5 Trends in Cardiology to Watch
Harvard Health
Known as “the father of modern cardiology,” Harvard Medical School
Professor Dr. Eugene Braunwald shares his perspective on promising
future directions in the field.
By Julie Corliss, Executive Editor, Harvard Heart Letter
Reviewed by Christopher P. Cannon, MD, Editor in Chief, Harvard Heart Letter;
Editorial Advisory Board Member, Harvard Health Publishing
January 1, 2024
Longtime readers of the Heart Letter know that most of our stories focus on steps you
can take right now to improve your heart health. But once in a while, we look ahead at
what’s on the horizon in this dynamic field. We consulted Dr. Eugene Braunwald,
Distinguished Hersey Professor of Medicine at Harvard Medical School, where he has
worked since 1972. At age 94, he continues to work and publish, adding to the more
than 1,100 articles he has authored since the early 1950s. His pioneering research
helped elucidate how heart attacks happen, which ushered in new ways to treat and
prevent them.
Dr. Braunwald’s discoveries also advanced the understanding of hypertrophic
cardiomyopathy, valvular heart disease, and heart failure. (His life and research are
described in Eugene Braunwald and the Rise of Modern Medicine, written by
former Harvard Heart Letter editor in chief Dr. Thomas H. Lee.) The trends Dr.
Braunwald is most excited about, summarized below, may one day affect heart health
at every stage of life — from birth to old age.
1. Primordial prevention
Dr. Braunwald: The future of cardiology will focus on preventing heart disease very
early in life, a concept known as primordial prevention. Instead of waiting until people
develop risk factors such as high blood pressure, high cholesterol, or diabetes and
treating them, we will be able to identify and prevent the development of those
conditions in the first place.
Many of these conditions are caused not by a single gene
but by many genes. We now have specialized genetic tests to create polygenic risk
scores that help predict cardiovascular risk [see “Genetic profiling for heart disease: An
update” in the October 2023 Heart Letter]. In the future, these tests will become more
accurate and less expensive, so I foresee doing these tests in newborns.
For example, if a baby has genes linked to the development of high blood pressure by
age 30, you could modify that child’s diet to prevent the problem. Focusing on prevention
very early in life could make a huge difference in reducing cardiovascular disease, which
remains the most common cause of death in adults worldwide.
2. Targeting inflammation
Dr. Braunwald: For people who already have heart disease, medications that lower
blood pressure and cholesterol are an important part of avoiding future heart problems.
Until recently, however, there haven’t been any drugs to address inflammation, which
ignites the artery-damaging process that leads to a heart attack. But in June 2023, the
FDA approved the anti-inflammatory drug colchicine [Lodoco] for people who have or
are at high risk for heart disease. The drug, which has been used for many years to
treat gout, can lower the risk of heart attack and related problems by about 30%.
Investigators and the pharmaceutical industry are now looking very closely at this
category of medications. Going forward, I predict there will be a whole battery of new
anti-inflammatory drugs. It will be similar to the current situation with high blood
pressure, where we have many different drugs that doctors can use to treat this common
problem.
3. Cardiac cell therapy
Dr. Braunwald: A heart attack cuts off blood flow to part of the heart’s muscle, creating
damage that scars the heart. Over time, especially in people with repeat heart attacks,
this can impair the heart’s ability to function normally, leading to heart failure. For more
than two decades, scientists have tried to repair damaged hearts using cardiac cell
therapy, also known as stem cell therapy. The original concept was to infuse large
numbers of stem cells derived from bone marrow into the heart to regenerate heart
muscle cells.
While the initial results appeared promising, these cells aren’t incorporated
into the heart muscle, and they quickly disappear. Now, several other techniques are
being explored, including isolating the substances released from transplanted cells that
appear to be responsible for their benefits. By making these substances — which
include factors that encourage blood vessel growth — in the lab, we might be able to
provide “cell therapy without cells.” I’m also excited about the promise of pluripotent
stem cells, a discovery based on technology that was awarded the 2012 Nobel Prize in
Medicine and Physiology. These are cells that have been reprogrammed into their
embryonic state and can therefore be directed to generate any type of adult cells,
including heart muscle cells.
4. Transplanting pig hearts
Dr. Braunwald: Despite steady progress in heart transplantation, many hundreds of
people die each year waiting for a heart transplant [see “An advance in heart
transplantation” in the July 2020 Heart Letter]. Over the years, there have been a
number of successful interspecies transplants — known as xenotransplantation —
including in non-human primates.
In the past two years, two men with end-stage heart failure received transplants using genetically modified pig hearts.
[One survived for six weeks, the other for two months]. Pigs are a logical choice because their hearts are
similar in size to a human’s. In both cases, several genes in the donor pig were
inactivated and human genes were inserted into the pig’s genome to stop the recipient
from rejecting the new organ. These early studies have paved the way for further
advances in xenotransplantation.
5. Improved left ventricular assist devices
Dr. Braunwald: A left ventricular assist device, or LVAD, is a small pump implanted in
the chest to help a greatly weakened, failing heart deliver blood to the body. In addition
to becoming smaller, more powerful, and less expensive, LVADs will undergo other
improvements in the coming years.
Current devices use a driveline, a cable that passes through the skin to connect the pump to a battery and control system worn outside the
body. In the future, devices will be charged through the skin without requiring a driveline,
which is a common place for infections. Another potential advance is the use of
biocompatible materials in the pump, which means patients might not need to take anticlotting
drugs. People with advanced heart failure may receive an LVAD temporarily
while waiting for a heart transplant, or even instead of a transplant, in what we call “destination therapy.”