Prognosis after acute coronary syndrome and myocardial infarction
THE CONTEXT
Prognosis depends on residual ischaemia, myocardial damage and ventricular arrhythmias, with different determinants of early death and later outcomes.
Timing of mortality
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In almost one-quarter of myocardial infarctions, death occurs within minutes without medical care. Half of deaths occur within 24 hours of symptom onset, and about 40% of all affected patients die within the first month.
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Patients who survive to reach hospital have a substantially better prognosis, with 28-day survival above 85%.
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Mortality in unstable angina is approximately half that in myocardial infarction.
Early versus late prognostic factors
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Early death is usually arrhythmic and is independent of infarct extent.
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Late outcomes depend on the extent of myocardial damage. Poor left ventricular function, AV block and persistent ventricular arrhythmias are unfavourable features.
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Anterior infarction has a worse prognosis than inferior infarction.
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Bundle branch block and high cardiac marker concentrations indicate extensive myocardial damage.
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Old age, depression and social isolation are associated with higher mortality.
Long-term survival
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Among survivors of an acute attack, more than 80% live for a further year, about 75% for 5 years, 50% for 10 years and 25% for 20 years.