Features of renal blood flow indicators in patients with chronic heart failure depending on the degree of renal dysfunction

Cardiovascular comorbidity involving chronic heart failure (CHF) and renal dysfunction (RD) represents a major clinical problem due to its high prevalence and association with increased mortality and adverse outcomes. Impaired myocardial contractility in CHF leads to reduced renal perfusion, activation of neurohormonal mechanisms, and progressive deterioration of renal function, thereby aggravating the course of heart failure. Assessment of renal hemodynamics may provide additional prognostic and pathophysiological insights into cardiorenal interactions.

Purpose: To investigate renal blood flow parameters in patients with CHF depending on the severity of renal dysfunction.

Materials and Methods: The study included 205 patients with CHF classified according to the New York Heart Association (NYHA): class I (n=59), class II (n=91), and class III (n=55). The mean age was 60.5±7.16 years. Renal function was assessed by estimating glomerular filtration rate (eGFR) using the CKD-EPI formula based on serum creatinine levels. Patients were divided into two groups according to eGFR (>60 ml/min and ≤60 ml/min). Doppler ultrasonography of the right and left renal arteries was performed to determine peak systolic velocity (Vs), end-diastolic velocity (Vd), mean velocity (Vmean), pulsatility index (PI), and resistive index (RI).

Results: Progressive deterioration of renal hemodynamics was observed with increasing functional class of CHF. In patients with class I CHF, significant reductions in Vmean (by 41.9% and 36.5%) and Vd (by 22.4% and 3.1%) were noted compared with controls, along with increased PI and RI values (p<0.001). In class II CHF, more pronounced decreases in Vmean (55.9% and 57.2%), Vd (35.3% and 18.7%), and Vs (16.8% and 14.6%) were observed (p<0.001), accompanied by further increases in PI and RI. In class III CHF, renal blood flow impairment was even more severe, with Vmean reduced by up to 60.6% and Vd by 36.1% (p<0.001). Renal dysfunction (eGFR ≤60 ml/min) was independently associated with significantly reduced Vs (by 15.4% and 17.8%), Vd (by 17.1% and 18.3%), and increased RI (by 12.9% and 13.4%) and PI (by 9.9% and 11.1%) compared with patients with preserved renal function (p<0.05–0.01).

Conclusions: In patients with CHF, renal blood flow parameters progressively worsen with increasing functional class and declining eGFR. Doppler-derived renal hemodynamic indices (PI, RI, Vs, Vd, Vmean) may serve as important markers of cardiorenal interaction severity and could be considered in risk stratification of patients with cardiovascular comorbidity

Dr. Gulnoza Zakirova is a cardiologist and leading scientific researcher specializing in chronic heart failure and cardiorenal interactions. She holds a Doctor of Medical Sciences (DSc) degree. She works at the Republican Specialized Scientific Practical Medical Center of Therapy and Medical Rehabilitation and at Tashkent State Medical University, Uzbekistan. Her research focuses on the clinical, humoral, and genetic mechanisms of endothelial dysfunction in patients with chronic heart failure and renal dysfunction. Dr. Zakirova is the author of numerous scientific publications and actively participates in international scientific conferences in cardiovascular medicine.