Abstract 4075: Recurrence of Acute Myocardial Infarction in a Statewide Database
Background. There are many reports on the incidence and mortality of acute myocardial infarction (MI). However, scant data are available on the occurrence of a second MI among patients who were discharged alive after a first MI.
Methods. We used the Myocardial Infarction Data Acquisition System (MIDAS), a database including all patients discharged with the diagnosis of acute MI from non-federal hospitals in New Jersey, to examine the occurrence of a second MI among 206,785 patients who were discharged alive after a first MI between 1986 to 2002.
Results. The rate of readmission for a second infarction within a year of discharge among patients discharged with a Q-wave (Q) MI decreased from 5.7% to 2.7%. For patients discharged with a non-Q (NQ) MI, the readmission rate has been higher and in recent years, more than twice as high (6.00%) as that for those discharged for QMI. The most common pattern was an occurrence of a QMI after discharge from a NQMI in each of the 17 years studied (26.40% in 1986 declining to 6.33% in 2002). Recurrent infarctions occurred early after discharge with about half of the reinfarctions up to one year occurring within 60 days. Multiple logistic regression identified age over 75 (OR 1.13), male (OR 1.04), diabetes mellitus (OR 1.47), hypertension (OR 1.20), non teaching hospital (OR 1.10), Medicaid (OR 1.35) or Medicare (OR 1.18) insurance compared to HMO and discharge with a NQMI (OR 1.15) as significant (p<0.05) predictors of occurrence of second MI. The in-hospital mortality of the second MI has declined from 25.11% in 1986 to 11.3% in 2002 but has been about 30% higher than the first MI in each of the 16 years studied.
Conclusions. The in-hospital and one year mortality of the second MI are higher than the first. Both the occurrence and mortality of the second MI are determined by factors similar to those related to long-term MI mortality (age, type of MI, co-morbidity and invasive procedures).