Reduced Ejection Fraction in Elite Endurance Athletes: Clinical and Genetic Overlap With Dilated Cardiomyopathy.

BACKGROUND: Exercise-induced cardiac remodeling can be profound, resulting in clinical overlap with dilated cardiomyopathy, yet the significance of reduced ejection fraction (EF) in athletes is unclear. The aim is to assess the prevalence, clinical consequences, and genetic predisposition of reduced EF in athletes. METHODS: Young endurance athletes were recruited from elite training programs and underwent comprehensive cardiac phenotyping and genetic testing. Those with reduced EF using cardiac magnetic resonance imaging (defined as left ventricular EF <50%, or right ventricular EF <45%, or both) were compared with athletes with normal EF. A validated polygenic risk score for indexed left ventricular end-systolic volume (LVESVi-PRS), previously associated with dilated cardiomyopathy, was assessed. Clinical events were recorded over a mean of 4.4 years. RESULTS: Of the 281 elite endurance athletes (22±8 years, 79.7% male) undergoing comprehensive assessment, 44 of 281 (15.7%) had reduced left ventricular EF (N=12; 4.3%), right ventricular EF (N=14; 5.0%), or both (N=18; 6.4%). Reduced EF was associated with a higher burden of ventricular premature beats (13.6% versus 3.8% with >100 ventricular premature beats/24 h; P=0.008) and lower left ventricular global longitudinal strain (-17%±2% versus -19%±2%; P<0.001). Athletes with reduced EF had a higher mean LVESVi-PRS (0.57±0.13 versus 0.51±0.14; P=0.009) with athletes in the top decile of LVESVi-PRS having an 11-fold increase in the likelihood of reduced EF compared with those in the bottom decile (P=0.034). Male sex and higher LVESVi-PRS were the only significant predictors of reduced EF in a multivariate analysis that included age and fitness. During follow-up, no athletes developed symptomatic heart failure or arrhythmias. Two athletes died, 1 from trauma and 1 from sudden cardiac death, the latter having a reduced right ventricular EF and a LVESVi-PRS >95%. CONCLUSIONS: Reduced EF occurs in approximately 1 in 6 elite endurance athletes and is related to genetic predisposition in addition to exercise training. Genetic and imaging markers may help identify endurance athletes in whom scrutiny about long-term clinical outcomes may be appropriate. REGISTRATION: URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=374976&isReview=true; Unique identifier: ACTRN12618000716268.

Relation of Alcohol Consumption to Left Ventricular Fibrosis Using Cardiac Magnetic Resonance Imaging.

Light-to-moderate regular alcohol consumption has been associated with reduced mortality, heart failure, and sudden death, with a well described "U-shaped" relationship. We sought to determine whether markers of diffuse ventricular fibrosis as assessed by cardiac magnetic resonance imaging (CMR) T1 mapping differ between nondrinkers and regular drinkers. We prospectively recruited 165 participants to undergo 3T CMR ventricular T1 mapping which included 120 regular light-to-moderate drinkers (7 to 28 standard drinks per week for >12 months) and 45 age and gender-matched nondrinking controls (1 standard drink ∼12 g alcohol). Diffuse ventricular fibrosis was assessed using ShMOLLI T1 mapping sequences performed in mid-short axis. Native T1, postcontrast T1 times and extracellular volume were compared in the left ventricle between regular drinkers and lifelong nondrinkers. In total 165 participants (mean age 59 ± 12 years, 70% male, 36% hypertension, mean LVEF 58 ± 11%) underwent CMR. Moderate alcohol intake (mean alcohol intake 16 ± 6 SDs/week) was associated with lower markers of diffuse ventricular fibrosis: native T1 time 1140 ± 47 vs 1173 ± 39 ms, p < 0.001; postcontrast T1 time 470 ± 47 vs 445 ± 43 ms, p = 0.01; extracellular volume 25.0 ± 2.7% vs 27.0 ± 2.8%, p = 0.003 despite similar LV size (p = 0.55) and mass compared with nondrinkers (p = 0.78). Quantity of alcohol intake and beverage type did not predict lower native T1 times. In conclusion, light-to-moderate or "social" alcohol consumption is associated with T1 changes on CMR suggestive of a reduction in diffuse ventricular fibrosis. These preliminary findings may provide some insights into the association between modest alcohol intake and reduction in sudden death and heart failure.

Electrocardiographic Features Differentiating Arrhythmogenic Right Ventricular Cardiomyopathy From an Athlete's Heart.

OBJECTIVES: This study sought to compare electrocardiogram (ECG) variants in athletic and arrhythmogenic right ventricular cardiomyopathy (ARVC) cohorts matched for the confounders of age, sex, and ethnicity. BACKGROUND: Anterior T-wave inversion (TWIV1-V4) is a common electrocardiographic finding in both athletes and patients with ARVC, and is a frequent conundrum in the setting of pre-participation screening. J-point elevation (JPE) has been proposed as an accurate means of identifying athletes, whereas disease markers, including premature ventricular contractions (PVCs) and low-voltage signals, have been associated with ARVC. METHODS: This study examined 200 subjects with TWI V1-V4, including 100 healthy athletes and 100 ARVC patients matched 1:1 for age, sex, and ethnicity (age: 21 ± 5 years for athletes vs. 22 ± 5 years for ARVC patients; 47% male; 97% Caucasian). The presence of TWI, JPE, PVCs, and left ventricular hypertrophy (LVH) were assessed. RESULTS: JPE was observed in 27% of athletes versus 16% of ARVC patients (p = 0.09). Thus, JPE had poor specificity (27%) and accuracy (60%) in identifying healthy athletes. In contrast, ARVC patients demonstrated a greater prevalence of precordial TWI beyond lead V3 (34% vs. 8%; p < 0.001), inferior TWI (31% vs. 3%; p < 0.001), PVCs (18% vs. 0%; p < 0.001), and lower LVH scores (SV1 + RV5; 19 ± 1 mm vs. 30 ± 1 mm; p < 0.001). These combined factors provided more reliable differentiation between health and disease (specificity 82%, accuracy 81%). CONCLUSIONS: PVCs and low QRS voltages are more prevalent among ARVC patients than athletes, whereas JPE is a relatively poor discriminator of health and disease when the confounders of age, sex, and ethnicity are considered.