We compared echocardiographic measurements and serum biomarkers of cardiac fibrosis/remodeling [troponin I, galectin-3, matrix metallopeptidase-2 and -9, N-terminal pro-brain natriuretic peptide, carboxy-terminal propeptide of type I procollagen, and soluble suppressor of tumorigenicity-2 (sST-2)/interleukin(IL)-1R4] in 53 male athletes [11 former professional (‘elite’) and 42 amateur-level (‘sub-elite’) cyclists or runners, aged 40–70 years] and 18 aged-matched controls. A subset of 15 subjects (5 controls, 3 sub-elite and 7 elite athletes) also underwent cardiac magnetic resonance imaging (cMRI).
Elite and sub-elite athletes had greater echocardiography-determined left ventricular myocardial mass indexed to body surface area than controls (113 ± 22, 115.2 ± 23.1 and 94.8 ± 21 g/m2, respectively, p = 0.008 for group effect), with similar results for left (50.5 ± 4.4, 48.2 ± 4.3 and 46.4 ± 5.2 mm, p = 0.008) and right (38.6 ± 3.8, 41.1 ± 5.5 and 34.7 ± 4.3 mm, p < 0.001) ventricular end-diastolic diameter, and cMRI-determined left atrial volume indexed to body surface area (62.7 ± 8.1, 56.4 ± 16.0 and 39.0 ± 14.1 ml/m2, p = 0.026). Two athletes showed a non-coronary pattern of small, fibrotic left ventricular patches detected by late gadolinium enhancement. No group effect was noted for biomarkers.
Regardless of their competition level at a younger age, veteran endurance athletes showed an overall healthy, non-pathological pattern of cardiac remodeling. Nonetheless, the physiopathology of the ventricular fibrotic patches detected warrants further investigation.