Objectives:
Mental stress-induced myocardial ischemia (MSIMI) is a transient myocardial ischemic response to mental stress. Women are about two times more likely to develop MSIMI compared to men, which could potentially explain their worse morbidity and mortality after myocardial infarction (MI). We sought to examine the associations between experiences of everyday discrimination, as a gender-related stressor, and both MSIMI and conventional (exercise/pharmacologic)-induced myocardial ischemia among young survivors of MI.
Hypothesis:
Reports of everyday discrimination are associated with a higher prevalence of MSIMI, but not conventional ischemia in those with recent MI; furthermore, this relationship is stronger among young women compared to men.
Methods:
We studied 295 post-MI patients (145 women, 150 men) aged 25-61 years. Participants underwent single-photon emission computed tomography (SPECT) perfusion imaging at rest, after mental stress, and after exercise/pharmacological stress. Perfusion defect scores of myocardial segments were summed, with the summed difference score between stress and rest scores used to determine the presence of ischemia under both stress conditions. The Everyday Discrimination Scale (EDS) was assessed via questionnaire and used to measure exposure to experiences of discrimination (possible range 1-4).
Results:
EDS scores ranged from 1-3.8 (mean 1.7; SD 0.6). After adjustment for sociodemographic and cardiovascular risk factors, indicators of MI severity and symptoms of depression, each one point increase in average exposure to everyday discrimination (more frequent exposure) was associated with a doubling of odds of MSIMI (OR=2.46 [1.21 – 5.00]), but was not associated with exercise/pharmacological-induced ischemia (OR=0.75 [0.41 – 1.36]). These results were more robust among women, who demonstrated a nearly four-fold increase in odds of MSIMI with each one-point increase in average discrimination score compared to a two-fold increase among men, however there was no evidence of interaction by gender.
Conclusion:
Among young post-MI patients, experiences of everyday discrimination were positively associated with risk of MSIMI, but not associated with conventional stress ischemia. The risk of MSIMI tended to be greater among women than men, potentially implicating discrimination in triggering a physiological response to which women are particularly vulnerable.
Heart-brain interactions in mental stress-induced myocardial ischemia
