Objective: To assess whether improvements in preventative care for people with diabetes have resulted in a relative decrease in the burden of coronary artery disease (CAD) compared to people without diabetes.
Methods: All patient-level linked coronary angiography and hospital separation data at a large Australian tertiary referral hospital between 2013 and 2019 were obtained. Indication for angiography and extent of CAD were based on original classification by treating cardiologists, classified as no disease, mild, moderate or severe. Propensity scores were estimated to match people with and without diabetes on a 1:1 ratio. Ordinal logistic regression models were fitted to assess trends in CAD severity in people with and without diabetes over time with adjusted odds ratios (adjOR) reported.
Results: For 3,016 people identified in the coronary angiography database and matched using propensity scores, 1508(50%) were diagnosed with diabetes. Angiographic evidence of CAD was detected in 1155(77%) and 1257(83%) people without and with diabetes. For people with diabetes there was an increased risk of more extensive CAD in 2018 compared to 2013 (adjOR: 2.02 95% C.I. 1.36, 2.99). This risk appears to have been attenuated in 2019 with no significant change in CAD burden between 2013 and 2019 (adjOR: 1.33 95% C.I. 0.90, 1.98). In contrast, there was no effect of time on CAD burden in people without diabetes.
Conclusions: The initial increase in severity of disease burden seen in our study for people with diabetes compared to those without diabetes may represent improved CAD screening rather than suboptimal application of preventative therapies. Possibly, greater recent use of newer glucose lowering medications with cardiovascular protective effects accounts for the attenuation of CAD burden in 2019 for people with diabetes. These findings highlight the importance of aggressive risk factor modification for people with diabetes to minimize the development and progression of CAD.
K.V. Kiburg: None. A.I. MacIsaac: None. V. Sundararajan: None. R. MacIsaac: None.