Association Between Vascular Access Creation and Deceleration of Estimated Glomerular Filtration Rate Decline in Late-Stage Chronic Kidney Disease Patients Transitioning to End-Stage Renal Disease

Keiichi Sumida; Miklos Z. Molnar; Praveen K. Potukuchi; Fridtjof Thomas; Jun Ling Lu; Vanessa A. Ravel; Melissa Soohoo; Connie M. Rhee; Elani Streja; Kunihiro Yamagata; Kamyar Kalantar-Zadeh; Csaba P. Kovesdy

Disclosures

Nephrol Dial Transplant. 2017;32(8):1330-1337. 

In This Article

Results

Patients' baseline characteristics at the time of dialysis initiation are presented in Table 1. Among 3026 patients with an AVF/AVG, the mean ± standard deviation age was 67.0 ± 10.8 years, 97.9% were male, 35.2% were African-American and 74.8% were diabetic. Of the patients with an AVF/AVG, 2147 (71%) had a mature AVF/AVG at the time of dialysis initiation, among whom there was a lower prevalence of diabetes mellitus and congestive heart failure versus those with a non-mature AVF/AVG (Supplementary data, Table S2). Compared with patients without an AVF/AVG (n = 3514), those with an AVF/AVG were more likely to be married and had a lower prevalence of cardiovascular disease, congestive heart failure, liver disease and malignancy. They were also more likely to use vitamin D analogs, phosphate binders and erythropoietin stimulating agents (ESAs); were less likely to use ACEIs/ARBs, aspirin, anti-platelet agents other than aspirin, and warfarin; had higher serum albumin, urea nitrogen and creatinine levels; and had lower serum cholesterol and pre-dialysis eGFR levels.

Before the AVF/AVG creation [median (IQR) 1.4 (0.5, 2.6) years] and during the interval between the AVF/AVG creation and dialysis initiation [median (IQR) 0.5 (0.2, 1.2) years], there were a median (IQR) of 20 (12, 29) and 7 (4, 12) serum creatinine measurements per patient, respectively. In patients without an AVF/AVG, there were a median (IQR) of 18 (11, 28) and 5 (4, 7) serum creatinine measurements before [median (IQR) 1.7 (0.7, 2.9) years] and after [median (IQR) 0.5 (0.5, 0.5) years] the 6-month index date prior to dialysis, respectively.

Figure 2 shows the predicted slopes of eGFR in multilevel mixed-effects models pre- and post-AVF/AVG creation in patients with an AVF/AVG, paralleled with those without an AVF/AVG. In unadjusted models, the eGFR decline accelerated in patients without an AVF/AVG [median (IQR), −6.0 (−10.2, −3.3) versus −16.3 (−26.2, −9.5) mL/min/1.73 m2/year (P < 0.001) preceding and following the 6-month index date prior to dialysis initiation, respectively], while a significant deceleration of eGFR decline was seen after the AVF/AVG creation in those with an AVF/AVG [median (IQR), −5.6 (−8.8, −3.4) versus −4.1 (−4.8, −3.2) mL/min/1.73 m2/year (P < 0.001) before and after AVF/AVG creation, respectively] (Figure 2A). After adjustment for confounders, the estimated median (IQR) eGFR slopes before and after the 6-month index date in patients without an AVF/AVG were −20.6 (−23.5, −17.9) and −58.8 (−68.1, −51.6) mL/min/1.73 m2/year (P < 0.001), respectively, whereas the estimated median (IQR) eGFR slopes before and after AVF/AVG creation in those with an AVF/AVG were −18.1 (−20.6, −15.9) and −8.3 (−8.8, −7.5) mL/min/1.73 m2/year (P < 0.001), respectively (Figure 2B). These associations were similarly observed independent of AVF/AVG maturation status (Figure 3) and access type (Supplementary data, Figure S1) and in all examined subgroups (Figure 4), as well as in the propensity-matched cohort (Supplementary data, Table S3 and Figure S2).

Figure 2.

eGFR slopes (median, IQR) before and after AVF/AVG creation in patients with AVF/AVG, in contrast to non-AVF/AVG patients. Slopes were estimated from unadjusted (A) and multivariable-adjusted (B) mixed-effects models. Models were adjusted for fixed (age, sex, race, diabetes mellitus and Charlson comorbidity index) and time-dependent confounders (systolic BP and ACEIs/ARBs use). *P < 0.001. eGFR, estimated glomerular filtration rate; IQR, interquartile range; AVF, arteriovenous fistula; AVG, arteriovenous graft; BP, blood pressure; ACEIs, angiotensin-converting enzyme inhibitors; ARBs, angiotensin receptor blockers.

Figure 3.

eGFR slopes (median, IQR) before and after AVF/AVG creation in patients categorized by AVF/AVG maturation status. Slopes were estimated from unadjusted (A) and multivariable-adjusted (B) mixed-effects models. Models were adjusted for fixed (age, sex, race, diabetes mellitus and Charlson comorbidity index) and time-dependent confounders (systolic BP and ACEIs/ARBs use). *P < 0.001. eGFR, estimated glomerular filtration rate; IQR, interquartile range; AVF, arteriovenous fistula; AVG, arteriovenous graft; BP, blood pressure; ACEIs, angiotensin-converting enzyme inhibitors; ARBs, angiotensin receptor blockers.

Figure 4.

eGFR slopes (median, IQR) before and after AVF/AVG creation in selected subgroups in patients with AVF/AVG, in contrast to non-AVF/AVG patients. Slopes were estimated from unadjusted mixed-effects models. *P < 0.001. eGFR, estimated glomerular filtration rate; IQR, interquartile range; AVF, arteriovenous fistula; AVG, arteriovenous graft; BMI, body mass index; DM, diabetes mellitus; CVD, cardiovascular disease.

Figure S1.

eGFR slopes (median, IQR) before and after AVF/AVG creation in patients categorized by access type. Slopes were estimated from unadjusted (A) and multivariable-adjusted (B) mixed-effects models. Models were adjusted for fixed (age, sex, race, diabetes mellitus, and Charlson comorbidity index) and time-dependent confounders (systolic BP and ACEIs/ARBs use). *P <0.001
Abbreviations: eGFR, estimated glomerular filtration rate; IQR, interquartile range; AVF, arterio-venous fistula; AVG, arterio-venous graft; BP, blood pressure; ACEIs, angiotensin-converting enzyme inhibitors; ARBs, angiotensin receptor blockers

Figure S2.

eGFR slopes (median, IQR) before and after AVF/AVG creation in patients with AVF/AVG, in contrast with non-AVF/AVG patients in a propensity-matched cohort. Slopes were estimated from unadjusted mixed-effects models. *P <0.001
Abbreviations: eGFR, estimated glomerular filtration rate; IQR, interquartile range; AVF, arterio-venous fistula; AVG, arterio-venous graft

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