Silent myocardial infarction in women with type II diabetes mellitus and microalbuminuria

Abstract

Introduction: The aim of this study was to investigate whether asymptomatic women with diabetes mellitus (DM) without previous history of ischemic heart disease (IHD) and normal electrocardiogram (ECG) have suffered silent myocardial infarction (MI).

Methods: The study population consisted of 64-years old women with DM and albuminuria (n = 15) and aged- and body mass index-matched controls (n = 16). The patients were selected after screening of 240 women with previously known or unknown DM. The individuals with previous history of IHD and ECG suggesting the presence of IHD were excluded. All subjects were investigated with magnetic resonance imaging (MRI).

Results: MRI investigation has revealed the presence of subendocardial MI in the two DM women (13%). No MI was detected in the control group. MR coronary angiography detected the presence of significant stenosis in the proximal segment of left anterior descending (LAD) coronary artery in one DM woman. This patient developed unstable angina 1 week after the MRI investigation. The conventional angiography has confirmed the presence of significant stenosis in LAD demanding invasive revascularization by percutaneous coronary angioplasty. No difference was found in indices of left ventricular (LV) systolic function while diastolic function was disturbed in the DM group. There was a tendency for increased LV mass in the DM group. No difference was found in the LV volumes.

Conclusion: Clinically significant proportion of the women with DM and albuminuria without previous history of IHD have had silent MI. MRI screening of these high risk female patient is valuable diagnostic tool which may increase diagnostic accuracy and improve prognosis in DM patients with IHD.

Keywords: asymptomatic; diabetes mellitus; ischemic heart disease; silent myocardial infarction.

Figure 1

Short-axis view of LV from the two diabetic women with MRI-visible subendocardial infarction (arrow). In the patient with multi-vessel disease (left panel) the location of subendocardial MI is inferior while the patient with normal coronary angiogram (right panel) had smaller subendocardial MI located in the anterior LV wall. Abbreviations: LV, left ventricular mass; MI, myocardial infarction; MRI, magnetic resonance imaging.

Figure 2

Normal coronary angiogram from the patient with small anterior subendocardial infarction. This patient had recently diagnosed diabetes mellitus. Coronary angiography did not revealed any signs of obstructive atherosclerotic plaque in the large epicardial arteries. (Left panel) left anterior oblique view of the right coronary artery. (Right panel) Right anterior oblique view of left anterior descending artery (LAD) and left circumflex artery (LCx).

Figure 3

Coronary angiogram from the patient with inferior subendocardial infarction. There is evidence of multivessel disease. The images depicts occluded (arrow) right coronary artery (RCA) (left panel) and multiple significant stenosis (>50 % of reference lumen diameter) (arrows) in left anterior descending artery (LAD) and left circumflex artery (LCx) (right panel).

Figure 4

Coronary angiogram from the patient diabetes mellitus with developed unstable angina one week after that magnetic resonance imaging investigation suggested presence of significant coronary disease. Notice tight narrowing (arrow) in the proximal segment of left anterior descending artery (LAD).