Characteristics and Clinical Significance of Late Gadolinium Enhancement by Contrast-Enhanced Magnetic Resonance Imaging in Patients With Hypertrophic Cardiomyopathy

Abstract

Background-Myocardial late gadolinium enhancement (LGE) on contrast-enhanced magnetic resonance imaging (CE-MRI) of patients with hypertrophic cardiomyopathy (HCM) has been suggested to represent intramyocardial fibrosis and, as such, an adverse prognostic risk factor. We evaluated the characteristics of LGE on CE-MRI and explored whether LGE among patients with HCM was associated with genetic testing, severe symptoms, ventricular arrhythmias, or sudden cardiac death (SCD LGE positive (event rate of 0.94%/y, Pϭ0.01 versus LGE negative). Two additional heart failure-related deaths were recorded among LGE-positive patients. Univariate associates of SCD or appropriate ICD discharge were positive LGE (Pϭ0.002) and presence of nonsustained ventricular tachycardia (Pϭ0.04). The association of LGE with events remained significant after controlling for other risk factors. Conclusions-In patients with HCM, presence of LGE on CE-MRI was common and more prevalent among gene-positive patients.LGE was not associated with severe symptoms. However, LGE was strongly associated with surrogates of arrhythmia and remained a significant associate of subsequent SCD and/or ICD discharge after controlling for other variables. If replicated, LGE may be considered an important risk factor for sudden death in patients with HCM. (Circ Heart Fail. 2010;3:51-58.)

Cardiac fibrosis in mice with hypertrophic cardiomyopathy is mediated by non-myocyte proliferation and requires Tgf-β

“…Amounts of myocardial fibrosis in human HCM hearts correlate with the degree of hypertrophy (37), diminished ventricular performance (38), diastolic dysfunction (16), and energy demands (39) -factors that contribute to heart failure and may increase arrhythmic risk (40,41). As such, the benefit from inhibiting fibrosis in HCM could be substantial.…”

Swiss Cheese Myocardium: A Diagnostic and Prognostic Sign of HCM by Newer CMR Techniques

“…replacement, interstitial and plexiform type with overlapping patterns which alone cannot be differentiated from scarring seen in other types of cardiomyopathies seen as late gadolinium enhancements(LGE's).The histological correlate of LGE in HCM seems to be increased myocardial collagen rather than myocardial disarray which is also observed on histological specimens and is postulatedto reflect microvascular ischemia and microscopic replacement fibrosis due to small intramural coronary arteriole dysplasia. 5,6 Another alternative hypothesis for LGE in HCM suggested that the causative sarcomeric gene mutations might lead to a phenotypic expression of increased myocardial connective tissue deposition, 7 Hence there is a need to detect myocardial fibrosis and quantify the excessive collagen deposition in the Myocardium. Detection of myocardial fibrosis by LGE is variable in different HCM cohorts and is between 40-80%.Traditionally found patterns are patchy mid myocardial LGE, patchy LGE at RV insertion points and diffuse confluent trans mural pattern.…”

O diagnóstico da obstrução da via de saída do ventrículo esquerdo na cardiomiopatia hipertrófica

“…The association with the obstruction was not found in a study in which the prevalence of obstructive forms was similar between those with and without DE 76 . Longitudinal analyses showed relation between DE, sudden death and increased mortality, but it is still not proved [76][77][78] . Further investigations are necessary for the DE to be recognized as an independent prognosis predictor and a factor predisposing to sudden death 2 .…”

“…MRI with gadolinium detects and quantifies fibrosis areas with delayed enhancement (DE) of focal or diffuse character in 60-80% of patients with HCM, representing 0-40% of the LV myocardial mass [74][75][76][77][78] (Figure 4). The DE is associated with the record of nonsustained ventricular tachycardia in Holter in multivariate analyses 75,78 , as well as the left ventricular reshaping and evolution of terminal dilated forms 74 .…”

“…The DE is associated with the record of nonsustained ventricular tachycardia in Holter in multivariate analyses 75,78 , as well as the left ventricular reshaping and evolution of terminal dilated forms 74 . The association with the obstruction was not found in a study in which the prevalence of obstructive forms was similar between those with and without DE 76 .…”