the ∑ 4Skinfolds (β = -0.32; 95%CI -0.61 to -0.02; p<0.05). Moreover, "SB ≥ 2 h/d" was associated with increased cardio-metabolic risk (PR 1.59; 95%CI 1.05 to 2.39; p < 0.05), while "PA ≥ 60 min/d; SB < 2h" had a protective effect against cardio-metabolic risk (PR 0.48; 95%CI 0.25 to 0.91; p < 0.05). After adjustment for potential confounders, a positive association between SB and ∑ 4Skinfolds was shown (β = 0.28; 95%CI 0.04 to 0.53; p < 0.05). Furthermore, VO2max (mL/kg/min) tends to increase in those participants who do higher VPA and less SB (p = 0.042), and there was a protective effect of "VPA ≥ 30 min/d; SB < 2h" against cardio-metabolic risk (PR 0.24; 95%CI 0.07 to 0.85; p < 0.05).

CONCLUSION

The current study suggests that adolescents should be encouraged to decrease sedentary lifestyle and increase physical activity, especially vigorous physical activity, in order to reduce cardio-metabolic risk.

Changes in mid-life fitness predicts heart failure risk at a later age independent of interval development of cardiac and noncardiac risk factors: the Cooper Center Longitudinal Study

AIMS

Low mid-life fitness is associated with higher risk for heart failure (HF). However, it is unclear to what extent this HF risk is modifiable and mediated by the burden of cardiac and noncardiac comorbidities. We studied the effect of cardiac and noncardiac comorbidities on the association of mid-life fitness and fitness change with HF risk.

METHODS

Linking individual subject data from the Cooper Center Longitudinal Study (CCLS) with Medicare claims files, we studied 19,485 subjects (21.2% women) who survived to receive Medicare coverage from 1999 to 2009. Fitness estimated by Balke treadmill time at mean age of 49 years was analyzed as a continuous variable (in metabolic equivalents [METs]) and according to age- and sex-specific quintiles. Associations of mid-life fitness and fitness change with HF hospitalization after age of 65 years were assessed by applying a proportional hazards recurrent events model to the failure time data with each comorbidity entered as time-dependent covariates.

RESULTS

After 127,110 person years of Medicare follow-up, we observed 1,038 HF hospitalizations. Higher mid-life fitness was associated with a lower risk for HF hospitalization (hazard ratio [HR] 0.82 [0.76-0.87] per MET) after adjustment for traditional risk factors. This remained unchanged after further adjustment for the burden of Medicare-identified cardiac and noncardiac comorbidities (HR 0.83 [0.78-0.89]). Each 1 MET improvement in mid-life fitness was associated with a 17% lower risk for HF hospitalization in later life (HR 0.83 [0.74-0.93] per MET).

CONCLUSIONS

Mid-life fitness is an independent and modifiable risk factor for HF hospitalization at a later age.

Effect of physical activity on age-related changes in cardiac function and performance in women

BACKGROUND

Higher levels of physical activity are associated with reduced cardiovascular mortality but its effect on age-related changes in cardiac structure and function is unknown. The present study defines the effect of daily physical activity on age-related changes in cardiac structure, function, metabolism, and performance in healthy women.

METHODS AND RESULTS

Sixty-three healthy women were grouped according to age (young, 20-30 years, n=21; middle, 40-50 years, n=22; and older, 65-81 years, n=20) and daily physical activity level (low active<7500 and high active>12,500 steps/d). Participants underwent cardiac MRI including tissue tagging and 31P spectroscopy and exercise testing with noninvasive central hemodynamic measurements. Aging was associated with increased concentric remodeling (P<0.01) and left ventricular torsion (P<0.01), and a decline in diastolic function (P<0.01), cardiac phosphocreatine:ATP ratio (P<0.01), peak exercise cardiac power output (P<0.01), and O2 consumption (P<0.01). Older high-active women demonstrated a phosphocreatine:ATP ratio and relative peak O2 consumption similar to young low-active women, and 23% and 26% higher than older low-active women (phosphocreatine:ATP ratio, 1.9±0.2 versus 1.4±0.1; P<0.05 and O2 consumption, 24.1±3.8 versus 17.8±2.0 mL/[kg·min]; P<0.01). In older women, physical activity had no effect on eccentricity ratio (0.9±0.2 versus 0.8±0.1 g/mL; P=0.19), E/A ratio (1.3±0.5 versus 1.4±0.5; P=0.66), torsion (7.6±1.7 versus 8.0°±2.1°; P=0.20), and peak cardiac power output (3.4±0.7 versus 3.4±0.8 W; P=0.91).

CONCLUSIONS

A higher level of daily physical activity preserves cardiac metabolism and exercise capacity with aging but has limited effect on age-related changes in concentric remodeling, diastolic function, and cardiac performance.

Cardiac mass and function decrease in bronchiolitis obliterans syndrome after lung transplantation: relationship to physical activity?

Rationale

There is a need to expand knowledge on cardio-pulmonary pathophysiology of bronchiolitis obliterans syndrome (BOS) following lung transplantation (LTx).

Objectives

The purpose of this study was to assess MRI-derived biventricular cardiac mass and function parameters as well as flow hemodynamics in patients with and without BOS after LTx.

Methods

Using 1.5T cardiac MRI, measurements of myocardial structure and function as well as measurements of flow in the main pulmonary artery and ascending aorta were performed in 56 lung transplant patients. The patients were dichotomized into two gender matched groups of comparable age range: one with BOS (BOS stages 1–3) and one without BOS (BOS 0/0p).

Measurements and Main Results

Significantly lower biventricular cardiac mass, right and left ventricular end-diastolic volume, biventricular stroke volume, flow hemodynamics and significant higher heart rate but preserved cardiac output were observed in patients with BOS 1–3 compared to the BOS 0/0p group (p<0.05). In a stepwise logistic regression analysis global cardiac mass (p = 0.046) and days after LTx (p = 0.0001) remained independent parameters to predict BOS. In a second model an indicator for the physical fitness level - walking number of stairs - was added to the logistic regression model. In this second model, time after LTx (p = 0.005) and physical fitness (p = 0.01) remained independent predictors for BOS.

Conclusion

The observed changes in biventricular cardiac mass and function as well as changes in hemodynamic flow parameters in the pulmonary trunk and ascending aorta are likely attributed to the physical fitness level of patients after lung transplantation, which in turn is strongly related to lung function.

Physical activity and cardiorespiratory fitness as major markers of cardiovascular risk: their independent and interwoven importance to health status

The evolution from hunting and gathering to agriculture, followed by industrialization, has had a profound effect on human physical activity (PA) patterns. Current PA patterns are undoubtedly the lowest they have been in human history, with particularly marked declines in recent generations, and future projections indicate further declines around the globe. Non-communicable health problems that afflict current societies are fundamentally attributable to the fact that PA patterns are markedly different than those for which humans were genetically adapted. The advent of modern statistics and epidemiological methods has made it possible to quantify the independent effects of cardiorespiratory fitness (CRF) and PA on health outcomes. Based on more than five decades of epidemiological studies, it is now widely accepted that higher PA patterns and levels of CRF are associated with better health outcomes. This review will discuss the evidence supporting the premise that PA and CRF are independent risk factors for cardiovascular disease (CVD) as well as the interplay between both PA and CRF and other CVD risk factors. A particular focus will be given to the interplay between CRF, metabolic risk and obesity.

Physical activity, measures of obesity, and cardiometabolic risk: the Multi-Ethnic Study of Atherosclerosis (MESA)

BACKGROUND

The influence of higher physical activity on the relationship between adiposity and cardiometabolic risk is not completely understood.

METHODS

Between 2000-2002, data were collected on 6795 Multi-Ethnic Study of Atherosclerosis (MESA) participants. Self-reported intentional physical activity in the lowest quartile (0-105 MET-minutes/week) was categorized as inactive and the upper three quartiles (123-37,260 MET-minutes/week) as active. Associations of body mass index (BMI) and waist circumference categories, stratified by physical activity status (inactive or active) with cardiometabolic risk factors (dyslipidemia, hypertension, upper quartile of homeostasis model assessment of insulin resistance [HOMA-IR] for population, and impaired fasting glucose or diabetes) were assessed using logistic regression analysis adjusting for age, gender, race/ethnicity, and current smoking.

RESULTS

Among obese participants, those who were physically active had reduced odds of insulin resistance (47% lower; P < .001) and impaired fasting glucose/diabetes (23% lower; P = .04). These associations were weaker for central obesity. However, among participants with a normal waist circumference, those who were inactive were 63% more likely to have insulin resistance (OR [95% CI] 1.63 [1.24-2.15]) compared with the active reference group.

CONCLUSIONS

Physical activity was inversely related to the cardiometabolic risk associated with obesity and central obesity.

Association of cardiorespiratory fitness with left ventricular remodeling and diastolic function: the Cooper Center Longitudinal Study

OBJECTIVES

This study sought to compare the cross-sectional associations between fitness and echocardiographic measures of cardiac structure and function.

BACKGROUND

Cardiorespiratory fitness is inversely associated with heart failure risk. However, the mechanism through which fitness lowers heart failure risk is not fully understood.

METHODS

We included 1,678 men and 1,247 women from the Cooper Center Longitudinal Study who received an echocardiogram from 1999 to 2011. Fitness was estimated by Balke protocol (in metabolic equivalents) and also categorized into age-specific quartiles, with quartile 1 representing low fitness. Cross-sectional associations between fitness (in metabolic equivalents) and relative wall thickness, left ventricular end-diastolic diameter indexed to body surface area, left atrial volume indexed to body surface area, left ventricular systolic function, and E/e' ratio were determined using multivariable linear regression analysis.

RESULTS

Higher levels of mid-life fitness (metabolic equivalents) were associated with larger indexed left atrial volume (men: beta = 0.769, p < 0.0001; women: beta = 0.879, p value ≤0.0001) and indexed left ventricular end-diastolic diameter (men: beta = 0.231, p < 0.001; women: beta = 0.264, p < 0.0001). Similarly, a higher level of fitness was associated with a smaller relative wall thickness (men: beta = -0.002, p = 0.04; women: beta = -0.005, p < 0.0001) and E/e' ratio (men: beta = -0.11, p = 0.003; women: beta = -0.13, p = 0.01). However, there was no association between low fitness and left ventricular systolic function (p = NS).

CONCLUSIONS

Low fitness is associated with a higher prevalence of concentric remodeling and diastolic dysfunction, suggesting that exercise may lower heart failure risk through its effect on favorable cardiac remodeling and improved diastolic function.

Clusters of AMI risk factors and their association with left ventricular hypertrophy: a population-based study within the Skaraborg Project, Sweden

OBJECTIVES

Risk factors for acute myocardial infarction (AMI) are known to cluster and to be differently distributed in men and women. The aim of this study was to sex-specifically explore clusters of acknowledged AMI risk factors by factor analysis, and to study whether such clusters are associated with left ventricular hypertrophy (LVH), used as a subclinical measure of CHD.

METHODS

In 2001-2005, 2328 subjects (30-74 years) were randomly selected from two municipalities in Sweden (participation-rate 76%) and were assessed with regard to cardiovascular risk factors; 852 participants also had an echocardiographic examination performed.

RESULTS

Factor analysis identified three identical factors in men and women. WHR, HOMA-ir, systolic blood pressure, and ApoB/ApoA1 loaded significantly on the principal "metabolic factor", leisure-time physical activity and self-rated health loaded significantly on the "vitality factor", and smoking and alcohol consumption loaded significantly on the "addiction factor". The metabolic factor was associated with LVH in both men (P<0.001) and women (P<0.001), whereas the addiction factor was associated with LVH solely in men (P=0.002).

CONCLUSIONS

The consistent pattern in the clustering of acknowledged AMI risk factors suggests common underlying mechanisms in both men and women. However, whereas the metabolic factor was paramount in both men and women in the association with LVH, the addiction factor had an impact solely in men. As LVH often precedes AMI, a deeper understanding of risk factors for LVH, including consideration of the supposed sex differences, can be useful in order to explore prevention strategies for AMI.

Exercise increases age-related penetrance and arrhythmic risk in arrhythmogenic right ventricular dysplasia/cardiomyopathy-associated desmosomal mutation carriers

OBJECTIVES

This study sought to determine how exercise influences penetrance of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) among patients with desmosomal mutations.

BACKGROUND

Although animal models and anecdotal evidence suggest that exercise is a risk factor for ARVD/C, there have been no systematic human studies.

METHODS

Eighty-seven carriers (46 male; mean age, 44 ± 18 years) were interviewed about regular physical activity from 10 years of age. The relationship of exercise with sustained ventricular arrhythmia (ventricular tachycardia/ventricular fibrillation [VT/VF]), stage C heart failure (HF), and meeting diagnostic criteria for ARVD/C (2010 Revised Task Force Criteria [TFC]) was studied.

RESULTS

Symptoms developed in endurance athletes (N = 56) at a younger age (30.1 ± 13.0 years vs. 40.6 ± 21.1 years, p = 0.05); they were more likely to meet TFC at last follow-up (82% vs. 35%, p < 0.001) and have a lower lifetime survival free of VT/VF (p = 0.013) and HF (p = 0.004). Compared with those who did the least exercise per year (lowest quartile) before presentation, those in the second (odds ratio [OR]: 6.64, p = 0.013), third (OR: 16.7, p = 0.001), and top (OR: 25.3, p < 0.0001) quartiles were increasingly likely to meet TFC. Among 61 individuals who did not present with VT/VF, the 13 subjects experiencing a first VT/VF event over a mean follow-up of 8.4 ± 6.7 years were all endurance athletes (p = 0.002). Survival from a first VT/VF event was lowest among those who exercised most (top quartile) both before (p = 0.036) and after (p = 0.005) clinical presentation. Among individuals in the top quartile, a reduction in exercise decreased VT/VF risk (p = 0.04).

CONCLUSIONS

Endurance exercise and frequent exercise increase the risk of VT/VF, HF, and ARVD/C in desmosomal mutation carriers. These findings support exercise restriction for these patients.

Race differences in ventricular remodeling and function among college football players

Athletic training is associated with increases in ventricular mass and volume. Recent studies have shown that left ventricular mass increases proportionally in white athletes with a mass/volume ratio approaching unity. The objective of this study was to compare the proportionality in ventricular remodeling and ventricular function in black versus white National Collegiate Athletic Association Division I football players. From 2008 to 2011, football players at Stanford University underwent cardiovascular screening with a 12-point history and physical examination, electrocardiography, and focused echocardiography. Compared with white players, black players had on average higher left ventricular mass indexes (77 ± 11 vs 71 ± 11 g/m(2), p = 0.009), higher mass/volume ratios (1.18 ± 0.16 vs 1.06 ± 0.09 g/ml, p <0.001), and higher QRS vector magnitudes (3.2 ± 0.7 vs 2.7 ± 0.8, p = 0.002). Black race had an odds ratio of 14 (95% confidence interval 5 to 42, p <0.001) for a mass/volume ratio >1.2. Mass/volume ratio was inversely related to early diastolic tissue Doppler velocity e' (r = -0.50, p <0.001) but not to QRS vector magnitude (r = 0.065, p = 0.034). With regard to systolic indexes, there was no significant difference in the left ventricular ejection fraction, velocity of circumferential shortening, and isovolumic acceleration. In conclusion, black college football players exhibit more concentric ventricular remodeling, lower early diastolic annular velocities, and increased ventricular voltage compared with white players. Ventricular mass increases proportionally to volume in white players but not in black players.