Background: During the last decade, clinical trials consistently modified the therapeutic approach to coronary disease, and particularly to acute myocardial infarction. However, the magnitude of the contribution to the observed reduction in case fatality rates due the therapeutic improvement is still being debated.
Objectives: To determine the real degree of implementation of the "suggested treatments" on clinical practice, and to evaluate their global effect on coronary mortality.
Methods: Analysis of the type of administered treatment in two consecutive series of acute coronary events, observed during the year 1986 (500 events) and 1989 (907 events), registered by the MONICA Project-Brianza Area. We evaluated: pre-coronary times; type of hospitalization; type of treatment before, during and after the event; occurrence of cardiac arrest and cardiopulmonary resuscitation both in and out of hospital; global and specific fatality rates at 28 days.
Results: In the study period, overall coronary fatality rates changed from 29.4 to 23.6% (19% decrease-p < 0.05), fatality of confirmed AMI changed from 16.4 to 8.3% (49.4% decrease-p < 0.005); specific fatality for out of hospital cardiac arrest was unchanged (99%). Pre-coronary times were unmodified in the two periods of observation: hospitalization < 1 hr. in 20%, < 6 hr. in 50%, > 24 hr. in 10% of events. The percentage of cases admitted in CCU changed from 47.4 to 54.8% (from 71.6 to 86.4% of patients with confirmed AMI-p < 0.025). Thrombolysis in confirmed AMI changed from 29.3 to 43.2% (p < 0.001); antiplatelets treatment changed from 19.7 to 81.9% (p < 0.001); the use of betablockers went from 16.6 to 44% (p < 0.001) while the use of other agents was unmodified. Coronary arteriography and revascularization procedures continue to play a marginal role.
Conclusions: The MONICA registry experience shows that very important changes occurred in the treatment of coronary emergencies, particularly in the acute phase of myocardial infarction, suggesting that in our area, standardization of the therapeutic protocols might be responsible for the observed reduction of coronary fatality even though the advantages were observed only in hospitalized patients.