Venous impedance index and its relation with renal outcomes in patients with heart failure and renal dysfunction

Background. The prevalence of chronic kidney disease (CKD) is increasing every year, which increases the risk of cardiovascular disease and even death. In Cardiorenal syndrome type 2 (CRS2), chronic cardiac dysfunction causes renal dysfunction. The aim of this study was to evaluate Doppler ultrasound of renal veins, calculate venous impedance index (VII) and determine their associations with the prognosis of CRS2 syndrome in patients with a history of chronic heart disease and CKD with a good forward function. Methods. In this descriptive-analytical study, 49 patients referred to Imam Reza Hospital in Tabriz with heart failure and renal dysfunction were selected. Renal status, VII and ejection fraction (EF) were evaluated. Results. Mean age of the patients was 61.83±12.39 years, 42.9% of which were women and 57.1% were men. The durations of heart and renal failure were 33.16 ± 13.8 and 11.76±5.1 months, respectively. Significant associations were found between VII and EF of the right and left kidneys (P=0.01 and P =0.03, respectively). But there was no statistically significant relationship between renal function and EF (P =0.54). With increasing edema rate, both VII and EF were decreased; however, these associations were not statistically significant (P >0.05). Conclusion. According to the results, significant associations were found between VII and EF of right and left kidneys, however, no statistically significant correlations were observed between edema and VII mean and EF.