A prospective cohort design using was conducted via medical records review from May 2007 to Dec 2014. The institutional review board and ethics committee approved the study protocol and monitoring for the study.

We consecutively recruited patients aged 30 to 90 years who were to undergo PCI from the inpatient clinic at the Taichung Tzu Chi Hospital, Taiwan. According to isolated or coexistence of risk factors, the patients were divided into four groups: patients without DM or CKD, patients with DM alone, patients with CKD alone, and patients with both DM and CKD. Patients with a scheduled PCI and previous history of malignancy were excluded. Most patients obtained regular follow-up in the outpatient department (OPD). For some patients who were lost to follow-up, usually a phone call was used to contact the patients themselves or their families. A survey of cardiovascular mortality (CV mortality), all-cause mortality, myocardial infarction (MI), and repeated PCI procedures was completed at the end of the study.

Baseline characteristics including body habitus, biochemical data, angiographic findings from cardiac catheterization, exposed risk factors, and variant therapeutic strategies such as drug medications and invasive procedures (balloon angioplasty, bare metal stent deployment, or drug-eluting stent deployment) were all obtained for our study. Diabetes was defined as a fasting plasma glucose level of >126 mg/dL, a casual plasma glucose level of >200 mg/dL, or a hemoglobin A1c (HbA1c) level of >6.5% in this study [14]. Estimated glomerular filtration rate (eGFR) and chronic kidney disease (CKD) stage were divided into 5 stages: stage l, eGFR ≥90 mL/min/1.73 m²; stage 2, eGFR of 60–89 mL/min/1.73 m²; stage 3, eGFR of 30–59 mL/min/1.73 m²; stage 4, eGFR of 15–29 mL/min/1.73 m²; and stage 5, eGFR of <15 mL/min/1.73 m² or dialysis. CKD was defined as an eGFR of <60 mL/min/1.73 m², which was equal to or greater than CKD stage 3, in this study [15]. Hypercholesterolemia was defined as a serum cholesterol level of >200 mg/dL or an LDL-C level of >100 mg/dLFor the angiographic and hemodynamic data, we measured the central aortic pressure (CAP) and left ventricular ejection fraction (LVEF). The CAP was obtained by using a pigtail catheter while performing a coronary angiography. Angiographic findings including number of diseased vessels and lesion locations were calculated, and lesion severity and complexity were evaluated via the Synergy between PCI with Taxus and cardiac surgery score (Syntax Score) [16]. The left ventricular ejection was estimated through angiographic ventriculography or stress ventriculography.MI was defined as an MI attack after index PCI, accompanied by a 3-fold elevation in cardiac enzymes from the baseline value. General characteristics, major risk factors, angiographic findings, PCI strategies were analyzed, The primary end-points including all-cause death, cardiovascular death, myocardial infarction and repeated PCI were also compared among the 4 groups. The beginning of follow-up was the date of index PCI, and the duration of follow up was from the beginning through June 30, 2015 or if any of above primary end-points happened.

First, were did not fully evaluated the intensity of medication, such as tight blood glucose control or blood pressure control. Second, data entry bias may exist; functional evaluations of the atherosclerotic lesions such as fraction flow reserve (FFR) measurement, were not used that may have had an impact on the decision of index PCI enrollment; it has been reported that DM and CKD were independent predictors for FFR measurement. Besides, positive findings of FFR were lower in patients with CKD whereas index of microcirculatory resistance (IMR) was higher [25].Third, since the number of patients in the DM alone group was fewer than that of the other groups, that may have affected the power of this study. Fourth, since DES implantation had a lower adverse cardiac events rate in patients with diabetes or CKD than BMS implantation, patient selection bias may exist in this study.