Incidence of flow-limiting coronary artery stenoses in patients with diabetes - a coronary angiography natural history study

Abstract

Abstract Background Diabetes is an established risk factor for the development of coronary atherosclerosis. We sought to assess the association between diabetes and the incidence of coronary artery atherosclerosis progression on coronary angiography. Methods Using the Swedish Coronary Angiography and Angioplasty Registry (SCAAR), we included all coronary artery segments with mild to no atherosclerosis defined as <50% luminal obstruction in patients undergoing a first-time coronary angiography in Sweden between 1989 and 2017. Patients with two or more vessel disease were excluded as were patients with a previous history of coronary artery disease. In patients with one vessel disease, the diseased vessel including all its branches were excluded. Patients were followed for 15 years until a clinically indicated re-angiography was done, death occurred or end of follow-up (April 2018). The primary outcome was plaque progression to flow-limiting coronary artery stenosis defined as ≥50% luminal obstruction on repeat angiography assessed using epidemiological tables, Kaplan Meier event rates, and Cox proportional hazard models. The importance of selected risk factors (smoking, hypertension, hyperlipidemia, and established coronary artery disease) was assessed. Results A total of 2 661 245 coronary segments in 248 736 patients were included in the study. Diabetes was present in 30 533 patients and 320 815 coronary artery segments. Kaplan-Meier event rates and incidence rates (IR) per 1000 segment-years were higher in patients with diabetes (5.5%, IR 2.78 [95% CI 2.70–2.85] vs. 3.0%, 1.44 [1.42–1.46]) resulting in an almost two-folded hazard ratio (HR) of plaque progression (HR 1.93 [95% CI 1.87– 2.00]). The anatomical distribution of plaque progression was similar between the two cohorts on all levels of analysis (coronary artery level, main artery and branches level, and coronary segment level artery). Diabetic patients with established coronary artery disease had a significantly higher risk of future events compared to those without clinically significant coronary artery disease. Conclusions Diabetes was associated with an almost twofold higher incidence rate of plaque progression but did not appear to alter the anatomical location of plaque development compared to the absence of diabetes. Once coronary artery disease is established, the rate of atherosclerotic events accelerates. Therefore, adopting aggressive primary prevention strategies is crucial to reduce the risk of adverse outcomes in diabetic patients.Event rates and anatomical distributionProgression of stenoses by risk factor