[Frequency of silent and painful ischemia in patients with treated stable coronary insufficiency]

The present study was aimed at determining the frequency and circadian variations in symptomatic or silent myocardial ischemia in ambulatory patients with stable coronary disease. A comparative analysis was then made of the recordings on symptomatic and asymptomatic patients according to their medical history. Three hundred and twenty-one cardiologists recruited a total of 1,088 patients who were monitored for 4 days with a new type of electrocardiographic recorder. The patients were able to voluntarily start up the recorder in the case of cardiac discomfort or pain. The results showed that over a total recording period of 95,725 hours, the following data, which were validated by an experienced cardiologist, were obtained: 3,258 ischemic episodes, 2,963 (or 91%) of which were cases of silent ischemia, and 295 (or 9%) which were symptomatic. All the ischemic episodes involved a limited number of subjects, i.e., 271 patients. Of these, 148 (54.6%) were completely asymptomatic; only 63% of these patients with silent ischemia would have been detected if the recording had just lasted 24 hours. Moreover, the medical history showed a correlation between certain factors (such as poorly managed arterial hypertension, cardiac insufficiency, renal failure, arteritis of the lower limbs, and a waist-hip relation of over one in men) and an increase in the number of cases of silent ischemia. However, no single factor was found to be linked more to silent ischemia than to symptomatic ischemia. This investigation therefore shows the significant numeric incidence of silent ischemia. It raises the question of the need to prescribe treatment in at-risk subjects which includes recordings of long duration, so that silent ischemia, which may increase the risk of mortality, can be more readily detected.