Baylor University Medical Center Proceedings October 2017 - 405

retention time. Talose and taurine were quantiﬁed by ToF-MS with linear standard curves with
a lower limit of quantitation of 0.5 nmoles. Urine
creatinine was determined by liquid chromatography mass spectrometry (11). Results were reported
for talose and taurine in mmoles/mole creatinine.
The intraday and interday coeﬃcients of variation for both compounds were <10% for high
control and <15% for normal control. Since no
labeled internal standard was available for sulfuric acid, the peak areas for the unique mass were
reported and the data are considered semiquantitative. Thioredoxin and HSP27 were measured
by commercially available enzyme-linked immunosorbent assays obtained from IBL International
(Hamburg, Germany) and Invitrogen (Camarillo,
CA), respectively.
Categorical variables were reported as proportions and continuous variables as mean ± standard
deviation or median (range), if skewed. Comparisons between TRA and TFA were conducted with
chi-square/Fisher's exact test for proportions and
Student's t test or the Wilcoxon rank sum test for
continuous variables. Utilizing paired parametric/
nonparametric tests, we compared the pre and post
values of the natural log-transformed metabolites.
We also explored whether the pre, post, and delta
(post - pre) measures of the urinary biomarkers
diﬀered between the TRA and TFA procedures.
With a cohort size of 60, we had 95% observed Figure 1. Urinary biomarkers pre and post procedure by subjects.
power to detect a true paired diﬀerence of 0.5 pre
used during the procedure (Table 2). We found that the values
and post procedure with an alpha of 0.05, two-sided test. Analyof HSP, taurine, and sulfuric acid did not signiﬁcantly change
ses were performed using STATA 14.2. This study was approved
following the procedure. Alternatively, the values of thioredoxin
by the Baylor Health Care System institutional review board
decreased and talose increased postprocedure (Figures 1 and 2).
with a waiver of consent. The study was funded by the Baylor
The urinary biomarker values did not diﬀer according to proHealth Care System Foundation.
cedural approach at any time examined. The only exception
was postprocedural thioredoxin, for which signiﬁcantly higher
RESULTS
levels were found in the TFA group. The rates of change of these
A total of 69 patients consented to be part of this study,
and 60 patients who completed the study were included in the
analysis. The demographics and baseline characteristics were
similar between the two groups (Table 1). The median preprocedural glucose level was higher among those patients with TFA
than TRA (P = 0.001). A larger proportion of TFA patients
than TRA patients were found to be admitted to the hospital
within 30 days of the procedure (P = 0.02). The median (range)
number of catheter exchanges was 3 (1-5) for both TRA and
TFA (P = 0.33). The ﬂuoroscopy time was found to be similar
between TRA and TFA. Heparin was used in 93% of the radial
procedures according to clinical practice guidelines.
The values of HSP27, thioredoxin, taurine, and sulfuric
acid diﬀered signiﬁcantly by gender. Further, diabetic patients
had higher levels of talose than did nondiabetics. The levels of
talose were higher in patients who had >3 catheter exchanges
during the procedure. The levels of sulfuric acid postprocedure
were negatively correlated with the total amount of contrast
Figure 2. Box plot of urinary biomarkers pre and post procedure.
October 2017

Metabolites and arterial access

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Table of Contents for the Digital Edition of Baylor University Medical Center Proceedings October 2017