Impaired Kidney Function and 10-Year Outcome After Percutaneous Coronary Intervention—Interaction with Age, Sex, Diabetic Status and Clinical Presentation

<b>Background</b>: Limited evidence exists regarding the association of chronic kidney disease (CKD) with long-term outcomes following percutaneous coronary intervention (PCI). We aimed to assess the association of CKD with 10-year outcome after PCI. <b>Methods:</b> This study included 5571 patients with coronary artery disease (CAD) undergoing PCI. Patients were categorized in groups according to the estimated glomerular filtration rate (eGFR) values: eGFR ≥ 90 mL/min/1.73 m², (normal kidney function), 60 to <90 mL/min/1.73 m² (mild kidney impairment), 30 to <60 mL/min/1.73 m² (mild-to-moderate and moderate-to-severe kidney impairment) and <30 mL/min/1.73 m² (severe kidney impairment). The primary endpoint was all-cause mortality at 10 years. <b>Results:</b> All-cause deaths occurred in 155 patients (86.3%) with eGFR < 30 mL/min/1.73 m², 602 patients (59.1%) with eGFR 30 to <60 mL/min/1.73 m², 775 patients (31.3%) with eGFR 60 to <90 mL/min/1.73 m² and 220 patients (15.8%) with eGFR ≥ 90 mL/min/1.73 m² (adjusted hazard ratio = 2.16, 95% confidence interval 1.84 to 2.54, <i>p</i> < 0.001, for 30 mL/min/1.73 m² decrement in the eGFR). There were CKD-by-age (Pint < 0.001) and CKD-by-clinical presentation (Pint = 0.017) interactions showing a stronger association of CKD with mortality in younger patients and those presenting with acute coronary syndromes. The C statistic of the multivariable model for mortality increased from 0.748 [0.737-0.759] to 0.766 [0.755-0.777] (<i>p</i> < 0.001) after the inclusion of eGFR in the model. <b>Conclusions:</b> In patients with CAD undergoing PCI, CKD was associated with higher mortality at 10 years compared with patients with preserved renal function. The association between CKD and mortality was stronger in patients of younger age and those presenting with acute coronary syndromes.