Prognostic impact of proteinuria in diabetic patients without chronic kidney disease undergoing percutaneous coronary intervention

Diabetes mellitus (DM) and chronic kidney disease (CKD) are well-established risk factors for adverse outcomes following percutaneous coronary intervention (PCI). However, the combined impact of DM and CKD on prognosis is underexplored, and the role of proteinuria, particularly in non-CKD patients, remains inadequately addressed. This study therefore evaluates the prognostic significance of DM and CKD in post-PCI patients, with a focus on the independent impact of proteinuria. We retrospectively analyzed 4,887 patients who underwent PCI between 2000 and 2018, categorizing them into four groups based on DM and CKD status. Cardiovascular mortality was assessed using Kaplan-Meier survival analysis and multivariate Cox proportional hazard analysis. The prognostic impact of proteinuria (≥ 0.3 g/gCr) was evaluated within each subgroup. Patients with both DM and CKD exhibited the highest cardiovascular mortality risk (hazard ratio [HR] 3.04, 95% confidence interval [CI] 1.82–5.05; p < 0.001). Proteinuria was an independent predictor of cardiovascular mortality, with the strongest association observed in diabetic patients without CKD (HR 6.7, 95% CI 2.7–16.8; p < 0.001). The coexistence of DM and CKD synergistically elevates cardiovascular mortality risk after PCI. Proteinuria, especially in diabetic patients without CKD, is a potent prognostic marker. Targeting proteinuria may offer a novel therapeutic approach to improve outcomes in this high-risk population.