Trends in acute myocardial infarction hospitalization rates in Norway during 1994-2009; a CVDNOR project

Abstract

Purpose: AMI hospitalizations account for almost 90% of all AMI occurrences. They encompass incident and recurrent events; the first reflecting primary prevention and the second in-hospital care and secondary prevention. Our aim was to examine AMI hospitalization trends during 1994-2009 in Norway. Methods: All AMI hospitalizations during 1994-2009 were extracted from Cardiovascular disease in - CVDNOR, a research project including information on all patients hospitalized for a CVD event 1994-2009. First and recurrent hospitalizations were included. Overall age-standardized and age group specific hospitalization rates were calculated. Trends over time were explored by Poisson regression analyses, computing hospitalization rate ratios (HRR). Changes are reported separately for 1994-2000 and 2001-2009, to minimize the effect of changes in AMI diagnostic criteria (troponin introduction) around 2000-2001. Results: 241 207 AMI hospitalizations (39% women) were included. Overall, age-standardized hospitalization rates declined during 2001-2009 (HRR=0.93; 95% CI 0.92-0.95). In young adults (< 45 years) rates increased during 1994-2009; not significantly during 1994-2000 and significantly thereafter (HRR=1.11; 95% CI 1.01-1.21). In age group 85+ years, rates increased during 1994-2000 (HRR=1.53; 95% CI 1.45-1.62) but not thereafter. A decline was observed in age group 45-64 years only during 1994-2000 (HRR=0.90; 95% CI 0.87-0.94). In age group 65-84 years there was a decline both for 1994-2000 (HRR=0.96; 95% CI 0.93-0.98) and 2001-2009 (HRR=0.85; 95% CI 0.84-0.87) ![Figure][1] Age-standardized hospitalization rates Conclusion: Overall AMI hospitalizations rates in Norway declined after 2000, due to declining rates among patients 45-84 years. Increasing trends were observed in young adults and elderly over 85 years. [1]: pending:yes