Cardiovascular risk in patients with and without diabetes presenting with chronic coronary syndrome in 2004-2016

BACKGROUND: It was recently shown that new-onset diabetes patients without previous cardiovascular disease have experienced a markedly reduced risk of adverse cardiovascular events from 1996 to 2011. However, it remains unknown if similar improvements are present following the diagnosis of chronic coronary syndrome. The purpose of this study was to examine the change in cardiovascular risk among diabetes patients with chronic coronary syndrome from 2004 to 2016.

METHODS: We included patients with documentation of coronary artery disease by coronary angiography between 2004 and 2016 in Western Denmark. Patients were stratified by year of index coronary angiography (2004-2006, 2007-2009, 2010-2012, and 2013-2016) and followed for two years. The main outcome was major adverse cardiovascular events (MACE) defined as myocardial infarction, ischemic stroke, or death. Analyses were performed separately in patients with and without diabetes. We estimated two-year risk of each outcome and adjusted incidence rate ratios (aIRR) using patients examined in 2004-2006 as reference.

RESULTS: Among 5931 patients with diabetes, two-year MACE risks were 8.4% in 2004-2006, 8.5% in 2007-2009, and then decreased to 6.2% in 2010-2012 and 6.7% in 2013-2016 (2013-2016 vs 2004-2006: aIRR 0.70, 95% CI 0.53-0.93). In comparison, 23,540 patients without diabetes had event rates of 6.3%, 5.2%, 4.2%, and 3.9% for the study intervals (2013-2016 vs 2004-2006: aIRR 0.57, 95% CI 0.48-0.68).

CONCLUSIONS: Between 2004 and 2016, the two-year relative risk of MACE decreased by 30% in patients with diabetes and chronic coronary syndrome, but slightly larger absolute and relative reductions were observed in patients without diabetes.