Hiroyuki Takaoka MD, PhD, Presenter: Nothing to Disclose

Nobusada Funabashi MD, PhD, Abstract Co-Author: Nothing to Disclose

Koya Ozawa MD, Abstract Co-Author: Nothing to Disclose

Yoshio Kobayashi, Abstract Co-Author: Nothing to Disclose

To compare the value of non sustained ventricular tachycardia (VT) (NSVT) and myocardial fibrosis (MF) in risk stratification for major adverse cardiac events (MACE) in hypertrophic cardiomyopathy (HCM) patients without obstructed coronary arteries.

We selected 59 consecutive HCM patients (38 male, 61±15 years), who underwent cardiac CT (Light speed 16, GE Healthcare or Aquilion One, Toshiba Medical) and 24 hours of ECG monitoring within 12 months between 2002 and 2009. Patients had no significant luminal coronary artery stenosis (>50%) on CT, or previous myocardial infarction. If a contrast defect was observed in early phase CT images of the myocardium, a late phase acquisition was added. If abnormal late enhancement was observed at a corresponding site, we diagnosed MF. NSVT was defined as ³ 3 consecutive, premature, ventricular beats. Patients were followed for a median of 41 months after CT for MACE. MACE included cardiac death, heart failure, sustained VT (continued > 30 seconds), ventricular fibrillation and appropriate discharge of Implantable cardioverter defibrillators.

NSVT was detected in 26 patients. There was no significant difference in MACE between patients with and without NSVT (15% and 12%; P=0.98, respectively). No significant differences between HCM patients, with and without VT, were seen, at each time point and when the whole period of follow-up was compared with a Kaplan-Meier and log rank test (P=0.71). MF was detected by CT in 34 patients. Patients with MF had a higher risk of MACE (24%) than those without (0%; P=0.03). Significant differences between HCM patients, with and without MF, were also seen at each time point and when the whole period of follow-up was compared with a Kaplan-Meier and log rank test (P=0.01). 

MF is a stronger predictor of MACE than NSVT in HCM patients without obstructed coronary arteries following a median of 41 months.

Detection of focal MF on CT may be useful to predict the risk of MACE in HCM patients without obstructed coronary arteries. MACE did not occur in HCM patients without obstructed coronary arteries and MF.

Takaoka, H, Funabashi, N, Ozawa, K, Kobayashi, Y, The Presence of Myocardial Fibrosis is a Stronger Predictor of MACE than Occurrence of Non Sustained Ventricular Tachycardia in Cases of Hypertrophic Cardiomyopathy without Obstructed Coronary Arteries.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14016050.html