Objective: Mental stress-induced myocardial ischemia (MSMI) is thought not to be related to severity of coronary artery disease (CAD), in contrast to physical stress-induced myocardial ischemia (PSMI), but previous studies are conflicting and did not consider potential confounders or interactions.
Methods: We used single-photon emission tomography (SPECT) myocardial perfusion imaging in conjunction with a standardized psychological stressor and, on a separate day, with physical stress primarily via exercise treadmill testing, in 98 subjects with a history of myocardial infarction in the previous 6 months. We calculated a summed stress score (SSS) of perfusion defects with mental stress (MSSS) and physical stress (PSSS) using both a reader-independent, software-based method, and physician-based readings. Using linear regression analysis, we examined the association between the MSSS and two quantitative measures of CAD severity, the Gensini score and the Duke CAD Severity Index (DCSI). For comparison, we performed a similar analysis with the PSSS. We adjusted for all Framingham risk factors and depression status and assessed interaction effects with age.
Results: Forty-nine subjects were ≤ 50 years of age, 49 were female and 39 subjects were whites. For MSMI, there was no association between software-assessed MSSS and either the Gensini score or the DCSI, even after adjustment for Framingham risk factors, depression and medication status. For PSMI, we found a significant interaction effect between age and software-assessed PSSS for both Gensini score and DCSI. In subjects of age ≤ 50 years, PSSS was associated with both Gensini score (regression coefficient: 0.050, 95% CI: 0.014 to 0.086, p value= 0.006) and DCSI (regression coefficient: .067, 95% CI: 0.011 to 0.122, p value = 0.02). PSSS was not found to be associated with either Gensini score or DCSI in subjects older than 50 years. Similar results were found using physician-assessed outcome variables.
Conclusion: Mental stress-induces myocardial ischemia is not associated with CAD severity. In contrast, physical stress myocardial ischemia is positively associated with CAD, although this association is only observed in younger MI patients. Mechanisms other than plaque burden may underlie ischemia triggered by mental stress.
Table of Contents
Table of Contents
THESIS CHAPTER I. 1
THESIS CHAPTER II. 9
THESIS CHAPTER III. 28
Public Health Implications. 28
Future directions. 29
TABLES, FIGURES AND DERIVATION.. 30
About this Master's Thesis
|Committee Chair / Thesis Advisor|
|Is Mental Stress Induced Myocardial Ischemia Associated With Coronary Artery Disease Burden? ()||2018-08-28||