HOSPITAL MORTALITY IN ACUTE MYOCARDIAL-INFARCTION IN THE ERA OF REPERFUSION THERAPY (THE MYOCARDIAL-INFARCTION TRIAGE AND INTERVENTION PROJECT)

This study was conducted in 19 hospitals in the metropolitan Seattle a rea and included 6,270 unselected patients who had acute myocardial in farction (AMI) between January 1988 and April 1991. Hospital mortality was determined and related to patient demographic and clinical charac teristics, the use of reperfusion therapies, and to complications afte r AMI. Thrombolytic therapy or direct coronary angioplasty <6 hours fr om symptom onset was used to treat 1,185 (19%) and 524 (9%) patients, respectively. There were 629 (10%) hospital deaths; most occurred duri ng the first 3 days of hospitalization. Factors affecting mortality af ter admission included: recurrent chest pain, recurrent AMI, developme nt of heart failure, and the occurrence of stroke. After adjustment fo r age, treatment with thrombolytic therapy or direct angioplasty had n o independent effect on reducing the overall mortality rate. Hospital mortality rates for AMI have improved considerably since 1970, althoug h recurrent myocardial ischemic events continue to have an adverse eff ect on outcome. The current use of reperfusion treatments has had mini mal causal impact on overall mortality rates, principally because less than one third of patients, who are relatively ''low risk,'' are elig ible and receive these treatments.