Serum creatinine ratio: A novel predictor of mortality after percutaneous coronary intervention in patients with normal and abnormal renal function

Abstract

The occurrence of contrast induced nephropathy (CIN) is associated with increased mortality after percutaneous revascularization procedures. However, the exact correlation between various levels of creatinine elevation relative to the baseline and subsequent mortality in patients with chronic renal insufficiency (CRI) is not well established. In addition, the relationship between elevated postprocedural creatinine and ensuing mortality in patients with normal baseline renal function needs to be investigated. Methods: All percutaneous coronary intervention (PCI) patients (n = 12,997) were analyzed for any rise in serum creatinine (SCr): CRI group (BSC ≥ 1.5 mg/dl) (n = 1,853) and normal baseline renal function (NBR BSC < 1.5 mg/dl) group (n = 11,144). Patients in each group were analyzed for any elevation in SCr postprocedure and subdivided based on the SCr ratio [peak SCr/Baseline creatinine (BSC)] of 1.5. The overall incidence of CIN (defined as an increment of 25% over baseline creatinine) was 5.9%: 11.3% in the CRI group versus 5.1% in normal BSC group (P < 0.01). Recursive partitioning and Cox hazard modeling were used to assess significant variables associated with mortality within 1 year. Only serum creatinine ratio (SCrR) > 1.5 correlated with increased mortality in both CRI group as well as normal BSC group. Conclusions: SCrR > 1.5 predicts mortality at 1 year after PCI. The association between SCrR > 1.5 and increased mortality at follow-up is observed in patients with CRI as well as normal baseline renal function. SCrR may thus serve as a useful clinical tool for risk stratification and prognostication of patients after PCI.