Predicting factors for a false positive treadmill exercise stress test

Abstract

Background: The present study was conducted to determine whether the exaggerated blood pressure (BP) response as well as other factors during exercise stress test (EST) is associated with false positive treadmill EST. Material and Method: This is a retrospective (case-control) study. Patient upon whom EST was performed at Her Majesty Cardiac Center (HMCC), Siriraj Hospital, Mahidol University and for whom the result revealed positive EST and underwent coronary angiogram (CAG) during October 2007-July 2011. Results: 272 patients were included. 61% was male gender. There were 65 false positive cases (23.9%). Most patients are female (60%). No significant difference in baseline systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) was noted between true and false positive group. Using Multiple logistic regression analysis to determining the independent predictors of false positive EST, exaggerated BP response did not result in false positive EST and factors that were associated with the occurrence of false positive EST are female (OR 2.604, 95% CI 1.109-5.952, p = 0.018), the use of statin (OR 0.402, 95% CI 0.194-0.835, p = 0.015), the difference between the peak and the baseline HR (OR 1.049, 95% CI 1.028-1.071, p < 0.001) and time from abnormal to baseline ECG (OR 0.725, 95% CI 0.641-0.820, p < 0.001). Conclusion: The present study did not demonstrate that the exaggerated BP response during EST is associated with false positive EST.