Baylor University Medical Center Proceedings October 2017 - 404

Urinary metabolites in patients undergoing coronary
catheterization via the radial versus femoral artery approach
Anupama Vasudevan, BDS, MPH, PhD, Jeffrey M. Schussler, MD, Jane I. Won, BS, Paula Ashcraft, BS, Ivy Bolanos, BS,
Matthew Williams, BS, Teodoro Bottiglieri, PhD, Carlos E. Velasco, MD, and Peter A. McCullough, MD, MPH

The transradial approach (TRA) for coronary angiography and percutaneous coronary intervention is associated with lower rates of vascular
complications and acute kidney injury when compared to the transfemoral approach (TFA). Urine metabolites and proteins may be useful
in identifying the dynamic changes at the vascular endothelial cell level.
We attempted to explore the changes in the measurable signals of endothelial and nephron injury within 60 to 90 minutes after catheterization
among those with the TRA and TFA approaches. Consecutive patients of
a single interventionist who underwent coronary angiography between
June 2015 and May 2016 were included. Of the 60 patients included
in the analysis, the baseline characteristics were similar between those
with a TRA (n = 30) and TFA (n = 30) approach. The values of the biomarkers were natural log transformed for the analysis. We found that
the mean values of heat shock protein 27, taurine, and sulfuric acid did
not significantly change after the procedure. However, the median value
of thioredoxin decreased (P = 0.002) and that of talose increased (P =
0.01) after the procedure. None of the patients in our cohort experienced
vascular complications or acute kidney injury. No differences in the values
of urinary metabolites (pre, post, and delta) were found between TRA and
TFA except for postprocedural thioredoxin. In conclusion, this exploratory
study showed no difference in the patterns of acute vascular/renal injury
metabolic markers before and after catheterization irrespective of the
arterial access site.

he adoption of the transradial approach (TRA) for coronary angiography and percutaneous coronary intervention (PCI) is growing (1) due to the emerging data on
its potential advantages over the traditional transfemoral
approach (TFA) (2, 3). It is also possible that TRA causes less
aortic trauma, reducing the risk of irreversible cholesterol microembolism to the kidneys, which is a silent contributor to acute
kidney injury (AKI), a serious but preventable complication of
cardiac catheterization procedures (4). It is increasingly recognized that endogenous molecules released by dying cells activate
cellular receptors leading to downstream inﬂammation (5), and
normal repair processes beneﬁt from dampening the immune
response to these endogenous danger molecules. Systematic
urinalysis has identiﬁed several metabolites and proteins that
are indicative of kidney injury. For example, altered urinary
levels of taurine, talose, sulfuric acid, heat shock protein 27
404

(HSP27), and thioredoxin have been associated with kidney
damage (6-8). In this study, we explored the changes in the
patterns of the metabolites within 60 to 90 minutes after catheterization and also determined whether the signals diﬀered
between TRA and TFA.
METHODS
This was a prospective observational study where consecutive patients of a single interventionist who underwent coronary
angiography by TRA or TFA between June 2015 and May 2016
were invited to participate. Demographic and clinical data were
collected for patients enrolled in the study. Two urine samples
were collected for these patients: one before the procedure and
one 60 to 90 minutes after the last contrast injection. Both were
processed for the metabolites and proteins of interest. As TRA
patients are released from the hospital the day of the procedure,
we focused on the early signaling patterns within very short
time frames after the procedure. AKI was deﬁned based on the
KDIGO criteria (9).
Talose, taurine, and sulfuric acid were identiﬁed in urine
samples using a method that involved trimethylsilyl derivatization and separation on a Leco Pegasus 4D two-dimensional
gas chromatography (GC×GC)-time of ﬂight mass spectrometry (ToF-MS) (6, 10). D4-Taurine and 13C5-Ribose internal
standards were added to 25 μL of the urine specimen and
were treated with urease to remove urea; protein precipitation was then performed with ethanol. After drying down,
the sample was derivatized to volatile trimethylsilyl for separation by capillary GC×GC with temperature programming
and modulation. Detection was performed by ToF-MS with
identiﬁcation of the compounds by their mass spectra and
From Baylor Heart and Vascular Institute, Dallas, Texas (Vasudevan, Schussler,
Won, Velasco, McCullough); Texas A&M Health Science Center College of
Medicine, Dallas Campus, Dallas Texas (Vasudevan, Schussler, McCullough);
Baylor Scott & White Research Institute, Dallas, Texas (Vasudevan, Won); Baylor
University Medical Center, Dallas, Texas (Schussler, Velasco, McCullough); and
Baylor Scott & White Research Institute of Metabolic Disease, Dallas, Texas
(Ashcraft, Bolanos, Williams, Bottiglieri).
Funded by the Baylor Health Care System Foundation, Dallas, Texas.
Corresponding author: Peter A. McCullough, MD, MPH, Baylor Heart and
Vascular Institute, 621 N. Hall Street, Suite H030, Dallas, TX 75226 (e-mail:
peteramccullough@gmail.com).
Proc (Bayl Univ Med Cent) 2017;30(4):404-409

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