Chapter VII - Thoracic Organ Transplantation in the United States, 1995-2004

OVERVIEW

This chapter describes the current state of heart, lung, and heart-lung transplantation and examines trends over the past decade. Although there have been substantial advances in medical therapy since the mid-1990s, thoracic organ transplantation remains an important treatment option for selected patients with a failing heart, failing lungs, or both. Despite better donor organ selection and utilization, the number of transplants performed has declined in recent years and is still limited by the number of donor organs available [Table 1.6]. Outcomes for thoracic transplantation have improved, as is evident in the increased short-term patient survival rates. Among heart transplant recipients, short-term (three-month and one-year) patient survival has been improving since 1995, while long-term (three-year and five-year) survival has remained steady [Table 11.13]. Both short- and long-term patient survival rates have improved since 1995 for lung transplant recipients [Table 12.13a].

Additional highlights of this chapter, which covers waiting list characteristics, death rates of patients on the waiting list, characteristics of transplant recipients, and posttransplant outcomes for heart, lung, and combined transplants, include:

The number of heart transplants per million population continued to decrease over the past decade (from 8.99 procedures per million population in 1995 to 6.87 procedures per million population in 2004) [Table 11.5]. The most notable decline was among those ages 50 to 64 - from 35.86 transplants per million population in 1995 to 19.12 transplants per million population in 2004.

The total number of patients active on the heart waiting list continued to decline during the period [Table 11.1a]. This is primarily a reflection of the decline in the percentage of transplant candidates with a coronary artery disease classification.

The status of patients on the heart waiting list at the end of each calendar year has changed significantly since the creation of waiting list Status 1A and Status 1B [Table 11.1a]. The percentage of Status 2 patients declined from 84% in 1997 to 72% in 2004. At the same time, the percentage of Status 1B patients steadily increased, from 14% in 1999 to 21% in 2004.

Both the number and the rate of deaths of patients on the heart waiting list have declined significantly since 1995. Annual death rates per 1,000 patient years at risk declined from 259 in 1995 to 156 in 2004 [Table 11.3].

The waiting time for new lung waiting list registrants decreased significantly among registrants aged 11 years and older between 1999 and 2004 [Table 12.2].

For the sixth consecutive year, the number of patients on the active waiting list for a heart-lung transplant continued to decrease. From a high of 179 patients in 1998, the total number of active patients decreased to 83 in 2004 [Table 13.1a]. There were only 39 combined heart-lung transplants performed in 2004, a decline from a high of 69 in 1995 and an increase from a low of 27 in 2001 [Table 13.4].

Reported unadjusted patient survival rates at three months, one year, three years, and five years for heart-lung recipients were 70%, 58%, 52%, and 40%, respectively — lower than those for heart or lung recipients alone [Table 13.12].

In May 2005, a new deceased donor organ allocation system for lung transplantation was introduced (1, 2). The new system determines priority for receiving a lung transplant based primarily on severity of illness rather than time spent on the waiting list. The long-term impact of this new system is still to be determined; the development of the new system is addressed in the chapter on lung allocation (Chapter IX).

Heart

Heart Waiting List Characteristics

The waiting list characteristics presented here represent potential transplant recipients on the waiting list at the end of each calendar year from 1995 to 2004. The total number of patients active on the heart waiting list continued to decline during this time period [Table 11.1a], which is primarily a reflection of the decline in the percentage of transplant candidates with a coronary artery disease classification (Figure VII-1). There was a general reduction in the percentage of patients aged 35-64 years, the peak age range for candidates with coronary artery disease (Figure VII-2). This may reflect better outcomes resulting from improvements in medical, interventional, and surgical treatments for coronary disease. The decline in the percentage of 35-64 year-old patients began in 1997 and continued through 2004.

Other trends in characteristics of waiting list patients, such as blood type and country of residence, did not change [Table 11.1a]. The number of female patients on the waiting list continued to increase, from 20% in 1995 to 23% in 2004. There was also an increase in the percentage of patients with a previous organ transplant, from 3% in 1995 to 5% in 2004. Reflected in these percentages is the increase in the percentage of candidates with a previous heart or heart-lung transplant, from 2.6% in 1995 to 4.3% in 2004.

Patients' status at the end of each calendar year has changed significantly since the creation of Status 1A and Status 1B in 1999 [Table 11.1a]. The percentage of Status 2 patients declined from 84% in 1997 to 72% in 2004. At the same time, the percentage of Status 1B patients steadily increased, from 14% in 1999 to 21% in 2004 (Figure VII-3). This change indicates that a relatively large percentage of patients shifted from Status 2 to Status 1B.

The rules for listing as Status 1A include a high risk of dying within seven days of listing and having a ventricular assist device (VAD) in place or other complications such as a VAD infection or being on mechanical ventilatory support. As of January 1, 2004, 37% of patients listed as Status 1A remained listed as Status 1A at the end of 30 days [Table 11.2b]. At 60 days, 18% of patients listed initially as Status 1A were still listed as Status 1A.

Deaths on the Heart Waiting List

Both the number and the rate of deaths of patients on the waiting list have declined significantly since 1995. Annual death rates per 1,000 patient years at risk declined from 259 in 1995 to 156 in 2004 [Table 11.3] (Figure VII-4). This may reflect improved medical therapy and mechanical support for patients with advanced heart failure (3-5). The improvements in death rates occurred across age, ethnicity/race, gender, and blood type groups. From years 2000 to 2004, the death rate among Status 1A patients declined from 1,124 to 548 deaths per 1,000 patient years at risk, while the death rates among Status 1B and Status 2 patients declined less sharply (from 380 to 333 per 1,000 patient years at risk among Status1B patients; and from 106 to 97 per 1,000 patient years at risk among Status 2 patients).

Heart Transplant Recipient Characteristics

The number of transplant candidates undergoing heart transplantation increased steadily in the 1990s, reaching a peak in 1995, when 2,363 heart transplant procedures were performed [Table 11.4]. Since then there has been a steady decline in the number of heart transplant procedures performed per year; 2,016 transplants were performed in 2004 (Figure VII-5). The number of heart transplants per million population has also continued to decrease over the past decade (from 8.99 procedures per million population in 1995 to 6.87 procedures per million population in 2004) [Table 11.5]. The most notable decline occurred among those ages 50 to 64; the incidence in this group dropped from 35.86 transplants per million population in 1995 to 19.12 transplants per million population in 2004. One possible explanation for this gradual yet consistent decline is the improvement in medical and surgical management of patients with end-stage heart disease (3-7). Despite the decline in the total number of patients undergoing heart transplantation, the percentage of recipients aged 65 years and over remained in the range of 8.5%-10.3% of all heart transplants in the years 2000-2004, which is still higher than in 1995, when only 6% of recipients were aged 65 years or older [Table 11.4].

The waiting list status of heart transplant recipients at the time of transplantation has changed little since the inception of the new classification system in 1999. The percentage of heart transplant recipients who were Status 1A at the time of transplantation increased slightly between 2000 and 2004 (39.7% in 2000 to 40.6% in 2004) [Table 11.4]. During the same interval, the percentage of recipients who were Status 1B at the time of transplantation decreased from 34.2% to 32.6%. The percentage of patients undergoing heart transplant at Status 2 has remained mostly unchanged since 2000, increasing only from 26.0% in 2000 to 26.7% in 2004. With wider geographic sharing of donor hearts for candidates who are Status 1A and 1B (if approved by the OPTN Board of Directors), the number of patients undergoing a heart transplant at Status 2 is expected to decrease in favor of sicker candidates. More notable is the decline in the percentage of transplant candidates on life support (defined as inotrope infusion, intra-aortic balloon pump, or ventricular assist devices) at the time of transplantation, from 68% in 2003 to 53% in 2004 [Table 11.4]. The reason for this one-year decline is unknown. Heart transplant recipients' primary diagnoses have changed slightly since 1995, with an increase in the percentage of recipients diagnosed with cardiomyopathy as the primary diagnosis (from 43% in 1995 to 49% in 2004) and a decrease in the percentage of recipients diagnosed with coronary artery disease (47% in 1995 to 38% in 2004) [Table 11.4]. The term "cardiomyopathy" is broad and may include patients with ischemic cardiomyopathy. Therefore, the change in numbers may be a function of how the data were entered rather than a reflection of a change in disease prevalence. The percentage of heart transplant recipients with a diagnosis of congenital heart disease continues to increase (from 7% of recipients in 1995 to 10% in 2004) [Table 11.4].

Immunosuppression Therapy for Heart Transplantation

The immunosuppression regimen for heart transplantation has evolved over the past decade. Induction therapy was used in 47% of heart transplant recipients in 2004, compared to 35% of recipients in 1995. With regard to induction therapy agents, there has been a gradual decline in use of ATG/NRATG/NRATS and muromonab-CD3 (OKT3) and a gradual increase in use of rabbit antithymocyte globulin (Thymoglobulin),daclizumab (Zenapax), and basiliximab (Simulect) [Table 11.6a]. Triple drug therapy remains the cornerstone of immunosuppression therapy at one year after transplantation. Among recipients of heart transplants in 2003, 86% were on corticosteroids one year later, compared to 90% of recipients of transplants in 1994 [Table 11.6g]. Similarly, 88% of 2003 transplant recipients were on antimetabolites a year later, compared to 91% of recipients of transplants in 1994. As expected, there has been a change in the calcineurin inhibitor regimen: In 1994, 90% of heart transplant recipients were receiving cyclosporine preparations and 3.5% were on tacrolimus. In 2003, 54% of heart transplant recipients were on cyclosporine preparations and 53% were on tacrolimus. Similarly, azathioprine use decreased significantly, from use by 88% of recipients in 1994 to use by 9% of recipients in 2003, while the percentage of recipients using mycophenolate mofetil increased from 2% to 78% during the same time period. Another notable trend in immunosuppression use in the past decade is the declining number of recipients who needed treatment for rejection episodes for one year following transplantation (32% of recipients in 2003 compared to 40% of recipients in 1994). The decline attests to the greater potency of the new immunosuppression protocols [Table 11.6i]. Concurrent data on the incidence of infection and malignancy are not available.

Heart Transplant Outcomes

Deaths in the first year after heart transplantation have steadily decreased, from 179 deaths per 1,000 patient years at risk in 1995 to 131 deaths in 2003 [Table 11.7] (Figure VII-6). Advances in medical and surgical management of heart transplant recipients have translated into a declining death rate in the first year following transplant that is irrespective of ethnicity, sex, blood type, presence or absence of life support, hospitalization status, primary diagnoses, or the waiting list status at the time of transplantation. The most notable decline occurred in recipients less than 1 year old and recipients 11-17 years old. Death rates for recipients less than 1 year old decreased by about a third, and rates for recipients 11-17 years old decreased by more than half. In 2003, the death rate for waiting list Status 1A recipients in the first year after transplantation was still nearly twice the death rate for waiting list Status 2 recipients (156 deaths per 1,000 patient years at risk for Status 1A recipients vs. 95 deaths for Status 2 recipients). Donor age appears to be an important predictor of posttransplant survival. In 2003, the recipient death rate in the first year after transplantation was 135 deaths per 1,000 patient years at risk for donor age group 50-64 and 117 deaths per 1,000 patient years at risk for donor age group 35-49. This information should be interpreted within the context that no adjustment was made for recipient variables.

In 2003, adjusted patient survival rates at three months, one year, three years, and five years were 92%, 88%, 80%, and 73% [Table 11.11]. The adjusted five-year survival rate was lowest among recipients 65 years old or older (68%). The five-year adjusted patient survival rate was 70% among female recipients and 74% in male recipients. When examined at other time points — such as three months, one year, and three years — female recipients continued to have inferior adjusted survival compared to male recipients. At this point in time, it is unclear why women would not fare as well. If this observation persists, additional studies aimed at better understanding this finding would be warranted. The three-year and five-year survival data are based on cohorts of recipients of transplants in 2000-2003 and 1998-2003, respectively. Adjusted graft survival was nearly identical to adjusted patient survival with similar trends in each recipient age group and both genders [Tables 11.8, 11.11]. The unadjusted patient survival rate at three months, one year, three years, and five years increased steadily between 1995 and 2003 (Figure VII-7). As expected, the prevalence of people living with a functioning heart allograft increased from 11,644 in 1995 to 19,050 in 2004 [Table 11.14]. This expanding population is a testament to advances in the medical and surgical therapies for end-stage heart disease and posttransplant care, and may warrant a new discipline in cardiac care.

Lung

Lung Waiting List Characteristics

Lung transplantation currently remains a widely accepted therapy for patients with a variety of end-stage lung diseases. A new deceased donor organ allocation system was implemented in May 2005 (1, 2). Whereas the previous allocation system was based solely on time spent on the waiting list, the new one is based on a priority score that is determined by the severity of illness of patients on the waiting list and by posttransplant survival. The long-term impact of the new system on waiting list characteristics has yet to be determined. The development of the new system is reviewed in Chapter IX of this report.

The total number of patients on the lung transplant waiting list was 3,851 at the end of 2004, and has remained relatively stable since 2001 [Table 1.3]. However, since 1995 there has been a slight increase in the ratio of inactive to active waiting list patients (Figure VII-8). In 2004, there were 2,167 active waiting list patients and 1,684 inactive patients [Table 12.1b]. The increase in inactive patients probably has many causes, including the early listing of patients with less severe disease in order to accrue time on the waiting list (8). As the new donor allocation scheme is implemented, there may be significant changes in the number and distribution of patients on the waiting list. Another potential reason for the increase in the number of inactive patients on the waiting list is that therapies for end-stage lung diseases have been improved, particularly for primary pulmonary hypertension (PPH) (9). Indeed, there were more patients with PPH on the inactive waiting list than on the active waiting list in 2004 (18% vs. 8%, respectively).

The age distribution of patients on the active waiting list for a lung transplant has changed slightly over the past decade. In 2004, more than half of the patients on the waiting list were more than 50 years old [Table 12.1a]. The percentage of waiting list patients between the ages of 18 and 34 years decreased slightly (Figure VII-9). The difference in the age distribution may represent the increasing number of active waiting list patients with idiopathic pulmonary fibrosis (IPF), which may have led to a decrease in the percentage of patients with cystic fibrosis (CF) and PPH. There were no significant changes in the gender or ethnicity of patients who were on the active waiting list in 2004 compared to previous years. In 2004, active waiting list patients were most commonly female (55%), white (83%), and blood type O (50%), and had not received a previous transplant (97%). Approximately 45% of active waiting list patients had already waited more than a year for a lung transplant. While the distribution of time since listing has been similar for patients on the list at the end of each year since 1999, it is clearly different than in 1995, when only 28% of patients had waited more than a year (compared to 45% in 2004). In 2004, the most common diagnoses of active waiting list patients were chronic obstructive pulmonary disease (COPD), or emphysema (32%), IPF (19%), and CF (16%). The distribution of diagnoses in 2004 was similar to the distribution in 2003, but since 1995 there has been an overall increase in the percentage of patients with IPF and a slight decrease in the percentage of patients with CF, PPH, and alpha-1 antitrypsin deficiency-related emphysema (Figure VII-10).

The waiting time for new lung waiting list registrants decreased significantly among registrants ages 11 years and older between 1999 and 2004 [Table 12.2]. In addition, time to transplant was shorter in all ethnic groups except Asians, and in both males and females, in 2004 compared to 2003. The 25th percentile of time to transplant is shown in Figure VII-11.

Deaths on the Lung Waiting List

Death rates among waiting list patients have decreased since 1995, but the rate in 2004 was similar to the rate in 2003 [Table 12.3] (Figure VII-12). The average death rate in 2004 was 134 deaths per 1,000 patient years at risk. In 2004, females continued to have a slightly lower death rate than males (123 compared to 149 per 1,000 patient years at risk), which is consistent with the previous nine years. It is not clear whether the lower mortality rate among females is secondary to lower severity of illness, the distribution of underlying diagnoses, or the possible influence of gender on lung disease. Asians had a markedly lower death rate (83 per 1,000 patient years at risk) than did other ethnic groups. However, this result should be interpreted with caution, because the number of Asian patients on the transplant list is relatively small (76 patients). Patients aged 65 years and older and children between 1 and 5 years old had the highest death rates in 2004 (211 and 171 per 1,000 patient years at risk, respectively).

Deceased Donor Lung Transplant Recipient Characteristics

There were 1,157 deceased donor lung transplants performed in 2004 [Table 12.4a]. This number has remained relatively stable since 2001, but represents an increase in the number of transplants per year since 1995. The majority of transplant recipients in 2004 were between the ages of 50 and 64 years. The percentage of recipients in this age group was similar to the percentage in 2003, but had increased significantly since 1995. There has been a respective decrease in the percentage of transplants performed among patients between the ages of 35 and 49 years since 1995 (Figure VII-13). There have been no changes in the gender (50% female), ethnicity (86% white), or blood group type (45% type O) distribution of recipients of deceased donor lung transplants since 1995.

In 2004, there were somewhat more bilateral lung transplants performed compared to single lung transplants (56% versus 44%). This distribution differs from 1995, when 54% of the lung transplants were single lung transplants and 46% were bilateral lung transplants. The change probably reflects a growing preference among transplant centers for performing double lung transplants, because of the improved long-term survival among bilateral lung transplant recipients, particularly those with a diagnosis of emphysema (6). Emphysema remains the most common diagnosis among lung transplant recipients; 37% of all transplants were performed for this indication. IPF (24%) and CF (18%) were the next most common diagnoses. While this distribution is similar to the distribution in 2003, it has changed since 1995 (Figure VII-14).

Immunosuppression Therapy after Lung Transplantation

Immunosuppression after lung transplantation has changed significantly since 1995. Induction therapy was used in approximately 50% of all lung transplants performed in 2004, whereas it was used in only 29% of lung transplants in 1995 [Table 12.6a]. The induction therapies used most commonly in 2004 were basiliximab (23%) and daclizumab (15%). In 1995, antithymocyte globulin (ATG) induction therapy was the therapy used most commonly (in 23% of transplants). In 2004, baseline immunosuppression prior to discharge included corticosteroids (97%), tacrolimus (70%), and an antimetabolite, either azathioprine (44%) or mycophenolate mofetil (47%) [Table 12.6e]. Calcineurin inhibitor use has changed dramatically - from cyclosporine (77%) in 1995 to tacrolimus (70%) in 2004. For transplants in 2003, maintenance immunosuppression administered between discharge and one year posttransplant was essentially the same as immunosuppression prior to discharge, except that the use of sirolimus increased to 10% of lung transplant cases [Table 12.6g]. The immunosuppressive agent used most commonly to treat acute rejection within the first year after transplant was corticosteroids, which were used in 96% of acute rejection cases [Table 12.6i].

Deceased Donor Lung Transplant Outcomes

Among recipients of deceased donor lung transplants in 2003, the average death rate in the first year after transplantation was 184 deaths per 1,000 patient years at risk, a decrease since 2002, when the rate was 215 deaths per 1,000 patient years at risk, and a significant decrease since 1995, when the rate was 291 deaths per 1,000 patient years at risk [Table 12.7a]. Since 1995, the highest death rate has generally been in the group of recipients aged 65 years and over, who had a rate of 287 deaths per 1,000 patient years at risk among 2003 recipients. Death rates in the group aged 35-49 years decreased significantly from previous years, to 146 per 1,000 patient years at risk in 2003 recipients. First-year death rates among most ethnic groups were similar, except among Hispanics/Latinos, who appeared to have a higher death rate (319 per 1,000 patient years at risk). The reason for this difference is not clear; it may simply be a reflection of the small number of Hispanics/Latinos who received transplants in 2003 (47 transplant recipients). In 2004, there were no significant differences in death rates by gender.

Lung transplant recipients who had received a previous transplant had a higher death rate (402 per 1,000 patient years at risk) than first-time recipients [Table 12.7a]. In addition, recipients who were hospitalized, admitted to an intensive care unit, or on life support had a higher annual death rate in the first year after transplantation. Recipients with an underlying diagnosis of PPH continued to have the highest death rate in the first year after transplantation (285 per 1,000 patient years) compared to recipients with other diagnoses. They were followed by recipients with IPF (225 per 1,000 patient years) (Figure VII-15). There was a slightly higher death rate in the first year among recipients of double lung transplants than among those with single lung transplants. Recipients of lungs from donors who were 50-64 years old had a higher death rate (221 deaths per 1,000 patient years at risk) than did recipients of lungs from donors in the other age groups. Note, however, that these subgroup death rates have not been adjusted for other patient characteristics.

Adjusted for age, race, gender, and diagnosis, patient survival rates for deceased donor lung transplant recipients at three months, one year, three years, and five years were 91%, 83%, 64%, and 48%, respectively [Table 12.11]. Recipients over the age of 65 years had a slightly lower five-year survival rate (41%) than did younger recipients. An underlying diagnosis of PPH portended a poor three-month survival rate (76%), but five-year survival was comparable to rates for other diagnoses (55%). Lung transplant recipients with an underlying diagnosis of IPF or alpha-1 antitrypsin deficiency had lower survival rates at five years — 44% and 46%, respectively. African Americans and multiracial/other patients tended to have worse five-year survival rates (41% and 22%) than did whites, Hispanics/Latinos, and Asians. The latter three groups all had five-year survival rates of 50%. While the cause of this difference is unknown, it may be related to racial disparities in human leukocyte antigen (HLA) matching. Adjusted graft survival rates for the same time intervals and recipient demographics are similar to adjusted patient survival rates, because lung retransplantation is rarely performed. The reason that so few patients receive second lung transplants is that the outcomes are worse than outcomes of first-time transplants. In an unadjusted graft survival model, recipients who had received a previous lung transplant had lower survival rates than first-time recipients at three months, one year, three years, and five years (77%, 57%, 36%, and 24%, respectively) [Table 12.9a]. In addition, lung transplant recipients who were hospitalized, in the intensive care unit, or on life support at the time of transplant had lower graft survival rates at five years (45%, 35%, and 44%, respectively). Yearly transplant center volume has been reported previously to affect survival (1) . Between 2003 and 2004, it became clear that centers with a volume greater than 21 transplants per year had a higher five-year patient survival rate (54%) than did lower-volume centers (36%-48%) [Table 12.12a]. However, there was no significant difference in five-year patient survival among any of the other center volume categories. As was shown in previous SRTR reports, donor ages of 50-64 years and 65 years and over were associated with relatively lower five-year patient survival rates (43% and 35%). Both short-term and long-term patient survival rates after lung transplantation have, in general, improved since 1999 (Figure VII-16).

Heart-Lung

Heart-Lung Waiting List Characteristics

For the sixth consecutive year, the number of patients on the active waiting list for a heart-lung transplant continued to decrease. From a high of 179 patients in 1998, the total number of active patients decreased to 83 in 2004 [Table 13.1a] (Figure VII-17). Among these, 68% were female and 33% were male, all were U.S. residents, and none had received a transplant previously. The reason for the decline in the number of active waiting list patients is unclear, but difficulties in obtaining a combined heart-lung block and the relatively poor short- and long-term posttransplant survival outcomes could be factors. Most waiting list patients (81%) were adults older than 18 years. A total of 21% of the patients were older than 50 years, which is often considered the upper age limit for heart-lung transplantation. The most common diagnoses on the waiting list were congenital heart disease (35%), primary pulmonary hypertension (PPH) (18%), and cystic fibrosis (CF) (2%).

The median time to transplant has remained relatively stable, with the 25^th percentile of time to transplant at 284 days in 2004 [Table 13.2]. This is up from 225 days in 2003 and down from the decade high of 792 days in 1997. The increase since 2003 in time to transplant has resulted in an increase in the annual death rate, from 107 deaths per 1,000 patient years at risk in 2003 to 159 deaths in 2004 [Table 13.3]. There does not appear to be any influence of age, sex, ethnicity, or blood type on death rates on the waiting list, but the low number of waiting list registrants likely plays a role in this lack of detectable differentiation. The death rate per 1,000 patient years at risk among patients on the waiting list, by blood group, was 151 for type O, 170 for type A, and 207 for type B. The rate could not be determined for type AB because there were too few patients.

Heart-Lung Recipient Characteristics

There were only 39 combined heart-lung transplants performed in 2004, a decline from a high of 69 in 1995 and an increase from a low of 27 in 2001 [Table 13.4]. Only 15% of the recipients were less than 18 years old, and 67% were between the ages of 18 and 49 years. Thirty percent of recipients were hospitalized, and 26% were on life support at the time of transplant. Males and females were nearly equally represented, with males accounting for 49% of the recipients and females accounting for 51%. The most common diagnoses were congenital heart disease (28% of diagnoses) and PPH (31% of diagnoses). This pattern has not changed over the past decade.

Blood type does not appear to have had a significant impact on any aspect of heart-lung transplantation. Candidates with blood type O represented 54% of the waiting list, while 31% of candidates had type A, 11% had type B, and 4% had type AB [Table 13.1a]. Similarly, among recipients, 49% had blood type O, 23% had type A, 23% had type B, and 5% had type AB [Table 13.4].

Heart-Lung Recipient Outcomes

The SRTR database includes 55 transplant centers that performed heart-lung transplants between 1995 and 2004 [Table 13.15]. Thirty-four of these centers (63%) did not perform a combined transplant in 2004. Most centers that did perform heart-lung transplants performed only one transplant. The greatest number of combined transplants performed at one center was five, and two centers performed four transplants.

Reported unadjusted patient survival rates at three months, one year, three years, and five years were 70%, 58%, 52%, and 40% [Table 13.12]. The age-adjusted survival rates appeared to be better (at all time points) for recipients with PPH than for recipients with congenital heart disease [Table 13.11]. Survival rates for PPH were 79%, 79%, 71%, and 57% for the three-month, one-year, three-year, and five-year periods. For recipients with congenital heart disease, survival rates were 67%, 45%, 49%, and 40% (Figure VII-18). These results have not improved over the past decade.

The first-year posttransplant annual death rate, reported per 1,000 patient years at risk, was up to 857 for recipients with transplants in 2003, the last year with adequate follow-up [Table 13.7]. Fourteen of the 28 recipients of transplants that year died. Because the number of candidates on the active waiting list and the number of recipients are too small to permit multivariate analysis, the significance of these numbers is unknown. However, there is no evidence that the death rate in the first year after heart-lung transplantation was significantly related to place of residence, blood type, age, or indication for transplant. First-year mortality rates seem to be higher among recipients in the intensive care unit and on life support at the time of transplant.

The prevalence of people living with a functioning heart-lung transplant has changed little over the past decade, remaining in the 230-250 range [Table 13.14]. The steady prevalence reflects the fact that the number of transplant recipient deaths and the number of new recipients remain about the same from year to year. It also means that survival rates have not improved over the last decade, despite improvements in immunosuppression and general medical care.

Conclusion

Thoracic transplantation remains an important and viable treatment strategy for patients with end-stage heart and lung disease. The past few years have seen a decline in the total number of heart transplants performed and decreasing waiting list mortality. This is likely due to improvements in medical and surgical therapies for heart disease overall. The introduction of ventricular assist devices has changed the profile of patients waiting for and ultimately receiving heart transplants. In recent years, short- and long-term survival rates for lung transplant recipients have both improved, with a more marked increase in short-term survival. Compared to previous years and despite the persistent problem of donor organ availability, more double lung transplants than single lung transplants are being performed. Although waiting list characteristics had not changed substantially through 2004, recent changes in the organ allocation system for lung transplantation will likely change the profile of patients on the waiting list and those receiving transplants in the future. More time is needed to assess the overall impact of this new system. A limited number of heart-lung transplant operations are performed each year in the United States, probably due in part to the limited availability of heart-lung organ blocks. The survival outcomes of combined heart-lung transplants remain lower than those of heart or lung transplants alone.

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