The aim of the study was to improve the quality of prediction of cardiovascular events in patients with chronic kidney disease and hypertension based on the evaluation of additional markers of risk for cardiovascular disease, daily profile of blood pressure depending on the level of aldosterone.
Patients with chronic kidney disease (CKD) have a higher risk of death, comparing to the general population. Only 1-2% of patients with CKD survive to end-stage renal disease and to the beginning of renal replacement therapy, the majority of the patients with CKD die from cardiovascular disease at earlier stages. The presented dissertation describes an investigation of the risk of cardiovascular events in the patients with CKD and hypertension, investigation of the effectiveness of risk assessment based on the evaluation of coronary artery calcification index (CACS), condition of carotid arteries (CA) and serum aldosterone levels.
At the first stage (retrospective study) the analysis of data of 574 patients who received medical care in SE "Dnipropetrovsk Regional Clinical Hospital named after I.I. Mechnikov" was carried out. At this stage of the study were revealed a high prevalence of hypertension among patients with CKD (69.8%), its early onset (43,0 [30,2; 58,0] years) and its unsatisfactory level of control (<33,8%). In the majority of the patients with hypertension (71,4%) coronary artery calcification was detected (CACS >0 Agatston units (AU)), in 31,8% of the patients CACS >100 AU was detected. The frequency of CACS >100 AU in the male patients with hypertension was 40,2%, and changed slightly in the groups by GFR. The highest frequency of CACS >100 AU and atherosclerotic changes in CA were detected in the patients with GFR 30-59 ml/min.
Therefore, at the second stage (cross-sectional study) 57 patients with CKD stages I-II with hypertension were examined. At this stage, we studied the association of aldosterone levels with the daily profile of BP, arterial stiffness (AS), the state of the carotid and coronary arteries, and the global risk of cardiovascular events. The level of aldosterone in patients with CKD stages I-II with hypertension ranged within normal limits (≤90 pg/ml). Elevated aldosterone levels were observed in 10 (18,5%) patients. In the group of patients with CKD and hypertension and aldosterone ≥90 pg/ml, there was a tendency to higher AS according to estimated pulse wave velocity (ePWV).
In the group of the patients with hypertension and CKD and aldosterone ≥90 pg/ml CACS >100 AU was found more frequently (5 (55,6%) patients vs 9 (20,9%) patients, p=0,03). There were no significant differences in the state of CA and the structure of the global risk of cardiovascular events depending on the level of aldosterone. In most patients with CKD stages I-II and hypertension was detected a moderate risk of cardiovascular events according to SCORE chart (61,4%), and abnormalities of coronary (61,8%) and carotid (70,0%) arteries.
Significant predictors of high/very-high risk by SCORE were ePWV, mean daily, daytime, nighttime systolic BP, and the percentage of its reduction at night. Significant predictors of CACS >100 AU were age, aldosterone level, stenosis of CA, and morning systolic BP rise. When the age, aldosterone and stenosis of CA were included the model showed the best discriminating ability (AUC – 0,88 (0,76-1,00)). Significant predictors of CACS >0 AU were age, BMI and ePWV, AUC for age – 0,77 (0,64 - 0,90).
The novelty of the study and of the results. The understanding of the atherosclerotic impairment of carotid and coronary arteries in patients with hypertension and reduced renal function has been improved. Groups of patients who will benefit from CACS determination have been proposed. For the first time the potential of aldosterone levels in the prediction of CACS in patients with CKD was assessed. For the first time was stated that elevated aldosterone level is associated with a frequency of CACS >100 AU, but not with a frequency of carotid plaque.
The practical significance of the results. The presented work is an applied research. According to its results, the assessment of proteinuria before initiation of antihypertensive therapy in patients with CKD with hypertension is needed. Groups of patients with CKD and hypertension were proposed, who have a high risk of cardiovascular events and who will benefit from the additional investigation. The role of age, serum aldosterone and carotid artery condition for the prediction of CACS >0 AU and CACS >100 AU in patients with CKD and hypertension was demonstrated.
Key words: chronic kidney disease, arterial hypertension, cardiovascular risk, coronary artery calcification index, carotid artery ultrasound, daily profile of pressure, aldosterone.
