Abstract 14961: Is Mental Stress-Induced Myocardial Ischemia a Silent Phenomenon?
Objective: Mental stress-induced myocardial ischemia (MSMI) is a common phenomenon in CAD patients and an emerging prognostic factor. MSMI correlates with ambulatory ischemia, and in contrast to physical stress-induced myocardial ischemia (PSMI), is thought to be mostly silent. However, whether MSMI is related to angina symptoms in daily life has not been examined.
Methods: We studied 98 patients age 18-59 years who had a myocardial infarction in previous 6 months. Frequency of angina in past month was assessed with the Seattle Angina Questionnaire. Patients underwent [99mTc]sestamibi SPECT perfusion imaging at rest, after mental stress, and after exercise/pharmacological stress. Summed scores of perfusion defects were obtained with mental stress, physical stress, and at rest, using a reader-independent, software-based method. A summed difference score (SDS), the difference between stress and rest scores, was used to quantify ischemia under mental stress (MSDS) and physical stress (PSDS). We also identified a group of patients whose MSDS was larger than PSDS (MSDS+), denoting more propensity towards mentally-induced than physically-induced ischemia. Using parametric and non-parametric linear regression analyses, we examined the association between angina frequency, as dependent variable, with both MSDS and PSDS, as well as MSDS+ status.
Results: The mean angina frequency score was 16.6 (SD: 21.1); 41 subjects had at least 1 angina episode in past month, and 16 had at least 1 angina episode per week. Overall, 32 subjects were MSDS+. MSDS was associated with angina frequency in both unadjusted and adjusted analysis. After adjustment for age, sex, smoking, severity of CAD and depressive symptoms, each 1-point increase in MSDS was associated with 1.8 units increase in angina frequency scale (95% CI: 0.3 - 3.3, p=0.02). MSDS+ subjects had an adjusted 9-unit higher angina frequency than the rest of the patients (95% CI: 0.5 - 17.3, p=0.03). In contrast, PSDS was not associated with angina frequency. The results were similar with non-parametric linear regression.
Conclusion: Among young and middle-aged post-MI patients, MSMI, but not PSMI, is associated with angina frequency. Contrary to general belief, MSMI may not be a painless phenomenon.
- © 2013 by American Heart Association, Inc.