The evolution of hospital mortality from acute myocardial, infarction during last 15 years. Impact of reperfusion therapy

Introduction and objectives. There are not any conclusive data about the changes in in-hospital mortality in a non-selected series of patients admitted with acute myocardial infarction in different periods of time. We studied the in-hospital mortality of three extensive series of patients admitted to our Coronary Care Unit during different periods of time, the influence of reperfusion methods and their early application, as well as the changes in baseline characteristics of the three populations studied. Methods. The in-hospital mortality of 1,858 consecutively-admitted patients during three different periods of time (1983-1986, 1992-1994, and 1995-1998) were studied. The demographic data, the previous history and risk factors, the evolution during the acute phase and the treatment prescribed with special attention to the reperfusion methods applied and the delay on its administration were compared. Results. The differences in the baseline characteristics of the populations studied are described. In the two groups of the nineteen-nineties, an increase in the age and in the percentage of women, diabetics and hypertensives was compared. As for the characteristics of acute myocardial infarction, an increase of patients in Killip class 3 and 4 stands out besides other changes. Fibrinolitic treatment decreased during the third period due to the increment in primary angioplasty. There mere no significant differences in hospital mortality among the three series studied. The treatment with thrombolysis and primary angioplasty during the first two hours showed a significant independent reduction of mortality. Conclusions. The early application of thrombolysis and primary angioplasty showed an independent reduction of the hospital mortality in our study. Nevertheless the non-adjusted mortality rate did not show any change during the last 15 years.