PROGRESSION OF LATE GADOLINIUM ENHANCEMENT IN HYPERTROPHIC CARDIOMYOPATHY

Abstract

Listen

Translate article

Hypertrophic cardiomyopathy (HCM) is the most common genetic cardiomyopathy. Cardiac magnetic resonance imaging (CMR) with late gadolinium enhancement (LGE) is capable of noninvasive identification of myocardial fibrosis in HCM. The extent of LGE provides additional information for assessing the risk for sudden cardiac death among HCM patients. In this study we sought to assess the progression rate of myocardial fibrosis in HCM patients on two consecutive CMR scans, and to correlate it to clinical variables and cardiovascular outcomes. A total of 150 HCM patients (69.9% males, age at first CMR 50.8 ± 13.4 years) were enrolled in this study, with two sequential CMR’s separated by an interval of 4.7 ± 1.8 years. Quantification of late gadolinium enhancement (LGE, in grams) was used to assess the extent of myocardial fibrosis. 34 patients (23%) had no progression of LGE, 41 (27%) had progression of LGE <1 g, and 75 patients (50%) had progression of LGE ≥ 1g. In the first CMR, left ventricular (LV) ejection fraction was 61 ± 8%; LV mass 156 ± 62g, maximal wall thickness 18 ± 4 mm, and mean LGE was 6.7 ± 10.5 g (4.1 ± 5.8% of LV myocardial mass). In the second CMR there were significantly more patients with LGE (84.8% vs. 71%, p=0.008). Extent of LGE increased significantly (p<0.01) by 2.5 ± 7.9 g (0.58 g/year). Patients with younger age (p<0.0001), apical HCM (p=0.005), and higher baseline LGE (p<0.0001) had significantly higher rates of LGE progression. Baseline risk factors, LV ejection fraction, and maximal wall thickness did not affect the progression of LGE. In a multivariable model, younger age (p=0.01) and apical HCM (p=0.02) remained significantly associated with faster progression of LGE. There were no sudden cardiac death events. Five patients experienced an HCM related adverse event (2 HCM related admissions and three cerebral strokes). Risk of HCM related adverse events was significantly correlated with extent of LGE (p<0.0001) and progression rate of LGE (p=0.0039). LGE progression is evident in HCM patients, and is more prominent in younger patients and in apical HCM. Risk of HCM related adverse events was significantly correlated with extent and progression rate of LGE.