Screening for silent myocardial ischaemia in type 2 diabetic patients with additional atherogenic risk factors: applicability and accuracy of the exercise stress test

Abstract

Objective: Coronary artery disease (CAD), a major cause of mortality in patients with type 2 diabetes (T2D), is often diagnosed late because of silent myocardial ischaemia (SMI). Exercise electrocardiogram testing (ECG) stress is the most utilized screening test for SMI. Its applicability and accuracy, which have never been reported in asymptomatic high-risk T2D patients, have been investigated in this study. Design: A cross-sectional study with coronary angiography as the gold standard for detecting CAD was used. Methods: Two hundred and six consecutive T2D patients, without symptoms and resting ECG signs of ischaemia but with peripheral vascular disease (PVD) and/or $ two atherogenic factors, were studied. Ischaemia at ECG stress was indicated by horizontal or downsloping ST segment depression $ 1 mm at 0.08 s after the J point. CAD was defined by stenosis $ 70%. Results: Only 141/206 (68%) patients had a diagnostic test: 27 (19%) tested positive and 114 (81%) tested negative. Coronary angiography in 71 patients (the 27 who tested positive and 44 randomly selected patients who tested negative) indicated a CAD prevalence of 29% and the ECG stress accuracy was 79%. 'False negative' patients (18%) had a higher prevalence ðP , 0:01Þ of long duration of diabetes and PVD. Conclusions: This is the first study which provides insights into the applicability and accuracy of ECG stress in screening SMI in high-risk patients with T2D. Due to the high prevalence of CAD, alternative screening tests in patients unable to perform the test and in those with a high chance of being 'false negative' should be looked for and validated.

The TNFα Gene G(-308)A Polymorphism as a Marker for Myocardial Infarction in Type 2 Diabetes Mellitus

“…Moreover, the exclusion of CAD on the basis of a negative history of MI or angina pectoris, and absence of ischemic changes on electrocardiograms and during exercise stress testing, was disadvantaged by the possibility that some of the patients without MI may have experienced asymptomatic CAD. In a recent study, 18% of asymptomatic DM2 patients with a negative result of exercise stress testing, presented silent CAD with significant (≥70%) angiographically-documented coronary stenosis [17]. In conclusion, the G(-308)A polymorphism of the TNFα gene is not a risk factor for MI with DM2 in Slo venes of Slavic origin.…”

“…We studied Slovene patients of Slavic origin from independent families who had DM2 lasting more than 10 years: 142 with MI (MI group) and 310 DM2 patients with no history of CAD, and no signs of ischemic changes on electrocardiogram and no ischemic changes during sub maximal stress testing [17]. The diagnosis of MI was based on the World Health Organization criteria [18].…”

Detection of Silent Ischemia in Patients with Type 2 Diabetes

“…Sixteen percent had abnormal stress test whereas 9% had silent coronary artery disease as defined by angiography. In a study (Bacci et al, 2002) which evaluated 206 higher risk asymptomatic type 2 diabetes patients with peripheral arterial disease and at least 2 cardiovascular risk factors, 19% had an abnormal test and the positive predictive accuracy of the exercise ECG was 79%. These studies collectively support the notion that among higher-risk cohorts of asymptomatic patients with type 2 diabetes nearly 1/3 may have unrecognized coronary artery disease and exercise ECG may be useful in identifying these patients.…”

Type 2 Diabetes and Preventive Cardiology: Talking the Talk and Walking the Walk…

“…Studies using routine electrocardiographic exercise treadmill testing, 8 ambulatory electrocardiographic monitoring, 9 and myocardial perfusion scans 10 have each shown that the prevalence of silent ischemia varies between 20%-40% in asymptomatic patients with type 2 diabetes. The prevalence of angiographically demonstrable, significant coronary artery disease in patients with silent ischemia demonstrated by these means varied from 79%-95%.…”

“…The prevalence of angiographically demonstrable, significant coronary artery disease in patients with silent ischemia demonstrated by these means varied from 79%-95%. [8][9][10] Yet, investigations to diagnose ongoing ischemia in long-standing type 2 diabetes patients who are asymptomatic are not undertaken routinely and in some instances not even authorized by the third-party payer or health maintenance organization.…”