CT detection of subendocardial fat in myocardial infarction

OBJECTIVE. We sought to systemically analyze the characteristics of fat accumulation in patients with myocardial infarction (MI) relative to various clinical parameters. MATERIALS AND METHODS. We included 161 patients (129 men, 32 women; mean age, 60.7 years) who had previously been diagnosed with MI and had undergone CT coronary angiography between February 2003 and April 2005. We analyzed the characteristics of myocardial fat, if present, and compared the clinical parameters of the patients with and those without myocardial fat. RESULTS. Myocardial fat was found in the subendocardial region in 36 (22.4%) patients with MI. In all cases, the myocardial fat was located in the subendocardial region and was typically detected in the left anterior descending artery territory (75%, n = 27). The mean attenuation value of myocardial fat was -29.6 HU on unenhanced CT. Myocardial fat was more frequently associated with a greater infarct age, milder coronary artery stenosis, and fewer number of diseased vessels. Patients with myocardial fat had more severe regional wall motion abnormalities on follow-up echocardiography. Age, sex, the presence of ST elevation or Q wave, elevated levels of cardiac enzymes, ejection fraction, and end-diastolic left ventricular dimension on follow-up echocardiography, as well as the presence of arrhythmia, were not significantly different between the two groups. CONCLUSION. Myocardial fat was detected in 22.4% of MI patients and was more frequently associated with a longer postinfarct period, milder coronary artery stenosis, fewer number of diseased vessels, and more severe regional wall motion abnormalities.