Myocardial Infarction as the First Manifestation of Coronary Heart Disease: Rates of Heralded and Unheralded Myocardial Infarction

Some myocardial infarctions (MI) occur as the first manifestation of coronary artery disease. These are termed 'unheralded' events as they have not been preceded by other forms of coronary artery disease. Unheralded MIs are important because of the high likelihood of missed opportunities for prevention. The proportion of MIs that are 'unheralded' is unknown. This study aims to quantify the proportion of MIs that occur 'unheralded' and also give an estimate of the incidence of 'unheralded' MI in the UK, compared to 'heralded' MI and those with angina of recent onset (MIs with premonitory symptoms).