Impact of atherosclerotic disease progression on mid-term clinical outcome in diabetic patients in the drug-eluting stent era

Aims: To determine whether repeat revascularisation (RR) in diabetic patients treated with prior drugeluting stents (DES) is the result of either DES restenosis or native progression of atherosclerotic disease in the coronary vasculature, and to evaluate the impact of atherosclerotic disease progression on the midterm clinical outcome. Methods and results: We followed 316 consecutive diabetic patients (227 men, age 69±9 years) treated between June 2005 and September 2006 with at least one DES. During the follow-up (mean 590±194 days) the cumulative incidence of major adverse clinical events (MACE; death, non-fatal myocardial infarction [MI] and target vessel revascularisation [TVR]) was 17.1%. Thirty-eight patients underwent RR (37 PCI, 1 coronary artery bypass graft [CABG]). In 22 patients RR was performed for restenosis (18 after DES implantation and 4 after BMS implantation); four of these patients also required treatment for atherosclerotic disease progression (ADP). In 16 patients, PCI was performed for symptomatic ADP without restenosis. Thus ADP contributed to 53% of RR procedures and to 42% of TVR. Furthermore, in 6 of 10 patients (60%) admitted for MI, the culprit lesion was the result of ADP. Only history of PCI and PCI of the left main before the index procedure were found to be independent predictors for development of significant de novo lesion at follow-up (OR 4.1, 95% CI 1.6-10.4, p=0.002 and OR 4.7, 95% CI 0,003, p=0.003). No traditional risk factors were found to be predictors. Conclusions: Atherosclerotic disease progression was the cause of repeat revascularisation in more than 50% of diabetic patients treated previously with DES and had an important impact on their mid-term clinical outcome. MACE rates in clinical trials with long-term follow-up of diabetic patients can thus be influenced by native disease progression rather than DES failure and therefore should be interpreted with caution when addressing comparison of DES efficacy in diabetic patients.