Diabetes in Patients with CAD Independently Associated with Mortality, CV Events

Grace Halsey

In individuals with chronic coronary disease, the presence of diabetes increased the rate of death by 38% during a 5-year follow-up period in analysis of a worldwide patient registry.

Among patients worldwide with stable coronary artery disease (CAD), those with diabetes had a 38% higher rate of death and a 28% increased risk of a composite of heart attack, stroke, or death from a cardiovascular (CV) cause.

These data come from a new analysis of a global registry of patients with chronic coronary syndromes published online April 6, 2021, in the European Journal of Preventive Cardiology.

Analysis authors report that nearly 30% of patients with CAD have diabetes--a rate nearly 3 times that in the general population which they note to be approximately ~8% to 10%.

“Obesity and lack of exercise are common risk factors for both diabetes and heart disease and our results highlight the urgent need to improve nutrition and raise activity levels globally,” said study author Dr Emmanuelle Vidal-Petiot of Bichat-Claude Bernard Hospital, Paris, France, in a statement from the European Society of Cardiology. “Countries worst affected by diabetes are also at the epicentre of the obesity epidemic, which can be in part attributed to urbanisation and associated changes in physical activity and food intake.”

Global data gap for stable CAD

Vidal-Petiot et al write that compared with information on the impact of diabetes on prevalence of acute myocardial infarction (MI), data are limited on diabetes' impact on clinical outcomes in patients with chronic coronary syndromes (eg, angina, myocardial ischemia, or both; with previous MI or history of coronary revascularization; and with established CAD without symptoms or ischemia).

To gain understanding of the global impact of diabetes on this population and to assess potential regional differences, the investigators deigned an analysis of the CLARIFY (prospeCtive observational LongitudinAl RegIstry oF patients with stable coronary arterY disease) registry. The analysis included 32 694 patients with chronic coronary syndromes from 45 countries in Europe, Asia, America, the Middle East, Australia, and Africa. Patients were enrolled between 2009 and 2010 and followed up annually for 5 years.

The primary outcome of interest was defined as the composite of cardiovascular death, MI, and stroke; secondary outcomes were each component of the primary outcome, total death, and hospitalization for heart failure (HHF). The rate of coronary revascularization was also studied in analyses of the total population.

After adjustment for potential confounding variables (ie, age, sex, smoking status, body mass index, blood pressure, medications, other conditions) Cox proportional hazards modeling found the risk for the primary outcome as well as risks of all secondary outcomes remained higher for those with diabetes vs those without:

  • All-cause death: adjusted HR 1.38 (95% CI 1.27, 1.50)
  • CV death: 1.39 (95% CI 1.25, 1.54)
  • MI: 1.26 (95% CI 1.10, 1.43)
  • Stroke: 1.29 (95% CI 1.09, 1.52)
  • HHF: 1.15 (95% CI 1.03, 1.28)
  • Coronary revascularization: 1.14 (95% CI 1.04, 1.25)

Researchers wrote that, despite significant geographic disparities in the prevalence of diabetes, ranging from <20% in northern Europe to ~60% in Gulf countries, the prognostic value of diabetes after multivariable adjustment, was similar across regions worldwide. Interaction between diabetes and geography was non-significant for all outcomes.

Primary prevention, local and global

“Diabetes was linked with worse outcomes even in areas with the lowest prevalence. In Europe, for instance, diabetes was linked with a 29% greater risk of the combined outcome of heart attack, stroke, or cardiovascular death," said Vidal-Petiot in the ESC statement. "This indicates that management of these very high-risk patients with heart disease and diabetes should be improved. Each country needs to identify these patients and provide tailored educational and prevention programmes.”

The authors conclude: "Research on the epidemiology of diabetes needs to be combined with efforts in primary prevention of diabetes—weight control and exercise being the first steps—early detection of the disorder, and improved management of patients with established diabetes, both at the individual level and through health system interventions."