Case fatality rates after first acute coronary syndrome in persons treated for type 2 diabetes show an improving trend

Abstract

Aims/hypothesis We analysed whether the prognosis of a first acute coronary syndrome (ACS) in patients treated for type 2 diabetes has improved. We also compared the trends in patients with and without diabetes. Methods We used national registers to identify all patients with clinically known type 2 diabetes in Finland during the years 1988 to 2002 (n=222,940). All first-ever ACS events (n=43,412) among these patients were identified using the Hospital Discharge Register and the Causes of Death Register. From the National Cardiovascular Disease Register we identified all first ACS attacks (n=191,403) among non-diabetic patients in the country. Finally, we calculated annual age-standardised case fatality rates for ACS for three time periods: prehospital, days 0 to 27 and days 28 to 364 after the first ACS. Results The case fatality rate of first ACS declined significantly in both sexes at all time points considered. The declining trends were not different between patients with type 2 diabetes and those without. Among men aged 35 to 74 years, 58.5% (95% CI 57.6-59.4%) with type 2 diabetes and 44.1% (95% CI 43.8-44.5%) without diabetes had died from cardiovascular causes 1 year after their first ACS. Among women of the same age, the corresponding figures were 54.2% (95% CI 53.0-55.4%) and 36.5% (95% CI 35.9-37.1%). Men generally had higher case fatality rates than women. However, except for prehospital deaths, diabetic women had the same or even higher case fatality rates than non-diabetic men. Conclusions/interpretation The case fatality rates for first ACS show similar improving trends in patients with type 2 diabetes and in those without. However, case fatality rates have remained higher in patients with type 2 diabetes.

The disparity between long-term survival in patients with and without diabetes following a first myocardial infarction did not change between 1989 and 2006: an analysis of 6,776 patients in the Northern Sweden MONICA Study

“…The longest time series published comes from Finnish national data between 1988 and 2002 and reports similar decreases in fatality rates between diabetic and non-diabetic patients with no trends towards a reduced difference [9], which our data corroborate over a longer time period. Data from Sweden and Holland [6,8] 1995-2003 are also in accordance with the longer secular trends.…”

“…Some only included patients admitted to coronary care units [6]. In one case, only diabetic patients being treated with oral drugs or insulin were included [9]. Others cover a short time span [8], follow only one cohort over time and do not inform regarding secular trends [5].…”

“…Only a few report on mortality beyond 1 year [5,6,8] or exclusively after a first ever MI [5,8,9]. Three studies have however included a nationwide coverage and all ages [5,6,9].…”

“…Time trends in 1-year survival reported from national surveys in Sweden and Finland have shown no decrease in the mortality gap [6,9].…”

“…Long-term mortality after myocardial infarction (MI) in diabetic patients is 30-50% higher than among non-diabetic patients [5,6], and even further increased in diabetic women [7][8][9]. Time trends in 1-year survival reported from national surveys in Sweden and Finland have shown no decrease in the mortality gap [6,9].…”