Probing Dry-Weight Improves Left Ventricular Mass Index

Abstract

Background: Although probing dry-weight improves blood pressure control, its effect on echocardiographic left ventricular mass index (LVMI) is unknown. Methods: Shortly following dialysis, 292 echocardiograms in 150 patients participating in the DRIP trial were obtained at baseline and longitudinally every 4 weeks on 2 occasions. Results: At baseline, LVMI was 136.3 g/m² in the control group and 138.7 g/m² in the ultrafiltration group (p > 0.2 for difference). The change from baseline in LVMI in the control group was +3.5 g/m² at 4 weeks and +0.3 g/m² at 8 weeks (p > 0.2 for both changes). The change from baseline in LVMI in the ultrafiltration group was –7.4 g/m² at 4 weeks (p = 0.005) and –6.3 g/m² at 8 weeks (p = 0.045). With ultrafiltration, the change in LVMI diameter was –10.9 g/m² more compared to the control group at 4 weeks (p = 0.012) and –6.6 g/m² more compared to the control group at 8 weeks (p = 0.21). The reduction in interdialytic ambulatory blood pressure was also greater in response to probing dry-weight in those in the top half of LVMI at baseline (p = 0.02 for interaction effect at week 8). Conclusion: LVMI, an important determinant of prognosis among long-term dialysis patients, is responsive to probing dry-weight.

The interdialytic weight gain: a simple marker of left ventricular hypertrophy in children on chronic haemodialysis

“…While many definitions of 'dry weight' are used, it is essentially the lowest tolerated postdialysis weight (i.e. without symptomatic intradialytic hypotension) that allows the patient to maintain a normal interdialytic blood pressure, ideally without the use of antihypertensive medications [3,6]. Despite technological advances in intradialytic relative plasma volume monitoring [9,10] and bioimpedance analysis [11,12], the assessment of dry weight in children remains challenging [6].…”

“…Thus, physicians should be aware that a high blood pressure at the start of dialysis does not always imply extracellular overhydration and, therefore, cannot always be managed with increased ultrafiltration [12,14]. Lowering the extracellular volume to a normohydration or even underhydration status in order to optimize blood pressure control can be risky [3].…”

“…Multiple interventions have been shown to be effective in reducing LVH and, consequently, in reducing cardiovascular mortality, with a recent special interest in extracellular volume control to achieve euvolaemia [7,8,12,14,15]. To achieve euvolaemia many nephrologists prescribe high ultrafiltration rates [17], especially if the patient appears to tolerate it [3,8]. A patient's tolerance to a higher ultrafiltration rate depends on many factors, including maintaining normal haemoglobin levels, the use of bicarbonate dialysate buffe r, h i g h e r d i a l y s a t e s o d i u m c o n c e n t r a t i o n [ 5 ] , haemodiafiltration technology [18], ultrafiltration or sodium profiling, lowering dialysate temperature and on-line blood volume monitoring [9,10], and has dramatically improved over the last decades [6].…”

“…Nonetheless, even a well-tolerated high ultrafiltration rate, such as >1.24 % body weight loss per hour in adults, is associated with greater mortality [19]. Thus, although a relationship between IDWG and left ventricular mass index is shown by Paglialonga et al [1], the dialysis prescription used to reach the target dry weight should consider the risk of a high ultrafiltration rate, especially if tolerance is induced by a positive dialysate-to-plasma sodium gradient [3,8,13]. Clinical practice guidelines based on expert opinion have proposed limiting the ultrafiltration rate to 1.5 % of body weight loss per hour in children [6], but in the light of recent studies, simply targeting a dry weight at the expense of high ultrafiltration rates is also harmful.…”

“…Indeed, the authors demonstrate a significant correlation between IDWG and the left ventricular mass index, with those children with an IDWG of >4 % being at high risk of LVH. LVH has been associated with cardiovascular mortality in multiple paediatric and adult studies [2][3][4][5][6][7]. Here, we discuss the recent paradigm shift in the management of chronic dialysis patients, with a greater focus on volume control rather than a 'urea-centric' approach focussing on Kt/ Valone [8].…”