Objectives:
Previous studies indicated that depressed mood may act as a trigger of acute coronary syndromes, although the mechanisms are not clear. We aimed to examine the association between depression and mental stress-induced myocardial ischemia in young survivors of a myocardial infarction (MI), and the possible differential association of somatic and cognitive depressive symptom dimensions.
Hypothesis:
Higher levels of depressive symptoms are associated with a higher propensity to develop myocardial ischemia with mental stress.
Methods:
We studied 98 patients (49 women and 49 men) age 38-59 years who were hospitalized for acute MI in the previous 6 months. Patients underwent myocardial perfusion imaging with [99mTc]sestamibi single-proton emission computed tomography at rest, after mental stress (speech task), and after exercise treadmill stress. If unable to exercise (N=16), patients underwent pharmacological stress test with regadenoson. Myocardial perfusion defect scores were obtained with observer-independent software. A summed difference score, the difference between stress and rest perfusion defect scores, was used to quantify myocardial perfusion defects due to ischemia under both stress conditions. The Beck Depression Inventory-II (BDI-II) was used to measure depressive symptoms. Two separate scores of somatic and cognitive depressive symptoms were calculated. Multivariate linear regression models were used in the analysis.
Results:
There was a significant and graded positive association between depressive symptoms and summed difference score with mental stress. After adjustment for demographical and lifestyle factors, severity of coronary heart disease and medications, each incremental depressive symptom was associated with 0.14 higher ischemia perfusion defect score [β=0.14, 95% CI: (0.03, 0.24), p=0.01]. When somatic and cognitive depressive symptoms were examined separately, both somatic symptoms [β=0.17, 95% CI: (0.04, 0.30), p=0.01] and cognitive symptoms [β=0.31, 95% CI: (0.07, 0.56), p=0.01] showed a significant association with mental stress-induced ischemia. Depressive symptoms were not associated with ischemia induced by exercise or pharmacological stress.
Conclusion:
Among young post-MI patients, higher levels of both cognitive and somatic depressive symptoms are associated with a higher propensity to develop myocardial ischemia with mental stress, but not with exercise/pharmacological stress. Future studies should explore whether mental stress-induced ischemia explains the poorer prognosis associated with depressive symptoms in post-MI patients.
Depressive Symptoms Are Associated with Mental Stress-Induced Myocardial Ischemia after Acute Myocardial Infarction
