Trends in treatment and outcomes for acute myocardial infarction: 1975-1995.
OBJECTIVE
To review the trends in treatment and survival for patients with acute myocardial infarction over the last 20 years.


METHODS
Studies were identified through MEDLINE searches and review of study bibliographies. Additional data were obtained from the Health Care Financing Administration including data from Medicare claims files (part A). Thirty-day mortality rates were calculated using Medicare data and case fatality rates from the National Hospital Discharge Survey. Published meta-analyses were used to determine treatment effects. Published studies were included if they reported the use of therapies for acute myocardial infarction at a population level. Trends in the demographic characteristics of the patients as well as infarct characteristics, medication use, and revascularization were recorded.


RESULTS
The use of acute treatments that are known to improve survival among patients with myocardial infarction has increased markedly during the last 20 years, leading to an estimated 9.6% reduction (from 27.0% to 17.4%) in 30-day mortality. After adjusting for potential interactions between therapies, the increase in use of aspirin, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, and reperfusion can explain 71% of the decrease in the 30-day age- and sex-adjusted mortality rate from 1975 to 1995. The greatest effect of a given therapy was that of aspirin, which accounted for 34% of the decrease in 30-day mortality, followed by thrombolysis (17%), primary angioplasty (10%), beta-blockers (7%), and ACE inhibitors (3%). If other treatments (such as heparin or nonprimary angioplasty), whose effects on mortality are less certain, are included, up to 90% of the decrease in 30-day mortality can be explained by changes in treatment.


CONCLUSIONS
The primary reason for the decrease in early mortality from myocardial infarction during the last 20 years appears to be increased use of effective treatments.
Heidenreich
P A
PA
Veterans Affairs Palo Alto Health Care System, Palo Alto, California, USA.
McClellan
M
M
D015906:Angioplasty, Balloon, Coronary; D002317:Cardiovascular Agents / Q000627:therapeutic use; D001026:Coronary Artery Bypass; D006801:Humans; D015994:Incidence; D006278:Medicare; D009026:Mortality / Q000639:trends; D009203:Myocardial Infarction / Q000188:drug therapy / Q000401:mortality* / Q000601:surgery / Q000628:therapy*; D016032:Randomized Controlled Trials as Topic; D015912:Thrombolytic Therapy; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
D002317:Cardiovascular Agents