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

OBJECTIVE The goal of this study was to examine long-term trends in the inc idence, in-hospital and long-term mortality patterns in patients with an in itial 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 an d 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 Worceste r, Massachusetts residents (1990 census = 437,000) hospitalized with valida ted initial acute MI in all greater Worcester hospitals during 11 annual pe riods between 1975 and 1997. RESULTS The incidence of QWMI progressively decreased between 1975/78 (inci dence rate = 171/100,000 population) and 1997 (101/100,000 population). In contrast, the incidence of NQWMI progressively increased between 1975/78 (6 2/100,000 population) and 1997 (131/100,000 population). Hospital death rat es were 19.5% for patients with QWMI and 12.5% for those with NQWMI. After controlling for various covariates, patients with QWMI remained at signific antly increased risk for hospital mortality (adjusted odds ratio = 1.63; 95 % confidence interval: 1.35, 1.97). While the hospital mortality of QWMI ha s progressively declined over time (1975/78 = 24%; 1997 = 14%), the in-hosp ital mortality for NQWMI has remained the same (1975/78 = 12%; 1997 = 12%). These trends remained after adjusting for potentially confounding prognost ic factors. The multivariable adjusted two-year mortality after hospital di scharge declined over time for patients with QWMI and NQWMI. CONCLUSIONS Despite impressive declines in the incidence, in-hospital and l ong-term mortality associated with QWMI, NQWMI is increasing in frequency a nd has the same in-hospital mortality now as it did 22 years ago. (J Am Col l Cardiol 2001;37:1571-80) (C) 2001 by the American College of Cardiology.