Myocardial function in older male amateur marathon runners: assessment by tissue Doppler echocardiography, speckle tracking, and cardiac biomarkers.

BACKGROUND: Participation of older men in endurance races continues to increase. Recent studies on marathon runners raised concerns about a transient myocardial dysfunction and damage. The aim of our study was to compare the extent of marathon-induced myocardial dysfunction in young and older runners and to identify its potential correlation to elevated cardiac biomarkers.

METHODS: Twenty-eight older (aged 60-72 years) and 50 younger (22-59 years) male amateur athletes who participated in the 2006 Berlin Marathon were included in the study and examined by echocardiography (including tissue Doppler and speckle tracking echocardiography) and blood tests (including troponin T [TnT], N-terminal pro brain natriuretic peptide [NT-proBNP]) before, immediately after, and 2 weeks after the race.

RESULTS: Immediately after the marathon, there was no sign of systolic myocardial dysfunction (increase in fractional shortening, baseline 39.9% +/- 7.6% vs post 46.8% +/- 9.2%, P < .001, unchanged septal basal longitudinal 2-dimensional strain: 17.1% +/- 2.9%, 17.7% +/- 3.2%, P = .11). As a marker of diastolic function, E/E' was not altered significantly (7.6 +/- 2.1, 8.7 +/- 3.5, P = .15). The deceleration time of E and E' decreased in both groups immediately after the race, indicating a transient adaptation of diastolic myocardial function. Strain of the right ventricular free wall was decreased in the mid and apical segments after the race in both groups with normalization during follow-up. Tricuspid annular plane systolic excursion was not altered. Some 53.8% of all runners had increases in TnT or NT-proBNP after the race. Some 32% of controls and 29% of older runners had elevated levels of NT-proBNP (P = .75, TnT: 44% vs 29% P = .18). There was no correlation between NT-proBNP and TnT increase. The increases in biomarkers were not correlated to echocardiography parameters of systolic, diastolic, or right-sided heart dysfunction or to age, training level, running time, or renal function. All parameters returned to normal ranges after 2 weeks.

CONCLUSION: Left ventricular systolic function is preserved after a marathon in older runners. There are right ventricular functional changes as a sign of prolonged myocardial work load. There is no significant difference between older and young runners regarding transient diastolic dysfunction or biomarker release. The latter is not associated with echocardiography parameters of myocardial dysfunction.