Prevalence and prognostic significance of daily-life silent myocardial ischaemia in middle-aged and elderly subjects with no apparent heart disease

Aims We aimed to determine the prevalence and prognostic significance of daily-life silent myocardial ischaemia (SMI) in healthy middle-aged and elderly subjects with no previous heart disease. Methods and results Six hundred and seventy-eight healthy men and women between 55 and 75 years of age and with no history of cardiovascular disease or stroke were included. Baseline examinations included physical examination, fasting Laboratory testing, and 48 h ambulatory electrocardiogram monitoring. An episode of ischaemia was defined by a down-stoped or horizontal ST depression of at least 1 mm at a duration of at least 1 min. Seventy-seven subjects (11.4%) had SMI. ALL participants were followed for up to 5 years. In 77 subjects with SMI, 16 (20.7%) had an event (death or myocardial infarction). In 601 subjects without SMI, 50 (8.3%) had an event. The hazard ratios for SMI in relation to cardiac and combined events after correction for conventional risk factors were 3.1 [(1.24-7.97), P = 0.016] and 1.97 [(1.06-3.69), P = 0.033], respectively. Conclusion SMI as detected by Hotter monitoring was detected in 11.4% of these subjects and was associated with more than three-fold increase in the cardiac event rate after correction for risk factors, implying that this test could be used to identify high-risk individuals among these subjects.