Heart transplants

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Heart transplants

• Steff Chavez Human Physiology

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What is a heart transplant?

• An operation in which a diseased, failing heart
  is replaced with a healthier donor heart. (One
  must have heart failure)
• It is a last resortpreformed when other
  treatments and operations have failed to improve
  a patients condition sufficiently.
• A persons chance of survival is good if
  appropriate follow-up care is received.

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Heart failure
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Heart failure (congestive heart failure)

• Heart cannot meet the bodys demand for bloodit
  cannot pump enough blood to meet your bodys
  needs.
• Does not mean the heart is about to stop
  beatingrefers to the failure to pump
  sufficiently
• Caused by various conditions that, over time,
  result in a heart that cannot pump or fill
  efficiently because it is too weak or stiff.
• Can be treated with medicationscan provide
  symptom relief and help extend life.
• Lifestyle changes (exercise, reducing salt in
  diet, managing stress, treating depression,
  losing weight) can improve the quality of life of
  someone with heart failure.
• To prevent heart failure it is important to
  control risk factors coronary artery disease,
  high blood pressure, high cholesterol, diabetes,
  and obesity.

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Types of heart failure

• Left-sided heart failure
• Most common
• Fluid can backup into lungs
• Right-sided hart failure
• Fluid can backup in abdomen, legs, and feet
  (causes swelling)
• Can occur with left-sided heart failure
• Systolic heart failure
• Left ventricle cannot contract properly
• Pumping problem
• Diastolic heart failure
• Left ventricle cannot relax or fill properly
• Filling problem

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Most common conditions that can lead to heart
failure a transplant

• Coronary artery disease (most common)
• Cardiomyopathy
• Valvular heart disease
• Congenital heart defect
• Myocardial infarction (heart attack)
• High blood pressure
• Myocarditis (inflammation of heart muscle)
• Cardiac arrhythmias
• Pulmonary hypertension (high blood pressure in
  lungs vessels)
• Alcoholism or drug abuse
• Anemia (low red blood cell count)
• Previously failed heart transplant
• Other diseases diabetes, hyperthyroidism,
  hypothyroidism, emphysema, lupus, hemochromatosis
  (buildup of iron), amyloidosis (buildup of
  protein), and sarcoidosos (buildup of
  inflammatory cells) can contribute
• Acute causes viruses that attack the heart
  muscle, severe infections, blood clots, allergic
  reactions, certain medications
• In children
• Congenital heart defect
• Cardiomyopathy

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Symptoms of heart failure

• Shortness of breath (especially when exerting
  oneself and laying down)
• Fatigue
• Weakness
• Swelling of ankles, feet, and legs
• Rapid/irregular heartbeat
• Decreased ability to exercise
• Coughing and wheezing (sometimes with bloody
  phlegm)
• Abdomen swelling
• Sudden weight gain (from retention of fluids)
• Lack of appetite
• Nausea
• Difficulty concentrating
• Reduced alertness

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Complications of heart failure

• Kidney damage/failure
• Blood flow to kidneys can be reduced
• Heart valve damage
• Damage from blood and fluid buildup
• Liver damage
• Fluid buildup can put too much pressure on the
  liver
• Fluid buildup can lead to scarring on liver
• Heart attack and stroke
• Increased risk

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How to diagnose heart failure

• Blood tests
• Chest X-rays
• ECG (Electrocardiogram)
• Records hearts electrical activity
• Echocardiogram (most important)
• Distinguish between types of heart failure
• Assess how well (or not well) the heart is
  pumping
• Measures the ejection fraction percentage of
  blood pumped out of the left ventricle
• Healthy ejection fraction 50 (more than half
  the blood that fills the left ventricle is pumped
  out of the chamber with each beat)
• Stress test
• Cardiac CT or MRI (computerized tomography or
  magnetic resonance imaging)
• Angiogram (coronary catheterization)
• Helps identify narrowed arteries
• Can help assess strength of left ventricle as
  well as health of heart valves with a
  ventriculogram

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Medications for heart failure

• Ace inhibitors (Angiotensin-converting enzyme)
• Vasodilator (widens vessels)
• Helps lower blood pressure, improve blood flow,
  decrease hearts work
• Angiotensin II receptor blockers
• Digoxin (digitalis)
• Increases strength of muscle contractions in
  heart
• Can slow heartbeat
• Beta blockers
• Slow heart rate
• Lowers blood pressure
• Limit or reverse some heart damage
• Diuretics
• Make you pee a lot
• Expelling fluid from body so fluid buildup is
  decreased (especially in lungs)
• Aldosterone antagonists
• Diuretic
• Help reverse heart scarring which can lengthen
  lifespan

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Surgeries for heart failure

• Coronary bypass surgery
• Valve repair/replacement
• ICD (implantable cardioverter-defibrillator)
• Like a pacemaker
• Monitors rhythm
• Helps shock heart back to normal rhythm
• Can speed heartbeat up if too slow
• CRT (cardiac resynchronization therapy)
• Type of pacemaker that sends timed biventricular
  electrical impulses
• LVAD (left ventricular assist device)
• Help weakened hart pump
• Used as an alternative to heart transplant for
  those who cannot have a transplant
• Used for those waiting for heart transplant
• Heart transplant

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Back to heart transplants
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Some history

• First human heart transplant preformed on
  December 3, 1967
• Recipient 53 year old Lewis Washkansky
• Donor 25 year old Denise Darvall, fatally
  injured in a car crash
• Performed at Groote Schuur Hospital in Cape Town,
  South Africa
• Surgeon Dr. Christiaan Barnard
• First successful heart transplant performed by
  Norman Shumway at Stanford University on a dog in
  1958
• Lewis died 18 days later from pneumonia
• New heart functioned normally
• Surgeons all over the world willing to try and
  within 2 years 150 heart transplants were
  preformed
• But 80 of patients died within a year because
  vulnerable to infections
• By 1970, only 18 transplants
• Anti-rejection drugs were not as well developed
  as they are today
• Better developed drugs came in 1970s
• In 70s, patients started living for up to 5
  years
• First successful heart transplant in US took
  place in 1968
• First heat-lung transplant in 1981
• 2007 2,210 heart transplants preformed in the
  United States

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Risks of a heart transplant

• Rejection of heart
• Immune system will attack the foreign object
• Patient given immunosuppressants to reduce risk
  of rejection
• 25 of recipients show signs and symptoms of
  rejection even up to a full year after their
  transplant
• Typically rejection can be dealt with by
  adjusting medications
• Biopsies taken every few months to see if heart
  is being rejected
• Artery problems
• Artery walls can thicken, harden
• Blood circulation can be difficult (can cause
  heart attack, heart failure, arrhythmias, or
  sudden death)
• Side effects to medications
• Cancer (risk of immunosuppressants)
• Infection
• Immunosuppressants inhibit bodys ability to
  fight infection
• Most transplant patients acquire an infection in
  the first year and have to be admitted
• Bleeding
• Blood clots
• Breathing problems
• Kidney failure

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Evaluation process

• Psychological and social evaluations
• Stress
• Family support
• Financial issues
• Blood tests
• Diagnostic tests
• Evaluate overall health
• Assess health of lungs
• Immunizations
• To minimize development of certain infections
  that could end up affecting donor heart
• If good candidate for transplant, placed on UNOS
  list

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Restrictions

• Not everybody is a viable candidate for a heart
  transplant
• Age 65
• Have some other medical condition that shorten
  lifespan
• Peripheral artery disease (serious artery
  blockages in arms or legs)
• Have had cancer
• Unwilling to maker certain lifestyle changes such
  as not drinking, smoking, continuing drug abuse

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Donor-recipient matching system

• Medical urgency
• Blood type
• Antibodies developed by recipient
• Size of donor heart
• Time spent on waiting list

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Heart viability

• Transplant needs to occur within four hours of
  hearts removal from donor
• Hearts first offered to transplant centers close
  by
• Hearts come from people who have been declared
  brain dead
• Most common donors gun shot and car crash
  victims
• Must be declared brain dead by two physicians
• 1-2 of patients who die in hospitals are brain
  dead
• Donors either already donors or family consents
  to donate organs

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UNOS

• United Network for Organ Sharing
• Manages national transplant waiting list
• Manages database of every organ transplant in US
  since 1986
• Develop policies to best use the limited supply
  of organs

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OPTN

• Organ Procurement and Transplantation Network
• National Organ Transplant Act passed in 1987 by
  Congress established OPTN and Scientific Registry
  of Transplant Recipients
• Act stipulated that network be private sector,
  nonprofit
• OPTN is administered by UNOS

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The wait

• Can be days, months, years
• Average wait 3-5 years (all organs)
• There are not enough hearts for every person who
  needs one
• People die while waiting
• Can be removed temporarily if serious medical
  condition develops (infection, stroke)
• VADs can be used

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Position on list (and waiting times) can be
affected by

• Blood type
• Tissue type
• Height and weight of recipient
• Size of donated organ
• Medical urgency
• Time on waiting list
• Distance between the recipient, the donor organ,
  and the transplant center

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The list

• Today as of 608 AM
• Waiting list candidates 117,257 (all organs)
• Active candidates 74,608
• Transplants from January-November 2012 25,787
• Donors from January-November 2012 12,874
• 3,461 waiting for a heart transplant
• 2011 for hearts
• 67.8 transplants per 100 wait-list years
• http//srtr.transplant.hrsa.gov/annual_reports/201
  1/pdf/05_heart_12.pdf
• 2008 60 of those waiting for heart transplant
  underwent the transplant within the first 12
  months of listing
• By 12 months 25 were still waiting, 9.5 had died

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The procedure

• Usually lasts about 4 hours
• IV line will be started to administer fluids and
  medications during surgery
• Catheter inserted
• Anesthesia administered
• Incision made from center of chest to abdomen
  (just above the bellybutton)
• Sternum cut in half with a surgical saw
• Two halves of sternum separated to expose heart
• Pericardium opened
• Recipient aorta and pulmonary arteries are not
  replaced as part of transplant
• Tubes will be inserted into chest so that blood
  can be pumped through body by a heart-lung
  machine
• Once blood is diverted completely into heart lung
  machine diseased heart will be removed EXCEPT a
  recipient ventricle will be left in place
  (usually the left ventricle)
• Donor heart is sewn in to place and vessels
  connected
• Heart lung machine turned off, blood allowed back
  into heart
• Heart shocked to restart heartbeat
• Heart will be observed to make sure it is working
  properly and that no reconnected vessels are
  leaking

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Procedure continued

• Sternum wired back together
• Skin sewn back together
• Initial incision closed with sutures or surgical
  staples
• Tubes inserted into chest to train any blood or
  excess fluids from around the heart
• Dressing/bandage applied
• Will be in hospital for 7-21 days after procedure
• http//www.pbs.org/wgbh/nova/eheart/transplantwave
  .html

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Some fun pictures
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Heterotopic heart transplant

• Piggyback transplant
• Attach donor heart to recipients heart
• Hearts work together
• Donor heart takes stress off of recipients heart
• Used when recipients heart is too weak to
  function on its own

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Some statistics (United States)

• Roughly 79 transplants take place everyday (all
  organs)
• More than 28,000 transplants every year (all
  organs)
• One donor can help 50 people (with all of his/her
  organs/parts)
• Roughly 18 people die everyday waiting for a
  transplant (all organs)

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Survival rate in US

• 90 after one year
• 74 after five years

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Ethical Issues

• Organ shortage
• Note enough organs for everyone in need
• Organ shortage most problematic for hearts
  because a heart cannot come from a live donor
• The list
• Does the list determining who gets the next
  viable heart do so ethically?
• What is the most important factor?
• Should age play a role?
• Black market (for other organs)

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How do we get more donors?

• Persuade more people to become organ donors when
  they die
• Go to organdonor.gov to become a donor!
• Implement hospital policies and procedures to
  foster organ donation
• Obtain more organs from victims of brain and
  cardiac death
• Increase number of live donors
• Only 1 in 4 people have indicated that they are
  donors on appropriate forms in this country
• Age is not a limit for donation!

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The future of hearts

• Embryonic stem cells
• Get stem cells to become heart cells
• Replace damaged heart tissue
• Controversy
• primordial progenitor cells
• Study at Mass Gen
• Cells multiply and diversify into multipotent
  cardiovascular cell lineages for several weeks
• These cells give rise to production of other
  cells
• These cells present from weeks 11-18 of gestation
• These cells are gradually lost
• ISL1differentiation potential being assessed
• Regeneration, transplants (especially for
  myocardium)
• Trying to help understand how in development some
  cells lead to congenital heart defects

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Future continued

• Stimulate hearts ability to grow new cells
• Cell division believed to be bad for heart b/c
  can lead to many DNA replication errors and lead
  to disruption of electrical system
• Growing new organs
• Using body itself to nourish encourage engineered
  tissue to grow
• Growing entire organs is far away but growing
  structures may not be
• Study using intestinal tissue where intestinal
  tissue was grown. New tissue replaced diseased
  tissue.
• Bladders and windpipes have been grown
• Windpipe exact copy made from porous, fibrous
  plastic that was then seeded in stem cells that
  were taken from bone marrow. It was then placed
  in a type of incubator, then sewn in to the
  recipient
• Study where rat hearts and lungs were stripped of
  living cells, leaving the structure of the organ
• Scaffolds compounds that act like mortar to
  hold cells in their proper place that also play a
  major role in how cells are recruited for tissue
  repair
• Very expensive

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Future continued

• Study in zebrafish
• They regrow their cardiac tissue
• In 1 week, can repair 20 of its cardiac tissue
• Hopefully, one day, human heart can mend itself
• Key protein thymosine beta-4 which triggers
  growth of epicardium membrane
• Drugs to help heart mend itself being researched
  using this protein
• Goal those with diseases can make full recovery
• Goal make heart transplant surgery unnecessary
  because heart can repair damage itself

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Sources

• www.nhlbi.nih.gov
• www.Nyp.org
• www.mayoclinic.com
• www.cts.usc.edu
• www.heart.org
• www.unos.org
• www.pbs.org
• www.clevelandclinic.org
• www.hopkinsmedicine.org
• www.nytimes.com
• www.ohsu.edu
• www.history.com
• www.time.com
• www.optn.transplant.hrsa.gov/