Time trends in incidence, treatment, and outcome in acute myocardial infarction in Norway 2013-19.

Aims: Acute myocardial infarction (AMI) is a common cause of morbidity and mortality. The aim of the present study was to assess time trends in the incidence, treatment, and outcome of AMI in a nationwide registry-based cohort of patients.

Methods And Results: All patients with a first AMI registered in the Norwegian Myocardial Infarction Registry between 2013 and 2019 were included in this cohort study. The number of patients admitted to Norwegian hospitals with a first AMI decreased from 8933 in 2013 to 8383 in 2019. The proportion of patients with ST-elevation myocardial infarction (STEMI) was stable at 30% throughout the period, and the percentage of STEMI undergoing coronary angiography was stable at 87%. The proportion of patients with non-STEMI undergoing coronary angiography increased by 2.4% per year (95% confidence interval 1.6-3.3) from 58% in 2013 to 68% in 2019. More patients were discharged with secondary preventive medication at the end of study period. Age-adjusted 1-year mortality was reduced from 16.4% in 2013 to 15.1% in 2018. The changes over time were primarily seen in the oldest patient groups.

Conclusion: In the period 2013-19 in Norway, we found a reduction in hospitalizations due to a first AMI. Both the percentage of patients undergoing coronary angiography as well as the percentage discharged with recommended secondary preventive therapy increased during the period, and the age-adjusted 1-year mortality after AMI decreased. A national AMI register provides important information about trends in incidence, treatment, and outcome, and may improve adherence to guideline recommendations.