The incidence of MI, as well as 30-day mortality
following MI, decreased significantly in the period between 2000 and 2008 in a
large, community-based population, results of a new analysis indicated.
Researchers identified patients from the Kaiser
Permanente Northern California database aged 30 years or older who were
hospitalized for incident MI between 1999 and 2008. A total of 46,086 patients
hospitalized for MI were included in the analysis, with a total of 18,691,131
person-years of follow-up; of those, 15,271 patients (33.1%) presented with
STEMI and 30,815 patients (66.9%) presented with non-STEMI.
Age- and sex-adjusted incidence of MI increased from 274
cases per 100,000 person-years in 1999 to 287 cases per 100,000 person-years in
2000, followed by decreases each year thereafter. The incidence of MI
eventually decreased to 208 reported cases per 100,000 person-years in 2008,
representing a total relative decrease of 24% over the study period. The age-
and sex-adjusted incidence of STEMI also decreased throughout the study period,
from 133 cases per 100,000 person-years in 1999 to 50 cases per 100,000
person-years in 2008, P<.001). Additionally, 30-day mortality
following MI decreased from 10.5% in 1999 to 7.8% in 2008 (P<.001 for
linear trend), driven primarily by a decrease in the case fatality rate for
non-STEMI. The multivariable adjusted odds ratio for death at 30 days following
MI in 2008 was 0.76 (95% CI, 0.65-0.89), which was lower than the ratio
reported in 1999.
“The lower incidence of MI – particularly
STEMI – is probably explained, at least in part, by substantial
improvements in primary prevention efforts, and these trends occurred despite
the increased sensitivity of new biomarkers for the diagnosis of MI and the
increasing prevalence of selected CV risk factors,” the researchers noted
in their conclusion.
Yeh R. N Engl J Med. 2010;362:2155-2165.