29 What are the risks of recurrent ischaemic
events after myocardial infarction: prehospital, at
30 days and at 1 year?
Adam D Timmis
Data from the WHO MONICA project in 38 populations from 21
countries show that 49% and 54%, respectively, of all men and
women with an acute coronary event die within 28 days.^1 About
70% of these deaths occur out of hospital on day 1 and it is
generally accepted that a large proportion of these early deaths are
the result of ventricular fibrillation. Thus provision of rapid access
to a defibrillator remains the single most effective way to save lives
in acute coronary syndromes. Following hospital admission the
outcome of acute myocardial infarction is determined largely by
left ventricular function. Before the introduction of thrombolytic
and other reperfusion strategies, average in-hospital mortality from
acute myocardial infarction declined from 32% during the 1960s to
18% during the 1980s.^2 With the introduction of reperfusion
therapy further improvements in the short and long term prognosis
of acute myocardial infarction have been confirmed in several large
studies comparing cohorts of patients admitted before and after the
late 1980s.3,4Thus, in a group of patients who received CCU
treatment for acute myocardial infarction, we reported 30 day and 1
year mortality rates (95% confidence intervals) of 16.0%
(13.4–19.2%) and 21.7% (18.6–25.2%), rising to 19.6%
(16.6–23.0%) and 33.2% (29.5–37.2%), respectively, when a
combined end point of mortality plus non-fatal recurrent events
(unstable angina, myocardial infarction) was considered.^5
Multivariate predictors of better short term survival included
treatment with thrombolysis and aspirin, while predictors of
worse survival included left ventricular failure, advanced age and
bundle branch block. Whether survival after acute myocardial
infarction has continued to improve in the thrombolytic era is
unknown although the increasing application of effective
secondary prevention strategies provides grounds for optimism.
RReeffeerreenncceess
1 Tunstall-Pedoe H, Kuulasmaa K, Amouyel P et al. Myocardial infarc-
tions and coronary deaths in the World Health Organisation MONICA
Project. Registration procedures, event rates, and case fatality rates in