Prognostic value of mental stress testing in coronary artery disease

This study assesses the prognostic value of mental stress-induced ischemic left ventricular wall motion abnormalities and hemodynamic responses in patients with stable coronary artery disease (CAD). Seventy-nine patients (76 men and 3 women) with prior positive exercise test results were exposed to mental arithmetic and a simulated public speech stress in 2 prior studies. Ischemic wall motion abnormalities were monitored using echocardiography or radionuclide ventriculography (RNV). During mental stress testing, new or worsened ischemic wall motion abnormalities to mental stress and exercise were ascertained, as were peak changes in blood pressure and heart rate to mental stress. The occurrence of subsequent cardiac events (including cardiac death, nonfatal myocardial infarction, or revascularization procedures) was ascertained. New cardiac events were observed in 28 of 79 patients (35%) after a median follow-up duration of 3.5 years (range 2.7 to 7.3). Survival analysis indicated that 20 of 45 patients with mental stress ischemia (44%) experienced new cardiac events more frequently than those without mental stress ischemia (8 of 34; 23%; p = 0.048). Type of cardiac event did not differ between mental stress-positive and stress-negative patients. After controlling for baseline blood pressure and study group status (echocardiography vs RNV), there was a significantly higher relative risk of subsequent events for patients with high versus low peak stress-induced diastolic blood pressure responses (RR = 2.4, confidence interval 1.1 to 5.2; p = 0.03). These results demonstrate that ischemic and hemodynamic measures obtained from mental stress testing may be useful in assessing prognosis in CAD patients with prior positive exercise test results.