FOCUS ISSUE: HYPERTROPHIC CARDIOMYOPATHY: CLINICAL RESEARCH
Cardiac Magnetic Resonance Detection of Myocardial Scarring in Hypertrophic CardiomyopathyCorrelation With Histopathology and Prevalence of Ventricular Tachycardia
Deborah H. Kwon, MD*,
Nicholas G. Smedira, MD*,
E. Rene Rodriguez, MD ,
Carmela Tan, MD ,
Randolph Setser, PhD ,
Maran Thamilarasan, MD*,
Bruce W. Lytle, MD*,
Harry M. Lever, MD* and
Milind Y. Desai, MD*, ,*
* Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio
Department of Pathology, Cleveland Clinic, Cleveland, Ohio
Imaging Institute, Cleveland Clinic, Cleveland, Ohio
Manuscript received December 27, 2008;
revised manuscript received February 23, 2009,
accepted April 3, 2009.
* Reprint requests and correspondence: Dr. Milind Y. Desai, Director, Cardiac CT and MR, Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, Ohio 44195 (Email: desaim2{at}ccf.org).
Objectives: In hypertrophic cardiomyopathy (HCM) patients undergoing surgical myectomy, we sought to determine the association between pre-operative cardiac magnetic resonance (CMR) findings, small intramural coronary arteriole dysplasia (SICAD) on histopathology, and ventricular tachycardia (VT).
Background: Myocardial scarring (fibrosis) and SICAD are frequently observed on histopathology in HCM patients. CMR measures wall thickness and detects scar.
Methods: Sixty symptomatic HCM patients (62% men; mean age 51 ± 14 years), with preserved ejection fraction (mean 64 ± 5%) and no angiographic coronary disease underwent CMR (cine and delayed post-contrast) using a Siemens 1.5 T scanner, followed by septal myectomy. Maximal basal septal thickness was recorded on cine CMR. Scar was determined (percentage of total myocardium) on delayed post-contrast CMR images and quantified as none, mild (0% to 25%), moderate (26% to 50%), or severe (>50%). VT was assessed using Holter monitoring. Degree of SICAD was determined (normal, mild, moderate, and severe) on histopathology of surgical specimen.
Results: SICAD and scar were seen in 45 (75%) and 38 (63%) patients, respectively. In 15 patients without SICAD, 12 (80%) had no scar; 23 (70%) patients with mild SICAD had mild scar on CMR. On multivariate analysis, degree of SICAD was independently associated with scar on CMR (Wald chi-square statistic: 6.8, p < 0.01). Patients with basal septal scar on CMR had higher VT frequency compared with those without (27% vs. 5%, p = 0.03).
Conclusions: A strong association exists between degree of SICAD and myocardial scarring seen on CMR.
Key Words: hypertrophic cardiomyopathy small intramural coronary arteriole dysplasia myocardial scarring cardiac magnetic resonance
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Abbreviations and Acronyms
| | CAD = coronary artery disease | | CI = confidence interval | | CMR = cardiac magnetic resonance | | DHE-MRI = delayed hyperenhancement magnetic resonance imaging | | HCM = hypertrophic cardiomyopathy | | LV = left ventricle/ventricular | | LVEF = left ventricular ejection fraction | | LVOT = left ventricular outflow tract | | ROC = receiver-operating characteristic | | SCD = sudden cardiac death | | SICAD = small intramural coronary arteriole dysplasia | | VT = ventricular tachycardia |
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J. Am. Coll. Cardiol. 2009 54: A24.
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