[Clinical significance of late gadolinium enhancement on cardiovascular magnetic resonance in patients with hypertrophic cardiomyopathy].

INTRODUCTION AND OBJECTIVES: In patients with hypertrophic cardiomyopathy, myocardial fibrosis can be detected by late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging. We investigated the relationships between the extent of LGE, left ventricular morphology and function, and clinical characteristics.

METHODS: Both cine and gadolinium-enhanced magnetic resonance imaging were performed in 104 patients with hypertrophic cardiomyopathy.

RESULTS: Fifty patients (48%) showed LGE (range: 1-11 segments). The extent of LGE was positively correlated with maximum left ventricular wall thickness (r=0.53, P< .001), left ventricular mass (r=0.41, P< .001), and the number of hypokinetic segments (r=0.51, P< .001), and inversely correlated with ejection fraction (r=-0.32, P=.001), the magnitude of the subaortic gradient increase during exercise echocardiography (r=-0.26, P=.023), and age at diagnosis (r=-0.20, P=.04). Four of the five patients with an ischemic response on exercise echocardiography had > or =3 segments showing LGE (P=.003). Severe hypertrophy (i.e., > or =30 mm) and nonsustained ventricular tachycardia occurred more frequently as the number of LGE segments increased (P< .001 and P=.04, respectively).

CONCLUSIONS: Extensive LGE reflects greater disease expression. It is associated with more severe myocardial damage (i.e., a lower ejection fraction and a larger number of hypokinetic segments) and with adverse clinical characteristics (e.g., young age at diagnosis, severe hypertrophy, nonsustained ventricular tachycardia, and an ischemic response on exercise), suggesting that it may be closely linked to prognosis.