The prognostic value of the method for determining the estimated glomerular filtration rate in chronic heart failure with a preserved left ventricular ejection fraction: focus on cystatin C

The aim of the present study is to determine the prognostic value of GFR reduction according to the CKD-EPI formula, taking into account blood creatinine and a formula that simultaneously takes into account creatinine and cystatin C in patients who were hospitalized for the first time due to decompensation of chronic heart failure with a preserved left ventricular ejection fraction (HFSA) observation within 24 months. Materials and methods. The study included 117 patients (women – 65.8%, mean age 71.6 ± 9.1 years) hospitalized due to debugging of CHF and having a preserved left ventricular ejection fraction according to echocardiography. The study was a prospective observation for 2 years after the inclusion of each patient. On the first day of hospitalization, all serum samples were taken to determine the level of cystatin C. The estimated glomerular filtration rate (eGFR) was determined using the CKD-EPI formula, taking into account blood creatinine and the combined formula, including creatinine and cystatin C. The combination was used as an end point death and re-hospitalization within two years of follow-up. To determine the effect of a decrease in eGFR on the forecast, the Kaplan–Maer method and the log-rank test were used. Differences were considered statistically significant at p<0.05. The study was approved by the local ethics committee. Results. During the observation period, the mortality rate was almost 12%. At the same time, every third patient was repeatedly hospitalized within two years. In order to determine the effect of reducing GFR on reaching the end points, all patients were divided into groups with eGFR values of more or less than 45 ml/min/1.73 sq.m according to both formulas. When separating patients using the CKD-EPI formula, which includes only creatinine, the groups did not differ in terms of the frequency of reaching the combined end point, as well as its components: death and re-hospitalization. However, patients with eGFR values less than 45 ml/min/1.73 sq. M according to the combined formula data significantly more often reached the combined end point, mainly due to an increase in mortality. Conclusion. The data obtained suggest that adding cystatin C to the CKD-EPI formula and appropriately identifying patients with reduced eGFR has a high prognostic value for stratifying the risk of an unfavorable outcome after the first decompensation of HFSSFV.