Myocardial Infarction Twenty-Two Year (1975 to 1997) Trends in the Incidence, In-Hospital and Long-Term Case Fatality Rates From Initial Q-Wave and Non-Q-Wave Myocardial Infarction: A Multi-Hospital, Community-Wide Perspective

OBJECTIVES The goal of this study was to examine long-term trends in the incidence, in-hospital and long-term mortality patterns in patients with an initial non-Q-wave myocardial infarction (NQWMI) as compared with those with an initial Q-wave myocardial infarction (QWMI). BACKGROUND Limited data are available describing trends in the incidence and mortality from an initial QWMI and NQWMI from a multi-hospital community-wide perspective. METHODS Our study was an observational study of 5,832 metropolitan Worcester, Massachusetts residents (1990 census 5 437,000) hospitalized with validated initial acute MI in all greater Worcester hospitals during 11 annual periods between 1975 and 1997. RESULTS The incidence of QWMI progressively decreased between 1975/78 (incidence rate 5 171/100,000 population) and 1997 (101/100,000 population). In contrast, the incidence of NQWMI progressively increased between 1975/78 (62/100,000 population) and 1997 (131/100,000 population). Hospital death rates were 19.5% for patients with QWMI and 12.5% for those with NQWMI. After controlling for various covariates, patients with QWMI remained at significantly increased risk for hospital mortality (adjusted odds ratio 5 1.63; 95% confidence interval: 1.35, 1.97). While the hospital mortality of QWMI has progressively declined over time (1975/78 5 24%; 1997 5 14%), the in-hospital mortality for NQWMI has remained the same (1975/78 5 12%; 1997 5 12%). These trends remained after adjusting for potentially confounding prognostic factors. The multivariable adjusted two-year mortality after hospital discharge declined over time for patients with QWMI and NQWMI. CONCLUSIONS Despite impressive declines in the incidence, in-hospital and long-term mortality associated with QWMI, NQWMI is increasing in frequency and has the same in-hospital mortality now as it did 22 years ago. (J Am Coll Cardiol 2001;37:1571–80) © 2001 by the American College of Cardiology