For this study, the heart of control subjects and those with hypertension or hypertrophy will
be imaged using Hyperpolarized Pyruvate 13C Injection. Different forms of Hyperpolarized
Pyruvate 13C Injection are available, with the 13C labelling at different positions within
the molecule. These are equivalent from a safety perspective and covered by the same
Investigators Brochure, but offer different metabolic information. Two different labelling
patterns are investigated in this study. If images are successfully obtained, then insights
into heart failure treatments that normalize the detrimental metabolic changes may enable
earlier treatment and slow disease progression to CHF, ultimately reducing the high rates of
morbidity and mortality associated with this disease.
Prior to enrollment, all participants will be screened in order to ensure they meet the
study's inclusion and exclusion criteria and MRI eligibility. On the day of their scan, each
participant will have an intravenous line inserted and receive a glucose drink, prior to
scanning. The reason for this glucose drink is that a fed versus fasted state has been found
to give markedly different measurements in animal models and a choice of meal would be a
source of variability. The metabolic imaging will occur shortly after this drink.
For each scan, a 1.47 g sample of [1-13C]-pyruvic acid will be hyperpolarized using a SpinLab
polarizer (General Electric Co.). The solid-state sample will be dissolved to a concentration
of 250 mM pyruvate at biological pH. A 0.1 mmol/kg dose (approximately 20 mL) of this
solution will be injected through an intravenous line, followed by a 25 mL saline flush. The
13C image acquisition will begin at the end of the injection and will record data during
every heartbeat within the single breath-hold.
Heart rate and blood pressure will be monitored non-invasively, prior to the participant
being positioned within the MR scanner. Heart rate will continue to be monitored during and
after the scan and the participant will be monitored by the Study's Qualified Investigator or
medical designate for up to 1 hour post injection.
The 13C imaging will be preceded by the standard cardiovascular MRI workup including
breath-hold cine imaging to measure ejection fraction and LV mass (~30 minutes of scan time).
Each participant in group 2 will also receive an injection of gadolinium as part of their MRI
to determine evidence of late gadolinium enhancement. The recommended adult dose of 0.1ml/kg
will be given. Multi-slice T1 weighted gradient echo images will be acquired. Gadolinium will
be used to examine the metabolic profile in regions of scar and normal myocardium profile.
LGE imaging will be performed to identify regions of scar tissue or fibrosis.
All clinical procedures will be completed under the supervision of the Qualified
Investigator, or medical designate.
Each participant will receive a follow up telephone call on the 7th day following the
procedure to ascertain if any study related adverse events have occurred. The length of this
study for participants is a single visit that will require approximately 3 hours of their
time, except for participants in Groups 1C and 1F for whom the length for the study is two
visits separated by at least 2 weeks, each requiring 3 hours. The entire study is expected to
take about 3 years and the results should be known approximately six months after study
completion.