EXERCISE TOLERANCE TEST: A COMPARISON BETWEEN TRUE POSITIVE AND FALSE POSITIVE TEST RESULTS
AbstractBackground: To study the factors which predetermine the coronary artery disease in patientshaving positive Exercise Tolerance Test (ETT) after comparing the ETT test results and coronaryangiographic findings in true positive and false positive groups. Methods: This Cross-sectionalstudy was conducted at Punjab Institute of Cardiology, Lahore from January 1, 2004 to December31, 2004. All patients who had ETT done for chest pain diagnosis were studied. Patients wereadvised coronary angiography if ETT was positive for exercise induced ischaemia. One hundredand forty eight patients had coronary angiography done after positive ETT. Patients were dividedinto two groups depending upon the angiographic findings, i.e., true positive and false positive.Both groups were compared with each other. Results: Out of 148 patients, 126 (85.1%) patientshad true positive ETT and 22 (14.9%) patients had false positive ETT. The mean age of patients intrue positive group was 48.969.08 years and 50.97.85 years in false positive group. Onehundred and eighteen (93.7%) male patients and 8 (6.3%) female patients had true positive ETT,whereas 14 (63.6%) males and 8 (36.4%) females had false positive ETT (p<0.0001). There wasno statistically significant difference in the two groups in comparison of age and otherconventional risk factors like diabetes mellitus, hypertension, smoking, family history anddyslipidemia. Abnormal resting ECG had a statistically significant difference between the groups(p<0.04), likewise is hypertensive haemodynamic response during ETT (p<0.003). The symptomlimited ETT as compared to no symptoms during ETT also conferred a statistically significantdifference between the groups (p<0.0001). Strongly positive ETT was also associated with truepositive ETT (p<0.002). Amongst the vessels involved the most common was the LAD 113(89.7%), followed by LCX 80 (63.5%) and the RCA 72 (57.1%). Most of the patients 51 (40.5%)had three vessel disease as compared to SVD 34 (27%). Conclusion: It can be concluded thatamongst the patients who have positive ETT, females with abnormal resting ECG, who achievetarget heart rate and have a hypertensive haemodynamic response with no symptoms are likely tohave a false positive test result. Conversely male patients with normal resting ECG who do notachieve target heart rate, have a normotensive haemodynamic response and a strongly positive,symptom limited ETT are likely to have a true positive treadmill test result.Keywords: Exercise tolerance test, Coronary artery disease, Coronary angiography, true positive,false positive.
Ashley E A, Myers J, Froelicher V. Exercise testing in
clinical medicine. Lancet 2000;356:1592–7.
Gianrossi R, Detrano R, Mulvihill D, Lehmann K, Dubach P,
Colombo A, et al. Exercise-induced ST depression in the
diagnosis of coronary artery disease: a meta analysis.
Detrano R, Gianrossi R, Mulvihill D, Lechman K, Dubach P,
Colombo A, et al. Exercise-induced ST segment depression
in the diagnosis of multivessel coronary disease: a meta
analysis. J Am Coll Cardiol 1989;14:1501–8.
Shareiff S, Shah-e-Zaman K. Exercise Tolerance Test in patients
presenting with chest pain and normal electrocardiogram. J Coll
Physicians Surg Pak 2002;12(6):348–52.
Shareiff S, Shah-e-Zaman K. Sensitivity and Specificity of
Exercise Tolerance Test in patients with chest pain and normal
baseline Electrocardiogram. Pak J Cardiol 2002;13(3-4):91–5.
Zipes DP, Libby P, Bonow RO, Braunwald E. Exercise stress
testing, In Braunwald’s Heart Disease.7th ed 2005;
Philadelphia Elsevier Saunders: p153–86.
Lipinski M, Do D, Morise A, Froelicher V. What percent
luminal stenosis should be used to define angiographic
coronary artery disease for noninvasive test evaluation. Ann
Noninvasive Electrocardiol 2002;7(2):98–105.
Kwok YS, Kim C, Grady D, Redberg RF. Exercise testing
for coronary artery disease diagnosis in women: a meta
analysis. Circulation 1995;94:I-497.
Zhao D, Freeman DH, de Flippi CR. A meta-analysis of gender
differences in exercise testing. Circulation 1995;94:I-497.
Walling AD, Crawford MH. Exercise testing in women with
chest pain: applications and limitations of computer analysis.
Coronary Artery Dis 1993;4:783–9.
Okin PM, Kligfield P. Identifying coronary artery disease in
women by heart rate adjustment of ST-segment depression
and improved performance of linear regression over simple
averaging methods with comparison to standard criteria. Am
J Cardiol 1992;69: 297–302.
Robert AR, Melin JA, Detry JM. Logistic discriminant analysis
improves diagnostic accuracy of exercise testing for coronary
artery disease in women. Circulation 1991;83:1202–9.
Hachamovitch R, Berman DS, Kiat H. Effective risk
stratification using exercise myocardial perfusion SPECT in
women: gender-related differences in prognosis nuclear
testing. J Am Coll Cardiol 1996;28:34–44.
Morise AP, Diamond GA, Detrano R, Bobbio M. Incremental
value of exercise electrocardiography and thallium-201 testing
in men and women for the presence and extent of coronary
artery disease. Am Heart J 1995;130:267–76.
Williams MJ, Marwick TH, O’Gorman D, Foale RA.
Comparison of exercise echocardiography with an exercise
score to diagnose coronary artery disease in women. Am J
Bickell NA, Pieper KS, Lee KL. Referral patterns for
coronary artery disease treatment: gender bias or good
clinical judgement? Ann Intern Med 1992;116:791–7.
Alexander KP, Shaw LJ, Shaw LK, Delong ER, Mark DB,
Peterson ED. Value of exercise treadmill testing in women. J
Am Coll Cardiol 1998;32(6):1657–64.
Fearon W, Lee D, Froelicher V. The effect of resting ST
segment depression on the diagnostic characteristics of the
exercise treadmill test. J Am Coll Cardiol 2000;35:1206–11.
Gibbons RJ, Balady GJ, Bricker JT, Chaitman BR, Fletcher
GF, Froelicher VF, et al. ACC/AHA 2002 guideline update
for exercise testing. Summary article: A report of the
ACC/AHA Task Force on Practice Guidelines (Committee to
Update the 1997 Exercise testing Guidelines). J Am Coll
Fletcher GF, Balady GJ, Amsterdam EA, Chaitman B, Eckel
R, Fleg J, et al. Exercise standards for testing and training: A
statement for health care professionals from the American
Heart Association. Circulation 2001;104:1694–740.
Ellestad MH: Stress Testing: Priciples and Practice. 4th ed.
Philadelphia, FA Davis, 1996:21–34.
Froelicher VF, Myers J. Exercise and the Heart. 4th ed.
Philadelphia, WB Saunders, 2000:452–59.