(Circulation. 2000;102:e9024.)
© 2000 American Heart Association, Inc.
Cardiovascular News |
Cardiovascular News
Heart Transplant Survival Rate Best in High-Risk Group
A recent study of patients on the transplant waiting list in Germany, the Comparative Outcomes and Clinical Profiles In Transplantation (COCPIT) study by Mario Deng and colleagues, reports that heart transplants improve survival only in patients at greatest risk of dying. Those with a low or medium risk had no reduction in mortality through transplantation. The results appeared in the September 2, 2000 issue of the British Medical Journal (BMJ 2000;321:540–545).
The authors analyzed the survival benefit from heart transplantation in 889 patients listed for heart transplantation at all centers in Germany for a 1-year period in 1997. The patients were assigned according to the Heart Failure Survival Score to groups labeled as low, medium, and high risk of death from heart failure.
The patients at high risk had the highest global death rate (51%), compared with 32% for the medium-risk patients and 29% for the low-risk patients. There was no reduction in mortality risk associated with transplantation in the patients with a predicted low or medium risk. Deng and his colleagues recommend managing the medium- and low-risk patients with organ-saving approaches rather than transplantation.
In a related commentary, Dr. Tom Treasure and Dr. Andrew Murday speculate about whether the patients on the waiting list who have not received a transplant are the best comparison group to use, and suggest a clinical trial to explore the issue. They suggest, "It may be as ethical to allocate the limited supply of hearts within carefully designed clinical trials as by the clinical decisions of individuals." However, in an editorial, Dr. Susan Hunt cites the ethical and logistical complications of such trials such as blinding and use of placebos. She recommends continued medical treatment for heart failure and pursuit of alternatives to transplantation, including mechanical circulatory support devices.
Since the 1990s, the number of cardiac transplant patients has far surpassed the supply of donor hearts. The number of potential recipients is greater than 40 000 a year worldwide, whereas the number of cardiac donors is about 3500. According to Dr. OH Frazier, Director of Cardiopulmonary Transplant at the Texas Heart Institute in Houston, although there have been no prospective controlled randomized studies done on the subject, "This is an important issue to address. It recognizes the difficulties faced by modern cardiac transplantation regarding when patients should be listed and when transplantation should be performed." He continued, "Although the goals of this study are timely and should be explored, the conclusions are overstated." Frazier and his colleagues performed a controlled study on the survival benefit using a left ventricular assist device in severely ill patients. This was a monitored FDA study required for the demonstration of the safety and effectiveness of the Thermo Cardiosystems, Inc (TCI) LVAD as a bridge to transplant. This study, using concurrent controls, demonstrated overwhelming survival benefit for this very ill cardiac transplantation group (Ann Surg 1995;222:327–338).
However, Frazier added: "Survival is not the goal of transplantation. The goal of transplantation is the same as in the days of Dr. Christiaan Barnard, as a palliative procedure." In La Transplantation Cardiaque – Heart Transplantation Second World Symposium, 1969, Experience at Cape Town with Human to Human Heart Transplantation, Dr. Barnard wrote: "We began with dying patients and in a year and a half have one man surviving eighteen months post-operatively. Another man is able to play tennis nine months after a heart transplantation. These achievements, in our opinion, make heart transplantation a worthwhile procedure, and although we realize that this is not curative surgery, there are many other forms of palliative surgery which are accepted, and this form of palliation should be continued too. We have many critics who say this is not worthwhile, but are the persons really qualified to judge this are our patients. We are not treating our critics, we are treating our patients. When I asked Blaiberg (Dr. Philip Blaiberg): ’Tell me, when was this operation worthwhile?’ ... He replied: ‘Thirty minutes after it was performed, because then I could breath again without having to struggle for my breath.’"
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