Approximately 3 million Americans suffer from end-stage DCM, and another 400,000 are diagnosed annually [1]. Many of them suffer every day from heart failure and every year end-stage DCM is a contributing factor in nearly a quarter million deaths [2]. As the population ages, the incidence of end-stage DCM is expected to increase greatly [3].
In congestive heart failure (CHF), previously normal heart muscle becomes damaged, leading to a generalized weakening of the walls of the cardiac chambers [4]. To compensate for the weakening of their muscular walls, the cardiac chambers dilate in a process called "remodeling" [5]. The weakening and the dilation of the heart muscle eventually lead to heart failure [6].
Dilated Cardiomyopathy [7]
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Although in many cases no cause (etiology) is apparent, end-stage DCM probably resulted from damage to the myocardium produced by a variety of toxic, metabolic, or infectious agents. It may also be due to fibrous change of the myocardium from previous myocardial infarctions [8].
Patient prognosis depends on the stage of the disease but is typically characterized by a high mortality rate. End-stage DCM will cause death due to advanced, irreversible heart failure and other problems such as arrhythmias and stroke [9]. Other than heart transplantation, there are currently no curative treatment options for end-stage patients with this disease. However, other alternatives such as Ventricular Assist Device (VAD) and Cardiac Resynchronization Therapy (CRT) can also be applied.
[10]http://www.scimitarequity.com/blog/wp-content/uploads/cli_v2-300x258.gif
A Possible Solution - Heart Transplant
[11]Heart transplant is a surgical transplant procedure performed on patients with end-stage heart failure due to dilated cardiomyopathy or severe coronary artery disease.
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The most common procedure is to take a working heart from a recently deceased organ donor (allograft) and implant it into the patient. The patient's own heart may either be removed (orthotopic procedure) or, less commonly, left in to support the donor heart (heterotopic procedure).
Orthotopic procedure of cardiac transplantation. [12]
How heart is transplanted: [12]
A midline incision is made over the sternum to open the chest cavity to get to the heart.
The great vessels of the heart are attached to a heart-lung bypass machine that enables the body to maintain blood flow to the body and brain.
The unhealthy heart is removed and a healthy donor heart is then sutured into place.
The heart-lung bypass machine is removed and the new heart is restarted.
Heterotropic procedure of heart transplant. [13]
The heart is donated by someone who has been declared brain-dead but remains on life support. The donor heart must be matched as closely as possible to the patient's tissue type to reduce rejection of the new heart by the body. Because donor hearts are in short supply, transplant can only be carried out after extensive examination and investigation have been performed on both donor and patient to ensure the best possible outcome for both sides is achieved and to minimized complications. The patients need to be chronic enough to need a new heart, yet healthy enough to receive and survive with it. [14]
[15]http://a248.e.akamai.net/7/248/430/20080911223522/www.merckmedicus.com/ppdocs/us/common/cecils/b9781416028055500872/images/f001.jpg
The Risks of Heart Transplant
During the first year, 25% of heart transplant recipients have signs of a possible rejection. The recipient's immune system regards the new heart as a "foreign body" and attacks it. Thus, the patient has to receive life-long immunosuppressive drugs to suppress the immune system from rejecting the donor's heart.
Immunosuppressive drugs may weaken the patient's immune system and cause infections, cancer, diabetes melllitus, osteoporeosis as well as kidney disease. [16] Receiving heart from a close relative whose blood and tissue type match the patients can reduce the dosage of immunosuppressive drugs as it can reduce rejection.
Besides, failure of the donor heart may also happen over time, due to the same reasons that caused the original heart to fail and if the patient's body rejects the donor heart or if cardiac allograft vasculopathy develops. Patients who have a failed heart transplant can be considered for a retransplant. [17]
Additionally, the patients might have the risk of acquiring infection during the transplant. There is also a perioperative mortality of anaesthesia and surgery between 0.03% and 0.05% due to reverse reaction to medications and breathing problems. [18] However, in my opinion, the minute probability of mortality for the risk of anaethesia should not discourage a patient from undergoing heart transplant.
The Effectiveness of Heart Transplant
A heart transplant can restore the health and energy experienced prior to heart failure. The heart transplant recipients are placed in the advantaged position of leading their former normal and active lives, with prolonged life. [19]
After heart transplant, patients receive a new functioning heart and their bodies regain the normal heart's function. Quality of life is usually good, especially if the side effects of the immunosuppressant drugs can be kept to a minimum. [20] I believe that heart transplant is appropriate in treating end-stage DCM as the new heart is able to pump blood out of the heart to supply oxygen needed by respiring cells in the body. So, the patients do not need to require heart machines anymore.
The success rate one year after the transplant is 85% to 90% in year 2006. This study also shows that 75% are alive after five years; and between 50% and 60% are alive after ten years. [20] The operative mortality rate is about 8% for the first year from year 2000 to 2005, which are considered quite low. [20] Thus, I strongly agree that heart transplant is an effective solution to end-stage DCM due to its high success rate and relatively low mortality rate.
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Above figure shows the actuarial survival curve, with an initially sharp decrease over the first year followed by a less marked decline of approximately 2.2% yearly. [21]
Economic and Ethical Issues
The cost of heart transplant is very high. The estimated cost to transplant a heart without complications is approximately between US$140,000 to US$150,000. [22]
Estimated U.S. Average 2008 First-Year Billed Charges Per Transplant [22]
30 days pre-transplant
Procurement
Hospital transplant admission
Physician during transplant
180 days post-transplant admission
Immunosuppressant
TOTAL
Long-term management of heart transplant related to immunosuppression, complications, and psychosocial adjustments bring a large economic burden for those from poor families. This financial issue calls for government subsidies for those poor patients. Heart transplant should, as a matter of national policy, be considered a medically necessary part of care for patients with heart failure. Thus, government should continue to devote resources to this expensive and complex, but life-saving, technology.
However, some people argued that this substantial amount of money should be spent on improving the standards of public health and life instead of developing heart transplant. Nevertheless, I think that these controversial voices can be compromised if the government gives a balanced allocation for investment in heart transplant and the social welfare of general community.
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Ethically, heart transplant is objected by some people regarding their religious and social norm. In Japan, a dead person with an incomplete body before burial is considered a misfortune. Most family of the deceased have denied consent to the hearts due to not liking the idea of surgery on the body, not being sure if the patient would have agreed and not agreeing as a family whether to go ahead. Although age and sex of the potential donor did not affect the decision, families of ethnic minority donors were more likely to refuse consent than those of white donors. [23] Thus, I think informed consent, not killing in retrieving organs, respect for donor and family wishes, and prohibition of active euthanasia are among the principles that are important to this ethical foundation of heart transplant.
Also, more individuals should voluntarily register as organ donor to avoid the problem of family refusal. Although selling and buying of hearts can increase the supply of hearts, it is often being argued as hearts are being commercialized and this violates human dignity. Besides, most of these hearts are obtained illegally by unlawful people for the sake of making money. In my opinion, stringent laws should be enacted and enforced to curb illegal heart transplant market.
Even though there are some ethical arguments regarding heart transplant, I think that these arguments should not discourage critical DCM patients from undergoing heart transplant as they can upgrade their life after the transplant, following the currently increasing survival rates.
Alternative Solutions
Ventricular Assist Device (VAD)
Figure A shows the location of the heart and the typical equipment needed for an implantable LVAD. Figure B shows how the LVAD is connected to the heart. [24]
VAD is a mechanical circulatory device that is used to replace the function of a failing heart and is intended for short term use - for patients recovering from heart attacks or heart surgery) or long term use - for patients suffering from congestive heart failure, due to end-stage DCM. [25]
VADs are designed to assist either the right (RVAD) or left (LVAD) ventricle, or both at once (BiVAD). Which of these types is used depends primarily on the underlying heart disease and the pulmonary arterial resistance that determines the load on right ventricle. Long-term VADs are normally used as destination therapy and a bridge to recovery for DCM. [26]
[27]Bar Graph: Treatment of End-Stage Heart Failure
VAD is an effective alternative in case heart transplant could not be carried out due to unavailability of donors' hearts or other factors. It is a more realistic solution to end-stage DCM as it helps the heart to pump blood from the main pumping chamber to the rest of body, while the patients are waiting for new heart. In the last few years, VADs have improved significantly in terms of providing survival and quality of life among recipients. [28]
Also, VAD is immediately available, has planned intervention, achievable good level of physical activity and possible recovery of native heart. [29]
However, the patient needs to be constantly depending on continually power-supplied device, and risks including blood clots, bleeding, infection, and device malfunctions are involved with using VAD. [30]
When blood comes in contact with VAD, it tends to clot more. Blood clots can distrupt blood flow and may block blood vessel leading to important organs such as the brain, thus causing serious complications such as stroke or even death. [30]
The quote above illustrates the risks of VAD. This quote, obtained from National Library of Medicine of United States through its website www.nlm.nih.gov/medlineplus/ency is considered very valid and reliable as it agrees with the information provided by the online encyclopedia of A.D.A.M., Inc.
Accredited by American Accreditation HealthCare Commission or URAC, URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. A.D.A.M. Medical Review Board of Cardiology is headed by Marshall A. Corson, MD, Cardiology Section Chief Harborview Medical Center and Associate Professor of Medicine of University of Washington Medical School, Seattle, Washington. Besides, this article is constantly updated with the last update on 22nd May 2010.
Nevertheless, the risk of blood clotting can be reduced by taking anti-coagulants for as long as the patient is implanted with VAD.
Cardiac Resynchronization Therapy (CRT)
CRT is also another form of therapy for CHF caused by end-stage DCM. It uses a specialized pacemaker to re-coordinate the action of the right and left ventricles in patients with heart failure by pacing both ventricles simultaneously. [31] When the work of the two ventricles is coordinated, the heart's efficiency increases, and the amount of work it takes for the heart to pump blood is reduced. [32]
T0 S: septal contraction onset; T0 LW: lateral wall contraction onset; T0 A: apex contraction onset; T0 ANT: anterior contraction onset; T0 INF: inferior contraction onset; CRT: cardiac resynchronization therapy.
This figure shows the times of onset of contraction in different walls. IN CHF patients, inferior-to-anterior activation sequence was always with a bigger delay at baseline, which reduced after CRT. [34]
CRT Device [33]http://www.mayoclinic.org/images/crt-2col.jpg
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Studies with CRT have demonstrated its ability to improve the symptoms, the exercise capacity, and the feeling of well-being of many patients with moderate to severe heart failure. [35] Studies have also shown that CRT can improve both the anatomy and function of the heart - tending to reduce the size of the dilated left ventricle, and therefore improving the left ventricular ejection fraction. Most importantly, CRT can improve the survival of patients with heart failure. [35]
This source, an article entitled "The effect of cardiac resynchronization on morbidity and mortality in heart failure" is written by volunteer scientists and healthcare professionals. The statements have a rigorous review and approval process before being published. Many statements are written jointly with and reviewed by the American College of Cardiology and is published in highly recognized journals such as The New England Journal of Medicine. The evidence below from another source shows that the statements given from the article are true.
CRT reduces risk of all-cause mortality by 40%, heart failure (HF) due to DCM by 45% and sudden death by 46%. [36]
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