Background Estimated glomerular filtration rate (eGFR) predicts mortality and adverse cardiovascular events in people with chronic kidney disease. The significance of eGFR within the normal range and its long-term effect on clinical adverse events is unknown. We examined the effect of normal range or mildly reduced eGFR on long-term mortality in a large prospective registry. Methods The study included consecutive patients undergoing clinically-driven coronary angiography who had an eGFR ≥60 ml/min/1.73 m2. Baseline clinical characteristics were assessed, and patients were followed-up for the occurrence of all-cause mortality. Cox regression analysis was used to evaluate the impact of eGFR. Results A total of 4186 patients were recruited. Median follow-up time was 2883 days (7.9 years). Mean age was 62.0 ± 11.3 years with 77.4% males. Clinical presentation included acute coronary syndrome and stable angina. In a multivariable model adjusted for possible confounding factors, decreasing eGFR within the normal and mildly reduced range was inversely associated with long-term all-cause mortality with a hazard ratio (HR) of 1.32 for every decrease of 10 ml/min/1.732 in eGFR. Compared to eGFR > 100 ml/min/1.732, there was a graded association between lower eGFR values and increased long term mortality with a HR of 1.16 (0.59–2.31) for eGFR 90–100 ml/min/1.732, HR 1.54 (0.81–2.91) for eGFR 80–90 ml/min/1.732, HR 2.62 (1.41–4.85) for eGFR 70–80 ml/min/1.732 and HR 2.93 (1.58–5.41) for eGFR 60–70 ml/min/1.732. Conclusion eGFR within the normal and mildly reduced range is an independent predictor of long-term all-cause mortality in selected patients undergoing clinically driven coronary angiography.

Background: Transcatheter aortic valve replacement (TAVR), although associated with an increased risk for acute kidney injury (AKI), may also result in improvement in renal function. Objective: The aim of this study is to evaluate the magnitude of kidney function improvement (KFI) after TAVR and to assess its significance on long-term mortality. Design: This is a prospective single center study. Setting: The study was conducted in cardiology department, interventional unit, in a tertiary hospital. Patients: The cohort included 1321 patients who underwent TAVR. Measurements: Serum creatinine level was measured at baseline, before the procedure, and over the next 7 days or until discharge. Methods: Kidney function improvement was defined as the mirror image of AKI, a reduction in pre-procedural to post-procedural minimal creatinine of more than 0.3 mg/dL, or a ratio of post-procedural minimal creatinine to pre-procedural creatinine of less than 0.66, up to 7 days after the procedure. Patients were categorized and compared for clinical endpoints according to post-procedural renal function change into 3 groups: KFI, AKI, or preserved kidney function (PKF). The primary endpoint was long-term all-cause mortality. Results: The incidence of KFI was 5%. In 55 out of 66 patients patients, the improvement in kidney function was minor and of unclear clinical significance. Acute kidney injury occurred in 19.1%. Estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 was a predictor of KFI after multivariable analysis (odds ratio = 0.93 to develop KFI; confidence interval [95% CI]: 0.91-0.95, P < .001). Patients in the KFI group had a higher Society of Thoracic Surgery (STS) score than other groups. Mortality rate did not differ between KFI group and PKF group (43.9% in KFI group and 33.8% in PKF group) but was significantly higher in the AKI group (60.7%, P < .001). Limitations: The following are the limitations: heterozygous definitions of KFI within different studies and a single center study. Although data were collected prospectively, analysis plan was defined after data collection. Conclusions: Improvement in kidney function following TAVR was not a common phenomenon in our cohort and did not reduce overall mortality rate.