Abstract 14440: Impaired Myocardial Blood Flow is Associated With Late Gadolinium Enhancement in Hypertrophic Cardiomyopathy -Perfusion Study on Cardiac Magnetic Resonance Imaging
Introduction: Hypertrophic cardiomyopathy (HCM) generally shows ischemic signs, which is partially attributed to the disorder of myocardial perfusion. Recently, cardiac magnetic resonance imaging (CMR) has demonstrated the capabilities of stratifying HCM using late gadolinium enhancement (LGE). Stress perfusion test on CMR can quantitatively assess myocardial perfusion reserve (MPR), however its clinical role and relation to LGE are not fully investigated.
Methods: Three hundreds sixty consecutive cases which underwent ECG and CMR full study (cine imaging, T2 black blood, coronary MRA, stress perfusion test and LGE) at Cardiovascular Imaging Clinic (CVIC, Tokyo). The cases with LV hypertrophy were defined as more than 13mm in maximum LV wall thickness at end-diastole on the cine imaging. HCM was diagnosed based on asymmetric hypertrophy, mid-ventricular obstruction, and apical hypertrophy on the cine imaging. MPR was calculated as the ratio of stress/rest myocardial blood flow using intensity curve on stress perfusion test. The cases with ischemic heart disease were excluded from the study based on clinical history and coronary MRA. The control subjects which showed normal finding on CMR were investigated form comparison.
Results: There were 37 HCM and 24 concentric LVH cases (average age; 60.5±10.9 v.s 64.8±10.8, male; 62.2% v.s 75.0% n.s). MPR on HCM were lower than LVH (1.49±0.51 v.s 2.21±0.91, p<0.001) and control cases (2.38±0.95, p<0.001). The percentages of LGE were 89.5% in HCM and 20.8% in LVH respectively. MPR in HCM with LGE (N=33) were lower than those without LGE (N=4) (1.44±0.50 v.s 2.61±1.07 p=0.002). Multiple regression analysis verified LGE was the strongest factor for predicting MPR among existence of LVH, LV dysfunction (EF<50%) and negative T wave (p<0.001).
Conclusion: MPR was impaired in HCM with LGE compared with those without LGE. LGE was the strongest predictor of MPR impairment. The pathological relationship between MPR impairment and LGE in HCM needs to be clarified in the future research.
- © 2013 by American Heart Association, Inc.