Anesthesia and Vascular Access After final review of protocol eligibility and of MRI
safety, vascular access is obtained and sheaths are secured and covered with a sterile
drape for transfer to the MRI. The catheterization is performed with continuous recording
of electrocardiogram signals, transcutaneous hemoglobin ("pulse") oximetry, and under
direct observation of an anesthesia licensed independent provider.
Diagnostic Cardiac MRI Before MRI catheterization begins, a focused cardiac MRI is
performed to understand cardiac function and localize the proposed catheter trajectory
from the access site into the targeted cardiovascular chambers.
MRI-guided catheterization Next during real-time MRI, a passive catheter is advanced from
the access site into the targeted cardiovascular chambers under imaging guidance.
Hemodynamic measurements (using fluid-filled transducers connected to the catheters) and
blood hemoglobin saturation specimens are obtained from targeted cardiovascular chambers.
Additional clinically-indicated and, if time allows, up to 30 minutes of research MRI is
then performed before the subject is returned to the X-ray system.
Research MR Imaging Additional research cardiac MRI imaging to determine T1 and T2 values
is undertaken next, with 6 short axis slices and one long axis slice positions identified
for T1 map and T2 map acquisitions. The ICMR laboratory has a robust experience with
acquisition of parametric mapping sequences. T1 and T2 maps will provide a roadmap for
the cardiac biopsy that the patient requires in the xray suite.
Image Fusion to Guide Endomyocardial Biopsy At the conclusion of the MR imaging and
MR-guided right heart catheterization procedure, the subject is returned to the X-ray
suite for cardiac biopsy. Some cardiac biopsies are obtained in the usual fashion, and
some biopsy specimens are obtained using image overlay software to display the regions of
abnormal T1 and T2 onto the fluoroscopy system.
Conclusion of the procedure Following standard of care EMB, standard of care coronary
angiography is obtained when if clinically indicated, all catheters and sheaths are
removed and the subject is observed for complications in the cardiac procedure recovery
unit or intensive care unit for at least 6 hours.
Diagnostic Echocardiogram Standard clinical data with strain analysis will be collected
from the echocardiogram that is performed as a standard of care. Patients undergo a
clinically indicated echocardiogram exam following the catheterization procedure in the
Cardiac Post Recovery Unit (CPRU).
Blood Tests Serum for creatinine blood test will be collected at the time the clinically
indicated IV is placed. Creatinine Is the standard test used at Children's National to
assess kidney function. A total of 1cc of blood will be drawn to complete the test.
For subjects who consent to the optional study, an additional 5cc of blood work will be
drawn at the time that the intravascular catheter is inserted for the clinically
indicated cardiac catheterization procedure. The blood samples will be identified with
the study ID number only, and will be stored in a secure freezer owned and maintained by
the department of cardiology located at the Sheikh Zayed campus. This blood will be used
to identify serum biomarkers, and to validate the potential use for diagnostic purposes.
Follow-up procedures At the conclusion of the procedure, the subject is returned to the
X-ray table and all catheters are removed. The subject is observed for complications in
an advanced nursing recovery unit or intensive care unit for at least 6 hours. The
subject will be assessed for early and late complications at the time of discharge, and
again approximately 2-6 weeks ± 7 days post procedure.
MRI Image Analysis In all cardiomyopathy and heart transplant patients, T1 measurements
will be performed using offline analysis software according to our laboratory's
measurement SOP for parametric maps. In heart transplant patients only, T2 measurements
will be performed according to our laboratory's measurement SOP for parametric maps.
Following measurements, images will be created for Image Overlay onto the fluoroscopy for
patients undergoing clinically-indicated cardiac biopsy following the catheterization.
Biopsy Sample Analysis All biopsy samples will be evaluated clinically for evidence of
cellular rejection, and a clinical report will be generated per clinical standard of
care. In addition, each of the samples will undergo a separate staining procedure to
identify regions of fibrosis. Digital images will be taken of the stained samples. Image
processing software will be used to quantify percent fibrosis.
Historical Controls (for radiation exposure comparison, and biopsy yield comparison) Age
and diagnosis-matched historical controls will be identified from the last 10 years at
Children's National as a control population for specific purposes of comparing (1) EMB
yield without image overlay and (2) Radiation exposure during X-ray guided right heart
catheterization. Identical information will be obtained and stored in the same 45CFR
compliant database. Historical controls will be identified from the cardiac
catheterization database by searching for age and diagnosis. A waiver of consent will be
applicable here, as it would be inconvenient, insensitive and not feasible to consent
families who have already undergone treatment.
Subjects will not be provided additional information as a result of this research study.
Data will be reviewed in aggregate generating generalizable knowledge not applicable to
an individual subject
