Circulation August 20, 2019 Issue

Dr Carolyn
Lam:               
Welcome to Circulation on the Run, your weekly podcast summary
and backstage pass to the journal and its editors. I'm Dr Carolyn
Lam, associate editor from the National Heart Center and Duke
National University of Singapore.


Dr Gregory Hundley:       And I'm
Greg Hundley, associate editor from the Pauley Heart Center at
VCU Health in Richmond, Virginia.


                                               
Well, Carolyn, this week's feature is from Professor Carl
Lindstrom from Helsinki University Hospital and the University of
Helsinki and evaluates whether administration of simvastatin via
nasogastric tube in brain-dead individuals prior to cardiac
transplant donation improves transplant recipient cardiac-related
outcomes. It is a randomized trial using an inexpensive therapy,
and I look forward to that discussion with Professor Lindstrom.
How about we grab a cup of coffee and start off our discussion
today.


Dr Carolyn
Lam:               
All right, so here goes. The first paper that I want to discuss
really looks at the question, is DNA methylation related to
incident coronary heart disease? Well, Dr Agha from Columbia
University in New York and colleagues looked at this and profiled
epigenome-wide blood leukocyte DNA methylation in 11,461
individuals from nine population-based cohorts in the United
States and Europe using the Illumina Infinium 450K microarray and
prospectively ascertained coronary heart disease events.


Dr Gregory Hundley:       So
Carolyn, what did they find?


Dr Carolyn
Lam:               
Well, they found that differences in blood leukocyte DNA
methylation at 52 cytosine phosphate guanine sites were
associated with incident coronary heart disease or myocardial
infarction with a false discovery rate of less than 0.05. Several
of the differentially methylated loci mapped to genes related to
calcium regulation and kidney function. Exploratory analyses with
Mendelian randomization supported a causal effect of DNA
methylation on incident coronary heart disease at loci in active
regulatory regions with links to noncoding, RNAs and genes
involved in cellular and tissue structural components.


                                               
Very nice Caroline. So what's the summary for us clinically?


Dr Gregory Hundley:       So, these
findings really provide the first evidence that genomic
regulation via epigenetic modifications in kidney function and
calcium homeostasis related pathways may be involved in the
development of coronary heart disease. The findings of
epigenetic, loci related non-coding RNAs highlight pathways that
have not immersed in genome-wide studies of coronary heart
disease and therefore represent novel therapeutic targets, which
thus far have not been explored.


Dr Carolyn
Lam:               
Very good, Caroline. Well, I've got a basic paper that I want to
present and it's from professor Xander Wehrens from the Baylor
College of Medicine. And this study addresses factors that
promote atrial fibrillation. The investigators found that reduced
levels of protein phosphatase-1 regulatory subunit R3A in human
atria are causally linked to abnormal calcium handling and atrial
fibrillation pathogenesis.


                                               
In the absence of protein phosphatase-1 regulatory subunit R3A
reducing binding of PP1 catalytic subunit increases
phosphorylation levels of the ryanodine receptor, R2 calcium
release channel, and phospholamban. Complex zone, profiling, a
technique that combines native gel electrophoresis with mass
spectrometry to obtain the composition of multi protein
assemblies revealed that PP1 R3A is part of a macro molecular
protein complex containing the ryanodine calcium release channel
and the circuit 2APLN calcium uptake transporter.


Dr Gregory Hundley:       Wow.
Complex zone profiling. That's so cool, but what does it all mean
for us clinically, Greg?


Dr Carolyn
Lam:               
Well reduced levels of PP1 regulatory subunit contribute to
abnormal calcium release and re-uptake and atrial monocytes,
thereby promoting atrial fibrillation pathogenesis. And thus
normalizing levels of PP1R3A phosphatase sub unit may represent a
novel therapeutic approach to manage atrial fibrillation.


Dr Gregory Hundley:       That's so
cool. I next have a preclinical paper which contributes really to
the understanding of molecular basis of pathological myocardial
remodeling in heart failure. And this is from co-corresponding
authors, doctors, Jung, Liu, and Lin-Jung from Shanghai East
Hospital Tongji University School of Medicine in China. And the
paper really focused on Forkhead box transcription factor P1 or
Foxp1 in endothelial cells.


Dr Carolyn
Lam:               
So Foxp1 Carolyn, tell me a little bit more about that.


Dr Gregory Hundley:       Is it
good that you asked before I asked you. Forkhead box proteins P
or Foxp are large modular transcription repressors that bind to
DNA via their highly conserved Forkhead DNA binding domains. Fox
p1 is highly expressed in vascular endothelial cells and it's
essential for normal cardiac development.


                                               
So, these authors found significantly down regulated Fox P1
expression in cardiac endothelial cells during cardiac remodeling
induced by to angiotensin 2. Endothelial cell Fox P1 loss of
function resulted in cardiac dysfunction following angiotensin 2
infusion and in the transverse aortic constriction model with
severe cardiac fibrosis and mild adaptive cardiac hypertrophy.


                                               
Whereas endothelial cell Foxp1 gain of function protected against
pathological cardiac remodeling and improved cardiac dysfunction
transforming growth factor beta 1 signals were identified as
Foxp1 direct target genes in endothelial cells which mediated the
pathological cardiac fibrosis through cardiac fibroblasts
proliferation and myofibroblast formation and maladaptive cardiac
hypertrophy through TGF beta 1 promoted endothelial one
expression during pathological cardiac remodeling.


Dr Carolyn
Lam:               
Wow. Carolyn, this was very sophisticated work. What do we take
away from it clinically?


Dr Gregory Hundley:       These
data really identified endothelial Foxp1 mediated TGF beta 1
signal pathway involvement in the promotion of cardiac fibrosis
and cardiac hypertrophy via TGF beta 1 induction of the
endothelin one pathway. So targeted delivery of TGF beta 1
silencing RNA or small interfering RNA to inhibit endothelial
cell specific TGF beta 1 for the improvement of pathological
cardiac remodeling may actually represent a future novel
therapeutic strategy in managing this maladaptive cardiac
fibrosis and hypertrophy during progression of heart failure.


Dr Carolyn
Lam:               
That was an excellent summary of a very technical but informative
basic science paper. I'm going to shift gears a little bit and
talk a little bit about a study relating to clopidogrel and
aspirin from the point study.


                                               
This study comes from Claiborne Johnston at the Dell Medical
School and University of Texas. And in patients with acute minor
ischemic stroke or high risk transient ischemic attack enrolled
in the point trial. The combination of clopidogrel and aspirin
for 90 days reduced major ischemic events but increased major
hemorrhage compared to aspirin alone. This current paper is a
secondary analysis of Point and involves 4,881 subjects in which
the investigators assess the time course for benefit and risk
from the combination of clopidogrel and aspirin.


                                               
The primary efficacy outcome was a composite of ischemic stroke,
myocardial infarction or ischemic vascular death, and the primary
safety outcome was major hemorrhage. Risks and benefits were
estimated for delayed times of treatment initiation using left
truncated models.


Dr Gregory Hundley:       So, what
did the study show Greg?


Dr Carolyn
Lam:               
Well through 90 days, the rate of major ischemic events was
initially high, then decreased markedly while the rate of major
hemorrhage remained low but stayed constant throughout the study.
Using a model based approach the optimal change point for major
ischemic events was 21 days with a hazard ratio of 0.65 for
clopidogrel aspirin versus aspirin at a P value of 0.0015
compared to later at 22 to 90 days. Where that hazard ratio was
1.38 and the P value only 0.24.


                                               
And the models showed benefits of clopidogrel aspirin for
treatment delayed as long as three days after symptom onset. So
Carolyn, the authors conclude that the benefit of clopidogrel
aspirin occurs predominantly within the first 21 days and
outweighs the low but ongoing risk of major hemorrhage. When
considered with the results of the CHANCE study, a similar trial
treating with clopidogrel aspirin for 21 days and showing no
increase in major hemorrhage. The combined results suggest
limiting clopidogrel aspirin use to 21 days may maximize benefit
and reduce risk after TIA or minor ischemic stroke. Very
practical paper.


Dr Gregory Hundley:       Indeed.
Thanks Greg. That was nice.


Dr Carolyn
Lam:               
You bet.


Dr Gregory Hundley:       Welcome
everyone to our podcast and we're very pleased today to have Dr
Antti Nykänen from Helsinki University in Finland as well as an
associate editor, Justin Ezekowitz from Edmonton, Canada to
discuss a very interesting randomized clinical trial related to
the administration of simvastatin in those that are donors for
heart transplantation and looking at subsequent outcomes in the
patients that received the transplants. Antti, we're very excited
for you to bring this to circulation. This particular paper and I
wonder if you might outline for us what were your hypotheses that
you are trying to test and what was your overall study design.


Dr Antti Nykänen:
          
These things are routinely admitted to heart transplant
recipients starting one to two days after transplantation. As
previous clinical studies show that recipient that treatment has
beneficial long-term effects on mortality and cardiac allograft
vasculopathy. So in this clinical study, we basically tried to
answer the question whether having the statin effect on the board
even earlier before the transplant procurement by giving statins
to the organ donor, if that would protect the transplanted
hearts.


                                               
And this question was based potential rapid vascular and
cardioprotective effects of statin and when our previous
experimental study showing that treating the organ donor with
statins will decreases vascular profusion injury in a heart
transplant model. So basically we went on the test donor
simvastatin clinically and randomize brain dead heart transplant
donors either to a control group or to receive a signal 80
milligram dose of simvastatin before organ procurement.


Dr Gregory Hundley:       I'm
imagining that you would administer the simvastatin through
either an intravenous mechanism or perhaps an NG tube, something
like that. Maybe tell us a little bit about how you accomplish
this and then what were your study results?


Dr Antti Nykänen:
           So,
the simvastatin was administered to the donor via a nasogastric
tube so there is no intravenous simvastatin formulation
available. It needs to be absorbed and then activated through the
liver so that can form. So, what we did in our previous
experimental study was that we included a few clinical human
brain-dead donors and basically investigated whether by giving
simvastatin through the nasogastric tube would be metabolized and
if you could detect that in in the donor plasma.


                                               
And that was actually the case. So in a few hours we saw
up-regulated levels of simvastatin and also the active form in
the donor or so basically showing off that treatment in a
clinical brain dead donor of situation would be feasible. So we
went on to use that method, clinical study and basically our
primary outcome was plasma levels of cardiac injury biomarkers
after transplantation.


                                               
And interestingly by treating the donor with simvastatin
decreased and recipients for troponin INT levels six hours after
transplant's profusion. Therefore, it seems that organ donor’s
statin treatment reduces biomarkers of myocardial injury after
transplantation in a clinical setting.


Dr Gregory Hundley:       And did
you examine any other functional measures of these patients? For
example, ejection fraction by echo or anything, or was it
primarily a biomarker study? That's the first question. Second
question. Do you have any other information on other organs that
also may have been donated? Would the statin have impacted, for
example, liver transplantation?


Dr Antti Nykänen:
          
That's a good question. So we did follow up cardiac function and
the routine and serial measurements with the echocardiographic
and we did not find any changes in the left ventricle. It took
some traction after transplantation.


                                               
We did however find the decrease in proBNP levels into
recipients. And that was maybe then at one week after
transplantation and then it's leveled out after that.


                                               
And then regarding the next question about other transplanted
organs. So once he was in a multi organ donor situation, so the
same donor could have donated kidneys or livers, lungs, pancreas.
So we did a follow up of the close recipients also. And I can say
that there was no adverse effects, no decline in the survival or
primary function of the transplanted organs. And interestingly we
did find in the liver recipient that if the recipient received
the liver from a donor simvastatin treated the liver function
tests were better at day seven post-transplant.


Dr Gregory Hundley:       Very
interesting. And then lastly, just another outcome related
question. Sometimes I know these patients undergo assessments for
rejection by biopsy. Any information that you can share with us
on outcomes related to biopsies.


Dr Antti Nykänen:
           We
took routine biopsies, myocardial biopsies from the recipients
and we did not find any significant differences in the biopsy
program rejections either at 30 days or one year after
transplantation. We did also monitor, we checked some treatments,
so during the first 30 days there was significant decrease in the
amount of rejection treatments for hemodynamically rejects it
about not for the first year.


Dr Carolyn
Lam:               
Wow. Just fabulous results. Thank you so much Antti. So Justin, I
wanted to turn the conversation over toward you. Tell us about
post-transplant management of these patients and then how do you
see these study results integrating into our current standards of
care.


Dr Justin Ezekowitz:       
Thanks Greg and Dr Nykänen and thanks for also letting us look at
your work, which is terrific and extremely hard to do from the
translation of your original 2011 circulation publication in
animals and moving forward into the current publication years
later. And thinking forward into the next few years of how we
translate this into practice so that the current management after
transplantation obviously involve multiple anti-rejection
medications and many activities around detecting rejection is one
of the key ways in which patients are managed other than their
hemodynamics and other things that happen early.


                                               
What I was interested in is the generation of the idea where the
simvastatin will really affect the clinical outcomes on the
recipient and thinking that into the practice environment is,
it's a very simple intervention to think about that would be
easily applicable in, I think, most hospitals that do
transplantation as either the recipient or the donor.


                                               
And Dr Nykänen, when you think about translating this into
practice over either Europe or in Finland, I don't sense that
this is going to be very difficult. Statins are well tolerated.
The cardiology and other communities are very familiar with using
a statin. But do you anticipate any barriers to translating this
into practice as I think the guidelines may pick this up as
something of interest.


Dr Antti Nykänen:
           Yes,
I think we can show that it's feasible and we did a result on the
biomarkers, so indicating that the damage the heart undergoes
during the transplantation was smaller after donor statin
treatment, so it is feasible, it's very cheap and it generally
has a good safety profile. The timeframe for the treatment also
feeds into the window of creating a brain dead organ donor. So in
that sense it would be applicable in a donor treatment situation.


Dr Justin Ezekowitz:       
Right. And so I think this is the key point is even though it's a
smaller trial in terms of the cardiology thinks about its trials.
This is an area that doesn't have a lot of clinical trials were
randomized clinical trials and so any evidence of benefit with a
known, generally considered safe medication such as a statin, you
would think that we should be able to broadly apply pretty
quickly even on what are often not hard outcomes that are softer
outcomes.


                                               
Because the benefit to risk ratio is generally favorable here. Dr
Nykänen, my only other question to you is to think about the team
getting this done must have been incredibly hard, but do you
think there is a need for a larger trial to test this hypothesis
on clinical outcomes or do you think this is really as far as you
can go in the transplant world for an RCT.


Dr Antti Nykänen:
           So,
it's been a long road from artery to single center clinical
trial, which took time, so the patient numbers are fairly small
in our study. We had 42 in the control group on 42 in the
treatment group. I agree the risk benefit ratio is probably
beneficial. But for sure it would be very nice to see larger
studies that would look at the biomarker effects, but also would
look at the other clinical end points.


Dr Justin Ezekowitz:       
Right, and that's a great point. It's only 84 patients, but a
continued study of the area's important while perhaps
implementation studies could go on to take what you found in both
an animal translation into humans in a single center RCT and now
translation into a larger population of recipients and their
donors. I think that's probably the key next step in the
transplantation world which has a tougher time getting larger
number of patients into clinical trials for a variety of reasons.


                                               
So, congratulations to you and your team in getting this one to
the point where we could probably apply this in a reasonable way
with reasonable safety and an expected benefit to a broader group
of patients.


Dr Gregory Hundley:       Well this
has been a fascinating discussion, Antti as well as Justin and
what a relatively simple, clever idea that could have profound
outcomes for this transplant population. We certainly want to
thank you Antti for bringing this to circulation and sharing it
with our readership. Are there any few last words you'd like to
share with us before we close today?


Dr Antti Nykänen:
           Very
nice to see how things evolve after this. We will for sure try to
look more closely at the mechanisms and follow up the patient
population for a long term follow up. And I hope this will
stimulate some other experiments in the field.


Dr Gregory Hundley:       Justin,
any parting comments from the editorial team?


Dr Justin Ezekowitz:       
This is a great example of a full clinical trial that is
mechanistic, but also has MR outcomes, and I just want to
congratulate the authors on providing a very full picture of all
the pieces that it takes to do in a clinical trial environment.
Plus also collecting genetic and other biomarker material and
imaging material. So, my compliments to the authors both to
yourself, Dr Nykänen, but also the team that you assembled over
the last six or eight years of doing this project, which we know
was a huge task and my congratulations to you and your team.


Dr Gregory Hundley:       We want
to thank Dr Nykänen and his team from Finland and Justin
Ezekowitz. We look forward to chatting with you next week.


Dr Carolyn
Lam:               
This program is copyright American Heart Association, 2019