Exercise-Induced Cardiac Troponin Elevations: From Underlying Mechanisms to Clinical Relevance

The Effects of Circadian Rhythms and Exercise Preconditioning on Cardiac Troponin T Levels Following Graded Exercise

This study explored the impact of circadian rhythms on the circulating cardiac troponin T (cTnT) response to a graded exercise test (GXT) and examined whether an initial GXT influenced the cTnT response to a subsequent GXT performed 7-9 days later. Twenty-one healthy young males (age: 20.6 ± 2.2 years, body mass index: 22.2 ± 2.6 kg/m2, V̇O2max: 31.8 ± 8.7 mL.kg-1.min-1) participated in three trials: an initial GXT (GXT1), a resting control trial (CON) and a second GXT (GXT2), separated by at least 72 h. The serum cTnT levels were measured pre-exercise, 4 h post-exercise or during the control. In GXT1, the cTnT levels did not show significant changes (median [range], pre: 3.80 [3.00-10.59] ng.L-1, post: 4.22 [3.00-9.08] ng.L-1, p > 0.05). During CON, the cTnT levels decreased significantly from morning to early afternoon (3.52 [3.00-10.84] vs. 3.00 [3.00-7.57] ng.L-1, p < 0.05), reflecting a circadian rhythm. Interestingly, GXT1 appeared to prevent this circadian decline. Furthermore, in GXT2, the cTnT levels significantly decreased post-exercise (4.13 [3.00-15.48] vs. 3.24 [3.00-12.96] ng.L-1, p < 0.05), suggesting a possible "late exercise preconditioning" effect from GXT1. These findings suggest that GXT can interact with circadian rhythms, altering cTnT dynamics, and that prior exercise may induce prolonged cardioprotective effects. This study highlights the importance of accounting for circadian variability and late preconditioning effects in future research on exercise-induced cTnT release.

Impact of High Intensity Contact Physical Activity During a Match on Echocardiographic Parameters and High-Sensitivity Troponin I in Competitive Rugby Players

Background/Objectives: High-intensity physical activity, especially in contact sports, may have harmful effect on athletes' health. The aim of the study is to determine acute changes in the function of the left ventricle in rugby players after a competitive match. Methods: A prospective, clinical, observational case-control study was conducted. All cases were European Caucasian male athletes, older than 18 years, who had played for at least 60 min in the investigated match. A transthoracic echocardiography and blood tests were performed in all the participants two days before the match and within one hour after the match. Results: The total number of examinees was 34. Out of the 31 measured echocardiographic parameters, 22 showed a statistically significant change before and after the match. We also observed changes in echocardiographic parameters in relation to the increase in high-sensitivity troponin I. Two-dimensional left ventricle (LV) end-systolic (75 ± 10.5 vs. 67.1 ± 10 mL, p = 0.032) and LV end-diastolic (149.7 ± 24.6 vs. 133.8 ± 13.3 mL, p = 0.020) volumes, 3D LV end-systolic volume (75.8 ± 9.2 vs. 67.4 ± 9.5 mL, p = 0.014), indexed 2D LV end-diastolic volume (67.6 ± 9.3 vs. 61.4 ± 8 mL, p = 0.042), and indexed 3D LV end-systolic (34.3 ± 3.8 vs. 31 ± 4.8 mL, p = 0.033) volume after the match were significantly higher in players with troponin increase. Conclusions: High-intensity contact activity, such as rugby, leads to acute changes in echocardiographic parameters, especially in athlete's who experience elevation in troponin.

Dried Blood Spots to Assess Cardiovascular-Kidney-Metabolic Health

Dried blood spot sampling offers a scalable strategy to close diagnostic gaps and improve global surveillance for cardiovascular-kidney-metabolic syndrome. However, assay performance and the extent of validity vary widely between biomarkers used in cardiovascular-kidney-metabolic health assessment under different settings and have not been well described. To fill this gap, we conducted a systematic search of the literature and a narrative synthesis through April 2024 and included reports with laboratory or field validation measuring biomarkers that can be used in cardiovascular-kidney-metabolic health assessment. We categorized assays into categories based on laboratory validation: excellent performance (r>0.95 with gold standard methods and coefficients of variation <5%), very good performance (r>0.90 and coefficients of variation <10%), reasonable performance (r>0.80 and coefficients of variation <15%), and poor performance (r<0.80 or coefficients of variation >15%). The extent of validation was determined by the total number of field validation studies with strong agreement. Hemoglobin A1c has strong laboratory and field validation and should be considered for expansion into clinical testing in low-resource settings. Traditional lipid biomarkers showed poor performance in field validation studies, but apoB (apolipoprotein B), creatinine, cystatin C, and NT-proBNP (N-terminal prohormone of brain natriuretic peptide) showed promising initial laboratory validation results and deserve greater attention in field validation studies. High-sensitivity C-reactive protein has strong laboratory and field validation but has limited clinical utility. Dried blood spot assays have been developed for biomarkers that offer mechanistic insights including inflammatory and vascular injury markers, fatty acids, malondialdehyde, asymmetric dimethylarginine, trimethylamine N-oxide, carnitines, and omics.

Assessment of cardiovascular risk and physical activity: the role of cardiac-specific biomarkers in the general population and athletes

The first part of this Inter-Society Document describes the mechanisms involved in the development of cardiovascular diseases, particularly arterial hypertension, in adults and the elderly. It will also examine how consistent physical exercise during adolescence and adulthood can help maintain blood pressure levels and prevent progression to symptomatic heart failure. The discussion will include experimental and clinical evidence on the use of specific exercise programs for preventing and controlling cardiovascular diseases in adults and the elderly. In the second part, the clinical relevance of cardiac-specific biomarkers in assessing cardiovascular risk in the general adult population will be examined, with a focus on individuals engaged in sports activities. This section will review recent studies that suggest a significant role of biomarkers in assessing cardiovascular risk, particularly the presence of cardiac damage, in athletes who participate in high-intensity sports. Finally, the document will discuss the potential of using cardiac-specific biomarkers to monitor the effectiveness of personalized physical activity programs (Adapted Physical Activity, APA). These programs are prescribed for specific situations, such as chronic diseases or physical disabilities, including cardiovascular diseases. The purposes of this Inter-Society Document are the following: 1) to discuss the close pathophysiological relationship between physical activity levels (ranging from sedentary behavior to competitive sports), age categories (from adolescence to elderly age), and the development of cardiovascular diseases; 2) to review in detail the experimental and clinical evidences supporting the role of cardiac biomarkers in identifying athletes and individuals of general population at higher cardiovascular risk; 3) to stimulate scientific societies and organizations to develop specific multicenter studies that may take into account the role of cardiac biomarkers in subjects who follow specific exercise programs in order to monitor their cardiovascular risk.

The influence of prolonged aerobic exercise on cardiac, muscular, and renal biomarkers in trained individuals with obesity

PURPOSE

The aim of this study was to investigate the influence of prolonged aerobic exercise on cardiac, muscular and renal inflammatory markers in a group of trained obese men.

METHODS

Seventeen men (aged 40 ± 6 years; body mass index [BMI] 31.3 ± 2.8 kg m-2, maximal oxygen uptake [V'O2max] 41.5 ± 5.6 ml kg-1 min-1) ran a half, 30 km, or full marathon. Troponin I (cTnI), the n-terminal creatine kinase-myocardial band (CK-MB), pro b-type natriuretic peptide (NT-proBNP), lactate dehydrogenase (LDH), myoglobin, creatinine (CREA) and the estimated glomerular filtration rate (eGFR) were measured before (T0), immediately after (T1) and 3 days after the race (T2).

RESULTS

The concentrations of cTnI, myoglobin, LDH, CK-MB and CREA significantly increased (P < 0.05), whereas eGRF decreased at T1 (P < 0.05). All the above parameters returned to baseline at T2, except for eGFR, which remained lower than that at T0 (P < 0.05). A positive association was observed between ΔCK-MB (%) and the time spent in Zone 3 during the race (R = 0.686, P = 0.014). The Δmyoglobin (%) was positively correlated with race time, race mean speed and time in Zone 3 (R = 0.574-0.862, P < 0.05). The ∆CREA values were moderately correlated with the race mean HRMAX (%) and time spent in Zone 3 (%) (R = 0.514-0.610; P = 0.05). The ∆eGRF values were moderately inversely correlated with the time spent in Zone 3 (%) (R =  - 0.627; P < 0.05).

CONCLUSION

Changes in cardiac, muscular and renal inflammatory markers in trained men with obesity are consistent with those described in the literature in normal-weight individuals. Finally, running parameters, such as running time, average running intensity and time in Zone 3 appear to be responsible for the changes in cardiac, muscular and renal function markers after long-distance running.

The kinetics of cardiac troponin T release during and after 1- and 6-h maximal cycling trials

OBJECTIVES

In this study, the effects of short-duration high-intensity exercise and long-duration exercise on high-sensitivity cardiac troponin T (hs-cTnT) levels were compared.

METHODS

Twelve male amateur cyclists performed 1- and 6-h cycling trials. In both exercise trials, hs-cTnT was assessed at rest, immediately postexercise and at 1, 3, 6, 12, and 24 h postexercise. Additionally, hs-cTnT levels were assessed every hour during the 6-h trial.

RESULTS

Exercise resulted in an increase in hs-cTnT levels in all subjects. Circulating hs-cTnT levels increased in both exercise trials (p < 0.001), with higher peak values occurring after the 1-h trial compared with those of the 6-h trial (p = 0.023). The upper reference limit (URL) exceeded 83 % of the participants in the 1-h trial and 42 % of the participants in the 6-h trial. There was substantial individual variability in peak hs-cTnT in both trials. Values of hs-cTnT were greater after exercise than during exercise for the 6-h trial. For both exercise trials, the maximum postexercise hs-cTnT values correlated with the %HRMAX (r = 0.906 for the 1-h trial, r = 0.735 for the 6-h trial). For the 1-h trial, the maximum postexercise hs-cTnT values were observed at 3 h in all subjects. No significant difference in the hs-cTnT values was observed for the 6-h trial during the first 12 h postexercise.

CONCLUSIONS

Our results demonstrated greater hs-cTnT levels in young male participants after a 1-h cycling trial than after a 6-h cycling trial, despite a substantially greater energy expenditure and total external work completed in the 6-h trial. Postexercise hs-cTnT values are associated with relative exercise intensity.

Three-year changes in high-sensitivity cardiac troponin-T and total mortality in older adults

Elevated high-sensitivity cardiac troponin-T (hs-cTnT) is associated with mortality in older adults. However, little is known about the implications of changes over time. We investigated hs-cTnT 3-year change and its association with subsequent mortality in the Activity and Function in the Elderly Study. Participants with baseline and follow-up hs-cTnT < 5 ng/L built the reference group (G1 = 156). Five groups were defined among those with an increment over time: Undetectable at baseline: follow-up < 14 ng/L (G2 = 295), follow-up ≥ 14 ng/L (G3 = 24). Baseline 5 to <14 ng/L: follow-up < 14 ng/L (G4 = 101), follow-up ≥ 14 ng/L (G5 = 96). G6 included baseline and follow-up > 14 ng/L (n = 74). Cox-proportional hazards models evaluated the association with mortality adjusting for age, sex, education, cardiovascular disease, chronic kidney disease, number of medications, hs-CRP, and NT-proBNP. Among 745 participants (median age 75.9 years, 58.9% male) we observed 98 deaths (median follow-up 4.8 years). G1 had the lowest mortality rate (MR) (5.2 per 1000 person-years). The highest MR were observed by follow-up ≥ 14 ng/L: G3: 95.4 and G6: 100.4 per 1000 person-years, with an adjusted hazard ratio of 5.22 [95% CI 1.46, 18.65] and 3.40 [95% CI 1.02, 11.34], respectively. Hs-cTnT trajectories could help to identify older adults with a high mortality risk even after further adjustment including hs-CRP and NT-proBNP.

Composition of cardiac troponin release differs after marathon running and myocardial infarction

OBJECTIVES

Elevations of cardiac troponin T (cTnT) levels are common after strenuous exercise. We assessed whether the composition of cTnT release after marathon race differs from that of acute myocardial infarction (MI).

METHODS

Troponin composition was analysed in plasma samples taken from 45 runners after marathon race and from 84 patients with type 1 MI. The concentration of long cTnT (intact and mildly fragmented cTnT) was measured with a novel upconversion luminescence immunoassay, total cTnT with a commercial high-sensitivity cTnT assay, and the ratio of long to total cTnT (troponin ratio) was determined as a measure of troponin fragmentation.

RESULTS

Total cTnT exceeded the upper reference limit (>14 ng/L) in 37 (82%) runners. Troponin ratio was lower in runners ((IQR) 0.17 (0.11-0.24) vs 0.62 (0.29-0.96), p<0.001). With increasing troponin release the troponin ratio decreased (r=-0.497, p<0.001) in marathon runners and the concentration of long cTnT remained in all runners below 8.4 ng/L. In contrast to marathon runners, troponin ratio increased (r=0.565, p<0.001) with the increase of cTnT release in patients with MI. The median total and long cTnT concentrations were lower in marathon runners than in patients with MI (25 ng/L vs 835 ng/L and 4.1 vs 385 ng/L, p<0.001 for both).

CONCLUSION

In contrast to type 1 MI, only a small fraction of circulating cTnT exists as intact cTnT or long molecular forms after strenuous exercise and the difference in troponin composition is more pronounced in runners with higher troponin release.

TRIAL REGISTRATION NUMBER

NCT06000930.

Cardiac biomarkers alterations in rapid weight loss and high-intensity training in judo athletes: a crossover pilot study

BACKGROUND

Studies evaluating alterations in cardiac biomarkers in rapid sport-associated weight loss (RWL) and high-intensity sport-specific training (HISST) are lacking. This pilot study aimed to examine the effects of RWL and HISST on heart rate, blood pressure, cardiac biomarkers, and left ventricular systolic function. Nine elite male judokas participated in the presented survey.

METHODS

The athletes underwent a baseline assessment and two testing protocols, the first phase with RWL where they had to lose 5% of their body weight simultaneously with HISST, and the second phase after 7 days, in which only HISST was performed. Participants underwent electrocardiogram, biomarker, and transthoracic echocardiogram evaluation after each phase.

RESULTS

In the first phase (RWL and HISST) athletes, heart rate increased significantly, 58.11 (7.78) versus 79 (9.25), P=0.001; as well as cardiac biomarkers: lactate dehydrogenase isoenzyme 175.33 (31.22) vs. 238.56 (56), P=0.003; aspartate aminotransferase 16.56 (4.61) vs. 29 (9.96), P=0.027; creatine kinase isoenzyme-MB 13 (11.5;24) vs. 29.11 (10.05), P=0.004; and high sensitivity cardiac troponin 10 (0) vs. 14.49 (6.4), P=0.045. In the second phase, only HISST was associated with a significant increase in the alanine aminotransferase isoenzyme, 37.78 (11.22) vs. 26 (8.03), P=0.024, together with creatine kinase 472 (185;654) vs. 166.88 (56.57), P=0.01, compared to the initial measurement.

CONCLUSIONS

RWL combined with HISST produced significant alterations in cardiac biomarkers without impairment of left ventricular systolic function.

Elevation of cardiac enzymes and B-type natriuretic peptides following venous recanalization and stenting in chronic venous obstruction

BACKGROUND

B-type natriuretic peptides (BNP) and cardiac enzymes are both recognized biomarkers of heart health. Many studies have reported that using these indicators can assess cardiac condition and predict prognosis of patients undergoing surgery. Currently little is known on the effect of increased cardiac input after venous recanalization on cardiac physiology in patients with chronic venous obstruction (CVO).

OBJECTIVES

The aim of this study was to explore the effect of iliocaval recanalization and stenting on cardiac biomarkers in patients with CVO.

METHODS

This was a prospective study involving 60 patients in a single unit. Blood tests were collected 1 day before and 1 day after venous intervention. Three groups as group 1: patients with iliofemoral post-thrombotic syndrome (PTS) but without involvement of inferior vena cava (IVC) (n = 33); group 2: patients with iliofemoral PTS and involvement of IVC (n = 19) and group 3: patients with non-thrombotic vein lesion (NIVL) (n = 8) were compared based on cardiac biomarker levels.

RESULTS

Median concentration of post-operative BNP (259.60 pg/mL) was greater than preoperative levels (49.80 pg/mL) [interquartile range (IQR), 147.15/414.68 versus 29.85/82.88; p < 0.001]. The levels of CK-MB [preop: 3 U/l (IQR, 1.40/11.00) versus postop: 14 U/l (IQR, 12/17), p < 0.001] and troponin T [preop: 3.00 pg/mL (IQR, 3.00/5.25) versus postop: level of 6 pg/mL (IQR, 3.00/9.50), p < 0.001]. Post-procedure increases in cardiac enzymes showed significant differences in BNP (p = 0.023) and troponin T (p = 0.007) across the three groups, while CK-MB levels were not significantly different (p > 0.05). Intergroup comparisons of postoperative BNP: group 1 versus group 2 (p = 0.013), group 2 versus group 3 (p = 0.029), group 1 versus group 3 (p = 0.834); and postoperative troponin T: group 1 versus group 2 (p = 0.018), group 2 versus group 3 (p = 0.002), group 1 versus group 3 (p = 0.282). According to multiple linear regression analysis, length of stenting and level of preoperative BNP were independent determinants of postoperative BNP levels (p < 0.05), and preoperative troponin T affected postoperative troponin T independently (p < 0.05).

CONCLUSIONS

Troponin T, CK-MB and BNP seem to increase after venous recanalization and stent implantation, the elevation being more prominent for longer lesions.

Lifelong physiology of a former marathon world-record holder: the pros and cons of extreme cardiac remodeling

In a 77-year-old former world-record-holding male marathoner (2:08:33.6), this study sought to investigate the impact of lifelong intensive endurance exercise on cardiac structure, function, and the trajectory of functional capacity (determined by maximal oxygen consumption, V̇o2max) throughout the adult lifespan. As a competitive runner, our athlete (DC) reported performing up to 150-300 miles/wk of moderate-to-vigorous exercise and sustained 10-15 h/wk of endurance exercise after retirement from competition. DC underwent maximal cardiopulmonary exercise testing in 1970 (aged 27 yr), 1991 (aged 49 yr), and 2020 (aged 77 yr) to determine V̇o2max. At his evaluation in 2020, DC also underwent comprehensive cardiac assessments including resting echocardiography, and resting and exercise cardiac magnetic resonance to quantify cardiac structure and function at rest and during peak supine exercise. DC's V̇o2max showed minimal change from 27 yr (69.7 mL/kg/min) to 49 yr (68.1 mL/kg/min), although it eventually declined by 36% by the age of 77 yr (43.6 mL/kg/min). DC's V̇o2max at 77 yr, was equivalent to the 50th percentile for healthy 20- to 29-yr-old males and 2.4 times the requirement for maintaining functional independence. This was partly due to marked ventricular dilatation (left-ventricular end-diastolic volume: 273 mL), which facilitates a large peak supine exercise stroke volume (200 mL) and cardiac output (22.2 L/min). However, at the age of 78 yr, DC developed palpitations and fatigue and was found to be in atrial fibrillation requiring ablation procedures to revert his heart to sinus rhythm. Overall, this life study of a world champion marathon runner exemplifies the substantial benefits and potential side effects of many decades of intense endurance exercise.NEW & NOTEWORTHY This life study of a 77-yr-old former world champion marathon runner exemplifies the impact of lifelong high-volume endurance exercise on functional capacity (V̇o2max equivalent to a 20- to 29-yr-old), partly due to extreme ventricular remodeling that facilitates a large cardiac output during exercise despite reduced maximal heart rate. Although it is possible that this extreme remodeling may contribute to developing atrial fibrillation, the net benefits of extreme exercise throughout this athlete's lifespan favor increased health span and expected longevity.

Exercise-Induced Cardiac Troponin I Elevation Is Associated With Regional Alterations in Left Ventricular Strain in High-Troponin Responders

BACKGROUND

The implications of exercise-induced cardiac troponin elevation in healthy individuals are unclear. This study aimed to determine if individuals with a high exercise-induced cardiac troponin I (cTnI) response have alterations in myocardial function following high-intensity endurance exercise compared with normal-cTnI responders.

METHODS AND RESULTS

Study individuals were recruited from previous participants in a 91-km mountain bike cycling race (the North Sea Race) and were classified as high- (n=34) or normal-cTnI responders (n=25) based on maximal cTnI values after the recruitment race. The present study exposed all participants to 2 prolonged high-intensity exercises: a combined lactate threshold and cardiopulmonary exercise test and repeated participation in the North Sea Race. Echocardiography was performed before, immediately after, and 24 hours following exercise. All study individuals (n=59) had normal coronary arteries, and were aged 51±10 years; 46 (74%) were men. There were no differences in baseline characteristics between the high- and normal-cTnI responders. Maximal cTnI levels 3 hours after exercise were significantly higher in the high- compared with normal-cTnI group (P<0.001-0.027). Following exercise, there were no differences in global ventricular function between the 2 groups. In contrast, high-cTnI responders had significantly lower regional strain in the anteroseptal segments following exercise, with more profound changes after the race.

CONCLUSIONS

High-cTnI responders had lower anteroseptal segmental strain shortly after exercise than normal-cTnI responders. However, there were no permanent alterations in myocardial strain, indicating no short- or long-term adverse consequences of these exercise-induced alterations in myocardial function.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02166216.

Association Between High-Sensitivity Troponin (hs-cTnT) and Diagnosis of Myocarditis in Previously Healthy Pediatric Patients

Cardiac troponin is commonly used to screen for cardiac diagnoses in pediatric patients, as it is only released by myocardial tissue. There is limited data regarding high-sensitivity troponin T in pediatric populations and its clinical interpretation. We sought to determine how high-sensitivity troponin values are associated with myocarditis diagnosis. High sensitivity troponin levels were reviewed for pediatric patients at our center from February 2022 to February 2023. Basic demographic and presenting data (including age, gender, body mass index), and diagnoses (cardiac diagnosis, including myocarditis, vs non-cardiac) were compared for patients with elevated initial troponin levels (≥ 12 ng/L) vs. those with non-elevated values. Of the 308 patients included, 91 (29.5%) had elevated hs-cTnT and 45 (14.6%) had a cardiac diagnosis, of whom 8 (2.5%) were ultimately diagnosed with acute myocarditis. There was no meaningful difference in demographic characteristics between the elevated and non-elevated hs-cTnT groups. For patients with diagnosis of myocarditis (n = 8), median peak levels were 506.5 ng/L (182.0 to 1184.0) versus 6.0 ng/L (< 6.0 to 13.5) for those with all other diagnoses (n = 300) (p < 0.001). A high sensitivity troponin cut-off value of 90 ng/dL was established for diagnosis of myocarditis, providing high sensitivity (100%) and specificity of (95%).

Exercise-induced cardiac troponin elevations and cardiac ventricular dysfunction assessed by tissue Doppler echocardiography and speckle tracking among non-elite runners in Beijing marathon

OBJECTIVES

We aimed to identify the major determinants of cardiac troponin changes response to exercise among non-elite runners participating in the Beijing 2022 marathon, with a particular focus on the associations with the cardiac function assessed by tissue Doppler echocardiography and speckle tracking.

DESIGN

A prospective study.

METHODS

A total of 33 non-elite participants in the 2022 Beijing Marathon were included in the study. Echocardiographic assessment and blood sample collection were conducted before, immediately after, and two weeks after the marathon. Blood samples were analyzed using the same Abbot high-sensitivity cTnI STAT assay. Echocardiography included tissue Doppler and speckle tracking echocardiography.

RESULTS

Following the marathon, significant increases were observed in cardiac biomarkers, with hs-cTnI elevating from 3.1 [2.3-6.7] to 49.6 [32.5-76.9] ng/L (P < 0.0001). Over 72 % of participants had post-race hs-TnI levels surpassing the 99th percentile upper reference limit. There was a notable correlation between pre-marathon hs-cTnI levels (β coefficient, 0.56 [0.05, 1.07]; P = 0.042), weekly average training (β coefficient, -1.15 [-1.95, -0.35]; P = 0.009), and hs-cTnI rise post-marathon. Echocardiography revealed significant post-race cardiac function changes, including decreased E/A ratio (P < 0.0001), GWI (P < 0.0001), and GCW (P < 0.0001), with LVEF (β coefficients, 0.112 [0.01, 0.21]; P = 0.042) and RV GLS (β coefficients, 0.124 [0.01, 0.23]; P = 0.035) changes significantly associated with hs-TnI alterations. All echocardiographic and laboratory indicators reverted to baseline levels within two weeks.

CONCLUSIONS

Baseline hs-cTnI levels and weekly average training influence exercise-induced hs-cTnI elevation in non-elite runners. Echocardiography revealed post-race changes in cardiac function, with LVEF and RV GLS significantly associated with hs-TnI alterations. These findings contribute to understanding the cardiac response to exercise and could guide training and recovery strategies.

Effect of Single High-Dose Vitamin D3 Supplementation on Post-Ultra Mountain Running Heart Damage and Iron Metabolism Changes: A Double-Blind Randomized Controlled Trial

Exercise-induced inflammation can influence iron metabolism. Conversely, the effects of vitamin D3, which possesses anti-inflammatory properties, on ultramarathon-induced heart damage and changes in iron metabolism have not been investigated. Thirty-five healthy long-distance semi-amateur runners were divided into two groups: one group received 150,000 IU of vitamin D3 24 h prior to a race (n = 16), while the other group received a placebo (n = 19). Serum iron, hepcidin (HPC), ferritin (FER), erythroferrone (ERFE), erythropoietin (EPO), neopterin (NPT), and cardiac troponin T (cTnT) levels were assessed. A considerable effect of ultramarathon running on all examined biochemical markers was observed, with a significant rise in serum levels of ERFE, EPO, HPC, NPT, and cTnT detected immediately post-race, irrespective of the group factor. Vitamin D3 supplementation showed a notable interaction with the UM, specifically in EPO and cTnT, with no other additional changes in the other analysed markers. In addition to the correlation between baseline FER and post-run ERFE, HPC was modified by vitamin D. The ultramarathon significantly influenced the EPO/ERFE/HPC axis; however, a single substantial dose of vitamin D3 had an effect only on EPO, which was associated with the lower heart damage marker cTnT after the run.

Cardiac troponin concentrations following exercise and the association with cardiovascular disease and outcomes: rationale and design of the prospective TREAT cohort study

Exercise can produce transient elevations of cardiac troponin (cTn) concentrations, which may resemble the cTn release profile of myocardial infarction. Consequently, clinical interpretation of postexercise cTn elevations (ie, values above the 99th percentile upper reference limit) remains challenging and may cause clinical confusion. Therefore, insight into the physiological versus pathological nature of postexercise cTn concentrations is warranted. We aim to (1) establish resting and postexercise reference values for recreational athletes engaged in walking, cycling or running exercise; (2) compare the prevalence of (sub)clinical coronary artery disease in athletes with high versus low postexercise cTn concentrations and (3) determine the association between postexercise cTn concentrations and the incidence of major adverse cardiovascular events (MACE) and mortality during long-term follow-up. For this purpose, the prospective TRoponin concentrations following Exercise and the Association with cardiovascular ouTcomes (TREAT) observational cohort study was designed to recruit 1500 recreational athletes aged ≥40 to <70 years who will participate in Dutch walking, cycling and running events. Baseline and postexercise high-sensitivity cTnT and cTnI concentrations will be determined. The prevalence and magnitude of coronary atherosclerosis on computed tomography (eg, coronary artery calcium score, plaque type, stenosis degree and CT-derived fractional flow reserve) will be compared between n=100 athletes with high postexercise cTn concentrations vs n=50 age-matched, sex-matched and sport type-matched athletes with low postexercise cTn concentrations. The incidence of MACE and mortality will be assessed in the entire cohort up to 20 years follow-up. The TREAT study will advance our understanding of the clinical significance of exercise-induced cTn elevations in middle-aged and older recreational athletes. Trial registration number NCT06295081.

Cardiac Troponin and Treatment Effects of Omecamtiv Mecarbil: Results From the GALACTIC-HF Study

BACKGROUND

Omecamtiv mecarbil improves outcomes in patients with heart failure and reduced ejection fraction (HFrEF). We examined the relationship between baseline troponin levels, change in troponin levels over time and the treatment effect of omecamtiv mecarbil in patients enrolled in the Global Approach to Lowering Adverse Cardiac Outcomes through Improving Contractility in Heart Failure (GALACTIC-HF) trial (NCT02929329).

METHODS

GALACTIC-HF was a double-blind, placebo-controlled trial that randomized 8256 patients with symptomatic HFrEF to omecamtiv mecarbil or placebo. High-sensitivity troponin I (cTnI) was measured serially at a core laboratory. We analyzed the relationship between both baseline cTnI and change in cTnI concentrations with clinical outcomes and the treatment effect of omecamtiv mecarbil.

RESULTS

Higher baseline cTnI concentrations were associated with a risk of adverse outcomes (hazard ratio for the primary endpoint of time to first HF event or CV death = 1.30; 95% CI 1.28, 1.33; P < 0.001 per doubling of baseline cTnI). Although the incidence of safety outcomes was higher in patients with higher baseline cTnI, there was no difference between treatment groups. Treatment with omecamtiv mecarbil led to a modest increase in cTnI that was related to plasma concentrations of omecamtiv mecarbil, and it peaked at 6 weeks. An increase in troponin from baseline to week 6 was associated with an increased risk of the primary endpoint (P < 0.001), which was similar, regardless of treatment assignment (P value for interaction = 0.2).

CONCLUSIONS

In a cohort of patients with HFrEF, baseline cTnI concentrations were strongly associated with adverse clinical outcomes. Although cTnI concentrations were higher in patients treated with omecamtiv mecarbil, we did not find a differential effect of omecamtiv mecarbil on either safety or efficacy based on baseline cTnI status or change in cTnI.

Detectable troponin below the 99th percentile predicts survival in patients undergoing coronary angiography

Background

Cardiac troponin I (cTnI) above the 99th percentile is associated with an increased risk of major adverse events. Patients with detectable cTnI below the 99th percentile are a heterogeneous group with a less well-defined risk profile. The purpose of this study is to investigate the prognostic relevance of detectable cTnI below the 99th percentile in patients undergoing coronary angiography.

Methods

The study included 14,776 consecutive patients (mean age of 65.4 ± 12.7 years, 71.3 % male) from the Essen Coronary Artery Disease (ECAD) registry. Patients with cTnI levels above the 99th percentile and patients with ST-segment elevation acute myocardial infarction were excluded. All-cause mortality was defined as the primary endpoint.

Results

Detectable cTnI below the 99th percentile was present in 2811 (19.0 %) patients, while 11,965 (81.0 %) patients were below detection limit of the employed assay. The mean follow-up was 4.25 ± 3.76 years. All-cause mortality was 20.8 % for patients with detectable cTnI below the 99th percentile and 15.0 % for those without detectable cTnI. In a multivariable Cox regression analysis, detectable cTnI was independently associated with all-cause mortality with a hazard ratio of 1.60 (95 % CI 1.45-1.76; p < 0.001). There was a stepwise relationship with increasing all-cause mortality and tertiles of detectable cTnI levels with hazard ratios of 1.63 (95 % CI 1.39-1.90) for the first tertile to 2.02 (95 % CI 1.74-2.35) for the third tertile.

Conclusions

Detectable cTnI below the 99th percentile is an independent predictor of mortality in patients undergoing coronary angiography with the risk of death growing progressively with increasing troponin levels.

Association between physical activity and thyroid function in American adults: a survey from the NHANES database

OBJECTIVE

Physical activity (PA) is closely related to our lives, and the effects of PA on thyroid function have not been elucidated.

METHODS

Using data from the National Health and Nutrition Examination Survey (NHANES) 2007-2012, we included 5877 participants and analyzed the associations of thyroid function with weekly physical activity (PAM, expressed in metabolic equivalents of task) and physical activity time (PAT) in American adults. Univariate and multivariate logistic analyses were used to demonstrate the associations of PAM and PAT with the primary outcome. Linear regression analysis was performed to determine the associations between thyroid biochemical indicators/diseases and PAM/PAT.

RESULTS

Our study revealed noticeable sex differences in daily PA among the participants. The odds ratio of the fourth versus the first quartile of PAM was 3.07 (confidence interval, CI [1.24, 7.58], p = 0.02) for overt hypothyroidism, 3.25 (CI [1.12, 9.45], p = 0.03) for subclinical hyperthyroidism in adult men. PAT in the range of 633-1520 min/week was found to be associated with the occurrence of subclinical hyperthyroidism [p < 0.001, OR (95% CI) = 5.89 (1.85, 18.80)], PAT of the range of > 1520 min/week was found to be associated with the occurrence of overt hypothyroidism [p < 0.001, OR (95% CI) = 8.70 (2.80, 27.07)] and autoimmune thyroiditis (AIT) [p = 0.03, OR (95% CI) = 1.42 (1.03, 1.97)] in adult men. When PAM < 5000 MET*minutes/week or PAT < 1000 min/week, RCS showed an L-shaped curve for TSH and an inverted U-shaped curve for FT4. The changes in FT3 and TT3 in men were linearly positively correlated with PAM and PAT, while TT4 is linearly negatively correlated.

CONCLUSION

The amount of daily physical activity of American adults is strongly associated with changes in thyroid function, including thyroid hormone levels and thyroid diseases. Thyroid hormone levels were varied to a certain extent with changes in PAM and PAT.

The relationship between workload and exercise-induced cardiac troponin elevations is influenced by non-obstructive coronary atherosclerosis

The relationship between exercise-induced troponin elevation and non-obstructive coronary artery disease (CAD) is unclear. This observational study assessed non-obstructive CAD's impact on exercise-induced cardiac Troponin I (cTnI) elevation in middle-aged recreational athletes. cTnI levels of 40 well-trained recreational athletes (73% males, 50 ± 9 years old) were assessed by a high-sensitive cTnI assay 24 h before, and at 3 and 24 h following two high-intensity exercises of different durations; a cardiopulmonary exercise test (CPET), and a 91-km mountain bike race. Workload was measured with power meters. Coronary computed tomography angiography was used to determine the presence or absence of non-obstructive (<50% obstruction) CAD. A total of 15 individuals had non-obstructive CAD (Atherosclerotic group), whereas 25 had no atherosclerosis (normal). There were higher post-exercise cTnI levels following the race compared with CPET, both at 3 h (77.0 (35.3-112.4) ng/L vs. 11.6 (6.4-22.5) ng/L, p < 0.001) and at 24 h (14.7 (6.7-16.3) vs. 5.0 (2.6-8.9) ng/L, p < 0.001). Absolute cTnI values did not differ among groups. Still, the association of cTnI response to power output was significantly stronger in the CAD versus Normal group both at 3 h post-exercise (Rho = 0.80, p < 0.001 vs. Rho = -0.20, p = 0.33) and 24-h post-exercise (Rho = 0.87, p < 0.001 vs. Rho = -0.13, p = 0.55). Exercise-induced cTnI elevation was strongly correlated with exercise workload in middle-aged athletes with non-obstructive CAD but not in individuals without CAD. This finding suggests that CAD influences the relationship between exercise workload and the cTnI response even without coronary artery obstruction.

A case series of eight amateur athletes: exercise-induced pre-/syncope during the Zurich Marathon 2023

Background

Marathon running poses unique cardiovascular challenges, sometimes leading to syncopal episodes. We present a case series of athletes who experienced pre-/syncope during the Zurich Marathon 2023, accompanied by elevated cardiac biomarkers.

Case summary

Eight athletes (2 females, 6 males) aged 21-35 years, with pre-/syncope and various additional diverse symptoms such as dizziness and palpitations during the (half-)marathon, were admitted to two emergency departments in Zurich, Switzerland. Clinical evaluations included electrocardiogram, echocardiography, telemetry, coronary computed tomography (CT) scans, and cardiac biomarker assessments. High-sensitive troponin T (hs-cTnT) was elevated in all cases at initial assessment and returned to normal at follow-up. All athletes who received CT scans had normal coronary and brain CT results. None of the eight athletes had underlying cardiovascular disease. Renal function normalized post-admission, and neurological symptoms resolved within hours. Creatinine levels indicated transient acute kidney injury. A common feature was inexperience in running, inadequate race preparation, particularly regarding fluid, electrolyte, and carbohydrate intake, along with pacing issues and lack of coping strategies with heat.

Discussion

From a clinician perspective, the case series highlights the challenge in the management of patients with a pre-/syncopal event during strenuous exercise and elevated cardiac biomarkers. Diverse initial symptoms prompted tailored investigations. Adequate training, medical assessments, and awareness of syncope triggers are essential for marathon participants. Caution and pacing strategies are crucial, especially among novices in competitive running. This information is pertinent given the growing popularity of marathon events and prompts a standardized diagnostic approach after these events.

Relation between high-sensitivity troponin I serum levels and myocardial ischemia in patients with suspected chronic coronary syndrome: The RESET-MI study

BACKGROUND

Previous studies showed that exercise may increase cardiac troponin serum levels; whether the occurrence of myocardial ischemia influences the changes of exercise-induced troponin raise, however, remains debatable.

METHODS

We prospectively enrolled consecutive patients undergoing for the first time an elective stress myocardial perfusion scintigraphy (MPS) because of clinical suspicion of obstructive coronary artery disease (CAD). Patients were divided into 3 groups based on the evidence and degree of stress-induced myocardial ischemia at MPS: 1) group 1, no myocardial ischemia (≤4 %); 2) group 2, mild myocardial ischemia (5-10 %); 3) group 3, moderate-to-severe myocardial ischemia (≥10 %). High-sensitivity cardiac troponin I (cTnI) was measured immediately before (T0) and 1 hour (T1) and 4 h (T2) after the stress test.

RESULTS

One hundred-seven patients (71 males; age 65.6 ± 9.4 years) were enrolled in the study. Serum hs-cTnI concentrations (logarithmic values) significantly increased after MPS, compared to baseline, in the whole population, from 1.47±1.26 ng/L at T0, to 1.68±1.12 ng/L at T1 (p<0.001) and 2.15±1.02 ng/L at T2 (p<0.001 vs. both T0 and T1). The increase in hs-cTnI did not significantly differ between the 3 groups (p = 0.44). The heart rate achieved during the test was the strongest determinant of cTnI increase (p < 0.001) after the stress test.

CONCLUSIONS

In patients with suspected CAD, stress MPS induces an increase of cTnI that is independent of the induction and extension/severity of myocardial ischemia and is mainly related to myocardial work, as indicated by the heart rate achieved during the test.

The current paradigm of cardiac troponin increase among athletes

Although it is known that exercise improves cardiovascular health and extends life expectancy, a significant number of people may also experience an elevation in cardiac troponin levels as a result of exercise. For many years, researchers have argued whether exercise-induced cardiac troponin rises are a consequence of a physiological or pathological reaction and whether they are clinically significant. Differences in cardiac troponin elevation and cardiac remodeling can be seen between athletes participating in different types of sports. When forecasting the exercise-induced cardiac troponin rise, there are many additional parameters to consider, as there is a large amount of interindividual heterogeneity in the degree of cardiac troponin elevation. Although it was previously believed that cardiac troponin increases in athletes represented a benign phenomenon, numerous recent studies disproved this notion by demonstrating that, in specific individuals, cardiac troponin increases may have clinical and prognostic repercussions. This review aims to examine the role of cardiac troponin in athletes and its role in various sporting contexts. This review also discusses potential prognostic and clinical implications, as well as future research methods, and provides a straightforward step-by-step algorithm to help clinicians interpret cardiac troponin rise in athletes in both ischemic and non-ischemic circumstances.

Exercise-Induced Troponin Elevation in High-Performance Cross-Country Skiers

Background: Troponin I and T are biomarkers to diagnose myocardial infarction and damage. Studies indicate that strenuous physical activity can cause transient increases in these troponin levels, typically considered physiological. However, current data show differences in the exercise-induced increase in troponin I and T in elite athletes. Method: This prospective clinical study aimed to determine troponin I and T levels in 36 top cross-country skiers of the German national team (18 male, 18 female) after a standardized competition load over two days. All study participants underwent a comprehensive sports medical and cardiological evaluation, including ECG and echocardiography. A multivariable regression analysis was utilized to identify possible predictors of increased troponin I levels. Results: Only three male athletes (8.1%) showed an isolated increase in Troponin I (Ø 112.49 ng/L, cut off < 45.2 ng/L), while no increase in troponin T in the study population was detected. Conclusions: The analysis suggested several potential predictors for increased troponin I levels, such as height, weight, weekly training hours, and indications of an enlarged sports heart, though none achieved statistical significance. Knowing the different exercise-induced detectability of the various troponins in the clinical setting is essential.

Advances in research on biomarkers associated with acute myocardial infarction: A review

Acute myocardial infarction (AMI), the most severe cardiovascular event in clinical settings, imposes a significant burden with its annual increase in morbidity and mortality rates. However, it is noteworthy that mortality due to AMI in developed countries has experienced a decline, largely attributable to the advancements in medical interventions such as percutaneous coronary intervention. This trend highlights the importance of accurate diagnosis and effective treatment to preserve the myocardium at risk and improve patient outcomes. Conventional biomarkers such as myoglobin, creatine kinase isoenzymes, and troponin have been instrumental in the diagnosis of AMI. However, recent years have witnessed the emergence of new biomarkers demonstrating the potential to further enhance the accuracy of AMI diagnosis. This literature review focuses on the recent advancements in biomarker research in the context of AMI diagnosis.

Cardiovascular risk of veterans' football: An observational cohort study with follow-up

BACKGROUND

The cardiac stress for veteran football players during match is considerable. In this specific elderly population, the kinetics of exercise-induced cardiac troponin I (cTnI) and B-Type natriuretic peptide (BNP) could potentially be related to cardiovascular risk factors (CVRF) and cardiovascular disease and are therefore be investigated for their usefulness as an complement to established screening measures.

METHODS

cTnI and BNP was measured in 112 veteran football players (age: 51 ± 10 years) within 30 minutes pre- and post-match. Players with elevated cTnI (cTnI-positive) and a control group (out of the 112 veteran players) with normal cTnI (cTnI-negative) underwent cardiac follow-up 4.2 ± 3.5 months post-match, comprising history, resting and stress ECG (including 30 minutes pre- and post cTnI and BNP), and echocardiography.

RESULTS

In 33 players (29%) cTnI and in 6 players BNP (5%) exceeded the upper range limit for increased risk of myocardial damage (cTnI ≥ 5 ng/l) and myocardial wall stress (BNP ≥ 100 pg/ml) post-match, respectively. No correlation was observed between Δ cTnI (pre- vs. post-match) and the number of CVRF (r = -0.06, p = 0.50). Follow-up was conducted in 62 players (31 cTnI-positive and 31 cTnI-negative players) of which 6 (10%, 3 cTnI positive and 3 cTnI negative players) had cardiac abnormalities (hypertrophic cardiomyopathy n = 2, coronary artery disease n = 2, coronary artery anomaly n = 1, hypertensive heart disease n = 1).

CONCLUSION

Veterans' football matches elicit increases in BNP and particularly cTnI in a considerable number of players. However, these biochemical alterations do not indicate acute cardiac damage as evidenced by follow-up. Routine determination of cardiac biomarkers is unlikely to improve cardiovascular screening in veteran football players.

Exercise-induced cardiac troponin release in athletes with versus without coronary atherosclerosis

The magnitude of exercise-induced cardiac troponin (cTn) elevations is dependent on cardiovascular health status, and previous studies have shown that occult coronary atherosclerosis is highly prevalent among amateur athletes. We tested the hypothesis that middle-aged and older athletes with coronary atherosclerosis demonstrate greater cTn elevations following a controlled endurance exercise test compared with healthy peers. We included 59 male athletes from the Measuring Athletes' Risk of Cardiovascular events 2 (MARC-2) study and stratified them as controls [coronary artery calcium score (CACS) = 0, n = 20], high CACS [≥300 Agatston units or ≥75th Multi-Ethnic Study of Atherosclerosis (MESA) percentile, n = 20] or significant stenosis (≥50% in any coronary artery, n = 19). Participants performed a cycling test with incremental workload until volitional exhaustion. Serial high-sensitivity cTn (hs-cTn) T and I concentrations were measured (baseline, after 30-min warm-up, and 0, 30, 60, 120, and 180 min postexercise). There were 58 participants (61 [58-69] yr) who completed the exercise test (76 ± 14 min) with a peak heart rate of 97.7 [94.8-101.8]% of their estimated maximum. Exercise duration and workload did not differ across groups. High-sensitivity cardiac troponin T (Hs-cTnT) and high-sensitivity cardiac troponin I (hs-cTnI) concentrations significantly increased (1.55 [1.33-2.14]-fold and 2.76 [1.89-3.86]-fold, respectively) over time, but patterns of cTn changes and the incidence of concentrations >99th percentile did not differ across groups. Serial sampling of hs-cTnT and hs-cTnI concentrations during and following an exhaustive endurance exercise test did not reveal differences in exercise-induced cTn release between athletes with versus without coronary atherosclerosis. These findings suggest that a high CACS or a >50% stenosis in any coronary artery does not aggravate exercise-induced cTn release in middle-aged and older athletes.NEW & NOTEWORTHY Exercise-induced cardiac troponin (cTn) release is considered to be dependent on cardiovascular health status. We tested whether athletes with coronary atherosclerosis demonstrate greater exercise-induced cTn release compared with healthy peers. Athletes with coronary atherosclerosis did not differ in cTn release following exercise compared with healthy peers. Our findings suggest that a high CACS or a >50% stenosis in any coronary artery does not aggravate exercise-induced cTn release in middle-aged and older athletes.

Clinical Interpretation of Serum Troponin in the Era of High-Sensitivity Testing

Cardiac troponin (Tn) plays a central role in the evaluation of patients with angina presenting with acute coronary syndrome. The advent of high-sensitivity assays has improved the analytic sensitivity and precision of serum Tn measurement, but this advancement has come at the cost of poorer specificity. The role of clinical judgment is of heightened importance because, more so than ever, the interpretation of serum Tn elevation hinges on the careful integration of findings from electrocardiographic, echocardiographic, physical exam, interview, and other imaging and laboratory data to formulate a weighted differential diagnosis. A thorough understanding of the epidemiology, mechanisms, and prognostic implications of Tn elevations in each cardiac and non-cardiac etiology allows the clinician to better distinguish between presentations of myocardial ischemia and myocardial injury-an important discernment to make, as the treatment of acute coronary syndrome is vastly different from the workup and management of myocardial injury and should be directed at the underlying cause.

High-Sensitivity Cardiac Troponin Assays: Ready for Prime Time!

Rapid and accurate triage of patients presenting with chest pain to an emergency department (ED) is critical to prevent ED overcrowding and unnecessary resource use in individuals at low risk of acute myocardial infarction (AMI) and to efficiently and effectively guide patients at high risk to definite therapy. The use of biomarkers for rule-out or rule-in of suspected AMI has evolved substantially over the last several decades. Previously well-established biomarkers have been replaced by cardiac troponin (cTn). High-sensitivity cTn (hs-cTn) assays represent the newest generation of cTn assays and offer tremendous advantages, including improved sensitivity and precision. Still, implementation of these assays in the United States lags behind several other areas of the world. Within this educational review, we discuss the evolution of biomarker testing for detection of myocardial injury, address the specifics of hs-cTn assays and their recommended use within triage algorithms, and highlight potential challenges in their use. Ultimately, we focus on implementation strategies for hs-cTn assays, as they are now clearly ready for prime time.

An unusual case of marathon-related exercise associated collapse: Case report and some considerations for medical care at endurance mass participation events

This article presents a unique exercise-associated collapse case during a marathon, highlighting the significance of evidence-based management for athletes on field. The patient, a 61-year-old experienced runner, collapsed near the finish line of the Milano City Marathon. He was aided immediately with CPR and AED. After excluding, through validated algorithms, common and life-threatening causes of collapse, the patient was transferred to hospital. The patient underwent diagnostic procedures, including CT and MRI scans, and hormonal tests that revealed pituitary hemorrhage and underlying coronary artery disease. Follow-up assessments and personalized care were instrumental in the patient's successful recovery and safe return to exercise.

Treadmill running intensity and post-exercise increase in plasma cardiac troponin I and T-A pilot study in healthy volunteers

BACKGROUND

Plasma concentrations of cardiac troponins increase in healthy individuals after strenuous training, but the response to lower exercise intensities has not been characterized.

AIM

To determine whether exercise at moderate intensity significantly increases plasma cardiac troponins measured with different assays in healthy recreational athletes.

METHODS

Twenty-four self-reported healthy volunteers were instructed to complete three 60-min bouts of treadmill running at variable intensities: High-intensity training (HIT) including a maximal exercise test and an anaerobic threshold test followed by training at 80%-95% of maximum heart rate (HRmax ), Moderate-intensity training (MIT) at 60%-75% of HRmax , and Low-intensity training (LIT) at 45%-55% of HRmax . Blood samples were collected before and at 2, 4, and 6 h after HIT and 4 h after MIT and LIT. Troponin I and T were measured in plasma samples with assays from Abbot, Siemens, and Roche.

RESULTS

Plasma troponins measured with all assays were significantly increased compared to baseline after HIT but not after LIT. After HIT, the fraction of all participants with one or more values above the assay-specific 99th percentiles ranged from 13% to 61%. The biomarker criteria for acute myocardial injury were met after HIT for troponin T in 75% of female participants having no clinical evidence of coronary artery disease.

CONCLUSION

High-intensity, but not moderate- or low-intensity, training for 60 min induced a potentially clinically significant increase in plasma cardiac troponins in healthy volunteers. Results exceeding the population 99th percentiles were most frequent with the troponin T assay.

Exercise-Induced Blood Pressure Dynamics: Insights from the General Population and the Athletic Cohort

Blood pressure (BP) dynamics during graded exercise testing provide important insights into cardiovascular health, particularly in athletes. These measurements, taken during intense physical exertion, complement and often enhance our understanding beyond traditional resting BP measurements. Historically, the challenge has been to distinguish 'normal' from 'exaggerated' BP responses in the athletic environment. While basic guidelines have served their purpose, they may not fully account for the complex nature of BP responses in today's athletes, as illuminated by contemporary research. This review critically evaluates existing guidelines in the context of athletic performance and cardiovascular health. Through a rigorous analysis of the current literature, we highlight the multifaceted nature of exercise-induced BP fluctuations in athletes, emphasising the myriad determinants that influence these responses, from specific training regimens to inherent physiological nuances. Our aim is to advocate a tailored, athlete-centred approach to BP assessment during exercise. Such a paradigm shift is intended to set the stage for evidence-based guidelines to improve athletic training, performance and overall cardiovascular well-being.

Exercise-induced myocardial T1 increase and right ventricular dysfunction in recreational cyclists: a CMR study

PURPOSE

Although cardiac troponin I (cTnI) increase following strenuous exercise has been observed, the development of exercise-induced myocardial edema remains unclear. Cardiac magnetic resonance (CMR) native T1/T2 mapping is sensitive to the pathological increase of myocardial water content. Therefore, we evaluated exercise-induced acute myocardial changes in recreational cyclists by incorporating biomarkers, echocardiography and CMR.

METHODS

Nineteen male recreational participants (age: 48 ± 5 years) cycled the 'L'étape du tour de France" (EDT) 2021' (175 km, 3600 altimeters). One week before the race, a maximal graded cycling test was conducted to determine individual heart rate (HR) training zones. One day before and 3-6 h post-exercise 3 T CMR and echocardiography were performed to assess myocardial native T1/T2 relaxation times and cardiac function, and blood samples were collected. All participants were asked to cycle 2 h around their anaerobic gas exchange threshold (HR zone 4).

RESULTS

Eighteen participants completed the EDT stage in 537 ± 58 min, including 154 ± 61 min of cycling time in HR zone 4. Post-race right ventricular (RV) dysfunction with reduced strain and increased volumes (p < 0.05) and borderline significant left ventricular global longitudinal strain reduction (p = 0.05) were observed. Post-exercise cTnI (0.75 ± 5.1 ng/l to 69.9 ± 41.6 ng/l; p < 0.001) and T1 relaxation times (1133 ± 48 ms to 1182 ± 46 ms, p < 0.001) increased significantly with no significant change in T2 (p = 0.474). cTnI release correlated with increase in T1 relaxation time (p = 0.002; r = 0.703), post-race RV dysfunction (p < 0.05; r = 0.562) and longer cycling in HR zone 4 (p < 0.05; r = 0.607).

CONCLUSION

Strenuous exercise causes early post-race cTnI increase, increased T1 relaxation time and RV dysfunction in recreational cyclists, which showed interdependent correlation. The long-term clinical significance of these changes needs further investigation.

TRIAL REGISTRATION NUMBERS AND DATE

NCT04940650 06/18/2021. NCT05138003 06/18/2021.

Cardiac Biomarker Responses to Acute Exercise in Show Jumping Horses

Cardiac biomarkers are useful to identify cardiac muscle variations in human and equine medicine. The aim of this study was to investigate the acute effect of a bout of show jumping training on serum activity of cardiac and muscular biomarkers in healthy athletic horses to include cardiac troponin (cTnI), myoglobin (MB), aspartate amino transferase (AST), alanine amino transferase (ALT), creatine phosphokinase (CPK) and lactate dehydrogenase (LDH). Serum samples were collected from seven Italian Saddle horses (three geldings and four mares; 10 ± 3 years; mean body weight 480 ±70 kg), regularly trained for show jumping at rest, immediately after exercise (show jumping simulate trial) and during the recovery period (30 and 60 min after exercise). ANOVA was applied to all parameters, and Pearson correlation coefficient t (r) evaluated. Immediately after exercise there was an increase in cTnI (P < .01), MB (P < .01), and CPK (P < .005); a positive correlation between cTnI and AST and between AST and LDH; and a negative correlation between cTnI and ALT and between ALT and CPK. Thirty minutes after exercise, there was a positive correlation between AST and ALT and between AST and LDH, while 60 mintues after exercise, there was a positive correlation between MB and LDH and a negative correlation between AST and CPK. The results obtained demonstrate the cardiac and muscular response to short-term intense exercise show jumping exercise.

Xuebijing injection protects sepsis induced myocardial injury by mediating TLR4/NF-κB/IKKα and JAK2/STAT3 signaling pathways

OBJECTIVE

Compelling evidence has demonstrated that Xuebijing (XBJ) exerted protective effects against SIMI. The aims of this study were to investigate whether TLR4/IKKα-mediated NF-κB and JAK2/STAT3 pathways were involved in XBJ's cardio-protection during sepsis and the mechanisms.

METHODS

In this study, rats were randomly assigned to three groups: Sham group; CLP group; XBJ group. Rats were treated with XBJ or sanitary saline after CLP. Echocardiography, myocardial enzymes and HE were used to detect cardiac function. IL-1β, IL-6 and TNF-α in serum were measured using ELISA kits. Cardiomyocyte apoptosis were tested by TUNEL staining. The protein levels of Bax, Bcl-2, Bcl-xl, Cleaved-Caspase 3, Cleaved-Caspase 9, Cleaved-PARP, TLR4, p-NF-κB, p-IKKα, p-JAK2 and p-STAT3 in the myocardium were assayed by western blotting. And finally, immunofluorescence was used to assess the level of p-JAK2 and p-STAT3 in heart tissue.

RESULTS

The results of echocardiography, myocardial enzyme and HE test showed that XBJ could significantly improve SIMI. The IL-1β, IL-6 and TNF-α levels in the serum were markedly lower in the XBJ group than in the CLP group (p<0.05). TUNEL staining's results showed that XBJ ameliorated CLP-induced cardiomyocyte apoptosis. Meanwhile, XBJ downregulated the protein levels of Bax, Cleaved-Caspase 3, Cleaved-Caspase 9, Cleaved-PARP, TLR4, p-NF-κB, p-IKKα, p-JAK2 and p-STAT3, as well as upregulated the protein levels of Bcl-2, Bcl-xl (p <0.05).

CONCLUSIONS

In here, we observed that XBJ's cardioprotective advantages may be attributable to its ability to suppress inflammation and apoptosis via inhibiting the TLR4/ IKKα-mediated NF-κB and JAK2/STAT3 pathways during sepsis.

High-Sensitive Cardiospecific Troponins: The Role of Gender-Specific Concentration in the Diagnosis of Acute Coronary Syndrome (Descriptive Review)

Cardiospecific troponins are specifically localized in the troponin-tropomyosin complex and in the cytoplasm of cardiac myocytes. Cardiospecific troponin molecules are released from cardiac myocytes upon their death (irreversible damage in acute coronary syndrome) or reversible damage to cardiac myocytes, for example, during physical exertion or the influence of stress factors. Modern high-sensitive immunochemical methods for detecting cardiospecific troponins T and I are extremely sensitive to minimal reversible damage to cardiac myocytes. This makes it possible to detect damage to cardiac myocytes in the early stages of the pathogenesis of many extra-cardiac and cardiovascular diseases, including acute coronary syndrome. So, in 2021, the European Society of Cardiology approved diagnostic algorithms of acute coronary syndrome, which allow the diagnosis of acute coronary syndrome in the first 1-2 hours from the moment of admission of the patient to the emergency department. However, high-sensitive immunochemical methods for detecting cardiospecific troponins T and I may also be sensitive to physiological and biological factors, which are important to consider in order to establish a diagnostic threshold (99 percentile). One of the important biological factors that affects the 99 percentile levels of cardiospecific troponins T and I are gender characteristics. This article examines the role of gender-specific concentration of cardiospecific troponins in the diagnosis of acute coronary syndrome and the mechanisms of formation of gender-specific serum levels of cardiospecific troponins T and I.

Exercise-induced release of cardiac troponin is attenuated with repeated bouts of exercise: impact of cardiovascular disease and risk factors

Prolonged exercise can induce cardiac troponin release. As single bouts of exercise may protect against cardiac injury, we explored the hypothesis that the magnitude of exercise-induced release of troponin attenuates upon successive days of exercise. We also examined whether effects of successive exercise bouts differ between healthy participants and individuals with cardiovascular risk factors (CVRFs) and established cardiovascular disease (CVD). We examined cardiac troponin I (cTnI) concentrations from whole venous blood samples collected from the antecubital vein (10 mL) in 383 participants (61 ± 14 yr) at rest and immediately following four consecutive days of long-distance walking (30-50 km/day). Participants were classified as either healthy (n = 222), CVRF (n = 75), or CVD (n = 86). Baseline cTnI concentrations were significantly higher in participants with CVD and CVRF compared with healthy (P < 0.001). Exercise-induced elevations in cTnI were observed in all groups following all days of walking compared with baseline (P < 0.001). Tobit regression analysis on absolute cTnI concentrations revealed a significant day × group interaction (P = 0.04). Following day 1 of walking, post hoc analysis showed that exercise-induced elevations in cTnI attenuated on subsequent days in healthy and CVRF, but not in CVD. Odds ratios for incident cTnI concentrations above the upper reference limit were significantly higher compared with baseline on day 1 for healthy participants (4.90 [95% CI, 1.58-15.2]) and participants with CVD (14.9 [1.86-125]) and remained significantly higher than baseline on all subsequent days in CVD. The magnitude of postexercise cTnI concentrations following prolonged walking exercise significantly declines upon repeated days of exercise in healthy individuals and those with CVRF, whereas this decline is not present in patients with CVD.NEW & NOTEWORTHY We show the magnitude of postexercise cardiac troponin concentrations following prolonged walking exercise significantly declines upon repeated days of exercise in healthy individuals and those with cardiovascular risk factors, while this decline is not present in patients with established cardiovascular disease.

Effect of treadmill exercise stress testing on troponin levels in children and adolescents

BACKGROUND

Chest pain is a common complaint among paediatric patients and cardiac troponin (cTn) level is often part of the initial emergency department evaluation. It is well known that after intense endurance exercise cTn levels can be elevated in patients with otherwise healthy hearts, however the effect shorter duration exercise has on cTn levels in this population is not known.

OBJECTIVE

Determine the behaviour of cTn levels in healthy children and adolescent patients after short burst, high-intensity aerobic exercise.

METHODS

Patients without haemodynamically significant heart disease referred for a treadmill exercise stress test (EST) were recruited over a 6-month period. cTn levels were measured prior to exercise and 4 hours after exercise.

RESULTS

Thirteen patients enrolled. Indications for EST were exertional syncope (six), chest pain (four), and long QT syndrome (three). The median exercise time was 12.9 (9.9-13.7) minutes with an average endurance at the fiftieth percentile for age and maximum heart rate rose to an average of 92 (74-98)% of the predicted peak for age. cTn levels prior to exercise were undetectable in all patients. There was no cTn rise in any patient after exercise. There were no ischaemic changes or arrhythmias on exercise electrocardiograms.

CONCLUSION

Serum cTn levels do not rise significantly in healthy children after short duration, high-intensity aerobic exercise. Physicians evaluating paediatric patients with an elevated cTn level after less than prolonged strenuous activity likely cannot attribute this lab value solely to exercise and may need to undertake further cardiac investigation.

Impact of COVID-19 on Cardiovascular Disease

Coronavirus disease 2019 (COVID-19) is a viral infection with the novel severe acute respiratory distress syndrome corona virus 2 (SARS-CoV-2). Until now, more than 670 million people have suffered from COVID-19 worldwide, and roughly 7 million death cases were attributed to COVID-19. Recent evidence suggests an interplay between COVID-19 and cardiovascular disease (CVD). COVID-19 may serve as a yet underappreciated CVD risk modifier, including risk factors such as diabetes mellitus or arterial hypertension. In addition, recent data suggest that previous COVID-19 may increase the risk for many entities of CVD to an extent similarly observed for traditional cardiovascular (CV) risk factors. Furthermore, increased CVD incidence and worse clinical outcomes in individuals with preexisting CVD have been observed for myocarditis, acute coronary syndrome, heart failure (HF), thromboembolic complications, and arrhythmias. Direct and indirect mechanisms have been proposed by which COVID-19 may impact CVD and CV risk, including viral entry into CV tissue or by the induction of a massive systemic inflammatory response. In the current review, we provide an overview of the literature reporting an interaction between COVID-19 and CVD, review potential mechanisms underlying this interaction, and discuss preventive and treatment strategies and their interference with CVD that were evaluated since the onset of the COVID-19 pandemic.

Modern View on the Role of Sex-Specific Levels of High-Sensitive Cardiospecific Troponins T and I in the Diagnosis of Myocardial Infarction

It is well known that the molecules of cardiospecific troponins T and I are localized in the troponin-tropomyosin complex of the cytoplasm of cardiac myocytes and, due to the specific localization, these cardiospecific troponins are widely used as diagnostic biomarkers of myocardial infarction. Cardiospecific troponins are released from the cytoplasm of cardiac myocytes as a result of irreversible cell damage (for example, ischemic necrosis of cardiomyocytes in myocardial infarction or apoptosis of cardiac myocytes in cardiomyopathies and heart failure) or reversible damage (for example, intense physical exertion, hypertension, the influence of stress factors, etc.). Current immunochemical methods for determining cardiospecific troponins T and I have extremely high sensitivity to subclinical (minor) damage to myocardial cells and, thanks to modern high-sensitive methods, it is possible to detect damage to cardiac myocytes in the early (subclinical) stages of a number of cardiovascular pathologies, including myocardial infarction. So, recently, leading cardiological communities (the European Society of Cardiology, the American Heart Association, the American College of Cardiology, etc.) have approved algorithms for early diagnosis of myocardial infarction based on the assessment of serum levels of cardiospecific troponins in the first 1 - 3 h after the onset of pain syndrome. An important factor that may affect early diagnostic algorithms of myocardial infarction are sex-specific features of serum levels of cardiospecific troponins T and I. This manuscript presents a modern view on the role of sex-specific serum levels of cardiospecific troponins T and I in the diagnosis of myocardial infarction and the mechanisms of formation of sex-specific serum levels of troponins.

Gender Specificities of Cardiac Troponin Serum Levels: From Formation Mechanisms to the Diagnostic Role in Case of Acute Coronary Syndrome

Cardiac troponins T and I are the main (most sensitive and specific) laboratory indicators of myocardial cell damage. A combination of laboratory signs of myocardial cell damage (elevated levels of cardiac troponins T and I) with clinical (severe chest pain spreading to the left side of the human body) and functional (rise or depression of the ST segment, negative T wave or emergence of the Q wave according to electrocardiography and/or decrease in the contractility of myocardial areas exposed to ischemia according to echocardiography) signs of myocardial ischemia is indicative of the ischemic damage to cardiomyocytes, which is characteristic of the development of acute coronary syndrome (ACS). Today, with early diagnostic algorithms for ACS, doctors rely on the threshold levels of cardiac troponins (99th percentile) and on the dynamic changes in the serum levels over several hours (one, two, or three) from the moment of admission to the emergency department. That said, some recently approved highly sensitive methods for determining troponins T and I show variations in 99th percentile reference levels, depending on gender. To date, there are conflicting data on the role of gender specificities in the serum levels of cardiac troponins T and I in the diagnostics of ACS, and the specific mechanisms for the formation of gender differences in the serum levels of cardiac troponins T and I are unknown. The purpose of this article is to analyze the role of gender specificities in cardiac troponins T and I in the diagnostics of ACS, and to suggest the most likely mechanisms for the formation of differences in the serum levels of cardiac troponins in men and women.

Myocardial inefficiency is an early indicator of exercise-induced myocardial fatigue

Background

The effect of prolonged, high-intensity endurance exercise on myocardial function is unclear. This study aimed to determine the left ventricular (LV) response to increased exercise duration and intensity using novel echocardiographic tools to assess myocardial work and fatigue.

Materials and methods

LV function was assessed by echocardiography before, immediately, and 24 h after a cardiopulmonary exercise test (CPET) and a 91-km mountain bike leisure race. Cardiac Troponin I (cTnI) was used to assess myocyte stress.

Results

59 healthy recreational athletes, 52 (43-59) years of age, 73% males, were included. The race was longer and of higher intensity generating higher cTnI levels compared with the CPET (p < 0.0001): Race/CPET: exercise duration: 230 (210, 245)/43 (40, 45) minutes, mean heart rate: 154 ± 10/132 ± 12 bpm, max cTnI: 77 (37, 128)/12 (7, 23) ng/L. Stroke volume and cardiac output were higher after the race than CPET (p < 0.005). The two exercises did not differ in post-exercise changes in LV ejection fraction (LVEF) or global longitudinal strain (GLS). There was an increase in global wasted work (p = 0.001) following the race and a persistent reduction in global constructive work 24 h after exercise (p = 0.003).

Conclusion

Increased exercise intensity and duration were associated with increased myocardial wasted work post-exercise, without alterations in LVEF and GLS from baseline values. These findings suggest that markers of myocardial inefficiency may precede reduction in global LV function as markers of myocardial fatigue.

Prevention of Sudden Death in Sports: A Global and Multidisciplinary Observatory for Scientific Research and Knowledge Transfer (PREMUBID)

Background

The health benefits of sports and exercise training are well known. However, an acute bout of exercise transiently increases the risk of sudden cardiac death (SCD). To minimize the cardiovascular risks of exercise, more insight into the prevention and causes of SCD is needed.

Methods

The observatory for the prevention of sudden death in sports, PREMUBID, was created with the aim of fostering research to assess the benefits and risks of exercise at different volumes and intensities and to get insight into the underlying mechanisms of potentially cardiac (mal) adaptations.

Results

The observatory gathers researchers from a wide range of disciplines working at institutions in Europe and North America. The guiding principles of PREMUBID are to broaden the understanding of SCD in sports, strengthening collaborative research across the globe, and to develop, implement and evaluate robust pre-participation screening and emergency care strategies to further reduce the number of fatal cardiac events in sport events. During the inaugural meeting of the observatory, members and affiliated researchers discussed possibilities to initiate collaborative research projects and to exchange staff and students to share information and practices to prevent SCD. The final goal is to translate the obtained knowledge to understandable messages for the general population and healthcare workers to ensure that the population at large benefits from it.

Conclusions

The PREMUBID consortium aims to produce novel knowledge and insights in SCD prevention, in order to maximize the health benefits associated with acute and long-term exercise training.