Percutaneous drug-eluting stent implantation in diabetic patients: Short and long term outcomes from an observational study

Aim. The introduction of drug-eluting stents (DES) has markedly improved mid-term results of percutaneous coronary intervention (PCI) in diabetics. However, it is unclear whether the risk-benefit balance of DES in diabetics is maintained also at long-term and in insulin-requiring patients. We thus aimed to appraise long-term outcomes of diabetic patients treated with PCI with DES, stratifying according to insulin therapy. Methods. We retrospectively collected baseline, procedural and outcome data from all patients undergoing PCI with DES from July 2002 to June 2004 at our center. We distinguished three groups: insulin-requiring diabetics, non-insulin-requiring diabetics and patients without diabetes. The primary end-point was the long-term rate of major adverse cardiac events (MACE, i.e. the composite of death, myocardial infarction, or target vessel revascularization). We also considered stent thrombosis according to the Academic Research Consortium Definition. Results. We included a total of 1 266 patients, with 3% of insulin-requiring diabetes, 22% with non-insulin-requiring diabetes, and 75% without diabetes. There were significant differences across groups in prevalence of male gender (respectively, 32.4%, 74.6% and 81%, P<0.001), and DES usage (54.1%, 34%, and 30.4%, P=0.007). Thirty-day MACE occurred with similar frequency in the three groups (8.1%, 7.3% and 6.3%, P=0.78), with death in 3%, 2%, and 1.4% (P=0.71) and myocardial infarction in 5.4%, 1.8% and 0.8% (P=0.02). After a median follow-up period of 58 months, MACE occurred in 59.5% of patients with insulin-requiring diabetes, in 50.6% of non-insulin-requiring diabetics and in 38.9% of non-diabetics (P<0.001). Death occurred in 24.3%, 17.5% and 8.5%, (P<0.001), myocardial infarction in 10.8%, 6.6%, and 5.1% (P=0.25), repeat revascularization in 46%, 31.6%, and 30% (P=0.11), and definite stent thrombosis in 0%, 1.1%, and 1.3% (P=0.78). Conclusions. Our study confirms the high risk profile of diabetic patients, especially when ischemic disease it is known. In this setting, diabetic and comorbidities fix the price not only in term of need of further revascularization, but mainly in survival decrease. It can be concluded that not only revascularization but also - and especially - comorbidities treatment plays a determinant role reducing follow-up events. Further research on additional pharmacologic treatments or hybrid revascularization strategies may mitigate the burden of morbidity and mortality.