Background - Cardiovascular disease (CVD) is the main cause of death in individuals with and without diabetes mellitus (DM). The detection of valid CVD risk factors is important for a reliable risk stratification and, consequently, the early onset of preventive or therapeutic interventions. Data on the long-term prognostic value of risk factors is currently limited and it is debatable whether novel measures (e.g.microvascular retinal changes, apoliproteins, inflammatory markers, etc.) provide a better estimation of CVD risk than traditional risk factors (age, sex, dyslipidemia, hypertension, smoking, overweight). Risk factors may also be of use in predicting the success of specific therapeutic interventions. Potential differences between patient groups with variable underlying CVD risk (e.g. presence or absence of DM) must be taken into account.
Objectives - To assess the prognostic value of traditional and novel CVD risk factors in diabetic and non-diabetic patients. The specific goals are threefold:
1.To assess whether the long-term prognostic value of CVD risk factors onmortality differs between patients with type 1 and type 2 DM and to assess changes over time (study A).
2.To assess the prognostic value of retinal microvascular measures asfactors of increased CVD risk in patients with and without DM (study B).
3.To assess the prognostic value of clinical and morphological riskfactors on the effectiveness of drug-eluting coronary stents in patients with and without DM (study C).
Methods - Study A will encompass the 30-year follow-up of the Swiss arm of the ‘WHO Multinational Study of Vascular Disease in Diabetes’. This study will assess the long-term prognostic value of traditional and novel risk factors as well as potential changes in the prognostic value of risk factors over time, based on the longest follow-up in the field of observational studies in individuals with DM. Study B will investigate the value of recently developed techniques in the automated analysis of retinal microvascular changes as prognostic markers of CVD outcomes in 980 diabetic and non-diabetic patients from the Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT). Study C will combine the individual patient data(IPD) from all randomised controlled trials directly comparing the sirolimus-eluting (CypherTM) stent and the paclitaxel-eluting (TaxusTM) stent by using meta-analytic techniques. Providing the largest body of evidence (5,392 patients) this IPD-meta-analysis will investigate whether one drug-eluting stent (DES) is superior over the other in patients with or without DM. By performing analyses of specific strata this study will assess the role of clinical and morphological measures on the rates of restenosis and, consequently, the need for revascularization procedures as well as on safety outcomes after coronary stenting with DES.
Expected Value - The results of study A will give insight into the long-term prognostic value of traditional and novel CVD risk factors on mortality in diabetic patients. Study B will contribute to a broader understanding of the association of retinal microvascular changes and CVD in diabetic and non-diabetic patients. Study C will enhance our understanding of the role of risk factors in the development of restenosis, revascularization and safety outcomes after stenting with DES.All 3 studies will contribute to an improved risk stratification of diabetic and non-diabetic patients in clinical practise.