Left Ventricle Systolic Function Assessment in Hypertensive Nephropathy Patients

Objective: To investigate left ventricular systolic function in chronic kidney disease (CKD) patients Design and method: We examined 36 untreated non-diabetic essential hypertensive patients with II and III stage of hypertensive CKD and 15 essential hypertensive subjects. Echocardiography and ambulatory blood pressure monitoring was performed for all patients. Glomerular filtration rate (GFR) assessed by CKD-EPI formula. Patients underwent echocardiography with determination of left ventricular (LV) systolic function with conventional echocardiographic methods: left ventricular ejection fraction (LVEF), Mitral annular plane systolic excursion (MAPSE), Mitral annular systolic velocity, Left-ventricular myocardial performance index (MPI). Global longitudinal strain (GLS) of LV obtained by speckle-tracking. NT-proBNP level was evaluated for all patients. Results: CKD patients and essential hypertensive subjects had no significant difference between LV systolic function values evaluated with LVEF. At the same time we observed significantly lower values of MAPSE, Mitral annular systolic velocity and higher LV MPI in CKD patients, p<0,05 in all cases. Highly significant GLS decline was observed in CKD patients comparing to essential hypertensive subjects (p<0,01). Patients with CKD had higher NT-proBNP blood level, p<0,05. In univariate correlation analysis GFR was more closely related to LV GLS (r=0,537, p<0,01) rather than Mitral annular systolic velocity (r=0,355, p <0,05), MAPSE and LV MPI (r=0,350, p<0,05 and r=0,325, p<0,05 respectively). NT-proBNP was higher in CKD patients comparing to essential hypertensive patients, p<0,05. Among all conventional echocardiographic measures of LV systolic function, LV global longitudinal strain demonstrated the strongest association with NT-proBNP (r=0,572, p<0,01). Conclusions: Hypertensive nephropathy patients have early impairment of LV systolic function detected by significantly higher LV MPI, lower Mitral annular systolic velocity as well as MAPSE and highly significant GLS decline comparing to essential hypertensive subjects. There was more significant relationship between GFR and LV GLS rather than Mitral annular systolic velocity, MAPSE and LV MPI. LV GLS showed the strongest relationship with NT-proBNP compared with other echocardiographic indices of LV systolic function, indicating that GLS is the most sensitive echocardiographic marker of myocardial wall stress in hypertensive nephropathy patients.