Vasilios Liakopoulos

Ambulatory Pulse Wave Velocity Is a Stronger Predictor of Cardiovascular Events and All-Cause Mortality Than Office and Ambulatory Blood Pressure in Hemodialysis Patients.

Arterial stiffness and augmentation of aortic blood pressure (BP) measured in office are known cardiovascular risk factors in hemodialysis patients. This study examines the prognostic significance of ambulatory brachial BP, central BP, pulse wave velocity (PWV), and heart rate–adjusted augmentation index [AIx(75)] in this population. A total of 170 hemodialysis patients underwent 48-hour ambulatory monitoring with Mobil-O-Graph-NG during a standard interdialytic interval and followed-up for 28.1±11.2 months. The primary end point was a combination of all-cause death, nonfatal myocardial infarction, and nonfatal stroke. Secondary end points included: (1) all-cause mortality; (2) cardiovascular mortality; and (3) a combination of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, resuscitation after cardiac arrest, coronary revascularization, or hospitalization for heart failure. During follow-up, 37(21.8%) patients died and 46(27.1%) had cardiovascular events. Cumulative freedom from primary end point was similar for quartiles of predialysis-systolic BP (SBP), 48-hour peripheral-SBP, and central-SBP, but was progressively longer for increasing quartiles for 48-hour peripheral-diastolic BP and central-diastolic BP and shorter for increasing quartiles of 48-hour central pulse pressure (83.7%, 71.4%, 69.0%, 62.8% [log-rank P=0.024]), PWV (93.0%, 81.0%, 57.1%, 55.8% [log-rank P<0.001]), and AIx(75) (88.4%, 66.7%, 69.0%, 62.8% [log-rank P=0.014]). The hazard ratios for all-cause mortality, cardiovascular mortality, and the combined outcome were similar for quartiles of predialysis-SBP, 48-hour peripheral-SBP, and central-SBP, but were increasing with higher ambulatory PWV and AIx(75). In multivariate analysis, 48-hour PWV was the only vascular parameter independently associated with the primary end point (hazard ratios, 1.579; 95% confidence intervals, 1.187–2.102). Ambulatory PWV, AIx(75), and central pulse pressure are associated with increased risk of cardiovascular events and mortality, whereas office and ambulatory SBP are not. These findings further support that arterial stiffness is the prominent cardiovascular risk factor in hemodialysis.

PREVALENCE AND CONTROL OF HYPERTENSION WITH THE USE OF AMBULATORY BLOOD PRESSURE RECORDING IN HEMODIALYSIS PATIENTS

Objective: To date, there is no commonly accepted definition for hypertension in patients with chronic kidney disease undergoing hemodialysis. A recent expert consensus suggests hypertension in dialysis to be defined based on ambulatory blood pressure monitoring (ABPM). The aim of this study is to evaluate the prevalence and control of hypertension using ABPM in a large hemodialysis population according to the latest definitions. Design and method: A total of 160 hemodialysis patients underwent 48-hour ABPM, during a regular hemodialysis session and the subsequent interdialytic interval. Hypertension was defined as (i) pre-hemodialysis BPu200a>u200au200a=u200a140/90 mmHg or use of antihypertensive agents (ii) ambulatory BPu200a>u200au200a=u200a130/80 mmHg (over 44-hours or over the second 24hour period) or use of antihypertensive agents. Phenotypes of hypertension control were defined as: 1) concordant control (pre-hemodialysis BPu200a<u200a140/90 mmHg and ambulatory-BPu200a<u200a130/80 mmHg), 2) concordant lack of control (pre-hemodialysis BPu200a>u200au200a=u200a140/90 mmHg and ambulatory-BPu200a>u200au200a=u200a130/80 mmHg), 3) “white coat” phenomenon (pre-hemodialysis BPu200a>u200au200a=u200a140/90 mmHg and ambulatory-BPu200a<u200a130/80 mmHg) and 4) masked hypertension (pre-hemodialysis BPu200a<u200a140/90 mmHg and ambulatory-BPu200a>u200au200a=u200a130/80 mmHg). Results: Based on pre-hemodialysis BP levels, the prevalence of hypertension was 91.3% Based on the ABPM covering the total 44-hour or the 2nd 24-hour interdialytic period, the prevalence was 88.8%. The proportion of hypertensive patients receiving treatment was 124 (84,9%). With the use of pre-hemodialysis BP and ABPM during 44-hours, 12 (10.1%) of hypertensive patients had concordant BP control, 87 (58.8%) of patients had lack of control, 29 (19.6%) had a white-coat phenomenon, and 17 (11.5) masked hypertension, respectively. In multivariate logistic regression analysis, only use of antihypertensive agents was independently associated with increased odds for lack of control (reverse causation). Conclusions: Hypertension prevalence in hemodialysis patients is overwhelmingly high. The rates of control rates are different when calculated from office and ambulatory BP recordings. In the population studied, almost one out of three patients had white-coat or masked hypertension.

NEBIVOLOL AND IRBESARTAN REDUCE POST-HEMODIALYSIS AND AMBULATORY BP IN PATIENTS WITH INTRADIALYTIC HYPERTENSION: A RANDOMIZED CROSS-OVER STUDY

Objective: Blood pressure (BP) increase during or immediately after hemodialysis is an abnormal hemodynamic response to ultrafiltration and occurs in 5–20% of patients. Intradialytic hypertension is associated with adverse clinical outcomes and is often poorly diagnosed and controlled. This study aimed to evaluate the effects of nebivolol and irbesartan in 24hour ambulatory BP in hemodialysis patients with intradialytic hypertension. Design and method: This is a randomized cross-over study in 38 hemodialysis patients (age: 60.4u200a±u200a11.1 years, male: 65.8%) with intradialytic hypertension, defined as mean intradialytic rise >u200au200a=u200a10 mmHg in systolic BP (SBP) over 6 consecutive hemodialysis sessions. After baseline evaluation, patients were randomly assigned to nebivolol 5u200amg and subsequently irbesartan 150u200amg, or vice versa. Half of the patients received a single drug-dose 1 hour before hemodialysis (nu200a=u200a19) or for a whole week, before evaluation (nu200a=u200a19). A two-week wash-out period took place before the initiation of the second drug. All subjects underwent 24hour ambulatory BP monitoring starting before a midweek session. Results: In total, 20 (52.6%) patients received nebivolol first and 18 (47.4%) received irbesartan first. Patients receiving a single dose of either nebivolol or irbesartan had lower post-dialysis SBP and diastolic BP (DBP) [Baseline: 161.6u200a±u200a16.3/95.4u200a±u200a12.3; Nebivolol: 146.1u200a±u200a20.4 (pu200a=u200a0.003), 84.5u200a±u200a11.8 (pu200a<u200a0.001); Irbesartan: 144.7u200a±u200a29.9 (pu200a=u200a0.003), 86.8u200a±u200a18.0 (pu200a=u200a0.047) mmHg; respectively], non-significantly lower 24-hour SBP and lower DBP [Baseline: 147.8u200a±u200a16.0/87.7u200a±u200a11.9; Nebivolol: 144.0u200a±u200a19.5 (pu200a=u200a0.070), 83.3u200a±u200a11.7 (pu200a=u200a0.015); Irbesartan: 143.1u200a±u200a21.7 (pu200a=u200a0.171), 84.7u200a±u200a12.8 (pu200a=u200a0.095) mmHg]. Patients on weekly administration of either nebivolol or irbesartan had significantly lower post-dialysis SBP and DBP (Baseline: 167.1u200a±u200a13.6/99.8u200a±u200a10.6 Nebivolol: 145.2u200a±u200a16.6 (pu200a<u200a0.001), 91.0u200a±u200a11.8 (pu200a=u200a0.003); Irbesartan: 147.1u200a±u200a23.8 (pu200a=u200a0.002), 87.6u200a±u200a12.5 (pu200a=u200a0.001) mmHg), significantly lower 24-hour SBP and DBP (Baseline: 148.2u200a±u200a12.5/91.7u200a±u200a9.7 Nebivolol: 139.2u200a±u200a10.4 (pu200a<u200a0.001), 85.2u200a±u200a7.7 (pu200a=u200a0.001); Irbesartan: 142.9u200a±u200a15.7 (pu200a=u200a0.188), 85.5u200a±u200a9.9 (pu200a=u200a0.015) mmHg; accordingly) and significantly lower daytime and nighttime ambulatory SBP and DBP. No significant differences in BP reduction between nebivolol and irbesartan were observed. Conclusions: Both nebivolol and irbesartan reduce post-dialysis and 24-hour BP in patients with intradialytic hypertension. Weekly administration had greater effect and nebivolol seemed numerically slightly more potent than irbesartan; permanent administration of these agents may be more effective than pre-dialysis dosing.