Impact of Chronic Kidney Disease in Patients Undergoing Percutaneous Coronary Intervention: Improved but Not Solved

Chronic kidney disease (CKD) is an independent risk factor for the development of coronary artery disease, and for the progression to more severe coronary heart disease. 1) CKD is also associated with adverse outcomes in those with existing cardiovascular disease. he most frequent cause of CKD is diabetic nephropathy. Nearly 45% of incident renal failure is attributed to diabetes and another 20% is attributed to chronic hypertension. 3) Nowadays it is not uncommon for interventional cardiologists to encounter diabetic patients with associated CKD in proportion to increasing numbers of patients who need percutaneous coronary intervention (PCI). The large numbers of patients with CKD treated with PCI have been found to suffer from a markedly higher mortality of about 40% within 3-4 years after PCI. 4) Patients with diabetic nephropathy undergoing PCI have increased risk of contrast-induced nephropathy (CIN), an annoying problem not to be overlooked. There is a complicated relationship between CIN, comorbidity, and mortality. Abe et al. 5) reported that CIN was significantly correlated with long-term mortality in patients with CKD but not in those without CKD. During the last decade, there have been remarkable advancements in optimal medical therapy, interventional techniques and devices, which made it possible to reduce procedure-related complications in patients undergoing PCI. It was expected that these advancements would reduce the adverse effect of CKD on clinical outcomes. However, updated data sets reflecting these changes are rare. Significantly, the study performed by Kim et al. 6) provides the latest data regarding the impact of CKD for clinical outcomes in patients undergoing PCI.