Value of exercise tolerance testing in evaluation of diabetic patients presented with atypical chest discomfort

Gauging the Positive Predictive Value of Exercise Tolerance Test Using Angiographic Evaluation: A Cross-Sectional Analysis From a Developing Country

Background

Exercise tolerance test (ETT) and angiographic evaluation are important tools to evaluate patients presenting with ischemic cardiac pathologies. Angiographic evaluation is regarded as the gold standard diagnostic modality to diagnose coronary artery disease (CAD). Our study aims to evaluate the positive predictive value (PPV) of ETT to diagnose CAD using coronary angiography.

Methods

We conducted a cross-sectional study that analyzed 94 patients with a positive ETT test after the application of strict inclusion and exclusion criteria. All 94 patients were referred for angiography after a positive ETT test. Data collection was performed using a structured proforma, and analysis was carried out on Statistical Package for Social Sciences (SPSS) version 23 (IBM Corp., Armonk, NY). PPV for various demographic characteristics was calculated.

Results

Out of 94 patients, 76 were males and 18 were females with a mean age of 52.28 ± 7.55 years. A total of 35.1% of the patients had type-2 diabetes, and 31.9% were hypertensive. On coronary angiography, only 25 patients had normal findings, and 69 patients had a significant occlusion in at least one of the major coronary arteries. The overall PPV of the ETT against angiographic evaluation was 73.40%. The PPV for females, hypertensives, non-smokers, and non-diabetics was lower than the PPV of males, smokers, non-hypertensives, and diabetics.

Conclusion

Angiographic evaluation of patients with positive ETT findings has a high likelihood of false positivity especially among females, non-smokers, hypertensives, and non-diabetics. The results of ETT must be interpreted with caution in these subsets of the population. Invasive radiological modalities can be used for diagnosis; however, such modalities do not elucidate the functioning of myocardium under stress.

Exercise Treadmill Test in Patients with Diabetes Mellitus Type 2

There is a concern regarding the high incidence of coronary heart disease (CHD) among patients with diabetes mellitus (DM) type 2 since it is a leading cause of mortality in those patients. Exercise treadmill test (ETT) is proposed as a suitable, non-invasive method for identifying asymptomatic patients with ischemic changes, who would benefit from pharmacological treatment, thus contributing to a reduction of adverse cardiovascular events. Therefore the objective of our study was to evaluate myocardial ischemia in asymptomatic patients with DM type 2 by performing ETT. The present investigation was conducted in Health Center Pozega during the year 2018. 40 insulin-dependent, aged 33.05 ± 2.01 years, with DM type 2 were included in the study. They had nor history nor symptoms of cardiac disease. All patients underwent ETT according to Bruce protocol, while 12-lead ECG was recorded and blood pressure was monitored. All patients had negative ETT results. Also no ST segment depression, no signs of insufficiency of peripheral circulation, no changes in heart rhythm, no symptoms by the central nervous system were observed. Additionally response of heart rate and blood pressure to exercise was within physiological range. These promising findings indicate that diabetes didn’t alter myocardial integrity and function, thus suggesting that coronary reserve in examined patients was preserved.

Use of imaging and clinical data to screen for cardiovascular disease in asymptomatic diabetics

Background

There is increasing evidence to suggest that not all individuals with type 2 diabetes mellitus (T2DM) have equal risk for developing cardiovascular disease. We sought to compare the yield of testing for pre-clinical atherosclerosis with various approaches.

Methods

98 asymptomatic individuals with T2DM without known coronary artery disease (CAD) were enrolled in a prospective study and underwent carotid ultrasound, exercise treadmill testing (ETT), coronary artery calcium (CAC) scoring, and coronary computed tomography angiography (CTA).

Results

Of 98 subjects (average age 55 ± 6, 64 % female), 43 (44 %) had coronary plaque detectable on CTA, and 38 (39 %) had CAC score >0. By CTA, 16 (16 %) had coronary stenosis ≥50 %, including three subjects with CAC = 0. Subjects with coronary plaque had greater prevalence of carotid plaque (58 % vs. 38 %, p = 0.01) and greater carotid intima media thickness (0.80 ± 0.20 mm vs. 0.70 ± 0.11 mm, p = 0.02). Notably, 18 of 55 subjects (33 %) with normal CTA had carotid plaque. Eight subjects had a positive ETT, of whom five had ≥ 50 % coronary stenosis, two had <50 % stenosis, and one had no CAD. Among these tests, CAC scoring had the highest sensitivity and specificity for prediction of CAD.

Conclusion

Among asymptomatic subjects with T2DM, a majority (56 %) had no CAD by CTA. When compared to CTA, CAC was the most accurate screening modality for detection of CAD, while ETT and carotid ultrasound were less sensitive and specific. However, 33 % of subjects with normal coronary CTA had carotid plaque, suggesting that screening for carotid plaque might better characterize stroke risk in such patients.

Atypical chest pain in diabetic patients with suspected stable angina: impact on diagnosis and coronary outcomes

Aims

Silent myocardial ischaemia occurs commonly in diabetes. Whether altered perception of ischaemia also predisposes to atypical presentations with under-diagnosis of coronary disease is not known. To determine whether (i) patients with diabetes diagnosed with angina are more likely to report atypical symptoms compared with patients without diabetes, and (ii) atypical symptoms in patients with diabetes cause angina to go unrecognized, increasing the risk of coronary events.

Methods and results

Prospective, multicentre cohort study of 8662 ambulatory patients with suspected angina, of whom 906 had diabetes. We recorded detailed chest pain descriptors and fatal and non-fatal coronary events over a median of 3.08 years of follow-up. Proportionately more patients with than without diabetes received a diagnosis of angina (42.7 vs. 25.1%). Among patients with diabetes diagnosed with angina, a greater proportion had atypical chest pain compared with patients without diabetes (21.0 vs. 11.3%), but the hazard of fatal and non-fatal coronary events was similar. However, among patients diagnosed with non-cardiac chest pain, those with diabetes-most of whom had atypical symptoms-remained at greater risk of coronary events [2.29 (95% CI 1.54, 3.41)] and all-cause mortality [1.67 (95% confidence interval, CI 1.04, 2.69)] compared with non-diabetic patients.

Conclusion

Patients with diabetes and atypical symptoms are nearly twice as likely to be diagnosed with angina compared with non-diabetic patients. Those diagnosed with non-cardiac pain are at increased risk of coronary events. Our study emphasizes the need for more intensive investigation of diabetic patients with chest pain, particularly those presenting with atypical symptoms.