Background and Aim: In hemodialysis patients, 24-hour s interdialytic ABPM better detects TOD than dialysis unit blood pressure. Therefore, the present study was aimed to assess the diagnostic performance of 24-hours ABPM vs . dialysis unit BPs for the diagnosis of ECG-LVH in steady state chronic hemodialysis black patients. Methods: From March 31 to September 30, 2018, interdialytic ABPM was performed after a mid-week hemodialysis session for 24 hours using a Spacelab 90207 ABPM monitor in the non-access arm in 45 stable chronic hemodialysis black patients (age ≥ 20 years, hemodialysis for at least 3 months and informed consent) attending 3 hemodialysis centers in Kinshasa. Ambulatory BP was recorded every 20 minutes during the day (6 AM to 10 PM) and every 30 minutes during the night (10 PM to 6 AM). ECG-LVH was defined using Cornell product criteria. ROC curve method was used to assess the performance of dialysis unit BPs vs . interdialytic 24-hours ABPM in diagnosing ECG-LVH. P < 0.05 defined the level of statistical significance. Results: Whatever the method of BP measurement, all the SBP values were related to ECG-LVH with similar AUC and overlapping 95% CI; however, they were not significantly different from each other. 24-hours interdialytic ambulatory SBP (AUC 0.748; 95% CI 0.58 - 0.94) had the highest area under the curve. Conclusion: The present study showed that although all the two BP measurement methods equally detected ECG-LVH, 24-hours ABPM tended to have the highest diagnostic performance.
Hypertension, a common clinical finding among patients with chronic kidney disease (CKD), often remains poorly controlled in maintenance hemodialysis (MHD) and is associated with an increased risk for cardiovascular (CV) events [
· Participants
From March 31 to September 30, 2018, patients 20 years or older who had been on maintenance hemodialysis (MHD) for more than 3 months and were dialyzed 2 or 3 times a week in three dialysis units in Kinshasa, DR Congo (University of Kinshasa Hospital, Ngaliema Medical Center and Medical Center of Kinshasa) were consecutively enrolled in a cross-sectional on the predictive value of dialysis unit BPs (predialysis, intradialysis and postdialysis BPs) and interdialytic 24-hours ambulatory BP monitoring (ABPM) for the diagnosis of electrocardiographic-left ventricular hypertrophy (ECG-LVH). Inclusion criteria were age ≥ 20 years, regular hemodialysis for at least 3 months and informed consent. Patients with chronic atrial fibrillation (AF) or body mass index (BMI) ≥ 40 Kg/m2 were excluded. Patient’s medical records were used to collect data on past medical history, sociodemographic (age, gender, profession, marital status, financial support), dialysis (type of vascular access, type of dialysis, current month’s mean interdialytic weight gain and KT/V, number of sessions per week, dialysate sodium profile) and biological parameters (last month’s blood urea nitrogen, serum creatinine, serum albumin, total and ionized calcium, phosphorous) as well as current treatment. The study was approved by the Ethical Committee of Kinshasa School of Public Health and all patients gave written informed consent.
· Measurements
Peridialysis (pre- and postdialysis BPs) BP measurement was obtained by trained dialysis unit staff using a validated automated sphygmomanometer OMRON MIT5 Connect with patients at a sitting position, within 30 minutes prior to and following the dialysis session on the non-fistula arm or the non-dominant arm for patients using catheters. Three readings 1 to 3 minutes apart were recorded after the patient had been resting in a quiet room for at least 5 minutes; the average of the two last readings was used as the standard BP value for the present study. Intradialysis BP recordings were obtained by the dialysis unit staff using the sphygmomanometer equipped with hemodialysis machines without a specified technique. All BP recordings were averaged over two weeks surrounding the ambulatory BP measurement. Thus, depending on the number of session a weak (2 or 3 sessions a week), each patient had 4 or 6 predialysis, postdialysis BP recordings, respectively, to provide routine dialysis unit.
Interdialysis 24-hours ambulatory BP measurement (ABPM) was performed after a mid-week hemodialysis session for 24 hours using a GIMA ABPM PULSE RATE monitor (Gima Spa, Milano, Italia) in the non-access arm. Ambulatory BP was recorded every 20 minutes during the day (6 AM to 10 PM) and every 30 minutes during the night (10 PM to 6 AM). Patients were instructed to keep their arm immobile during measurement and follow their daily activity. Awake and sleep readings were calculated for each patient by self-reported sleep and wake times by means of a diary. Patients with <70% recording were excluded for the analysis.
· Outcome
Resting ECG records lasting less than 3 months were retrieved from patients’ medical files whereas it was performed in patients with ECG records lasting more than 3 months. Left ventricular mass (LVM) was estimated using Cornell product index; ECG-LVH was defined LMV > 2.440 mm.sec [
· Statistical analyses
Baseline characteristics were summarized as mean (standard deviation) or median (interquartile range) for continuous variables and as absolute (n) and relative (in %) frequencies for categorical variables. The comparison of means of dialysis unit BP and 24-hours ABP was performed using one way analysis of variance (ANOVA). Receiver operating characteristic (ROC) analysis was conducted for evaluating the predictive performance (Area Under the Curve, AUC) of 24-hours ABP vs dialysis unit BP and for the diagnosis of ECG-LVH. P value < 0.05 defined the level of statistical significance.
· General and hemodialysis characteristics of the study population
Of the 62 patients eligible for the study, 17 of them were excluded [non-consent: 2, dialysis arrest: 1, hemodynamic instability: 5, death during the study: 4, travel abroad: 3 and non-valid ABP recordings (arrhythmia: 1, intolerance: 1)]. Finally, 45 patients (31 men and 14 women) constituted the sample population of the present study (
Hemodialysis parameters of the study population are depicted in
· Dialysis unit and interdialytic 24-h ambulatory BP measurements
· Dialysis unit BPs vs. 24-h ABPM for the diagnosis of ECG-LVH
Variables | All (n = 45) |
---|---|
Age, years | 59.1 ± 12.3 |
Gender, n (%) | |
M | 31 (68.8) |
F | 14 (31.2) |
Initial Kidney disease, n (%) | |
Hypertension | 25 (55.6) |
Diabetes | 13 (28.9) |
CGN | 8 (17.8) |
Others | 4 (8.9) |
BMI, Kg/m2 | 24.4 ± 3.9 |
Hypertension, n (%) | 44 (97.8) |
DHT, years | 12.1 ± 3.1 |
Antihypertensive drugs, n (%) | |
CCB | 39 (86.7) |
Diuretic | 29 (64.4) |
ACEIs | 14 (31.8) |
Betablockers | 12 (26.6) |
ARBs | 9 (20.0) |
Others | 9 (20.0) |
ECG-LVH, n (%) | 11 (24.4) |
Hemoglobin, g/dL | 11.1 ± 1.9 |
Hematocrit, % | 33.2 ± 5.9 |
BUN, mg/dL | 111.4 ± 46.5 |
Creatinine, mg/dL | 9.2 ± 3.6 |
Albumin, g/dL | 36.8 ± 13.9 |
Sodium, mmol/L | 128.9 ± 29.6 |
Potassium, mmol/L | 5.4 ± 1.6 |
Calcium, mmol/L | 2.13 ± 0.31 |
Data are expressed as mean ± standard deviation, absolute (n) and relative (in percent) frequencies. Abbreviations: M, male F, female CGN, chronic glomerulonephritis BMI, body mass index DHT, duration of hypertension CCB, calcium channel blocker ACEIs, angiotensin converting enzyme inhibitors ARBs, angiotensin type 1 receptor blockers ECG-LVH, electrocardiographic-left ventricular hypertrophy BUN, blood urea nitrogen.
Variables | All (n = 45) |
---|---|
Type, n (%) | |
HD | 6 (13.3) |
HDF | 22 (48.9) |
HD/HDF | 17 (37.8) |
Dialysis duration, mo | 34.3 ± 10.8 |
Vascular access, n (%) | |
Catheter | 28 (62.2) |
AVF | 17 (37.8) |
KT/V | 1.2 ± 0.2 |
IDWG, Kg | 1.9 ± 0.4 |
RD, mL/day | 338.8 ± 36.6 |
>500 | 6 (20.7) |
200 - 400 | 12 (41.4) |
<200 | 11 (37.9) |
EPO, n (%) | 45 (100) |
EPO dosing, IU/Kg/week | 11,187.8 ± 2450.5 |
IV iron therapy, n (%) | 41 (91.1) |
IV Iron dosing, mg/week | 130.6 ± 46.7 |
Financial support, n (%) | |
Patient/family | 8 (17.8) |
Private and public entreprises | 35 (77.8) |
Government | 2 (4.4) |
Data are expressed as mean ± standard deviation, absolute (n) and relative (in percent) frequencies. Abbreviations: HD, hemodialysis HDF, hemodiafiltration AVF, arteriovenous fistulae KT/V, dialysis efficacy EPO, erythropoietin IU, international unit IV intravenous.
Variable | PreHD | PostHD | IntraHD | 24 h-ABPM | p |
---|---|---|---|---|---|
SBP, mmHg | 152.3 ± 19.4 | 149.2 ± 18.6 | 153.4 ± 22.0 | 141.1 ± 17.8 | 0.014 |
DBP, mmHg | 88.5 ± 13.6 | 86.5 ± 10.9 | 95.1 ± 10.4 | 82.1 ± 12.5 | 0.705 |
PP, mmHg | 63.8 ± 11.9 | 62.7 ± 14.5 | 58.3 ± 11.0 | 59.0 ± 11.8 | 0.957 |
MAP, mmHg | 109.8 ± 14.7 | 107.4 ± 12.1 | 114.5 ± 16.0 | 101.8 ± 13.4 | 0.405 |
Data are expressed as mean ± standard deviation Abbreviations: PreHD, prehemodialysis PostHD, Posthemodialysis IntrHD, intrahemodialysis SBP, systolic blood pressure DBP, diastolic blood pressure PP, pulse pressure MAP, mean arterial blood pressure.
the highest area under the curve followed by IntraHD (AUC 0.715; 95% CI 0.58 - 0.94), PreHD (AUC 0.708; 95% CI 0.53 - 0.88) and PostHD (AUC 0.685; 95% CI 0.51 - 0.85) SBPs, respectively.
The main findings of the present study are as follows. First, average levels of 24-h interdialytic ambulatory BP levels were lower compared with those obtained with dialysis unit measurements. Second, whatever the BP measurement method, all SBP predicted equally ECG-LVH without significant difference from each other; 24-h interdialytic ambulatory SBP had the highest area under the curve followed by intradialytic SBP.
24-h interdialytic ambulatory BP levels were in average lower than that obtained by dialysis unit BP measurements. This finding is consistent with that of Argawal et al. [
Whatever the BP measurement method used, all SBP equally predicted ECG-LVH with 24-h interdialytic ambulatory SBP having the highest AUC. Consistent with our finding, Agarwal et al. [
Intradialytic BP had the second highest area under the curve for diagnosing ECG-LVH in the present study. Another way to improve diagnostic accuracy of peridialysis BP measurements is to consider intradialytic BP recordings obtained via an automatic cuff attached to the HD machine [
The interpretation of the results of the present study should take into account some limitations. First, the cross-sectional nature of the study precludes the establishment of any temporal relationship between the variables of interest. Second, the relatively small study sample size did not allow much power to statistical tests to detect potential association between the variables of interest. Third, single peridialytic BP and 24-h ambulatory BP measurements could have led to under- or overestimation of average BP levels. Fourth, electrocardiogram a less sensitive method was used to assess left ventricular mass and left ventricular hypertrophy.
Although all BP measurement methods equally diagnosed ECG-LVH among the present case series, 24-h interdialytic ambulatory BP measurement had the highest diagnostic performance compared to dialysis unit BP measurements.
The authors gratefully thank the medical staff of all the participating ICUs (Professor Dr. Jean Robert Rissassi Makulo, Head of University of Kinshasa Hospital; Prof Dr. Eleuthère Vita Kintoki, Head of the Division of Cardiology/University of Kinshasa Hospital; Dr. Nyakabasa, Head of Ngaliema Medical Center; Dr. Rodolph, Head of Kinshasa Medical Center, Dr. Justine Busangu Bukabau, Head Medical Staff of Kinshasa Medical Center) for their outstanding help during the conduct of the present study. The authors would like also to express their deepest gratitude to all the participants who facilitate by their informed consent the implementation of the present study.
CKI collected data, participated in data analysis and reviewed the manuscript.
FBBL conceived the study, participated in data analysis and drafted the manuscript.
YL participated in data collection and reviewed the manuscript.
TM participated in data collection and reviewed the manuscript.
NU participated in data collection and reviewed the manuscript
AN conducted statistical analysis of data and reviewed the manuscript.
VMM reviewed the manuscript.
EKS participated in statistical analysis of data and reviewed the manuscript.
NMN reviewed the manuscript.
EVK reviewed the manuscript.
The authors declare no conflicts of interest regarding the publication of this paper.
Ilunga, C.K., Lepira, F.B.B., Makulo, J.R.R., Lubenga, Y., Mvunzi, T., Utshudi, N., Nkodila, A., Mokoli, V.M., Sumaili, E.K., Nseka, N.M. and Kintoki, E.V. (2019) Interdialytic 24-Hours Ambulatory Blood Pressure versus Dialysis Unit Blood Pressure for the Diagnosis of Electrocardiographic-Left Ventricular Hypertrophy in Chronic Hemodialysis Black Patients. World Journal of Cardiovascular Diseases, 9, 846-856. https://doi.org/10.4236/wjcd.2019.911075