Regression of Left Ventricular Mass in Athletes Undergoing Complete Detraining Is Mediated by Decrease in Intracellular but Not Extracellular Compartments

Detraining among Athletes-Is Withdrawal of Adaptive Cardiovascular Changes a Hint for the Differential Diagnosis of Physically Active People?

An athlete's training aims to achieve the highest possible sports results by improving physical dispositions which lead to cardiac adaptive changes. The annual training cycle is divided into periods. The preparatory period begins with gradually increasing training intensity and volume until the competitive period occurs, when the athlete's maximum performance is expected. Finally, the athlete enters a phase of loss of fitness, which is called detraining. Detraining is a time of resting both physically and mentally from the training regime and usually lasts about 4 weeks for endurance athletes. We collected data from much research on athletes' detraining. According to these data, the earliest change after detraining seems to be a decrease in left ventricular wall thickness and left ventricular mass, followed by decreased performance parameters, diastolic diameter of the left ventricle and size of the left atrium. A reversal of adaptive changes affects the left heart chamber first, then the right atrium and, finally, the right ventricle. Training reduction is often proposed as a method of differentiating an athlete's heart from cardiomyopathies. The aim of this study is to consider the diagnostic value of detraining in differentiating athletes' hearts from cardiomyopathies. We suggest that detraining cannot be conclusive in differentiating the disease from adaptive changes. Although a withdrawal of the characteristic morphological, functional and electrocardiographic changes occurs in healthy athletes during detraining, it can also concern individuals with cardiomyopathies due to the lower expression of abnormal features after decreased training loads. Therefore, a quick diagnosis and individual assessments using imaging and genetic tests are essential to recommend a proper type of activity.

Cardiac functional adaptation to resistance and endurance exercise training: a randomized crossover study

Few training studies have assessed the impact of different modes of exercise on changes in cardiac function. This study investigated changes in left ventricular (LV) systolic and diastolic function following endurance (END) and resistance (RES) training in healthy participants. Sixty-four individuals participated in a randomized crossover design trial, involving 12 wk of END and RES training, separated by a 12-wk washout. Echocardiograms assessed systolic function [ejection fraction (EF) and global longitudinal strain (GLS)], diastolic function [mitral valve early velocity (E), tissue Doppler velocity (e'), their ratio (E/e')], and left atrial volume indexed to body surface area (LA ESVi). LV mass (LVM) increased with both RES (Δ5.3 ± 11.9, P = 0.001) and END (Δ7.5 ± 13.9, P < 0.001). Once adjusted for lean body mass (LVMi), changes remained significant following END. E/e' improved following END (Δ-0.35 ± 0.98, P = 0.011) not RES (Δ0.35 ± 1.11, P =0.157; P = 0.001 between modes). LA ESVi increased with END (Δ2.0 ± 6.1, P = 0.019) but not RES (Δ1.7 ± 5.7, P = 0.113). EF and GLS were not impacted significantly by either mode of training. Adaptation in LVM and LA volumes, as well as diastolic function, was exercise mode specific. Twelve weeks of intensive END increased LVM, LA volumes, and increased diastolic function. Following RES, LVM increased, although this was attenuated after accounting for changes in lean body mass. There were no changes in systolic function following either mode of exercise training.NEW & NOTEWORTHY Different types of exercise training induce distinct physiological adaptations however few exercise training studies have assessed the impact of different modes of exercise on cardiac function. This study investigated changes in left ventricular systolic and diastolic function following exercise training. Participants completed both endurance and resistance training separated by a 12-wk washout period so each participant is their own control. We present adaptations in cardiac structure and diastolic function are exercise mode specific.

Effects of detraining on left ventricular mass in endurance-trained individuals: a systematic review and meta-analysis

AIMS

Detraining refers to a loss of training adaptations resulting from reductions in training stimulus due to illness, injury, or active recovery breaks in a training cycle and is associated with a reduction in left ventricular mass (LVM). The purpose of this study was to conduct a systematic review and meta-analysis to determine the influence of detraining on LVM in endurance-trained, healthy individuals.

METHODS AND RESULTS

Using electronic databases (e.g. EMBASE and MEDLINE), a literature search was performed looking for prospective detraining studies in humans. Inclusion criteria were adults, endurance-trained individuals with no known chronic disease, detraining intervention >1 week, and pre- and post-detraining LVM reported. A pooled statistic for random effects was used to assess changes in LVM with detraining. Fifteen investigations (19 analyses) with a total of 196 participants (ages 18-55 years, 15% female) met inclusion criteria, with detraining ranging between 1.4 and 15 weeks. The meta-analysis revealed a significant reduction in LVM with detraining (standardized mean difference = -0.586; 95% confidence interval = -0.817, -0.355; P < 0.001). Independently, length of detraining was not correlated with the change in LVM. However, a meta-regression model revealed length of the detraining, when training status was accounted for, was associated with the reduction of LVM (Q = 15.20, df = 3, P = 0.0017). Highly trained/elite athletes had greater reductions in LVM compared with recreational and newly trained individuals (P < 0.01). Limitations included relatively few female participants and inconsistent reporting of intervention details.

CONCLUSION

In summary, LVM is reduced following detraining of one week or more. Further research may provide a greater understanding of the effects of sex, age, and type of detraining on changes in LVM in endurance-trained individuals.

LBBB and heart failure-Relationships among QRS amplitude, duration, height, LV mass, and sex

BACKGROUND

Height, left ventricular (LV) size, and sex were proposed as additional criteria for patient selection for cardiac resynchronization therapy (CRT) but their connections with the QRS complex in left bundle branch block (LBBB) are little investigated. We evaluated these.

METHODS

Among patients with "true" LBBB, QRS duration (QRSd) and amplitude, and LV hypertrophy indices, were correlated with patient's height and LV mass, and compared between sexes.

RESULTS

In this study cohort (n = 220; 60 ± 12 years; left ventricular ejection fraction [LVEF] 21 ± 7%; mostly New York Heart Association II-III, QRSd 165 ± 19 ms; 57% female; 70% responders [LVEF increased ≥5%]), LV mass was increased in all patients. QRS amplitude did not correlate with LV mass or height in any individual lead or with Sokolow-Lyon or Cornell-Lyon indices. QRSd did not correlate with height. In contrast, QRSd correlated strongly with LV mass (r = .51). CRT response rate was greater in women versus men (84% vs. 58%, p < .001) despite shorter QRSd [7% shorter (p < .0001)]. QRSd normalized for height resulted in a 2.7% and for LV mass 24% greater index in women.

CONCLUSION

True LBBB criteria do not exclude HF patients with increased LV mass. QRS amplitudes do not correlate with height or LV mass. Height does not affect QRSd. However, QRSd correlates with LV size. QRSd normalized for LV mass results in 24% greater value in women in the direction of sex-specific responses. LV mass may be a significant nonelectrical modifier of QRSd for CRT.

Preeclampsia's Cardiovascular Aftermath: A Comprehensive Review of Consequences for Mother and Offspring

Preeclampsia (PE), a multisystem hypertensive disorder affecting 2-8% of pregnancies, has emerged as a novel risk factor for cardiovascular disease (CVD) in affected mothers and in their offspring. Between 10 and 15 years following gestation, women with a history of PE have double the risk of CVD, nearly 4 times the risk of hypertension, and increased all-cause mortality. Offspring exposed to PE in utero carry an increased risk of CVD and congenital heart defects. Due to the multifactorial nature of both PE and CVD, a clear dependency has been difficult to establish. The interplay between CVD and PE is an area of active investigation, likely involving placental, genetic, and epigenetic factors resulting in enduring endothelial, vascular, and immune dysfunction. Fetal developmental programming induced by adverse intrauterine environments, epigenetic changes triggered by oxidative stress, and underlying genetic predisposition play pivotal roles in the development of CVD in offspring exposed to PE. Though the literature has discussed the cardiovascular outcomes associated with PE for nearly a decade, patient risk perception and health care provider awareness remain low, representing a substantial missed opportunity for early intervention in this vulnerable population. This review article will discuss the pathophysiology of preeclampsia, its intersection with CVD, and the long-term cardiovascular consequences for affected mothers and their offspring. Our objective is to increase health care provider awareness and garner greater research interest in this important topic.

CMR Mapping: The 4th-Era Revolution in Cardiac Imaging

Cardiac magnetic resonance (CMR) imaging has witnessed substantial progress with the advent of parametric mapping techniques, most notably T1 and T2 mapping. These advanced techniques provide valuable insights into a wide range of cardiac conditions, including ischemic heart disease, cardiomyopathies, inflammatory cardiomyopathies, heart valve disease, and athlete's heart. Mapping could be the first sign of myocardial injury and oftentimes precedes symptoms, changes in ejection fraction, and irreversible myocardial remodeling. The ability of parametric mapping to offer a quantitative assessment of myocardial tissue properties addresses the limitations of conventional CMR methods, which often rely on qualitative or semiquantitative data. However, challenges persist, especially in terms of standardization and reference value establishment, hindering the wider clinical adoption of parametric mapping. Future developments should prioritize the standardization of techniques to enhance their clinical applicability, ultimately optimizing patient care pathways and outcomes. In this review, we endeavor to provide insights into the potential contributions of CMR mapping techniques in enhancing the diagnostic processes across a range of cardiac conditions.

Cardiac magnetic resonance assessment of athletic myocardial fibrosis; Benign bystander or malignant marker?

The benefits of exercise are irrefutable with a well-established dose-dependent relationship between exercise intensity and reduction in cardiovascular disease. Differentiating the physiological adaptation to exercise, termed the "athlete's heart" from cardiomyopathies, has been advanced by the advent of more sophisticated imaging modalities such as cardiac magnetic resonance imaging (CMR). Myocardial fibrosis on CMR is a mutual finding amongst seemingly healthy endurance athletes and individuals with cardiomyopathy. As a substrate for arrhythmias, fibrosis is traditionally associated with increased cardiovascular risk. In this article, we discuss the aetiologies, distribution and potential implications of myocardial fibrosis in athletes.

Identification of non-ischaemic fibrosis in male veteran endurance athletes, mechanisms and association with premature ventricular beats

Left ventricular fibrosis can be identified by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) in some veteran athletes. We aimed to investigate prevalence of ventricular fibrosis in veteran athletes and associations with cardiac arrhythmia. 50 asymptomatic male endurance athletes were recruited. They underwent CMR imaging including volumetric analysis, bright blood (BB) and dark blood (DB) LGE, motion corrected (MOCO) quantitative stress and rest perfusion and T1/T2/extracellular volume mapping. Athletes underwent 12-lead electrocardiogram (ECG) and 24-h ECG. Myocardial fibrosis was identified in 24/50 (48%) athletes. All fibrosis was mid-myocardial in the basal-lateral left ventricular wall. Blood pressure was reduced in athletes without fibrosis compared to controls, but not athletes with fibrosis. Fibrotic areas had longer T2 time (44 ± 4 vs. 40 ± 2 ms, p < 0.0001) and lower rest myocardial blood flow (MBF, 0.5 ± 0.1 vs. 0.6 ± 0.1 ml/g/min, p < 0.0001). On 24-h ECG, athletes with fibrosis had greater burden of premature ventricular beats (0.3 ± 0.6 vs. 0.05 ± 0.2%, p = 0.03), with higher prevalence of ventricular couplets and triplets (33 vs. 8%, p = 0.02). In veteran endurance athletes, myocardial fibrosis is common and associated with an increased burden of ventricular ectopy. Possible mechanisms include inflammation and blood pressure. Further studies are needed to establish whether fibrosis increases risk of malignant arrhythmic events.

Flat Magnetic Stimulation for Stress Urinary Incontinence: A 3-Month Follow-Up Study

BACKGROUND

flat magnetic stimulation is based on a stimulation produced by electromagnetic fields with a homogenous profile. Patients with stress urinary incontinence (SUI) can take advantage of this treatment. We aimed to evaluate medium-term subjective, objective, and quality-of-life outcomes in patients with stress urinary incontinence to evaluate possible maintenance schedules.

METHODS

a prospective evaluation through the administration of the International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF), the Incontinence Impact Questionnaire (IIQ7), and the Female Sexual Function Index (FSFI) was performed at three different time points: at the baseline (T0), at the end of treatment (T1), and at 3-month follow-up (T2). The stress test and the Patient Global Impression of Improvement questionnaire (PGI-I) defined objective and subjective outcomes, respectively.

RESULTS

25 consecutive patients were enrolled. A statistically significant reduction in the IIQ7 and ICIQ-SF scores was noticed at T1 returned to levels comparable to the baseline at T2. However, objective improvement remained significant even at a 3-month follow-up. Moreover, the PGI-I scores at T1 and T2 were comparable, demonstrating stable subjective satisfaction.

CONCLUSION

despite a certain persistence of the objective and subjective continence improvement, the urinary-related quality of life decreases and returns to baseline values three months after the end of flat magnetic stimulation. These findings indicate that a further cycle of treatment is probably indicated after 3 months since benefits are only partially maintained after this timespan.

Regression of cardiac hypertrophy in health and disease: mechanisms and therapeutic potential

Left ventricular hypertrophy is a leading risk factor for cardiovascular morbidity and mortality. Although reverse ventricular remodelling was long thought to be irreversible, evidence from the past three decades indicates that this process is possible with many existing heart disease therapies. The regression of pathological hypertrophy is associated with improved cardiac function, quality of life and long-term health outcomes. However, less than 50% of patients respond favourably to most therapies, and the reversibility of remodelling is influenced by many factors, including age, sex, BMI and disease aetiology. Cardiac hypertrophy also occurs in physiological settings, including pregnancy and exercise, although in these cases, hypertrophy is associated with normal or improved ventricular function and is completely reversible postpartum or with cessation of training. Studies over the past decade have identified the molecular features of hypertrophy regression in health and disease settings, which include modulation of protein synthesis, microRNAs, metabolism and protein degradation pathways. In this Review, we summarize the evidence for hypertrophy regression in patients with current first-line pharmacological and surgical interventions. We further discuss the molecular features of reverse remodelling identified in cell and animal models, highlighting remaining knowledge gaps and the essential questions for future investigation towards the goal of designing specific therapies to promote regression of pathological hypertrophy.

Left Ventricular Adaptation to Exercise Training via Magnetic Resonance Imaging: Studies of Twin Responses to Understand Exercise THerapy

PURPOSE

Changes in left ventricular mass (LVM) and end-diastolic volume (EDV) in response to exercise training are important determinants of functional capacity in health and disease, but the impact of different exercise modalities remains unclear.

METHODS

Using a randomized crossover design we studied the impact of resistance (RES) and endurance (END) training using cardiac magnetic resonance imaging in previously untrained monozygotic (MZ) and dizygotic (DZ) twin pairs (n = 72; 22 MZ pairs, 14 DZ same-sex pairs; 26.1 ± 5.4 yr). Twins, as pairs, undertook 3 months of RES and 3 months of END training (order randomized), separated by a 3-month washout.

RESULTS

Group results revealed that END increased LVM (P < 0.001) and EDV (P = 0.007), whereas RES did not (P > 0.05). A higher proportion of individuals responded to END than RES for LVM (72% vs 38%, P < 0.001) and EDV (67% vs 40%, P = 0.003). Baseline cross-sectional intraclass correlations were higher for MZ than DZ twin pairs for all variables (e.g., LVM heritability = 0.42), but no significant correlations were apparent between pairs for change in any variable in response to either RES or END (P > 0.05).

CONCLUSIONS

Our findings indicate that cardiac adaptation in response to exercise is modality-specific and that low responders to one mode of exercise can be high responders to an alternative. Heritability estimates based on cross-sectional data, which suggested a genetic contribution to LVM, do not accord with estimates based on training effects, which indicated limited genetic impact on adaptation in this 3-month study of exercise training. This study has implications for understanding the physiological and health impacts of typically used exercise modalities on cardiac adaptation in previously untrained individuals.

Coronary microvascular function and visceral adiposity in patients with normal body weight and type 2 diabetes

OBJECTIVE

This study sought to assess whether diabetes affects coronary microvascular function in individuals with normal body weight.

METHODS

Seventy-five participants (30 patients with type 2 diabetes [T2D] who were overweight [O-T2D], 15 patients with T2D who were lean [LnT2D], 15 healthy volunteers who were lean [LnHV], and 15 healthy volunteers who were overweight [O-HV]) without established cardiovascular disease were recruited. Participants underwent magnetic resonance imaging for assessment of subcutaneous, epicardial, and visceral adipose tissue areas, adenosine stress myocardial blood flow (MBF), and cardiac structure and function.

RESULTS

Stress MBF was reduced only in the O-T2D group (mean [SD], LnHV = 2.07 [0.47] mL/g/min, O-HV = 2.08 [0.42] mL/g/min, LnT2D = 2.16 [0.36] mL/g/min, O-T2D = 1.60 [0.28] mL/g/min; p ≤ 0.0001). Accumulation of visceral fat was evident in the LnT2D group at similar levels to the O-HV group (LnHV = 127 [53] cm² , O-HV = 181 [60] cm² , LnT2D = 182 [99] cm² , O-T2D = 288 [72] cm² ; p < 0.0001). Only the O-T2D group showed reductions in left ventricular ejection fraction (LnHV = 63% [4%], O-HV = 63% [4%], LnT2D = 60% [5%], O-T2D = 58% [6%]; p = 0.0008) and global longitudinal strain (LnHV = -15.1% [3.1%], O-HV= -15.2% [3.7%], LnT2D = -13.4% [2.7%], O-T2D = -11.1% [2.8%]; p = 0.002) compared with both control groups.

CONCLUSIONS

Patients with T2D and normal body weight do not show alterations in global stress MBF, but they do show significant increases in visceral adiposity. Patients with T2D who were overweight and had no prior cardiovascular disease showed an increase in visceral adiposity and significant reductions in stress MBF.

Cardiac effects of detraining in athletes: A narrative review

BACKGROUND

Routine physical activity stimulates numerous morphologic and functional adaptations of the cardiac system, which are commonly referred to as exercise-induced cardiac remodeling (EICR). EICR has been well documented in elite and recreational athletes, but comparatively little is known about the "reverse" cardiac adaptations during detraining in an athletic population.

OBJECTIVE

To assess the morphologic and functional cardiac effects of detraining in athletes.

METHODS

Eligible studies were identified in PubMed from inception to May 2020. Studies were included if they assessed the cardiac effects of detraining periods in athletes.

RESULTS

A total of 16 studies from the literature search were identified and included in this review. These studies included athletes from multiple different sporting disciplines and detraining periods ranged from 3 weeks to 13 years. Detraining periods led to significantly decreased right ventricular and left (LV) ventricular dimensions, LV mass, and LV wall thickness, but only limited changes in systolic and diastolic functional parameters were observed.

CONCLUSIONS

From the limited data available in this population, cardiac atrophy has been observed with short periods of detraining (1-8 weeks) but often spares systolic and diastolic heart function. Supplemental exercise training during times of rehabilitation to combat cardiac regression has not been vigorously studied in athletes, so the ideal frequency, intensity, and modality of exercise needed to maintain EICR remains unclear.

Empagliflozin Reduces Myocardial Extracellular Volume in Patients With Type 2 Diabetes and Coronary Artery Disease

OBJECTIVES

This study sought to evaluate the effects of empagliflozin on extracellular volume (ECV) in individuals with type 2 diabetes mellitus (T2DM) and coronary artery disease (CAD).

BACKGROUND

Empagliflozin has been shown to reduce left ventricular mass index (LVMi) in patients with T2DM and CAD. The effects on myocardial ECV are unknown.

METHODS

This was a prespecified substudy of the EMPA-HEART (Effects of Empagliflozin on Cardiac Structure in Patients with Type 2 Diabetes) CardioLink-6 trial in which 97 participants were randomized to receive empagliflozin 10 mg daily or placebo for 6 months. Data from 74 participants were included: 39 from the empagliflozin group and 35 from the placebo group. The main outcome was change in left ventricular ECV from baseline to 6 months determined by cardiac magnetic resonance (CMR). Other outcomes included change in LVMi, indexed intracellular compartment volume (iICV) and indexed extracellular compartment volume (iECV), and the fibrosis biomarkers soluble suppressor of tumorgenicity (sST2) and matrix metalloproteinase (MMP)-2.

RESULTS

Baseline ECV was elevated in the empagliflozin group (29.6 ± 4.6%) and placebo group (30.6 ± 4.8%). Six months of empagliflozin therapy reduced ECV compared with placebo (adjusted difference: -1.40%; 95% confidence interval [CI]: -2.60 to -0.14%; p = 0.03). Empagliflozin therapy reduced iECV (adjusted difference: -1.5 ml/m²; 95% CI: -2.6 to -0.5 ml/m²; p = 0.006), with a trend toward reduction in iICV (adjusted difference: -1.7 ml/m²; 95% CI: -3.8 to 0.3 ml/m²; p = 0.09). Empagliflozin had no impact on MMP-2 or sST2.

CONCLUSIONS

In individuals with T2DM and CAD, 6 months of empagliflozin reduced ECV, iECV, and LVMi. No changes in MMP-2 and sST2 were seen. Further investigation into the mechanisms by which empagliflozin causes reverse remodeling is required. (Effects of Empagliflozin on Cardiac Structure in Patients With Type 2 Diabetes [EMPA-HEART]; NCT02998970).

Cardiovascular Magnetic Resonance and Sport Cardiology: a Growing Role in Clinical Dilemmas

Exercise training induces morphological and functional cardiovascular adaptation known as the "athlete's heart" with changes including dilatation, hypertrophy, and increased stroke volume. These changes may overlap with pathological appearances. Distinguishing athletic cardiac remodelling from cardiomyopathy is important and is a frequent medical dilemma. Cardiac magnetic resonance (CMR) has a role in clinical care as it can refine discrimination of health from a disease where ECG and echocardiography alone have left or generated uncertainty. CMR can more precisely assess cardiac structure and function as well as characterise the myocardium detecting key changes including myocardial scar and diffuse fibrosis. In this review, we will review the role of CMR in sports cardiology.