Trends in incidence, severity, and outcome of hospitalized myocardial infarction.

Abstract

BACKGROUND:

In 2000, the definition of myocardial infarction (MI) changed to rely on troponin rather than creatine kinase (CK) and its MB fraction (CK-MB). The implications of this change on trends in MI incidence and outcome are not defined.

METHODS AND RESULTS:

This was a community study of 2816 patients hospitalized with incident MI from 1987 to 2006 in Olmsted County, Minnesota, with prospective measurements of troponin and CK-MB from August 2000 forward. Outcomes were MI incidence, severity, and survival. After troponin was introduced, 278 (25%) of 1127 incident MIs met only troponin-based criteria. When cases meeting only troponin criteria were included, incidence did not change between 1987 and 2006. When restricted to cases defined by CK/CK-MB, the incidence of MI declined by 20%. The incidence of non-ST-segment elevation MI increased markedly by relying on troponin, whereas that of ST-segment elevation MI declined regardless of troponin. The age- and sex-adjusted hazard ratio of death within 30 days for an infarction occurring in 2006 (compared with 1987) was 0.44 (95% confidence interval, 0.30 to 0.64). Among 30-day survivors, survival did not improve, but causes of death shifted from cardiovascular to noncardiovascular (P=0.001). Trends in long-term survival among 30-day survivors were similar regardless of troponin.

CONCLUSIONS:

Over the last 2 decades, a substantial change in the epidemiology of MI occurred that was only partially mediated by the introduction of troponin. Non-ST-segment elevation MIs now constitute the majority of MIs. Although the 30-day case fatality improved markedly, long-term survival did not change, and the cause of death shifted from cardiovascular to noncardiovascular.

• Authors: Véronique L Roger, Susan A Weston, Yariv Gerber, Jill M Killian, Shannon M Dunlay, Allan S Jaffe, Malcolm R Bell, Jan Kors, Barbara P Yawn, Steven J Jacobsen
• Journal: Circulation (Circulation) Vol. 121 Issue 7 Pg. 863-9 (Feb 23 2010) ISSN: 1524-4539 [Electronic] United States
• PMID: 20142444 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Troponin
• Creatine Kinase

Topics

• Aged
• Creatine Kinase (analysis, metabolism)
• Female
• Hospitalization (statistics & numerical data, trends)
• Humans
• Incidence
• Male
• Myocardial Infarction (diagnosis, epidemiology, therapy)
• Severity of Illness Index
• Survival Rate
• Treatment Outcome
• Troponin (analysis)