Association Between Mental Stress-Induced Inferior Frontal Cortex Activation and Angina in Coronary Artery Disease.

BACKGROUND

The inferior frontal lobe is an important area of the brain involved in the stress response, and higher activation with acute mental stress may indicate a more severe stress reaction. However, it is unclear if activation of this region with stress correlates with angina in individuals with coronary artery disease.

METHODS

Individuals with stable coronary artery disease underwent acute mental stress testing using a series of standardized speech/arithmetic stressors in conjunction with high resolution positron emission tomography imaging of the brain. Blood flow to the inferior frontal lobe was evaluated as a ratio compared with whole brain flow for each scan. Angina was assessed with the Seattle Angina Questionnaire's angina frequency subscale at baseline and 2 years follow-up.

RESULTS

We analyzed 148 individuals with coronary artery disease (mean age [SD] 62 [8] years; 69% male, and 35.8% Black). For every doubling in the inferior frontal lobe activation, angina frequency was increased by 13.7 units at baseline ([Formula: see text], 13.7 [95% CI, 6.3-21.7]; =0.008) and 11.6 units during follow-up ([Formula: see text], 11.6 [95% CI, 4.1-19.2]; =0.01) in a model adjusted for baseline demographics. Mental stress-induced ischemia and activation of other brain pain processing regions (thalamus, insula, and amygdala) accounted for 40.0% and 13.1% of the total effect of inferior frontal lobe activation on angina severity, respectively.

CONCLUSIONS

Inferior frontal lobe activation with mental stress is independently associated with angina at baseline and during follow-up. Mental stress-induced ischemia and other pain processing brain regions may play a contributory role.