OBJECTIVES To determine whether the detection of unrecognised myocardial infarction (MI) using late gadolinium-enhanced (LGE)-magnetic resonance imaging (MRI) can provide prognostic information in diabetic patients with normal ECG as well as normal global and regional left ventricular (LV) function.

METHODS From 449 diabetic patients who had complete cine- and LGE-MRI, 321 patients with histories of CAD, ischaemic ECG changes and abnormal cine MRI findings (LV ejection fraction <50 % or presence of regional wall motion abnormality) were excluded. The presence and extent of LGE were determined in the remaining 128 patients. Follow-up information was obtained for the occurrence of major adverse cardiovascular events (MACE) defined as cardiac death, acute MI, heart failure, unstable angina and significant ventricular arrhythmias in 120 patients.

RESULTS Of 120 patients, 18 (15 %) had LGE. During follow-up (median, 27 months), six patients with LGE (33.3 %) and four patients without LGE (3.9 %) experienced MACE, resulting in an annualised event rate of 7.7 % and 0.9 %, respectively (log-rank P <0.001). The presence of LGE was associated with an eight-fold increased hazard for MACE (HR, 8.84; P = 0.001).

CONCLUSIONS LGE-MRI can detect unrecognised MI and may improve the risk stratification of diabetic patients with no CAD history, normal ECG and normal LV systolic function.

KEY POINTS • Late gadolinium-enhanced magnetic resonance imaging (LGE-MRI) can identify subtle myocardial abnormalities. • LGE-MRI can detect myocardial infarction missed by ECG and cine-MRI. • Unrecognised MI detected by LGE-MRI was associated with adverse cardiac events. • LGE-MRI helps clinicians to assess diabetic patients with unrecognised MI.