Association of Changes in Vector Length with Changes in Left Ventricular Mass Among Patients on Maintenance Hemodialysis: A Secondary Analysis of the Frequent Hemodialysis Network Daily Trial

Enass Elsayed; Youssef M K Farag; Katherine Scovner Ravi; Glenn M Chertow; Finnian R Mc Causland

doi:10.34067/KID.0000000000000443

Association of Changes in Vector Length with Changes in Left Ventricular Mass Among Patients on Maintenance Hemodialysis: A Secondary Analysis of the Frequent Hemodialysis Network Daily Trial

Kidney360. 2024 Apr 24. doi: 10.34067/KID.0000000000000443. Online ahead of print.

Authors

Enass Elsayed^{1

2}, Youssef M K Farag^{3

4}, Katherine Scovner Ravi^{1

2}, Glenn M Chertow⁵, Finnian R Mc Causland^{1

2}

Affiliations

¹ Brigham and Women's Hospital, Boston, MA, USA.
² Harvard Medical School, Boston, MA, USA.
³ Bayer US, LLC.
⁴ Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
⁵ Departments of Medicine, Epidemiology and Population Health, and Health Policy, Stanford University School of Medicine, Stanford, CA, USA.

PMID: 38656312
DOI: 10.34067/KID.0000000000000443

Abstract

Background: Hypervolemia is thought to be a major contributor to higher left ventricular mass (LVM), a potent predictor for cardiovascular mortality among patients on maintenance hemodialysis. We hypothesized that a decrease in vector length (a bioimpedance proxy of hypervolemia) would be associated with an increase in LVM.

Methods: Using data from the Frequent Hemodialysis Network Daily Trial (n=160) we used linear regression to assess the association of changes in vector length from baseline to month 12 with changes in magnetic resonance imaging (MRI) measures of LVM and other cardiac parameters. We adjusted models for the randomized group, baseline vector length, age, sex, race, body mass index, vascular access, dialysis vintage, history of hypertension, heart failure, and diabetes, residual kidney function, pre-dialysis systolic blood pressure (BP), ultrafiltration rate, serum-dialysate sodium gradient, hemoglobin, phosphate, angiotensin-converting enzyme inhibitor or angiotensin receptor blocker use, erythropoietin dose, and equilibrated Kt/V.

Results: The mean age was 50 ±13 years; 35% were female. In the fully adjusted models, a decline in vector length (per 50 Ω/m; i.e., increase in volume) was associated with a 6.8 g (95%CI -0.1, 13.7) and 2.6 g/m2 (95%CI -1.2, 6.3) increase in LVM and LVM index, respectively; and an increase of 15.0 mL (95%CI 7.5, 22.4), 7.3 mL (95%CI 3.0, 12.7), 7.8 mL (95%CI 3.0, 12.7), and -0.9 % (95%CI -3.1, 1.3) in left ventricular (LV) end-diastolic volume (LVEDV), end-systolic volume (LVESV), stroke volume (LVSV), and ejection fraction (LVEF), respectively. The lowest tertile of change in vector length (i.e., greater increase in volume) was associated with greater increases in LVEDV and LVSV, versus the highest tertile. There was no evidence of heterogeneity by randomized group.

Conclusions: Change in vector length, a bioimpedance-derived proxy of volume status, was inversely associated with indices of left ventricular mass and volume measured by cardiac MRI in patients randomized to conventional or frequent hemodialysis over 12 months.

Abstract

Grants and funding