Supplementary Material for: Impact of Mild-to-Moderate Chronic Kidney Disease on One Year Outcomes after Percutaneous Coronary Intervention

Background/Aim: Patients with severe chronic kidney disease (CKD) have a higher risk of adverse events after percutaneous coronary intervention (PCI). There is conflicting evidence regarding the benefit of drug-eluting stents (DES) in patients with CKD. This study is aimed at assessing the effect of mild-to-moderate CKD on PCI outcomes, and determining if DES reduce adverse events amongst these patients. Method: We used our PCI database to determine demographic, procedural and outcome variables for 1960 consecutive patients (October 2009-October 2012). Kidney function was measured by the estimated glomerular filtration rate (eGFR - CKD-Epidemiology Collaboration creatinine based). Multivariate analysis was performed to determine independent variables associated with mortality and major adverse cardiovascular events (MACE). Results: The independent variables, predictive of 12-month mortality in PCI patients, were: age >64 years (hazard ratio [HR] 3.10 [95% CI 1.73-5.55], p < 0.001), 3-vessel disease (HR 1.72 [95% CI 1.10-2.68], p = 0.016) and CKD stage. Compared to stage 1 CKD (eGFR >89), HR of death increased in a progressive pattern below eGFR <75: eGFR 60-74, HR 2.40 (95% CI 1.2-4.78), p = 0.013, eGFR 45-59, HR 3.27 (95% CI 1.55-6.9), p = 0.002, eGFR 30-44, HR 4.10 (95% CI 1.82-9.24), p = 0.001, eGFR <30, HR 7.97 (95% CI 3.65-17.40), p < 0.001. In patients with eGFR <75, multivariate analysis demonstrated that DES use was an independent predictor of lower MACE (HR BMS vs. DES 1.8, p = 0.0044). Conclusion: Age, severity of CKD and 3-vessel disease were independent predictors of mortality following PCI. The mortality risk in CKD patients increased progressively with eGFR <75. The use of DES was associated with a lower rate of MACE in CKD patients with eGFR <75.