Surgical Treatment for Congestive Heart Failure

LaDale Simpson March 1, 2007

Statistics

• • • • • • Congestive Heart Failure is a common medical problem affecting over 5 million Americans annually 1.5-2.0% of the U.S. population at any given time is inflicted with this disease Over 500,000 cases are newly diagnosed annually Leading cause of hospitalization (80%) in patients over 65 years of age The impact of heart failure on society is massive, as approximately $40 billion annually is spent on inpatient and outpatient visits. An additional $500 million is estimated to be spent on medications each and every year

What is CHF?

• • • Congestive heart failure arises when a person’s heart is unable to keep up with its required workload.

The pumps in an affected heart are weakened, thus causing the blood to move throughout the circulatory system at a reduced speed.

As a result, the heart is unable to pump much-needed oxygen and nutrients to meet the body’s demand.

What is CHF?

• • • • The chambers in the heart thus respond by stretching to hold more blood or by hardening and becoming thick. This allows the body, for a short time, to compensate for the inadequacy of the valves, but with time the muscle walls of the heart begin to weaken as well. In response, the kidneys often cause the body to retain fluid, particularly water and sodium.

This fluid can accumulate in the arms, legs, ankles, feet or lungs, causing congestion throughout the body.

Risk Factors

• CHF is closely associated with many major risk factors including: – Age – Smoking – History of alcohol abuse – Metabolic syndrome – Coronary artery disease – Hypertension – Valve disease – Diabetes mellitus – Obesity – Family history of heart failure

Types of CHF

• • • • • • • There are 2 main types of congestive heart failure: systolic dysfunction and diastolic dysfunction.

Systolic dysfunction occurs when the heart is unable to empty completely with contraction, and therefore, inadequate amount of blood is sent out into circulation.

Testing for systolic dysfunction is done by measuring the ejection fraction.

A normal ejection fraction is more than 55% of the blood volume.

An ejection fraction ≤45% indicates systolic dysfunction.

If your ejection fraction is normal then you assume the patient has a diastolic dysfunction.

This occurs when the heart contracts normally, but the ventricles do not relax properly or are too stiff to fill completely.

Stages of CHF

• • • • • In 2001, the American Heart Association developed four stages (A-D) to classify patients suffering from congestive heart failure, which were later revised in 2005.

Stage A: patients that are high risk to develop CHF but have no structural damage or symptoms pertaining to the disease.

Stage B: patients have some sort of structural damage to the heart, usually detected with an echocardiogram test, but are yet to experience any symptoms Stage C: patients are those patients who have structural damage and also have prior or current symptoms.

Stage D: patients are patients who, even after receiving optimum medical care, still have advanced symptoms. These are the patients that become candidates for surgical procedures and/or mechanical assist devices, and often require hospitalization or hospice care.

Surgery

• • • Surgery is not often used to treat patients with congestive heart failure.

However, it can be a logical method of treatment in cases in which traditional treatments are not working for whatever reason. These such surgeries present a great risk, thus physicians seek to identify patients who have the greatest to gain from surgical intervention.

Heart Transplant

• • • • • Perhaps the only current treatment that is capable of fully reversing the congestive heart failure is receiving a complete heart transplant, in which surgeons replace the damaged heart with a healthy one taken from a donor who has been pronounced brain dead.

Surgeons remove the healthy heart from the donor, keep it in a cooled environment, and then it is transported to the medical facility in which the recipient is waiting for it. The back walls of the atrias in the recipient’s body are kept intact and the atrias of the new heart are sewn together at this point. Blood vessels are then reconnected.

Timing is everything, as a healthy heart can only exist out of the human body for 4-6 hours.

Heart Transplant

• • • • • • There is a much greater number of patients who suffer from congestive heart failure and could potentially benefit from a heart transplant than there are healthy donated hearts. Due to this fact, there is a strictly screened heart transplant list. Possible patients are evaluated on many different levels including age, medical history, diagnostic test results, social history and psychosocial evaluation. Only patients who are believed to be able to survive the surgery and who will comply with years of disciplined living afterwards are considered for the list. This list is prioritized according to the severity of illness, blood type and geographic location. Once a patient is added to the donor list it is a long, stressful wait before he or she might receive a healthy heart

Left Ventricular Assist Device

• • • The left ventricular assist device (LVAD) serves as a “bridge to transplantation” for patients in whom medical therapy has not worked and are waiting for a heart transplant, or as a destination therapy for patients who are non transplant candidates due to age or comorbidity This device supplements the function of the left ventricle when its pumping ability is damaged It is a portable, battery-powered pump which is implanted in the abdominal wall and is connected to the heart in two places.

Left Ventricular Assist Device

• • • • The pump pulls blood from the left ventricle and then sends it to the aorta, from which blood is pumped out into circulation. Thus, this allows blood to keep pumping through the heart at the rate in which the body demands.

An additional tube extends from the LVAD to the outside of the body and transports wires to a controller which the patient typically wears on a belt. The batteries are normally located on a shoulder holster which also connects to the controller.

Left Ventricular Assist Device

• • Left ventricular assist devices are typically worn for weeks to months and serve to buy time for the patient, regardless of whether he or she is a candidate for a heart transplant. It allows the patient to return home and attempt to live a semi-normal life.

Coronary Artery Bypass Graft

• • • The most common type of surgical procedure performed on a patient suffering from congestive heart failure is a coronary artery bypass graft (CABG). During a bypass operation an artery or vein is removed from another healthy part of the patient’s body, such as a leg, arm or the chest wall. This removed blood vessel is then surgically attached in a way that it allows blood to bypass, or go around, the affected portion of the pre-existing blood vessel and thus becomes a graft.

Coronary Artery Bypass Graft

• • • A coronary artery bypass traditionally calls for an open-heart surgery and the use of a heart-lung bypass machine to circulate the blood while the patient is having the surgery. Minimally invasive procedures have been developed in which multiple smaller openings, or “keyholes,” are made in the chest.

This procedure has many benefits: – less scarring – shorter hospital stay – faster recovery – less bleeding during surgery – reduced chance of post-operative infection – less pain afterwards

Coronary Angioplasty

• • • • Coronary angioplasty is a medical surgery that is used to restore blood flow through a narrowed or blocked artery in the heart.

A narrow, hollow catheter with a balloon on the end is inserted into a blood vessel in the arm or upper thigh and is guided to the diseased portion of the artery.

It is then inflated, which forces any plaque that is responsible for the narrowing outward against the wall of the artery, thus widening the artery and restoring the blood flow. After the widening of the artery takes place, the balloon and catheter are removed.

Coronary Angioplasty

• • • • • Since its development in 1977 the stent has decreased the risk by 50% of an artery closing again after an angioplasty. Stents are tiny structures made of wire mesh that surgeons insert to prop open arteries that have been dangerously narrowed or clogged with fatty plaque. The first stents were made with a bare metal but now most of them are coated with medications that aid the recovery of the artery from the surgery. The usage of plaque removers and lasers have also provided beneficial tools to aid angioplasty. Plaque removers are used to cut away the plaque while lasers dissolve plaque in the arteries while performing the angioplasty.

Electrical Signaling

• • • • • The pumping of a normal, healthy heart is achieved from impulses sent through the organ by its very own electrical system. It is vital that this rhythm of squeezing blood through the heart is done at a steady rate, for if not, the heart will ultimately lose its functioning capability. Some patients have an abnormality of this electrical system in the heart: – bradycardia – tachycardia The majority of congestive heart failure patients suffer from an additional abnormality of this rhythm, in which the two ventricles do not contract simultaneously.

Treatment of all three of these conditions may be done surgically, with implantation of some sort of electrical device.

Electrical Signaling

• • • • A pacemaker is a small device that aids a heart’s SA node. This device detects heart rate of a patient. When the heart rate drops below a set rate (which is determined by a physician) it send an electrical impulse that passes through the heart’s muscle, just as the SA node does. Thus, the heart contracts and pumps as it is intended to, correcting the bradycardia.

Electrical Signaling

• • • • • A pacemaker is implanted just below the skin of the chest of the patient in a minor procedure. It is comprised of a pulse generator and the leads. The generator houses the battery and a tiny computer that monitors the patient’s heart rate and determines when to send an electrical impulse. The leads are wires that are threaded through the veins into the heart and implant in the heart muscle. They are the connection that sends impulses from the generator as needed.

• • • •

Implantable Cardiovascular Defibrillator

Tachycardia is repaired by a device known as an implantable cardiovascular defibrillator, or ICD. It, also, is a pace-making device that is placed just below the skin of the patient’s heart which monitors its rate and rhythm. When the ICD detects an abnormally fast heart rate, it delivers a series of small electrical impulses in a similar manner as the typical pacemaker. This impulse causes the heart to beat in a normal, slower rhythm again.

Cardiac Resynchronization Therapy

• • • The hearts of some congestive heart failure patients have a delay in electrical conduction through the left bundle branch, which transmits the heart’s electrical impulses to the left ventricle from the left atrium. This is termed a left bundle branch block, or LBBB, and causes a delay in left ventricular contraction compared to that of right ventricular contraction. This results in an asynchronous contraction, which further weakens the heart’s pumping efficiency.

Cardiac Resynchronization Therapy

• • • The recommended treatment for LBBB is cardiac resynchronization therapy, or CRT, which requires a sort of biventricular pacemaker. Tiny electrical impulses are sent via leads to the right atrium and then to the two ventricles concurrently, ensure their simultaneous contractions. This method of surgical treatment eliminates the delay caused by the LBBB and is typically recommended for patients suffering from stage D congestive heart failure.

Heart Valve Repair

• • • • Heart valves are flaps of tissues that ensure that blood traveling through different chambers of the heart and into circulation moves in the proper direction and does not flow back from where it came from. Heart valve disease can be caused by infection, congenital heart disease or aging, and may cause the valves to either not close properly, resulting in a leaky valve, or not open completely, resulting in a decrease in blood flow. Both of these circumstances make the heart work harder than normal and may worsen the extent of congestive heart failure the patient is suffering from.

Depending on the severity of the condition, defective valves may need to be either repaired or completely replaced.

Heart Valve Repair

• • • • Complete valve replacement involves the removal of a damaged valve and insertion of a new valve in its place. This new valve may be an artificial valve made of metal or plastic, or may be a donated valve from a human donor. During this surgery a patient is connected to a heart-lung machine. Following the surgery the patient must be placed on a regimen of anticoagulation therapy to prevent blood clots in the area of the new valve.

Heart Valve Repair

• • • • New developments over the years have developed a minimally invasive repair option for patients. With this most advanced technology a damaged valve can be repaired with an incision between the ribs of approximately 2.5 cm in diameter, opposed to the traditional open-heart surgery. This surgery, called a mini-thoracotomy, lessens a patient’s post-operative scarring, recovery time and discomfort. The “Bow Tie” procedure uses a single stitch to join the valve leaflets when they do not properly come together, and can be done in a minimally invasive manner.

• • • •

Heart Valve Repair

Mitral regurgitation is a condition in which the mitral valve – the valve between the left atrium and the left ventricle – allows backflow of the blood from the ventricle into the atrium after is has been pumped through the valve. This condition is existent in virtually all patients with congestive heart failure and is due to remodeling of the left ventricle.

Mitral valve repair typically involves restructuring the leaflets of the valves and providing a sort of support with a ring.

Preservation of the mitral valve contributes to decreasing wall stress, improving systolic and diastolic function and enhances proper geometry of the left ventricle.

Left Ventricular Reconstruction

• • • • • In a failing heart, the normal elliptical shape of the left ventricle is lost. The ventricle dilates and remodels in response to its inability to pump efficiently, creating a spherical shape. Ironically, this remodeled shape eventually turns from being compensatory and beneficial to a contributing cause of heart failure and mitral regurgitation. As the ventricle walls pull apart the mitral valve is no longer able to close completely, thus regurgitation takes place. In this instance it proves beneficial to reconstruct the shape of the left ventricle.

• • • • • • • •

Left Ventricular Reconstruction

The leading procedure by today’s standards is the Dor procedure. With this technique a mannequin device is used to remove any scar tissue in the left ventricle that may be present from previous damage. The surgeon enters the left ventricle through the anteroapical scar. Once the dead tissue determined, a Dacron patch is sutured for the ventricle to close over. This prevents destruction of the left ventricle. Another leading surgery involves a polyester mesh cardiac support device, the Acorn CorCap. The device wraps around the ventricle from posterior to anterior, using sutures, and girdles the heart, helping to retain its elliptical shape. It provides more end diastolic support and reduces wall stress.

Post-Operative Recovery

• • • • • • • Patients who receive a surgical measure of treatment for congestive heart failure often face a long road of recovery following the procedure. These patients are given a strict set of guidelines in which they are responsible to follow for a period of weeks to months. The patient should take proper care of any incisions in which he or she obtained with the procedure. They should be kept clean and dry, using only a mild soap and water to clean them. If there are any signs of an infection, such as drainage, opening of the incision line, redness or warmth around the area or an increase in body temperature then a physician should be contacted immediately. If the patient underwent an open-heart procedure a physician should also be contacted if he or she feel as if the sternum has moved or feels like it has popped Pain relievers are typically given to make a patient feel more comfortable, but the patient and/or his or her family should take care to make sure that no more than the prescribed dosage is taken.

Conclusion

• • • • • Congestive heart failure has become an emerging epidemic the in the world today, affecting over 5 million Americans in our country alone. Pharmacologic treatments are considered a first option for its treatment, but a wave of new, surgical courses of treatments has began to develop. It is essential for critical appraisal of these surgical therapies so that they can be offered to the growing population suffering from heart failure. Although a complete heart transplant is considered to be the gold standard of treatment for a failing heart, there are far too few donor hearts to supply an ever-growing population who potentially could benefit from them. This is why it is crucial to seek other approaches to correcting this problem.

Conclusion

• • All of the methods described have proven beneficial to expanding the duration and increasing the quality of the lives of congestive heart failure patients, and have allowed the majority of them who have received the operations to maintain a normal lifestyle. Although these surgeries are currently considered to be a bridge to transplantation, prolonging life until a donor heart may come available in the future it is a great possibility that they will be considered an equally life-saving method.

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