Aging and pain perception in ischemic heart disease.

Age is a recognized risk factor for coronary artery disease, but the relationship between age and silent ischemia is not well understood. We analyzed the data from 35 rest/stress radionuclide ventriculography examinations in patients with documented ischemic coronary artery disease who had experienced 1 mm ST segment depression accompanied by angina during exercise testing. An index of ischemic cardiac pain perception (PPI) was calculated by subtracting the time of onset of 1 mm ST segment depression from the time of onset of angina. The mean value of PPI was -97 +/- 311 seconds. PPI was significantly correlated with age (r = 0.37, p = 0.03). This suggests that as age increases, perception of pain during myocardial ischemic episodes becomes muted. This relationship remained significant when we controlled for the presence of medication and severity of disease (change in ejection fraction from rest to peak exercise). These findings suggest that age is an independent risk factor for a decreased perception of ischemic cardiac pain, and thus for silent myocardial ischemia.