Cardiac magnetic resonance detection of myocardial scarring in hypertrophic cardiomyopathy: correlation with histopathology and prevalence of ventricular tachycardia.
OBJECTIVE
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.
Kwon
Deborah H
DH
Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio 44195, USA.
Smedira
Nicholas G
NG
Rodriguez
E Rene
ER
Tan
Carmela
C
Setser
Randolph
R
Thamilarasan
Maran
M
Lytle
Bruce W
BW
Lever
Harry M
HM
Desai
Milind Y
MY
D000293:Adolescent; D000328:Adult; D000368:Aged; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D016001:Confidence Intervals; D003331:Coronary Vessels / Q000473:pathology; D004452:Echocardiography; D005260:Female; D005355:Fibrosis / Q000175:diagnosis / Q000473:pathology / Q000601:surgery; D006346:Heart Septum / Q000601:surgery; D006801:Humans; D016015:Logistic Models; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009206:Myocardium / Q000473:pathology*; D016017:Odds Ratio; D009820:Ohio / Q000453:epidemiology; D015995:Prevalence; D013318:Stroke Volume; D017180:Tachycardia, Ventricular / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology*; D016277:Ventricular Function, Left; D055815:Young Adult