Predisposing factors and consequences of elevated biomarker levels in long-distance runners aged >or=55 years

Determinants of Interindividual Variation in Exercise-Induced Cardiac Troponin I Levels

Background Postexercise cardiac troponin levels show considerable interindividual variations. This study aimed to identify the major determinants of this postexercise variation in cardiac troponin I (cTnI) following 3 episodes of prolonged high-intensity endurance exercise. Methods and Results Study subjects were recruited among prior participants in a study of recreational cyclists completing a 91-km mountain bike race in either 2013 or 2014 (first race). In 2018, study participants completed a cardiopulmonary exercise test 2 to 3 weeks before renewed participation in the same race (second race). Blood was sampled before and at 3 and 24 hours following all exercises. Blood samples were analyzed using the same Abbot high-sensitivity cTnI STAT assay. Fifty-nine individuals (aged 50±9 years, 13 women) without cardiovascular disease were included. Troponin values were lowest before, highest at 3 hours, and declining at 24 hours. The largest cTnI difference was at 3 hours following exercise between the most (first race) (cTnI: 200 [87-300] ng/L) and the least strenuous exercise (cardiopulmonary exercise test) (cTnI: 12 [7-23] ng/L; P<0.001). The strongest correlation between troponin values at corresponding times was before exercise (r=0.92, P<0.0001). The strongest correlations at 3 hours were between the 2 races (r=0.72, P<0.001) and at 24 hours between the cardiopulmonary exercise test and the second race (r=0.83, P<0.001). Participants with the highest or lowest cTnI levels showed no differences in race performance or baseline echocardiographic parameters. Conclusions The variation in exercise-induced cTnI elevation is largely determined by a unique individual cTnI response that is dependent on the duration of high-intensity exercise and the timing of cTnI sampling. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02166216.

The role of modern cardiovascular imaging in (suspected) coronary artery disease in competitive athletes

This overview addresses different non-invasive imaging methods in diagnosing CAD before clearing the athlete for participation in sports activity. Keep in mind the risks and benefits of exercising for the competitive athlete and to use the SCORE-information as a first evaluation tool. It is essential to gather relevant information and to complement anatomical evaluations with functional evaluations. Exercise testing also has an added value in athletes as it will inform both the physician and the athlete on the aerobic fitness of the individual, a key factor in risk assessment.

International recommendations for electrocardiographic interpretation in athletes

Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural, or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes. However, in most countries a shortage of physician expertise limits wider application of the ECG in the care of the athlete. A critical need exists for physician education in modern ECG interpretation that distinguishes normal physiological adaptations in athletes from distinctly abnormal findings suggestive of underlying pathology. Since the original 2010 European Society of Cardiology recommendations for ECG interpretation in athletes, ECG standards have evolved quickly over the last decade; pushed by a growing body of scientific data that both tests proposed criteria sets and establishes new evidence to guide refinements. On 26-27 February 2015, an international group of experts in sports cardiology, inherited cardiac disease, and sports medicine convened in Seattle, Washington, to update contemporary standards for ECG interpretation in athletes. The objective of the meeting was to define and revise ECG interpretation standards based on new and emerging research and to develop a clear guide to the proper evaluation of ECG abnormalities in athletes. This statement represents an international consensus for ECG interpretation in athletes and provides expert opinion-based recommendations linking specific ECG abnormalities and the secondary evaluation for conditions associated with SCD.

Challenges in high-sensitive troponin assay interpretation for intensive therapy

Cardiac troponins T and I are considered highly sensitive and specific markers for the diagnosis of acute myocardial infarction. Currently, a series of nonprimary cardiac abnormalities may manifest as an elevation in high-sensitive assays. The reduction in their detection limits has allowed earlier diagnosis and the use of evidence-based therapeutic measures; however, this characteristic has increased the spectrum of detectable noncoronary heart diseases, which poses challenges for characterizing acute coronary syndromes and creates a new role for these tests in known disorders in intensive care units, especially sepsis. Management of patients through a greater understanding of how these markers behave should be re-evaluated to ensure their correct interpretation.

The influence of non-modifiable and modifiable factors on cardiac biomarkers after marathon running

BACKGROUND

This study investigated the influence of modifiable (training) and non-modifiable factors (age and gender) on cardiac troponin I (cTnI) and B-type natriuretic peptide (BNP) levels post-marathon.

METHODS

Thirteen female and nine male recreational runners participated in the 2015 Hartford Marathon. A venous blood draw was taken from each subject at 24 hours pre-race, immediately post-race and 24 hours post-race.

RESULTS

Weekly mileage and weekly long runs were recorded for a 12-week period prior to the marathon. No association was found between age and BNP (P=0.11, P=0.50) or cTnI (P=0.69, P=0.28) for either post-race time points. No association was found between gender and cTnI for either post-race time points (P=0.09, P=0.57). However, BNP elevation, at 24 hours post-race was more pronounced in females than males (P=0.047). For cTnI levels immediately post-race, a negative association was found for average weekly mileage (P=0.006), while a positive association was found for the number of long runs exceeding 20 miles (P=0.05). No association between training and BNP were found.

CONCLUSIONS

These results suggest that female runners may experience greater cardiac stress than males. In addition, runners with greater weekly training mileage experienced less cardiac stress post-race, while runners who ran too many 20+ mile long runs, experienced more cardiac stress post-marathon.

2706 km cycling in 2 weeks: effects on cardiac function in 6 elderly male athletes

OBJECTIVES

Physiological effects of exercise on trained and untrained individuals have been studied extensively. Typically, young or middle-aged individuals are examined before and after short periods of vigorous exertion.

METHODS

We studied 6 elderly male athletes (61 ± 8 years (mean ± SD); baseline [Formula: see text]O₂max 48 ± 5 ml·kg^-1·min^-1) with focus on cardiac function and biomarkers following 14 consecutive days of moderate intensity exercise. Cardiac dimensions, function, biomarkers, and other measures of cardiovascular health were examined at baseline and 2 and 28 h after the last day of cycling a total of 2706 km.

RESULTS

Data collected after the cessation of exercise on the 14th day revealed significant increases in average size of the left atrium (3.5 ± 0.4 to 4.0 ± 0.3 cm; p = 0.02) and left ventricular end systolic volume (47 ± 2 to 52 ± 5 ml; p = 0.004), with no other significant changes in cardiac size or function. Small, transient increases in cardiac biomarkers (troponin T, creatine kinase myocardial band, and N-terminal pro-brain natriuretic peptide) (p < 0.01) were observed 2 h after completion of cycling but no changes in systolic (including strain-analyses) or diastolic cardiac function were observed at rest. [Formula: see text]O₂max was significantly lower at the 28 h time point than at baseline (p < 0.02). Plasma concentrations of total- (p < 0.01) and low-density lipoprotein-cholesterol (p < 0.01) were markedly lower after exercise. Systolic blood pressure was unchanged, but diastolic pressure was significantly lower after exercise than at baseline.

CONCLUSIONS

The results suggest that repeated moderate intensity exercise in elderly men was associated with a transient increase in cardiac biomarkers while cardiac function remained unaltered. A favorable reduction in blood lipids and diastolic blood pressure were seen for >28 h after the end of activity. An unexplained symptomless severe plasma hyponatremia developed in 3 of 6 subjects 28 h after the end of activity.

Myocardial fatigue in recreational marathon runners: A speckle-tracking echocardiography study

Background

Prolonged aerobic exercise such as marathon running produces supraphysiological hemodynamic stress that can potentially affect the athlete's cardiac homeostasis. While cardiac structural and functional adaptations in professional athletes are well characterized, only a limited information is available for recreational runners undergoing this supraphysiological stress.

Methods

Premarathon and post-marathon echocardiography was performed in 50 recreational marathon runners [age 40.8 ± 7.5 years, 44 (88%) males; running distance 42.195 km]. All the runners received 4-month training for the marathon. The baseline echocardiogram and N-terminal B-type natriuretic peptide (NT-proBNP) were obtained before training, whereas the post-marathon study was performed within 10 days (7.27 ± 0.92 days) of completion of marathon. Two-dimensional speckle-tracking echocardiography was used for characterizing the changes in myocardial mechanics.

Results

There was a significant reduction in heart rate post-marathon, whereas the levels of NT-proBNP increased significantly (86.0 ± 9.5 pg/ml vs 106.5 ± 24.2 pg/ml, p = 0.001). The left ventricular (LV) end-diastolic volume (61.8 ± 16.5 ml vs 72.8 ± 5.1 ml, p < 0.001), LV mass (120.2 ± 30.0 gm vs 160.3 ± 43.0 gm, p < 0.001), and LV ejection fraction (64.9 ± 5.6% vs 72.0 ± 5.7%, p < 0.001) also increased significantly. However, there was a significant attenuation in LV global longitudinal (−19.3 ± 2.71% vs −16.5 ± 4.6%, p = 0.003) and circumferential strain (−17.2 ± 2.41% vs −15.2 ± 2.6%, p = 0.001) post-marathon. The LV global radial strain showed a nonsignificant reduction.

Conclusion

Recreational marathon runners have reduced longitudinal and circumferential shortening of the left ventricle with elevation of NT-proBNP. However, the LV ejection performance remains maintained because of an increase in the LV end-diastolic volume and mass. These changes suggest the possibility of “myocardial fatigue” occurring in response to supraphysiological hemodynamic stress of marathon running.

International Recommendations for Electrocardiographic Interpretation in Athletes

Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural, or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes. However, in most countries a shortage of physician expertise limits wider application of the ECG in the care of the athlete. A critical need exists for physician education in modern ECG interpretation that distinguishes normal physiological adaptations in athletes from distinctly abnormal findings suggestive of underlying pathology. Since the original 2010 European Society of Cardiology recommendations for ECG interpretation in athletes, ECG standards have evolved quickly over the last decade; pushed by a growing body of scientific data that both tests proposed criteria sets and establishes new evidence to guide refinements. On February 26-27, 2015, an international group of experts in sports cardiology, inherited cardiac disease, and sports medicine convened in Seattle, Washington, to update contemporary standards for ECG interpretation in athletes. The objective of the meeting was to define and revise ECG interpretation standards based on new and emerging research and to develop a clear guide to the proper evaluation of ECG abnormalities in athletes. This statement represents an international consensus for ECG interpretation in athletes and provides expert opinion-based recommendations linking specific ECG abnormalities and the secondary evaluation for conditions associated with SCD.

International criteria for electrocardiographic interpretation in athletes: Consensus statement

Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes. However, in most countries a shortage of physician expertise limits wider application of the ECG in the care of the athlete. A critical need exists for physician education in modern ECG interpretation that distinguishes normal physiological adaptations in athletes from distinctly abnormal findings suggestive of underlying pathology. Since the original 2010 European Society of Cardiology recommendations for ECG interpretation in athletes, ECG standards have evolved quickly, advanced by a growing body of scientific data and investigations that both examine proposed criteria sets and establish new evidence to guide refinements. On 26-27 February 2015, an international group of experts in sports cardiology, inherited cardiac disease, and sports medicine convened in Seattle, Washington (USA), to update contemporary standards for ECG interpretation in athletes. The objective of the meeting was to define and revise ECG interpretation standards based on new and emerging research and to develop a clear guide to the proper evaluation of ECG abnormalities in athletes. This statement represents an international consensus for ECG interpretation in athletes and provides expert opinion-based recommendations linking specific ECG abnormalities and the secondary evaluation for conditions associated with SCD.

Troponin and exercise

Cardiac troponins are the preferred biomarkers in diagnostic of myocardial infarction, but these markers also can rise in response to exercise. Multiple studies have assessed troponins post-exercise, but the results have varied and there have been disagreements about the mechanism of troponin release. The aim of this paper was to review the literature, and to consider factors and mechanisms regarding exercise-induced increase of troponin. 145 studies were found after a search in pubmed and inclusion of additional articles found in the reference list of the first articles. Results showed that troponin rises in 0-100% of subjects after prolonged heavy exercise like marathon, but also after short-term and intermittent exercise like 30min of running and basketball. The variation can be due to factors like intensity, age, training experience, variation in sample size, blood sample timing and troponin assay. The pattern of troponin level post-exercise corresponds to release from the cytosolic compartment of cardiomyocytes. Increased membrane permeability might be caused by production of reactive oxygen species or alterations in calcium, pH, glucose/fat metabolism or in communication between integrins. Other suggested mechanisms are increased cardiovascular stress, inflammation, vasculitis, release of troponin degradation products in "blebs", dehydration, impaired renal clearance and expression of cardiac troponin in skeletal muscle. It can be concluded that both heavy and light exercise may cause elevated troponin, which have to be considered when patient are suspected to have a myocardial infarction. Several factors probably influence post-exercise levels of troponin, but the mechanism of release is most likely physiologic.

Sudden cardiac death in athletes

A 'paradox of sport' is that in addition to the undisputed health benefits of physical activity, vigorous exertion may transiently increase the risk of acute cardiac events. In general, the risk of sudden cardiac death (SCD) approximately doubles during physical activity and is 2- to 3-fold higher in athletes compared to nonathletes. The incidence of SCD in young athletes is in fact very low, at around 1-3 per 100,000, but attracts much public attention. Variations in incidence figures may be explained by the methodology used for data collection and more importantly by differences between subpopulations of athletes. The incidence of SCD in older (≥ 35 years) athletes is higher and may be expected to rise, as more and older individuals take part in organized sports. SCD is often the first clinical manifestation of a potentially fatal underlying cardiovascular disorder and usually occurs in previously asymptomatic athletes. In the young (<35 years), SCD is mainly due to congenital/inherited cardiac abnormalities, whilst coronary artery disease (CAD) is the most common cause in older athletes. Cardiac screening including family/personal history, physical examination and resting electrocardiogram (ECG) may identify individuals at risk and has the potential to decrease the risk of SCD in young athletes. Screening including the ECG has a high sensitivity for underlying disease in young athletes, but the specificity needs to be improved, whereas the sensitivity of screening without the use of ECG is very low. The screening modality recommended for young athletes is of limited value in older athletes, who should receive individualized screening with cardiac stress testing for patients with high risk of underlying CAD. As cardiovascular screening will never be able to identify all athletes at risk, adequate preparedness is vital in case of a potentially fatal event at the sporting arena/facility. Firstly, we will review the magnitude of the problem of SCD in athletes of different ages, as well as the aetiology. Secondly, we will focus on how to prevent SCD in athletes of all ages, reviewing cardiovascular screening recommendations as well as emergency preparedness and arena safety.

Cardiac risks associated with marathon running

Context:

A recent cluster of sudden cardiac deaths in marathon runners has attracted considerable media attention and evoked concern over the safety of long-distance running and competition. This review discusses the acute and potential long-term risks associated with marathon running and puts these into perspective with the many health benefits afforded by habitual vigorous exercise.

Evidence Acquisition:

Data sources included peer-reviewed publications from 1979 to January 2010 as identified via PubMed and popular media.

Results:

Marathon running is associated with a transient and low risk of sudden cardiac death. This risk appears to be even lower in women and is independent of marathon experience or the presence of previously reported symptoms. Most deaths are due to underlying coronary artery disease. The value of preparticipation screening is limited by its insensitivity and impracticality of widespread implementation. Appropriate preparation and deployment of trained medical personnel and availability of automatic external defibrillators are expected to have a major impact on survival from cardiac arrests during marathons. Cardiac biochemical and functional abnormalities are commonly observed transiently following completion of a marathon, although their clinical significance is unknown.

Conclusions:

Sudden cardiac deaths associated with marathon running are exceedingly rare events. Prevention should focus on recognition and investigation of prodromal symptoms, if present, and access to rapid defibrillation and trained medical personnel. The robust association of endurance running with improved quality of life and longevity underscores the importance of putting risks into perspective with other well-established health benefits of regular vigorous exercise.

The kinetics of highly sensitive cardiac troponin T release after prolonged treadmill exercise in adolescent and adult athletes

The nature and kinetics of postexercise cardiac troponin (cTn) appearance is poorly described and understood in most athlete populations. We compared the kinetics of high-sensitivity cTn T (hs-cTnT) after endurance running in training-matched adolescents and adults. Thirteen male adolescent (mean age: 14.1 ± 1.1 yr) and 13 male adult (24.0 ± 3.6 yr) runners performed a 90-min constant-load treadmill run at 95% of ventilatory threshold. Serum hs-cTnT levels were assessed preexercise, immediately postexercise, and at 1, 2, 3, 4, 5, 6, and 24 h postexercise. Serum NH2-terminal pro-brain natriuretic peptide (NT-pro-BNP) levels were recorded preexercise and 3, 6, and 24 h postexercise. Left ventricular function was assessed preexercise, immediately postexercise, and 6 h postexercise. Peak hs-cTnT occurred at 3–4 h postexercise in all subjects, but was substantially higher ( P < 0.05) in adolescents [median (range): 211.0 (11.2–794.5) ng/l] compared with adults [median (range): 19.1 (9.7–305.6) ng/l]. Peak hs-cTnT was followed by a rapid decrease in both groups, although adolescent data had not returned to baseline at 24 h. Substantial interindividual variability was noted in peak hs-cTnT, especially in the adolescents. NT-pro-BNP was significantly elevated postexercise in both adults and adolescents and remained above baseline at 24 h in both groups. In both groups, left ventricular ejection fraction and the ratio of early-to-atrial peak Doppler flow velocities were significantly decreased immediately postexercise. Peak hs-cTnT was not related to changes in ejection fraction, ratio of early-to-atrial peak Doppler flow velocities, or NT-pro-BNP. The present data suggest that postexercise hs-cTnT elevation 1) occurred in all runners, 2) peaked 3–4 h postexercise, and 3) the peak hs-cTnT concentration after prolonged exercise was higher in adolescents than adults.

Metabolic markers in sports medicine

Physical exercise induces adaptations in metabolism considered beneficial for health. Athletic performance is linked to adaptations, training, and correct nutrition in individuals with genetic traits that can facilitate such adaptations. Intense and continuous exercise, training, and competitions, however, can induce changes in the serum concentrations of numerous laboratory parameters. When these modifications, especially elevated laboratory levels, result outside the reference range, further examinations are ordered or participation in training and competition is discontinued or sports practice loses its appeal. In order to correctly interpret commonly used laboratory data, laboratory professionals and sport physicians need to know the behavior of laboratory parameters during and after practice and competition. We reviewed the literature on liver, kidney, muscle, heart, energy, and bone parameters in athletes with a view to increase the knowledge about clinical chemistry applied to sport and to stimulate studies in this field. In liver metabolism, the interpretation of serum aminotransferases concentration in athletes should consider the release of aspartate aminotransferase (AST) from muscle and of alanine aminotransferase (ALT) mainly from the liver, when bilirubin can be elevated because of continuous hemolysis, which is typical of exercise. Muscle metabolism parameters such as creatine kinase (CK) are typically increased after exercise. This parameter can be used to interpret the physiological release of CK from muscle, its altered release due to rhabdomyolysis, or incomplete recovery due to overreaching or trauma. Cardiac markers are released during exercise, and especially endurance training. Increases in these markers should not simply be interpreted as a signal of cardiac damage or wall stress but rather as a sign of regulation of myocardial adaptation. Renal function can be followed in athletes by measuring serum creatinine concentration, but it should be interpreted considering the athlete's body-mass index (BMI) and phase of the competitive season; use of cystatin C could be a reliable alternative to creatinine. Exercise and training induce adaptations in glucose metabolism which improve glucose utilization in athletes and are beneficial for reducing insulin insensitivity in nonathletes. Glucose metabolism differs slightly for different sports disciplines, as revealed in laboratory levels. Sport activities induce a blood lipid profile superior to that of sedentary subjects. There are few reports for a definitive conclusion, however. The differences between athletes and sedentary subjects are mainly due to high-density lipoprotein cholesterol (HDLC) concentrations in physically active individuals, although some differences among sport disciplines exist. The effect of sports on serum and urinary markers for bone metabolism is not univocal; further studies are needed to establish the real and effective influence of sport on bone turnover and especially to establish its beneficial effect.

Troponin elevation in coronary vs. non-coronary disease

Acute myocardial infarction is defined as myocardial cell death due to prolonged myocardial ischaemia. Cardiac troponins (cTn) are the most sensitive and specific biochemical markers of myocardial injury and with the new high-sensitivity troponin methods very minor damages on the heart muscle can be detected. However, elevated cTn levels indicate cardiac injury, but do not define the cause of the injury. Thus, cTn elevations are common in many disease states and do not necessarily indicate the presence of a thrombotic acute coronary syndrome (ACS). In the clinical work it may be difficult to interpret dynamic changes of troponin in conditions such as stroke, pulmonary embolism, sepsis, acute perimyocarditis, Tako-tsubo, acute heart failure, and tachycardia. There are no guidelines to treat patients with elevated cTn levels and no coronary disease. The current strategy of treatment of patients with elevated troponin and non-acute coronary syndrome involves treating the underlying causes. The aim of this paper is to review data from studies of non-ACS patients with acutely elevated troponin who in clinical practice may be difficult to discriminate from ACS patients.