Therapy for myocardial infarction: effect on trends in coronary disease mortality.

There has been a gradual decrease in hospital mortality rate following myocardial infarction (MI) since 1950, possibly due to improved therapy. For a valid comparison of mortality rates in various countries, it will, however, be necessary to know the characteristics of the individual patient populations. Factors such as age, time of admission to the CCU, use of thrombolytic agents, patency of the infarct related artery, left ventricular ejection fraction, smoking status as well as conventional risk factors need to be assessed before a valid comparison can be made or conclusions reached concerning trends in mortality after MI. As new and effective therapy for reducing mortality in patients with infarcts are introduced such as Beta blockers, thrombolysis, aspirin, and converting enzyme inhibitors one should be cautious in drawing conclusions as to trends in mortality from the results of clinical trials of these agents until one has a clear understanding of the risk factors of the population studied. Without this information, we may be no closer to an understanding of the cause of changing trends in mortality over the next decade than to understanding the trends over the last two decades.