Fortnightly Review: Management of patients after their first myocardial infarction

Abstract

In the past 20 years there has been a steady improvement in the short term prognosis of patients with myocardial infarction,1 following the introduction of ß blockers, thrombolysis, and aspirin. Patients treated with thrombolytic drugs have a lower overall mortality after myocardial infarction but remain at risk of non-fatal reinfarction or death, and in one study almost half of all survivors of acute myocardial infarction died or suffered a further ischaemic event within three years.2 It is therefore important to have a strategy to identify patients at high risk, to reduce the subsequent development of cardiac failure and mortality, and to have effective measures for secondary prevention to reduce the incidence of reinfarction as well as to promote rehabilitation. ### Risk stratification The amount of myocardial damage and the degree of left ventricular dysfunction, which may be limited by the presence of a patient infarct related artery, together with the extent of underlying coronary disease, influence prognosis after myocardial infarction.3,4 In the 1960s Killip and Kimball showed that the presence and increasing severity of cardiac failure predicted a poor outcome and that hospital mortality was more than 80% if cardiogenic shock developed.5 A decade later Norris developed an index including the patient's age, history of previous infarction, systolic blood pressure on admission, site of infarction, and radiographic evidence of cardiac enlargement or pulmonary congestion.6 Increasing age, a history of previous infarction, and radiographic evidence of cardiac failure and cardiomegaly were shown to be associated with a worse prognosis. The extent of myocardial damage can now be estimated from straightforward, non-invasive investigations that can quantify the degree of ventricular dysfunction. Residual myocardial ischaemia and a tendency to ventricular arrhythmias also influence prognosis after infarction, and the investigation and assessment of all three are discussed below. ### Extent of ventricular dysfunction The degree …