Microvascular complications, coronary artery disease and the risk of cardiovascular disease in diabetes patients undergoing coronary angiography: a cohort study from the Western Denmark Heart Registry

Abstract

Abstract Background Diabetes is associated with an increased risk of both microvascular macrovascular complications. The association between microvascular disease and cardiovascular risk, however, is less explored. Aims We aimed to estimate the cardiovascular risk associated with microvascular disease in diabetes patients with and without coronary artery disease. Methods We included every patient who underwent coronary angiography in Western Denmark between 2003–2016. Patients were stratified by microvascular disease (defined as diagnosis retinopathy, nephropathy, or peripheral neuropathy) and coronary artery disease by angiography. Outcomes included major adverse cardiovascular events (myocardial infarction, ischemic stroke, and cardiac death) as a combined outcome and as separate outcomes. Patients were followed for a maximum of 10 years. We estimated 10-year cumulative incidence of each outcome. Incidence rate ratios (IRR) were estimated by a modified Poisson regression model using diabetes patients with neither microvascular disease nor coronary artery disease as reference. Results We included 19,295 patients with diabetes, of whom 1,268 (6.6%) had microvascular disease, 10,161 (52.7%) had coronary artery disease, 3,113 (16.3%) had both microvascular disease and coronary artery disease, and 4,753 (24.6%) had neither microvascular nor coronary artery disease. Median follow-up was 5.9 years (interquartile range 3.3–9.0) Patients with microvascular disease had an increased risk of major adverse cardiovascular events compared to diabetes patients with neither microvascular disease nor coronary artery disease (13.6% versus 10.0%, adjusted IRR 1.45, 95% CI 1.19–1.77, Figure 1). This increased risk was driven by a 3.9% higher risk of ischemic stroke (adjusted IRR 1.53, 95% CI 1.14–2.05, Figure 2), while microvascular disease was not associated with an increased risk of myocardial infarction (adjusted IRR 1.08, 95% CI 0.72–1.62) or cardiac death (adjusted IRR 0.99, 95% CI 0.63–1.56). Patients with both microvascular disease and coronary artery disease had the highest risk of major adverse cardiovascular events (29.3%, adjusted IRR 3.06, 95% CI 2.67–3.50). Conclusion Microvascular disease in diabetes patients without angiographic coronary artery disease is associated with an increased cardiovascular risk. However, this was driven by a higher risk of ischemic stroke than by higher rates of myocardial infarction or cardiac death. In fact, diabetes patients with microvascular disease but no coronary artery disease had the same risk of ischemic stroke as those with combined microvascular disease and coronary artery disease. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): Aarhus University Hospital