Ischemia and Cardiac Events

Objective.\p=m-\Toassess the clinical significance of mental stress\p=m-\inducedmyo- cardial ischemia in patients with coronary artery disease (CAD). Design and Setting.\p=m-\Cohortstudy in outpatients in a tertiary care teaching hospital assessed at baseline and followed up for up to 5 years. Subjects.\p=m-\Atotal of 126 volunteer patients (112 men, 14 women; mean age, 59 years) with documented CAD and exercise-induced myocardial ischemia. Outcome Measures.\p=m-\Patientsunderwent baseline mental stress and exercise testing using radionuclide ventriculography and 48-hour Holter monitoring. Patients were subsequently contacted by mailed questionnaires or telephone to document cardiac events, including death, nonfatal myocardial infarction, and cardiac revas- cularization procedures. Logistic regression and Cox proportional hazards models were used to examine the prognostic value of the ischemic measures after adjust- ing for such potential confounding factors as age, baseline left ventricular ejection fraction (LVEF), and history of myocardial infarction. Results.\p=m-\Twenty-eightpatients (22%) experienced at least 1 cardiac event. Baseline mental stress\p=m-\inducedischemia was associated with significantly higher rates of subsequent cardiac events (odds ratio, 2.8; 95% confidence interval (CI), 1.0-7.7; P<.05). The LVEF change during mental stress was significantly related to event-free survival (risk ratio (RR), 2.4; 95% CI, 1. 12-5. 14;P=.02), controlling for age, history of prior myocardial infarction, and baseline LVEF. This relationship re- mained significant after controlling for electrocardiogram (ECG)\p=m-\definedischemia during exercise (RR, 2.2; 95% CI, 1.01-4.81; P<.05). The RR for ECG-defined is- chemia during exercise testing was 1.9 (95% CI, 0.95-3.96; P=.07) and the RR for ambulatory ECG ischemia was 0.75 (95% CI, 0.35-1.64; P=.47). Conclusions.\p=m-\Thepresence of mental stress\p=m-\inducedischemia is associated with significantly higher rates of subsequent fatal and nonfatal cardiac events, in- dependent of age, baseline LVEF, and previous myocardial infarction, and predicted events over and above exercise-induced ischemia. These data suggest that the re- lationship between psychological stress and adverse cardiac events may be me- diated by the occurrence of myocardial ischemia. (JAMA. 1996;275:1651-1656)