The impact of normal range estimated glomerular filtration rate on mortality in selected patients undergoing coronary angiography - A long-term follow-up

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/1.73²in 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/1.73²and 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.