Allometric scaling for left ventricular mass and geometry in male and female athletes of mixed and endurance sports.

BACKGROUND: The athlete's heart (AH) defines the phenotypical changes that occur in response to chronic exercise training. Echocardiographic assessment of the AH is used to calculate LV mass (LVM) and determine chamber geometry. This is, however, interpreted using standard linear (ratiometric) scaling to body surface area (BSA) whereas allometric scaling is now widely recommended. This study (1) determined whether ratiometric scaling of LVM to BSA (LVMiratio) provides a size-independent index in young and veteran athletes of mixed and endurance sports (MES), and (2) calculated size-independent beta exponents for allometrically derived (LVMiallo) to BSA and (3) describes the physiological range of LVMiallo and the classifications of LV geometry. METHODS: 1373 MES athletes consisting of young (< 35 years old) (males n = 699 and females n = 127) and veteran (> 35 years old) (males n = 327 and females n = 220) were included in the study. LVMiratio was calculated as per standard scaling and sex-specific LVMiallo were derived from the population. Cut-offs were defined and geometry was classified according to the new exponents and relative wall thickness. RESULTS: LVMiratio did not produce a size independent index. When tested across the age range the following indexes LVMi/BSA0.7663 and LVMi/BSA0.52, for males and females respectively, were size independent (r = 0.012; P = 0.7 and r = 0.003; P = 0.920). Physiological cut-offs for LVMiallo were 135 g/(m2)0.7663 in male athletes and 121 g/(m2)0.52 in female athletes. Concentric remodelling / hypertrophy was present in 3% and 0% of young male and female athletes and 24% and 17% of veteran male and female athletes, respectively. Eccentric hypertrophy was observed in 8% and 6% of young male and female athletes and 9% and 11% of veteran male and female athletes, respectively. CONCLUSION: In a large cohort of young and veteran male and female MES athletes, LVMiratio to BSA is not size independent. Sex-specific LVMiallo to BSA with LVMi/BSA0.77 and LVMi/BSA0.52 for male and female athletes respectively can be applied across the age-range. Population-based cut-offs of LVMiallo provided a physiological range demonstrating a predominance for normal geometry in all athlete groups with a greater percentage of concentric remodelling/hypertrophy occurring in veteran male and female athletes.

Biventricular Myocardial Fibrosis and Sudden Death in Patients With Brugada Syndrome.

BACKGROUND: Electrophysiological, imaging, and pathological studies have reported the presence of subtle structural abnormalities in hearts from patients with Brugada syndrome (BrS). However, data concerning disease involvement outside of the right ventricular outflow tract are limited. OBJECTIVES: This study sought to characterize the presence and distribution of ventricular myocardial fibrosis in a cohort of decedents experiencing sudden cardiac death caused by BrS. METHODS: The authors evaluated 28 whole hearts from consecutive sudden cardiac death cases attributed to BrS and 29 hearts from a comparator group comprised of noncardiac deaths (control subjects). Cardiac tissue from 6 regions across the right and left ventricle were stained with Picrosirius red for collagen and tissue composition was determined using image analysis software. Postmortem genetic testing was performed in cases with DNA retained for analysis. RESULTS: Of 28 BrS decedents (75% men; median age of death 25 years), death occurred in sleep or at rest in 24 of 28 (86%). The highest proportion of collagen was observed in the epicardial right ventricular outflow tract of the BrS group (23.7%; 95% CI: 20.8%-26.9%). Ventricular myocardium from BrS decedents demonstrated a higher proportion of collagen compared with control subjects (ratio 1.45; 95% CI: 1.22-1.71; P < 0.001), with no significant interactions with respect to sampling location or tissue layer. There was insufficient evidence to support differences in collagen proportion in SCN5A-positive cases (n = 5) when compared with control subjects (ratio 1.23; 95% CI: 0.75-1.43; P = 0.27). CONCLUSIONS: Brugada syndrome is associated with increased collagen content throughout right and left ventricular myocardium, irrespective of sampling location or myocardial layer.

Risk of atrial fibrillation in athletes: a systematic review and meta-analysis.

OBJECTIVE: A systematic review, meta-analysis and meta-regression were performed on selected studies to investigate the incidence of atrial fibrillation (AF) among athletes compared with non-athlete controls. DESIGN: Meta-analysis with heterogeneity analysis and subsequent meta-regression to model covariates were performed. The mode of exercise (endurance and mixed sports) and age were the a priori determined covariates. DATA SOURCES: PubMed, MEDLINE, Science Direct, SPORTDiscus and the Cochrane library were searched. ELIGIBILITY CRITERIA: Research articles published after 1990 and before 2 December 2020 were included if they reported the number of AF cases in athletes with non-athlete (physically active or inactive) control groups, were case-control or cohort studies and if data allowed calculation of OR. RESULTS: The risk of developing AF was significantly higher in athletes than in non-athlete controls (OR: 2.46; 95% CI 1.73 to 3.51; p<0.001, Z=4.97). Mode of exercise and risk of AF were moderately correlated (B=0.1259, p=0.0193), with mixed sport conferring a greater risk of AF than endurance sport (B=-0.5476, p=0.0204). Younger (<55 years) athletes were significantly more likely to develop AF compared with older (≥55 years) athletes (B=-0.02293, p<0.001). CONCLUSION: Athletes have a significantly greater likelihood of developing AF compared with non-athlete controls, with those participating in mixed sport and younger athletes at the greatest risk. Future studies of AF prevalence in athletes according to specific exercise dose parameters, including training and competition history, may aid further in delineating those at risk.

The heart of the ageing endurance athlete: the role of chronic coronary stress.

Moderate physical exercise is associated with an irrefutable reduction in cardiac morbidity and mortality. The current guidelines recommend at least 150 min of moderate exercise or 75 min of vigorous exercise per week. Endurance athletes perform exercise at a level that is 10- to 20-fold greater than these recommendations. These athletes reveal several structural and functional cardiac adaptations including increased cardiac size, enhanced ventricular filling, and augmentation of stroke volume even at the highest heart rates. The long-term effects of endurance exercise on the heart are unknown. Endurance exercise is associated with a transient increase in serum concentrations of biomarkers of cardiac damage and ventricular dysfunction which improves within 72 h. Over the past decade, there have been emerging studies reporting attenuated mortality benefit amongst individuals who perform the highest volume of exercise. Studies in lifelong male athletes aged above 40 years old show a higher prevalence of high coronary artery calcium scores (>300 Agatston units), a higher coronary plaque burden, and myocardial fibrosis compatible with subclinical myocardial infarction compared with relatively sedentary healthy controls, raising speculation that lifelong intense exercise imposes chronic coronary stress on the heart. This review article will provide a critical analysis of the existing data.

The effects of endurance exercise on the heart: panacea or poison?

Regular aerobic physical exercise of moderate intensity is undeniably associated with improved health and increased longevity, with some studies suggesting that more is better. Endurance athletes exceed the usual recommendations for exercise by 15-fold to 20-fold. The need to sustain a large cardiac output for prolonged periods is associated with a 10-20% increase in left and right ventricular size and a substantial increase in left ventricular mass. A large proportion of endurance athletes have raised levels of cardiac biomarkers (troponins and B-type natriuretic peptide) and cardiac dysfunction for 24-48 h after events, but what is the relevance of these findings? In the longer term, some endurance athletes have an increased prevalence of coronary artery disease, myocardial fibrosis and arrhythmias. The inherent association between these 'maladaptations' and sudden cardiac death in the general population raises the question of whether endurance exercise could be detrimental for some individuals. However, despite speculation that these abnormalities confer an increased risk of future adverse events, elite endurance athletes have an increased life expectancy compared with the general population.

Accuracy of the 2017 international recommendations for clinicians who interpret adolescent athletes' ECGs: a cohort study of 11 168 British white and black soccer players.

AIM: To investigate the accuracy of the recently published international recommendations for ECG interpretation in young athletes in a large cohort of white and black adolescent soccer players. METHODS: 11 168 soccer players (mean age 16.4±1.2 years) were evaluated with a health questionnaire, ECG and echocardiogram; 10 581 (95%) of the players were male and 10 163 (91%) were white. ECGs were retrospectively analysed according to (1) the 2010 European Society of Cardiology (ESC) recommendations, (2) Seattle criteria, (3) refined criteria and (4) the international recommendations for ECG interpretation in young athletes. RESULTS: The ESC recommendations resulted in a higher number of abnormal ECGs compared with the Seattle, refined and international criteria (13.2%, 4.3%, 2.9% and 1.8%, respectively). All four criteria were associated with a higher prevalence of abnormal ECGs in black athletes compared with white athletes (ESC: 16.2% vs 12.9%; Seattle: 5.9% vs 4.2%; refined: 3.8% vs 2.8%; international 3.6% vs 1.6%; p<0.001 each). Compared with ESC recommendations, the Seattle, refined and international criteria identified a lower number of abnormal ECGs-by 67%, 78% and 86%, respectively. All four criteria identified 36 (86%) of 42 athletes with serious cardiac pathology. Compared with ESC recommendations, the Seattle criteria improved specificity from 87% to 96% in white athletes and 84% to 94% in black athletes. The international recommendations demonstrated the highest specificity for white (99%) and black (97%) athletes and a sensitivity of 86%. CONCLUSIONS: The 2017 international recommendations for ECG interpretation in young athletes can be applied to adolescent athletes to detect serious cardiac disease. These recommendations perform more effectively than previous ECG criteria in both white and black adolescent soccer players.

Sudden Death and Left Ventricular Involvement in Arrhythmogenic Cardiomyopathy.

BACKGROUND: Arrhythmogenic cardiomyopathy (ACM) is an inherited heart muscle disorder characterized by myocardial fibrofatty replacement and an increased risk of sudden cardiac death (SCD). Originally described as a right ventricular disease, ACM is increasingly recognized as a biventricular entity. We evaluated pathological, genetic, and clinical associations in a large SCD cohort. METHODS: We investigated 5205 consecutive cases of SCD referred to a national cardiac pathology center between 1994 and 2018. Hearts and tissue blocks were examined by expert cardiac pathologists. After comprehensive histological evaluation, 202 cases (4%) were diagnosed with ACM. Of these, 15 (7%) were diagnosed antemortem with dilated cardiomyopathy (n=8) or ACM (n=7). Previous symptoms, medical history, circumstances of death, and participation in competitive sport were recorded. Postmortem genetic testing was undertaken in 24 of 202 (12%). Rare genetic variants were classified according to American College of Medical Genetics and Genomics criteria. RESULTS: Of 202 ACM decedents (35.4±13.2 years; 82% male), no previous cardiac symptoms were reported in 157 (78%). Forty-one decedents (41/202; 20%) had been participants in competitive sport. The adjusted odds of dying during physical exertion were higher in men than in women (odds ratio, 4.58; 95% CI, 1.54-13.68; P=0.006) and in competitive athletes in comparison with nonathletes (odds ratio, 16.62; 95% CI, 5.39-51.24; P<0.001). None of the decedents with an antemortem diagnosis of dilated cardiomyopathy fulfilled definite 2010 Task Force criteria. The macroscopic appearance of the heart was normal in 40 of 202 (20%) cases. There was left ventricular histopathologic involvement in 176 of 202 (87%). Isolated right ventricular disease was seen in 13%, isolated left ventricular disease in 17%, and biventricular involvement in 70%. Among whole hearts, the most common areas of fibrofatty infiltration were the left ventricular posterobasal (68%) and anterolateral walls (58%). Postmortem genetic testing yielded pathogenic variants in ACM-related genes in 6 of 24 (25%) decedents. CONCLUSIONS: SCD attributable to ACM affects men predominantly, most commonly occurring during exertion in athletic individuals in the absence of previous reported cardiac symptoms. Left ventricular involvement is observed in the vast majority of SCD cases diagnosed with ACM at autopsy. Current Task Force criteria may fail to diagnose biventricular ACM before death.

Direct transfemoral transcatheter aortic valve implantation without balloon pre-dilatation using the Edwards Sapien XT valve.

OBJECTIVES: To evaluate the feasibility and safety of direct transcatheter aortic valve implantation (TAVI) by the transfemoral approach without balloon pre-dilatation using the Edwards SapienXT valve. BACKGROUND: TAVI is established in selected high-risk patients with severe aortic stenosis. Balloon aortic valvuloplasty (BAV) is recommended prior to valve implantation, but may contribute to procedural risk. It is unknown whether this is necessary for successful passage and deployment of the device. METHODS: 81 patients (mean age 84 [95%CI:82-85.8], 62% male, median EuroScore 22.8% [95%CI:20.5-27]) undergoing transfemoral TAVI (35 by direct implantation [direct group]; 46 with balloon pre-dilatation [balloon group]) between 2010 and 2013 were analyzed for efficacy and safety endpoints. RESULTS: Procedural success was 100%. Pre and post-procedural peak gradients in the direct group were 66mmHg (95%CI:59-72.8) and 14mmHg (95%CI:12-17.8)(P < 0.0001) compared to 76.5mmHg (95%CI:73.7-94.0) and 17mmHg (95%CI:16-19)(P < 0.0001) in the balloon group. Post-dilatation was performed in 4/35(11.4%) of the direct group and 3/46(6.5%) of the balloon group (P = 0.83). Post procedure moderate AR was present in 1/35(2.9%) in the direct group and none in the balloon group. In-hospital mortality (2.9% direct vs. 0% balloon group), stroke (2.9% vs. 4.4%), tamponade (2.9% vs. 2.2%), major vascular complications (2.9% vs. 8.7%) and new permanent pacing (2.2% vs. 0) were similar. Pacing time, inflations, radiation dose and contrast use were all significantly lower in the direct group. CONCLUSIONS: Direct implantation of the Edwards SapienXT valve during TAVI by the transfemoral route appears safe, efficacious and feasible in those without extreme calcification. © 2016 Wiley Periodicals, Inc.