Sports cardiology: towards the sweet spot in competitive and leisure exercise

For the podcast associated with this article, please visit https://academic.oup.com/eurheartj/pages/Podcasts. Exercise and sports undoubtedly have a positive effect on overall fitness, and outcome in general. Of note, walking pace, handgrip force,1,2 and physical activity3,4 are associated with coronary artery disease and myocardial infarction. However, during exercise itself, the risk of sudden death following an infarction is slightly increased.5–7 Furthermore, when coronary artery disease has developed, most patients hesitate to be physically active again or increase their amount of exercise. Thus, the ‘Recommendations for participation in leisure time or competitive sports in athletes–patients with coronary artery disease: a position statement from the Sports Cardiology Section of the European Association of Preventive Cardiology (EAPC)’ authored by Mats Borjesson from the Sahlgrenska University Hospital/Ostra in Goteborg, Sweden, and colleagues, an update of earlier recommendations from the Sports Cardiology section of the European Association of Preventive Cardiology of 2005, is a timely document.8 Obviously, patients with coronary artery disease, coronary artery anomalies, or spontaneous coronary dissection are all potentially exposed to myocardial ischaemia during increased oxygen demand. When patient–athletes are assessed for eligibility for competitive sports, it is understood that the patient–athlete should be eligible to participate in sport at a very high intensity level, without any limitation, since maximal exertion may well occur during competition. In advising such patient–athletes, one should carefully balance the documented benefits of exercise programmes with potential risk. Given the wealth of evidence supporting the benefits of exercise, individuals should be restricted from participating in competitive sport only when a substantial risk of adverse events or disease progression is present. Thus, these recommendations, based on available current evidence, encourage physical activity including participation in sports and, with reasonable precaution, ensure a high level of safety for all individuals with coronary artery disease. Similar to coronary artery disease, myocardial diseases such as hypertrophic9–12 or dilated cardiomyopathy,13 left ventricular non-compaction,14 arrhythmogenic cardiomyopathy,15–17 and myo-pericarditis18,19 are associated with an increased risk of fatal arrhythmias and sudden cardiac death during exercise. In their position statement ‘Recommendations for participation in competitive and leisure time sport in athletes with cardiomyopathies, myocarditis, and pericarditis’, Antonio Pelliccia from the Institute of Sports Medicine and Science in Rome, Italy on behalf of the Sport Cardiology and Exercise Nucleus of the European Association of Preventive Cardiology stress the importance of identifying high-risk individuals in the pre-participation screening. Proper medical advice regarding the participation in competitive sports activities and/or regular exercise programmes is outlined in detail in the document.20 It is unknown whether different training modalities exert differential cellular effects. Telomeres and telomere-associated proteins play a major role in cellular ageing, with implications for global health.21–24 In their article entitled ‘Differential effects of endurance, interval, and resistance training on telomerase activity and telomere length in a randomized, controlled study’, Christian Werner et al. from the Universitätsklinikum des Saarlandes in Homburg, Germany examined 124 healthy previously inactive individuals over 6 months.25 Participants were randomized to no change in lifestyle or (i) aerobic endurance training; (ii) high-intensity interval training; or (iii) resistance training. Maximum oxygen uptake was increased by all training modalities, and telomerase activity in blood mononuclear cells was up-regulated two- to three-fold in both endurance exercise groups, but not with resistance training (Figure 1). Lymphocyte, granulocyte, and leucocyte telomere length increased in the endurance training, but not in the resistance training groups. MACS-TRAP assays revealed that a single bout of endurance training, but not resistance training, acutely increased telomerase activity in CD14+ and CD34+ leucocytes. Thus, endurance, interval, and resistance training induce specific cellular pathways in circulating leucocytes. Endurance and interval training, but not resistance training, increased telomerase activity and length which regulate cellular senescence, regenerative capacity, and healthy ageing. These novel findings are put into context in an Editorial by Ioakim Spyridopoulos from Newcastle University in Newcastle Upon Tyne, UK.26 Differential effects of training on telomerase activity and telomere length in circulating mononuclear cells. (A) Leucocyte telomere length was determined in genomic DNA isolates by real-time PCR. Beside telomere (T) DNA, the single (S) copy gene 36b4 was amplified to allow calculation of the T/S ratio for each subject at both time points. Data are represented as mean ± SD of T/S ratio per group. (B) Telomerase activity was determined by TRAP assay. Data are represented as mean ± SD of telomerase activity expressed as human embryonic kidney cell equivalents (from Werner CM, Hecksteden A, Morsch A, Zundler J, Wegmann M, Kratzsch J, Thiery J, Hohl M, Bittenbring JT, Neumann F, Böhm M, Meyer T, Laufs U. Differential effects of endurance, interval, and resistance training on telomerase activity and telomere length in a randomized, controlled study. See pages 34–46). Black athletes have an increased prevalence of repolarization anomalies and left ventricular hypertrophy compared with their white counterparts. Recent recommendations for ECG interpretation in athletes now account for some of these differences,27,28 but little attention is given to the possible impact of geographic origin on these individuals. In their article ‘Impact of geographical origin upon the electrical and structural manifestations of the black athlete’s heart’, Nathan Riding et al. from Aspetar in Doha, Qatar examined this aspect for the black athlete’s heart.29 Twelve-lead ECGs were obtained in 1698 male competitive athletes and echocardiography in 1222 African-American/Caribbean, South American, and West Asian black athletes and those from North, East, Middle, and West Africa, and compared them with ECGs of non-black athletes from south Europe and Arabic north African regions. Abnormal ECGs significantly varied by geographical origin. Repolarization abnormalities were more common among West (and Middle) African athletes than East and North Africans. Left ventricular hypertrophy was more common among African-American/Caribbean and West African athletes than West Asian, East African, and North African athletes (Figure 2). This result remained after accounting for body size. Thus, there is considerable variability in the cardiac electrical and structural remodelling response to exercise that appears to be at least partially dependent on geographic origin, a finding that is further discussed in an Editorial by Domenico Corrado from the Universita degli Studi in Padua, Italy.30 Incidence of hypertension in athletes according to peak exercise blood pressure at baseline evaluation (from Caselli S, Serdoz A, Mango F, Lemme E, Vaquer Sequì A, Milan A, Attenhofer Jost C, Schmied C, Spataro A, Pelliccia A. High blood pressure response to exercise predicts future development of hypertension in young athletes. See pages 62–68). Highly trained athletes achieve higher blood pressures at peak exercise compared with the general population, because of higher exercise performance; therefore, higher cut-off values have been proposed, but—although blood pressure variability is predictive31—the prognostic significance of exercise blood pressure has not yet been clarified. In their article entitled ‘High blood pressure response to exercise predicts future development of hypertension in young athletes’, Stefano Caselli and colleagues from the Cardiovascular Center Zurich, Hirslanden Klinik im Park in Zurich, Switzerland investigated this issue in 282 normotensive athletes.32 Of these, 141 with a high blood pressure to exercise were compared with 141 normotensive matched controls. For 7 years, no cardiac events occurred, but 8.5% of the athletes developed hypertension. Specifically, 13.5% had a high-pressure response compared with 3.5% in controls. Of note, the incidence of hypertension during follow-up was higher in the high-pressure responders. Multivariate analysis showed that baseline blood pressure and the high-pressure response strongly predicted incident hypertension. Specifically, a high blood pressure response was associated with a relative risk of 3.6 of developing hypertension. Thus, in highly trained and normotensive athletes, an exaggerated blood pressure response to exercise increases the risk for incident hypertension over a middle-term period. Future studies will have to show whether this is also associated with a higher cardiovascular event rate. The issue is complemented by two Discussion Forums related to the ‘2018 ESC guidelines for the diagnosis and management of syncope’ by Michele Brignole and colleagues from the ESC Scientific Document Group.33 In their contribution entitled ‘Use of droxidopa for the long-term treatment of neurogenic orthostatic hypotension’, Satish R. Raj and colleagues from the University of Calgary Cumming School of Medicine in Canada comment on the paper.34 Michele Brignole and colleagues respond to this comment in a detailed response.35 The editors hope that readers of this issue of the European Heart Journal will find it of interest. With thanks to Amelia Meier-Batschelet for help with compilation of this article.