Trends in long-term prognosis after acute coronary syndrome

Background Coronary heart disease incidence, mortality and short-term case-fatality have improved substantially during the past decades. Recent changes in the long-term prognosis among survivors of acute coronary syndrome are less well known. Our aim was to investigate the long-term prognosis of acute coronary syndrome. Design An observational myocardial infarction register study. Methods Data was derived from the population based Finnish Myocardial Infarction register. Patients aged 35 or higher, who had their first acute coronary syndrome during 1993-2011 and survived the first 28 days, were included in the analysis ( n = 13,336). Endpoints were fatal and non-fatal cardiovascular disease events and all-cause mortality at one year and three years after the index event. We also compared the prognosis of acute coronary syndrome survivors with the prognosis of an apparently healthy population with the same age, sex and area of residence, derived from the FINRISK study. Results Significant declines over time were observed in the risk of a new cardiovascular disease event. At three year follow-up the age- and study area-adjusted hazard ratio per calendar year was 0.969 (95% confidence interval 0.960-0.977, p = 4.63 × 10^-13) among men and 0.969 (95% confidence interval 0.961-0.978, p = 1.01 × 10^-11) among women. Despite the improvement in prognosis, the age-standardized three year cardiovascular disease free survival of acute coronary syndrome patients was significantly lower than in the FINRISK control group (for men p = 6.64 × 10^-27 and for women p = 2.11 × 10^-15). Conclusion The prognosis of acute coronary syndrome survivors has improved during the 18-year period but is still much worse than the prognosis of comparable general population.