Incidence and Prognosis of Unrecognized Myocardial Infarction: Based on 26 Years Follow-up in the Framingham Study

Abstract

The incidence of myocardial infarction (MI) reaches substantial proportions beyond age 45 in men and age 55 in women. Its occurrence in women lags behind that in men by 20 years, but the gap in incidence closes with advancing age (Table 1). A substantial part of atherosclerotic cardiovascular mortality progresses abruptly from inapparent disease to MI and death. Much of the premature mortality occurs with little warning in a population generally prone to accelerated atherogenesis, embedded in a morbidity only a part of which is apparent. Only 20% of Mis are preceded by chronic angina. Two of every three coronary heart disease deaths are unexpected, occurring suddenly outside the hospital. Half of coronary heart disease deaths are sudden, whether in subjects with prior overt coronary heart disease or not. One in every five coronary attacks presents with sudden death as the first, last, and only symptom. This report is concerned with the incidence and prognosis of unrecognized Mis.