Association of age and gender with risk for non-ST-elevation myocardial infarction

Abstract

Background

Age and gender associated risks for non-ST-elevation myocardial infarction (NSTEMI) at the population level are largely uncharacterized.

Design

Nationwide, population (26,724,165 person-years) based eight-year registry-study in Finland.

Methods

Gender- and age-associated frequency and incidence of NSTEMI were studied using a nationwide, population based registry of hospital admissions in patients aged ≥30 years during 2001–2008. Patients with NSTEMI as primary (88%), secondary (10%) or tertiary (2%) discharge diagnosis were included. Data was collected nationwide from all 22 hospitals with a coronary angiolaboratory.

Results

The study period included 48,584 NSTEMI admissions of which 55.3% (95% confidence interval (CI) 54.6–56.0%) were of men and 44.7% (CI 44.1–45.3%) were of women, with age-adjusted relative risk of 1.86 (CI 1.60–2.16, p < 0.0001) for male gender. Female patients were significantly older than males (77.8 SD 10.2 vs. 70.2 SD 11.9 years, p < 0.0001). Standardized incidence rate of NSTEMI was 20.6 (CI 20.4–20.8)/10,000 person-years overall, 28.7 (CI 28.3–29.0)/10,000 in men and 15.0 (CI 14.7–15.2)/10,000 in women. Men had a 2.36-fold (CI 2.23–2.49; p < 0.0001) age-adjusted relative risk for NSTEMI compared with women, with highest risk difference in population under 40 years of age (relative risk 4.48; CI 3.10–6.48, p < 0.0001). Incidence increased with age by an estimated gender-adjusted increase rate of 61% (CI 59–62%; p < 0.0001) per five-year increase in age.

Conclusions

Men have a 2.4-fold overall risk for NSTEMI compared with women, with highest relative risk in young adults. Incidence rate of non-ST-elevation myocardial infarction increases by an estimated 61% per five-year increase in age.