Abstract 15529: Exercise CMR to Differentiate Athlete’s Heart From Early Stage Dilated Cardiomyopathy
Introduction: It can be difficult to distinguish between early stage dilated cardiomyopathy (DCM) and left ventricular (LV) dilation with mildly reduced LV ejection fraction (EF) which is a common observation amongst endurance athletes (EAs). This has important consequences for clearance for competitive sport participation since DCM may precipitate fatal ventricular arrhythmias.
Hypothesis: We hypothesized that contractile reserve of both ventricles and atria would be preserved in EA but reduced in early stage DCM.
Methods: We prospectively included 9 EAs and 9 patients with DCM, all with LVEF 40-55% at inclusion, and 9 controls. First, cardiopulmonary exercise testing was performed to determine maximal power (Pmax). Then, cardiac magnetic resonance (CMR) imaging was performed at rest and during bicycle exercise at 25%, 50% and 66% of Pmax in combination with invasive pressure measurements to determine the functional response of both ventricles and atria to exercise.
Results: At rest, LVEF was higher in controls than in EAs and DCMs, the latter groups having similar values. However, the increase in LVEF during exercise was greater in EAs than in DCMs (13.8±3.1 vs 5.1±6.1 %; P = 0.004; Figure). Also, exercise-induced increases in right ventricular EF and left and right atrial (LA and RA) total emptying fraction were reduced in DCMs (P<0.05 for interaction; Figure). Receiver-operator characteristic curves demonstrated that a cut-off value of 11.2% for the increase in LVEF from rest to peak exercise differentiated EAs from DCMs [AUC=0.89, P=0.005], whereas resting LVEF (cut-off: 50.8%) was not predictive [AUC 0.69, P=0.171].
Conclusions: Evaluation during exercise facilitates differentiation between athlete’s heart and DCM. Endurance athletes with mildly reduced LVEF at rest have normal myocardial contractile reserve as compared to subjects with early DCM in whom biventricular and bi-atrial functional reserve is reduced during exercise.
Author Disclosures: G. Claessen: None. F. Schnell: None. J. Bogaert: None. N. Pattyn: None. D. Frederik: None. S. Dymarkowski: None. P. Claus: None. F. Carré: None. J. Van Cleemput: None. A. La Gerche: None. H. Heidbuchel: None.
- © 2016 by American Heart Association, Inc.