Temporal trends in socioeconomic disparity in clinical outcomes for patients with acute coronary syndrome

AIMS: Socioeconomic factors are well-established determinants of clinical outcomes among patients with acute coronary syndrome (ACS) although quality of care has improved the last decades. This study aims to investigate 20-years temporal trends of socioeconomic disparity in 1-year incidence of major adverse cardiac events (MACE) among ACS patients in Denmark.

METHODS: This population-based cohort study included all incident ACS patients in the Danish National Patient Registry during 1998-2017. Socioeconomic disparity was assessed by income and educational level. Patients were followed 1-year for MACE; defined as all-cause mortality, recurrent ACS, revascularization, stroke, or cardiac arrest. Adjusted MACE incidence rates (aIR) and hazard rate ratios (aHR) were computed with 95 % confidence intervals (CI) for five-year-periods. Changes in trends were examined from interaction analyses between the HR for five-year-periods and income and education, respectively.

RESULTS: The study included 220,887 patients with first-time ACS. The incidence of MACE decreased within all income and education levels. In 1998-2002 the MACE aIR among patients with low income was 885[95%CI:863-907] versus 733[711-756]/1000-person-year among those with high income (aHR: 1.19[95%CI:1.15-1.23]). The aIRs decreased to 506[489-522] and 405[388-423]/1000-person-year, respectively, in 2013-2017 (aHR: 1.23[1.17-1.29]). The aIRs of MACE decreased correspondingly within all educational levels from 1998 to 2002 to 2013-2017. However, the socioeconomic disparity according to the interaction analyses persisted both according to income and educational level.

CONCLUSION: Although 1-year clinical outcomes following ACS has improved substantially over the last decades, socioeconomic disparity persisted both according to income and education level.