Comparison of the exercise ECG and stress myocardial SPECT in detection of the significant coronary artery disease in asymptomatic patients with diabetes mellitus type 2
Abstract
BACKGROUND: Diabetes mellitus is known to be a risk factor of the coronary heart disease even in the asymptomatic patients. Only a limited number of reports comparing the significance of different noninvasive stress tests in establishing the diagnosis of the advanced coronary lesions exists.
OBJECTIVES: The aim of the study was to compare the significance of 12-lead exercise ECG and the myocardial SPECT in order to detect the significant coronary heart disease in asymptomatic type 2 diabetics. METHODS: 126 type 2 diabetic patients with negative history and no clinical or electrocardiographic signs of coronary heart disease were examined with the exercise ECG and the stress myocardial SPECT.
The selective coronary angiography (SCG) was recommended to all patients with an abnormal SPECT or (and) a positive exercise ECG. The SCG was recommended to patients with equivocal results of the stress myocardial SPECT as well.
RESULTS: 33 out of 126 examined patients (26.2%) had an abnormal, 33 equivocal and 60 normal stress myocardial SPECT. The exercise test could be evaluated in 99 examined patients (78%). 25 diabetics had positive test (19.8%).
The correlation between the results of 2 tests was very good (p=0.0001). 38 patients had SCG, 24 with the abnormal SPECT, 13 with equivocal and 1 with normal SPECT. Out of these 20 patients had positive, 10 negative and 8 non-assessable exercise ECG.
The relation between the presence of significant coronary stenosis (stenosis >70%) and the presence of abnormal stress myocardial SPECT was stronger (p=0.006) when compared with the positive exercise test (p=0.037). For the significant coronary stenosis the positive predictive value was 90% with the stress myocardial SPECT and 68% with the exercise ECG.
CONCLUSION: The significance of the exercise ECG is lower predominantly due to high proportion of patients with non-assessable results. For the presence of significant coronary stenosis the positive predictive value of the stress myocardial SPECT is better than that of the exercise ECG. (Tab. 2, Ref: 25.)