The kidney–heart axis in chronic heart failure: insights into intrarenal hemodynamics

Abstract

Background. The renal resistance index (RRI) is a Doppler parameter used to assess renal perfusion, with proven prognostic value in heart failure. Recent studies show significant correlations between RRI and the severity of cardiac dysfunction, especially in heart failure with preserved ejection fraction. Objective(s). Assessment of the correlation between conventional echocardiographic changes and intrarenal hemodynamic parameters in patients with heart failure with preserved ejection fraction. Materials and methods. The study included 200 patients. Patients underwent transthoracic echocardiography with color and pulsed Doppler. Doppler ultrasound of the renal vessels was also performed, during which the following were determined: renal resistance index (RRI), renal pulsatility index (RPI), acceleration time (AT), renal volume (RV), and the RV/RRI ratio. Results. In the analysis of the interdependence of the left heart cavity dimensions with intrarenal hemodynamic parameters, a statistically significant positive correlation of reasonable strength was noted between the anteroposterior diameter of the LA and RRI (r = 0.436, p < 0.01) with RPI (r = 0.358, p < 0.01), and a negative correlation with the RV/RRI ratio (r = -0.208, p < 0.01). Similarly, a significant correlation was found between the volume of the LA and the indexed volume of the LA with RRI (r = 0.333, p < 0.01) and (r = 0.410, p < 0.01), respectively, and with RPI (r = 0.245, p < 0.01) and (r = 0.296, p < 0.01), respectively. Conclusion(s). Based on these findings, we can conclude that intrarenal hemodynamics have a strong and significant correlation with diastolic dysfunction in patients with heart failure. Furthermore, RRI may serve as a prognostic predictor in patients with heart failure with preserved ejection fraction.