Gender-specific and age-specific differences in unstable angina pectoris admissions: a population-based registry study in Finland

OBJECTIVE: To evaluate gender-specific and age-specific differences in the occurrence of unstable angina pectoris (UAP) caused admissions. DESIGN: Population-based retrospective registry study in Finland. PARTICIPANTS: All consecutive patients aged ≥30 years hospitalised with a primary diagnosis of UAP in 22 hospitals with a coronary catheterisation laboratory during 5/2000–10/2009. PRIMARY OUTCOME MEASURES: Gender-specific and age-specific differences and trends in occurrence of UAP admissions. RESULTS: The study period included 27 282 admissions caused primarily by UAP. Of these, 61.9% occurred to men and 38.1% to women with age-adjusted relative risk (RR) of 1.85 (CI 1.61 to 2.14) for the male gender (p<0.0001). The standardised incidence rate of UAP during the whole study was 92.8 (CI 91.8 to 93.9)/100 000 person-years. The incidence rate increased gradually from 1.3 in the population aged 30–34 years to 268.0/100 000 in the population aged 75–84 years. Men had a 2.4-fold risk for UAP admission compared with women in the general population (incidence rate ratio 2.39; CI 2.24 to 2.56; p<0.0001). Gender difference was present in all age groups. UAP caused 22.4% of acute coronary syndrome admissions and 4.7% of all cardiovascular admissions. UAP was more likely to be the cause of cardiovascular admission in male patients (RR=1.25; CI 1.21 to 1.30, p<0.0001 compared with female patients), but there was no gender difference in acute coronary syndrome admissions. The incidence rate of UAP hospitalisations in the general population declined by an estimated 8% per study-year (p<0.0001). Declining incidence was evident regardless of gender and age. CONCLUSIONS: Men have a 2.4-fold overall RR for UAP admission compared to women in the general population. Admissions due to UAP have a declining incidence trend across the adult Finnish population.