Extension of donor criteria in cardiac transplantation: surgical risk versus supply-side economics

Utilization and Outcomes of Temporary Mechanical Circulatory Support for Graft Dysfunction After Heart Transplantation

Graft dysfunction is the main cause of early mortality after heart transplantation. In cases of severe graft dysfunction, temporary mechanical circulatory support (TMCS) may be necessary. The aim of this systematic review was to examine the utilization and outcomes of TMCS in patients with graft dysfunction after heart transplantation. Electronic search was performed to identify all studies in the English literature assessing the use of TMCS for graft dysfunction. All identified articles were systematically assessed for inclusion and exclusion criteria. Of the 5,462 studies identified, 41 studies were included. Among the 11,555 patients undergoing heart transplantation, 695 (6.0%) required TMCS with patients most often supported using venoarterial extracorporeal membrane oxygenation (79.4%) followed by right ventricular assist devices (11.1%), biventricular assist devices (BiVADs) (7.5%), and left ventricular assist devices (LVADs) (2.0%). Patients supported by LVADs were more likely to be supported longer (p = 0.003), have a higher death by cardiac event (p = 0.013) and retransplantation rate (p = 0.015). In contrast, patients supported with BiVAD and LVAD were more likely to be weaned off support (p = 0.020). Overall, no significant difference was found in pooled 30 day survival (p = 0.31), survival to discharge (p = 0.19), and overall survival (p = 0.51) between the subgroups. Temporary mechanical circulatory support is an effective modality to support patients with graft dysfunction after heart transplantation. Further studies are needed to establish the optimal threshold and strategy for TMCS and to augment cardiac recovery and long-term survival.

Cardiac Dysrhythmias during Donor Care

Organ procurement coordinators must treat various cardiac dysrhythmias (arrhythmias), including rhythm disturbances that may cause or follow a cardiac arrest, in about 15% to 50% of donors. Treatment decisions should be based on the particular dysrhythmia and its effect on donor blood pressure. Medications selected should be effective but short acting. In this article, data available in publications located through a PubMed search are reviewed and specific dysrhythmias that are likely to occur during donor care are described. Treatment recommendations are based on guidelines from the American Heart Association.

Treatment Goals during Care of Adult Donors That Can Influence Outcomes of Heart Transplantation

Myocardial dysfunction during care of adult donors can result from injury occurring before hospital admission or during the progression of brain death. Few evidence-based data correlate specific hemodynamic goals during donor care with outcomes of heart transplantation, although many recommendations exist. Spontaneous reversal of early heart damage or correction of poor cardiac performance can yield outcomes equivalent to outcomes in recipients who had ideal donors. Hemodynamic goals developed in the operating room can be applied in intensive care to improve outcomes of transplantation. These goals include maintenance of mean arterial pressure greater than 60 mm Hg, central venous pressure less than 12 mm Hg, cardiac output greater than 3.8 L/min, cardiac index greater than 2.1, and systemic vascular resistance between 800 and 1200 dyne · sec · cm−5. The ejection fraction and other echocardiographic data also provide helpful guidance when determining whether a heart is suitable for transplantation and during therapy. Titration of cardiovascular variables often requires invasive monitoring to ensure that cardiac preload, afterload, and contractility are optimal.

Solid organ donation in a child after extracorporeal membrane oxygenation, orthotopic heart transplantation, and ventricular assist device support

Use of high-risk or marginal donors is the most viable short-term means to boost the organ supply and bridge the widening gap between the number of patients on the waiting list for organ transplantation and the insufficient numbers of organ donors. Expansion of the donor pool requires an understanding of the impact on survival likely to result from extending one or more high risk factors. Use of extended donor pool results in shorter waiting list times and limits the morbidity and mortality associated with long-term mechanical support needed to support diseased organs. In this report, we present one such example of expanding donor pool in which a pediatric patient donated a solid organ after two heart transplants and successful use of ECMO and VAD.

Impact of donor left ventricular hypertrophy on survival after heart transplant

Left ventricular hypertrophy (LVH) of the donor heart is believed to increase the risk of allograft failure after transplant. However this effect is not well quantified, with variable findings from single-center studies. The United Network for Organ Sharing database was used to analyze the effect of donor LVH on recipient survival. Three cohorts, selected in accordance with the American Society of Echocardiography guidelines, were examined: recipients of allografts without LVH (<1.1 cm), with mild LVH (1.1-1.3 cm) and with moderate-severe LVH (≥ 1.4 cm). The study group included 2626 patients with follow-up of up to 3.3 years. Mild LVH was present in 38% and moderate-severe LVH in 5.6% of allografts. Predictors of mortality included a number of donor and recipient characteristics, but not LVH. However, a subgroup analysis showed an increased risk of death in recipients of allografts with LVH and donor age >55 years, and in recipients of allografts with LVH and ischemic time ≥ 4 h. In the contemporary era, close to half of all transplanted allografts demonstrate LVH, and survival of these recipients is similar to those without LVH. However, the use of allografts with LVH in association with other high-risk characteristics may result in increased mortality.

Use of cardiac allografts with mild and moderate left ventricular hypertrophy can be safely used in heart transplantation to expand the donor pool

OBJECTIVES

The purpose of this study was to evaluate outcomes of heart transplantation (HTx) and changes in left ventricular wall thickness (LVWT) post-HTx using donors with left ventricular hypertrophy (LVH).

BACKGROUND

Limited data are available on use of donor hearts with LVH in HTx.

METHODS

We reviewed 427 patients who underwent HTx: 62 received hearts with LVH (interventricular septum [IVS] or posterior wall [PW] thickness >or=1.2 cm) by echocardiography, and 365 received hearts without LVH. The median follow-up was 3.8 years (range 0 to 16.2 years).

RESULTS

Recipient age was 56 +/- 11 years and donor age was 30 +/- 12 years. Baseline recipient characteristics were similar in both groups. Donors with LVH were older (35 +/- 12 years vs. 29 +/- 12 years, p = 0.001) and had higher rates of intracranial hemorrhage (38% vs. 15%, p = 0.001). The LVWT was increased in the LVH group compared with LVWT in the non-LVH group (IVS: 1.28 +/- 0.18 cm vs. 0.85 +/- 0.19 cm, PW: 1.27 +/- 0.19 cm vs. 0.85 +/- 0.20 cm, p = 0.0001 for both groups). Mild LVH (1.2 to 1.3 cm) was found in 42%, moderate (>1.3 to 1.7 cm) in 53%, and severe (>1.7 cm) in 5% of donors with LVH. Left ventricular wall thickness regression occurred in both IVS and PW (1.28 +/- 0.18 cm vs. 1.10 +/- 0.13 cm vs. 1.13 +/- 0.14 cm, and 1.27 +/- 0.19 cm vs. 1.11 +/- 0.11 cm vs. 1.13 +/- 0.14 cm, at baseline, 1 year, and 5 years, respectively; p < 0.001 for change from baseline to 1 and 5 years for both locations). Patients with or without donor LVH had similar 1-year (3.5% vs. 9.5%, p = 0.2) and 5-year survival rates (84 +/- 5.9% vs. 70 +/- 2.7%, p = 0.07).

CONCLUSIONS

Short- and long-term survival rates and rates of LVH at follow-up were similar in both groups, suggesting that donor hearts with mild and moderate LVH can be safely used in HTx.

Extracorporeal Membrane Oxygenation for Perioperative Cardiac Allograft Failure

The utility of mechanical support in pretransplant stabilization and postcardiotomy shock is well established, but its use in perioperative cardiac allograft failure (PCAGF) rescue has not been well documented. Ventricular assist devices (VADs) have been applied to PCAGF rescue with acceptable results. However, studies have not described the results of using extracorporeal membrane oxygenation (ECMO) in PCAGF. We evaluated the outcome of PCAGF rescue with ECMO. A retrospective review of 204 consecutive heart transplants revealed 19 cases of PCAGF requiring ECMO rescue. Donor-, surgery- and ECMO-related variables were evaluated for association with operative mortality, success of weaning, and survival rate. Transplant recipients included 14 males and 5 females with median age of 44.2 years. Weaning rate was 84.2% and survival rate was 52.6%, with duration of ECMO support 157 +/- 129 hours. Long ischemic time is a PCAGF risk factor (206.8 +/- 96.1 minutes vs. 158.3 +/- 60.8 minutes in non-PCAGF, p < 0.05). PCAGF etiology included primary graft failure (n = 7); right heart failure secondary to pulmonary hypertension, coagulopathy/intraoperative hemorrhage (n = 7); and sepsis (n = 2). Compared with data from VAD-supported PCAGF, ECMO had a better weaning and graft survival rates (p < 0.05). ECMO is another choice for PCAGF rescue. It has an acceptable survival rate and may be considered instead of VADs as a first-line rescue for PCAGF.

Cardiac donor management: another point of view

The shortage of suitable donor hearts is an important limiting factor in heart transplantation and continues to produce discussion about adequate donor management with regard to graft quality. Recent recommendations, such as limiting the doses of catecholamines for maintenance therapy of cardiac donors, have causes up to two thirds of cardiovascular surgeons to refuse a heart graft from a donor treated with dopamine doses greater than 10 microg/kg/min although endogenous catecholamines may cardiac and pulmonary complications in organ donors, these conditions may be treated using similar agents. Perhaps it is the magnitude of the endogenous catecholamine surge that produces the pathology; thereafter, the levels, may quickly decrease to the point of catecholamine depletion at the receptor level so that exogenous administration is not deleterious and even can have beneficial effects. In the hemodynamic management of organ donors, administration of catecholamines with alpha and beta-1 effects may be needed in sufficient doses to reverse the loss of sympathetic tone at the vascular and cardiac level. Hemodynamic responses display a great individual variability; therefore, a maximal dose should not be set. Catecholamine administration increases coronary artery perfusion pressure, thus optimizing the cardiac performance. Furthermore, it is possible that immunomodulatory effects of catecholamines influence acute allograft rejection rates.

Mechanical support for the failing cardiac allograft: a single-center experience

BACKGROUND

Mechanical support for pre-transplant stabilization is established, but its use in peri-operative graft failure (PGF) has not been well documented. With liberal acceptance criteria being used to enlarge the donor pool, an increased incidence of graft failure might be expected. We evaluated the incidence and outcome of PGF at our institution.

METHODS

A retrospective review of 462 consecutive adult heart transplants performed between January 1993 and December 1999 revealed 20 cases of PGF. Donor-, surgery- and device-related variables were evaluated for association with operative mortality, survival and successful device weaning.

RESULTS

Transplant recipients included 17 men and 3 women, median age 56.5 years (20 to 66 years). PGF etiology included primary graft failure (n = 9); right heart failure (RHF) secondary to pulmonary hypertension, coagulopathy/intra-operative hemorrhage or sepsis (n = 9); and hyperacute rejection (n = 2). Device types included RVAD (n = 11), LVAD (n = 4), BIVAD (n = 3) and IABP (n = 2). The wean rate was 45%. Duration of device support ranged from 2 to 965 hours. Early ventricular recovery (within 96 hours) was associated with significantly better 30-day and 2-year survival. Weaned patients had an 88% 30-day and 67% 2-year survival, whereas the overall survival rate was 79% at 2 years (p = not significant).

CONCLUSIONS

Early ventricular recovery is an important predictor of successful weaning and survival. In view of the prohibitive mortality associated with PGF and the dismal prognosis with re-transplantation, we advocate aggressive use of mechanical assistance for PGF, with an acceptable survival benefit.

Long-term results of cardiac transplantation

Heart transplantation is a successful therapeutic option for patients with end-stage heart cardiomyopathy. From April 1991 to December 2000, 345 patients underwent heart transplantation at the Juan Canalejo Hospital. The mean age of recipients was 54.5 +/- 11.4 years; 286 (83%) were male patients. Idiopathic (52.2%) and ischemic (34.9%) end-stage cardiomyopathy were the main causes leading to transplantation. Ninety-four patients had undergone a previous heart operation. The mean left ventricular ejection fraction was 22.8 +/- 11.4. Forty patients (11.5%) were transplanted in urgent (status I) condition. The mean time spent on the waiting list was 35.9 days. In-hospital mortality was 10.6% and 24% for transplantations performed on an elective and urgent basis, respectively. Operative (30-day), one-year and six-year survival was 87.2%, 81.3% and 64%, respectively. In terms of actuarial survival, there were no significant differences with regard to the recipient's age, sex, previous cardiac surgery, and the etiology of the end-stage cardiomyopathy. The six-year actuarial survival for recipients receiving hearts from female donors was 59% compared with 72% for male donors (p = 0.05). There has been a low incidence of rejection, as well as cardiac graft vasculopathy. Actuarial survival at six years was 66% for patients transplantated on an elective basis compared with 57% for patients transplanted on an urgent basis (p = 0.04). The aim of the study was to evaluate long-term results for patients who underwent orthotopic heart transplantation. In our experience, status I is associated with a higher mortality.

Use of two recipient lists for adults requiring heart transplantation

OBJECTIVE

An alternate (second) adult recipient list was used to match excluded potential recipients with nonstandard donor hearts that would otherwise be unused.

METHODS

The only absolute criterion for entering the alternate recipient list was age: 65 years old before 1998 and 70 years old after that. Group I consisted of alternates who underwent transplantation, and group II consisted of 401 contemporaneous recipients. Hearts were first offered to regularly listed patients. At least one of the following donor risks accounted for allocation to an alternate: coronary artery disease, reused transplanted heart, high-risk behavior, hepatitis seropositivity, decreased left ventricular ejection fraction, high inotropic requirement, left ventricular hypertrophy, age older than 55 years plus another risk, and small donor with no other matches.

RESULTS

Of 102 alternates, 82 were listed were because of age. After a median wait of 107 days, 62 alternates underwent transplantation. Median alternate recipient age was 67 years (vs 54 years, P <.001). Median donor age was 45 years (vs 31 years, P <.001). Survival for alternates at 90 days was 82% (vs 91%, P =.04). Significant recipient predictors of early mortality on multivariable analysis (n = 463) were previous cardiac surgery (odds ratio 2.74, 95% confidence interval 1.37-5.48) and renal dysfunction (odds ratio 1.39, 1.10-176). Alternate listing did not independently predict early or late mortality. Late (>90 days) death rates per 1000 person-months were 4.3 and 3.6 for groups I and II (relative risk 1.2, 0.62-2.36).

CONCLUSIONS

Use of two adult recipient lists facilitated allocation of unused donor organs. Satisfactory long-term survival supports the use of an alternate recipient list.

Consensus conference report: maximizing use of organs recovered from the cadaver donor: cardiac recommendations, March 28-29, 2001, Crystal City, Va

The shortage of available donor hearts continues to limit cardiac transplantation. For this reason, strict criteria have limited the number of patients placed on the US waiting list to approximately 6000 to 8000 per year. Because the number of available donor hearts has not increased beyond approximately 2500 per year, the transplant waiting list mortality rate remains substantial. Suboptimal and variable utilization of donor hearts has compounded the problem in the United States. In 1999, the average donor yield from 55 US regions was 39%, ranging from 19% to 62%. This report provides the detailed cardiac recommendations from the conference on "Maximizing Use of Organs Recovered From the Cadaver Donor" held March 28 to 29, 2001, in Crystal City, Va. The specific objective of the report is to provide recommendations to improve the evaluation and successful utilization of potential cardiac donors. The report describes the accuracy of current techniques such as echocardiography in the assessment of donor heart function before recovery and the impact of these data on donor yield. The rationale for and specific details of a donor-management pathway that uses pulmonary artery catheterization and hormonal resuscitation are provided. Administrative recommendations such as enhanced communication strategies among transplant centers and organ-procurement organizations, financial incentives for organ recovery, and expansion of donor database fields for research are also described.

Heart transplantation: a thirty-year perspective

Heart transplantation has evolved over the past 30 years into a mainstay of therapy for heart failure patients. As the surgical technique and basic immunology were defined, heart transplantation became a real therapeutic option. Over the next few decades, thoracic transplant teams at Stanford University and other institutions refined this mode of therapy. This review addresses the history, current surgical technique, recipient and donor selection, postoperative care, immunosuppression, short- and long-term complications, and clinical outcomes associated with this procedure.

Ex-vivo mitral valve repair prior to orthotopic cardiac transplantation

Mitral valve annuloplasty was performed prior to orthotopic cardiac transplantation in two donor hearts which were diagnosed with moderate to severe mitral regurgitation. The technical aspects are reviewed of ex-vivo mitral valve repair with concomitant heart transplantation. The recipients were classified as United Network for Organ Sharing (UNOS) I and both patients have had an excellent postoperative recovery. Over 2-year follow-up demonstrates normal mitral valve function without regurgitation.

The use of donor hearts with left ventricular hypertrophy

BACKGROUND

We reviewed 37 patients who received donor hearts with left ventricular hypertrophy (LVH) to determine which factors affected outcomes.

METHODS

Thirty-seven patients underwent orthotopic heart transplantation (1994 through 1998) with donor hearts qualified as having LVH by echocardiography (EC) and/or electrocardiogram (ECG). We performed univariate analysis on 18 donor and recipient risk factors for mortality. We calculated 12-month survival curves using Kaplan-Meier estimates and compared them using the log-rank test. A contemporaneous cohort of 221 patients who received optimal hearts within the same institution served as a control for survival.

RESULTS

Median follow-up was 18 months (1 to 53). Median recipient age was 58 ye ars (25 to 75), and median donor age was 47 years (12 to 63). Median donor/recipient height and weight ratios were 1.01 (0.9 to 1.19) and 1.16 (0.77 to 2.02), respectively. Two-month survival was 86.4%, and 12-month survival was 73.0%. Survival for the control group was 91. 6% at 2 months and 86.9% at 12 months. Clinically inferior survival curves were observed when donors had known hypertension (n = 17, 95% vs 71% at 2 months, 76% vs 65% at 12 months), ischemia > 180 minutes (n = 18, 95% vs 72% at 2 months, 78% vs 65% at 12 months), LVH by ECG (n = 10, 85% vs 80% at 2 months, 77% vs 56% at 12 months), and greater than mild or unknown ECHO grade (n = 18, 89% vs 72% at 2 months, 84% vs 59% at 12 months, p = 0.11).

CONCLUSIONS

Donor hearts with mild LVH may be used selectively, particularly if there are no ECG criteria and if ischemia time is short. Caution is indicated for donors with documented history of hypertension. Precise measurement of LV wall thickness by EC is needed in all donors to estimate severity and to complement ECG interpretation.

Intensive care management of paediatric organ donors and its effect on post-transplant organ function

OBJECTIVES

1. To document the clinical course of paediatric beating heart organ donors. 2. To evaluate the effect of the ICU management of pediatric donors on the immediate function of transplanted organs. 3. To examine the validity of current donor selection criteria.

DESIGN

Retrospective chart review and case series study.

SETTING

Multidisciplinary ICU of tertiary referral paediatric hospital.

PATIENTS

All patients who became solid organ donors between January 1980 and July 1990.

OUTCOME MEASURES

1. Incidence of major physiological abnormalities of the cardiovascular, pulmonary, renal and metabolic systems. 2. Number of organs retrieved and transplanted, reasons for non-transplantation of donated organs. 3. Immediate post-transplant function of transplanted organs.

RESULTS

Seventy-seven organ donors were identified from whom 134 kidneys, 31 livers and 12 hearts were transplanted. Sixty (78%) patients developed diabetes insipidus. Sustained hypotension occurred in 41 (53.2%) and was commoner in patients treated with inotropic agents in the presence of a low central venous pressure and in patients with diabetes insipidus who did not receive anti-diuretic hormone replacement. Twenty-seven patients suffered at least one cardiac arrest. The data on post-transplant function were obtained for 129 kidneys (from 70 donors) 30 livers and 9 hearts. Fifty-two kidneys, 10 livers and 2 hearts were transplanted from donors who had suffered at least one cardiac arrest without apparent adverse effect on post-transplant organ function. Thirty-six kidneys from 31 donors suffered either acute tubular necrosis (ATN) or primary non-function. The donors of these organs spent longer in ICU (60.6 +/- 45.7 h versus 41.8 +/- 30.1 h p = 0.045) and had a higher mean maximum serum sodium concentration (163.4 +/- 10.9 versus 158.5 +/- 9.5 mmol/l p = 0.05) than those without these complications. The serum creatinine concentration and degree of inotropic support did not predict post-transplant function. Standard biochemical tests for hepatic function, the dose of inotropic agent received, time in ICU and incidence of hypotension did not predict post-transplant liver function.

CONCLUSIONS

Aggressive fluid resuscitation and management of diabetes insipidus may promote stability in paediatric organ donors. Donor cardiac arrest does not alter the ICU course or compromise post-transplant organ function. The current criteria used for donor selection failed to predict post-transplant organ function and their use may increase organ wastage.

Secular trends in cardiac transplant recipient and donor management in the United States, 1990 to 1994. A multi-institutional study. Cardiac Transplant Research Database Group

BACKGROUND

The growth of the US cardiac transplant waiting list has outpaced the increase in donors, resulting in a widening gap between the number of waiting recipients and available donors. These trends have generated concern that longer waiting times may result in more patients deteriorating to urgent status and that transplanting only patients who are in an advanced state of decompensation will reduce posttransplant survival. Furthermore, the shortage of donors may result in extending the guidelines for donor acceptability to a degree that increases graft failure and posttransplant mortality. We measured these secular trends in the Cardiac Transplant Research Database to provide current data on time-dependent changes in US cardiac transplant practice and survival.

METHODS AND RESULTS

At the time of this analysis, the Cardiac Transplant Research Database included all 2749 patients transplanted from January 1, 1990, to June 30, 1994, in the 25 participating transplant centers. During this 4.5-year period, the median waiting time for recipients who received a transplant increased from 2.7 to 3.5 months (P < .0001), and the proportion of recipients whose status was urgent at transplantation increased from 41% to 60% (P < .0001). Donor ischemic time increased from 150 to 166 minutes (P < .0001), and the proportion of donors requiring pressor support increased from 68% to 85% (P < .0001). Despite these changes in practice, the 1-year survival rate remained constant at 84% during this 4.5-year interval. There was no significant difference in 1-year survival rate between urgent status patients (83%) and nonurgent status patients (85%) (P = .08).

CONCLUSIONS

The widening gap between the number of waiting recipients and the number of donors has resulted in a continuing trend toward transplanting urgent status recipients and to a liberalization of donor acceptance criteria. Despite these changes, posttransplant survival has remained constant.

Transesophageal echocardiographic assessment of left ventricular function in brain-dead patients: are marginally acceptable hearts suitable for transplantation?

BACKGROUND

The brain-dead donor supply has become one of the criteria limiting the performance of heart transplantation. Conventional screening criteria are too limiting and exclude suitable heart donors. Echocardiography is now widely available and is a reliable tool to assess left ventricular dysfunction in brain-dead donors. Yet few data are available on the degree of left ventricular dysfunction where a transplantation is possible.

METHODS

Fifty-five potential brain-dead heart donors (age 38 +/- 11 years) were prospectively evaluated by transesophageal echocardiography (TEE) before harvesting. Fractional area change (FAC) was used to assess left ventricular function in potential brain-dead donors. Transplanted hearts were evaluated on the fifth postoperative day. The transplantation was considered a success if the recipient was alive, not retransplanted, without an assistance device or an epinephrine infusion of more than 1 mg/h and showed an ejection fraction above 40%.

RESULTS

Of the 55 potential heart donors, 20 exhibited an FAC of less than 50%. Forty hearts were harvested, 36 of which were successfully transplanted. Nine patients had an FAC below 50% (group H2) and 27 had an FAC over 50% (group H1). Four patients died: 2 from hemorrhage (FAC > 50% in donors); 1 from right and one from left ventricular dysfunction (FAC < 50% in donors). The FAC increased significantly from 51 +/- 15% to 57 +/- 11% in 18 hearts that underwent TEE in donors and afterwards in recipients. Overall actuarial survival was 86.2% versus 64.6% at 1 and 2 years in group H1 and group H2, respectively (p = NS).

CONCLUSIONS

TEE is useful to assess left ventricular function in potential brain-dead donors. An FAC less than 50% is present in 36% of potential heart donors. Because left ventricular dysfunction is often reversible shortly after transplantation, an FAC below 50% may not necessarily preclude the use of hearts for transplantation.

Safe ex vivo coronary angiography with isosmotic contrast agent

Plain-film coronary angiography of the cardiac explant on the operating table should be considered when conventional cardiac catheterization is desired but unavailable. We compared the effects of three contrast solutions on cold-preserved, isolated guinea pig hearts. Hearts were excised, perfused for 30 minutes, and arrested with Plegisol solution at 7 degree C. Twenty minutes after arrest, experimental hearts were perfused with one of three solutions: hyperosmolar Hexabrix solution (n = 6), hyperosmolar Renografin-76 solution (n = 6), or diluted, isosmotic Omnipaque solution (n = 8). The hearts were flushed with cold Plegisol solution 5 minutes later. Control hearts received no contrast during arrest (n = 9). The hearts were reperfused after 1 hour of arrest, and coronary blood flow (in millimeters per minute), left ventricular developed pressure (in millimeters of mercury), and rate of developed pressure (in millimeters of mercury per second) were measured. Endothelium-dependent smooth muscle relaxation to bradykinin administration and endothelium-independent relaxation to sodium nitroprusside administration were also assessed. No significant difference in myocardial or endothelial function was noted between control hearts and hearts perfused with Omnipaque solution. Hearts perfused with Renografin solution or Hexabrix solution, however, were found to have significantly impaired endothelial and myocardial function. We conclude that an isosmotic contrast solution should be used for ex vivo coronary angiography in cold-preserved hearts to avoid impairment of endothelial and myocardial function.

Non-heart-beating donors: a model of thoracic allograft injury

4ACKGROUND. Non-heart-beating donors (NHBDs) have been proposed for the critical shortage of donors for cardiac and pulmonary transplantation. We determined the effects of prearrest hypoxia and postarrest warm ischemia on cardiac and pulmonary allografts procured from NHBDs undergoing hypoxic arrest. METHODS. Rabbit hearts and lungs were procured from separate donors and placed on isolated blood perfusion circuits. Controls were excised and perfused without ischemia. Heart from NHBDs underwent either prearrest hypoxic perfusion alone or consecutive periods of prearrest hypoxic perfusion and 20 minutes of postarrest warm ischemia. A third group of hearts underwent 30 minutes of warm, global ischemia alone. Two groups of pulmonary allografts were studied using similar hypoxic perfusion/20-minute ischemia and 30-minute ischemia donors. RESULTS. Prearrest hypoxic perfusion clearly causes significant dysfunction of cardiac allografts from NHBDs compared with nonischemic controls. Prearrest hypoxic perfusion combined with postarrest ischemia results in an additive degree of dysfunction more severe than a similar period of warm ischemia alone. Both groups of experimental lungs displayed function similar to that of nonischemic controls in terms of pulmonary hemodynamics, airway resistance, and oxygenation potential. CONCLUSIONS. We conclude that prearrest hypoxic perfusion significantly contributes to the dysfunction of NHBD cardiac allografts. Pulmonary allografts may be more amenable to procurement of NHBDs.

Transmission of invasive aspergillosis from a subclinically infected donor to three different organ transplant recipients

OBJECTIVE

To describe a cluster of donor-transmitted cases of invasive aspergillosis.

DESIGN

Case series of epidemiologically linked cases of invasive aspergillosis.

SETTING

Two tertiary care centers with solid-organ transplant programs.

PATIENTS

Two kidney recipients, one heart recipient, and the single donor.

MEASUREMENTS

Routine clinical, microbiological, and pathologic investigation as dictated for patient care. Epidemiologic analysis to establish linkage among cases.

RESULTS

Three allografts (two kidneys and a heart) from a single donor transmitted invasive aspergillosis to the recipients. Three weeks after transplantation, the two kidney recipients had fever and urine cultures positive for Aspergillus fumigatus. The infected kidneys had multiple Aspergillus abscesses and had to be removed to cure the patients. The heart recipient had a negative workup when a diagnosis of aspergillosis was made for the kidney recipients but presented three months later with aspergillus endocarditis with hematogenous spread to the eyes and to the skin. Treatment included eye surgery, aortic valve replacement, and antifungal therapy; control of infection ensued. The donor was intensely immunosuppressed (17 days post-liver transplantation with death from intracerebral bleeding) but had no clinical or autopsy evidence of aspergillosis. Donor tracheal secretions obtained at the time of organ harvest later grew A fumigatus.

CONCLUSION

Expanded criteria for organ donation have to be balanced against infectious risk to organ recipients. A fumigatus can be transmitted from a subclinically infected donor to solid-organ transplant recipients.

Cardiac allograft failure: successful use of biventricular assist device

Nonspecific primary allograft dysfunction is an important cause of perioperative death in cardiac transplant recipients. We report a case of severe nonspecific allograft dysfunction that was ultimately reversible after 18 days of biventricular mechanical circulatory support. Allograft recovery was echocardiographically recognized by a positive inotropic response to isoproterenol and milrinone. This case illustrates the potential for recovery of even extreme allograft dysfunction.

Functional and morphologic adaptation of undersized donor hearts after heart transplantation

OBJECTIVES

This study analyzes our experience with transplantation of small donor hearts in a subgroup of moribund patients who could not be bridged to transplantation with mechanical assist devices.

BACKGROUND

The major problem facing transplant programs in the United States is the lack of donor heart availability. One method of expanding the donor pool may be to liberalize the criteria for an acceptable donor heart.

METHODS

We analyzed the growth and adaptation of 14 undersized and 14 conventionally sized donor hearts over a period of 10 weeks after heart transplantation. The left ventricular systolic and diastolic diameters, septal and posterior wall thicknesses, left ventricular mass calculated by the Penn convention and left ventricular ejection fraction were obtained by M-mode and two-dimensional echocardiography and documented by a single reader in blinded manner. Echocardiographic measurements were obtained before implantation and at 5 and 10 weeks after orthotopic heart transplantation.

RESULTS

The mean (+/- SD) donor/recipient weight ratios were 0.53 +/- 0.06 for undersized hearts and 0.98 +/- 0.05 for normal-sized hearts. All 28 patients received similar immunosuppressive regimens, including intravenous steroids, cyclosporine and azathioprine. The length of hospital stay after transplantation did not vary significantly between the two groups. All the patients had at least one rejection episode during the 10-week study period. There was a tendency toward higher pulmonary pressures in undersized hearts, which was not statistically significant. Heart rate was significantly higher for undersized hearts, due in part to the use of theophylline or terbutaline to maintain tachycardia. There was a significant increase in left ventricular systolic and diastolic dimensions in undersized hearts compared with conventionally sized hearts. Undersized hearts increased in left ventricular mass over the 10-week period, whereas the conventionally sized donor hearts did not change between 5 and 10 weeks.

CONCLUSIONS

In undersized hearts the increase in left ventricular mass and internal dimensions, with preservation of the posterior/septal wall thickness ratio, suggests that the left ventricle adapts to the larger recipient circulation early after transplantation. Despite denervation and a mismatched load, undersized transplanted hearts adapt appropriately to their new hemodynamic milieu.

Determinants of hospital survival after cardiac transplantation

To identify the preoperative factors that influence hospital survival after transplantation we analyzed our consecutive experience of 183 transplantations in 179 patients over a 10-year period. There were 151 male and 29 female transplant recipients ranging in age from 10 days to 70 years (mean, 48 +/- 1 years). Diagnoses included coronary disease in 110 patients, cardiomyopathy in 55 patients, valvular disease in 6 patients, and congenital heart disease in 9 patients. Seventy-seven had undergone a previous cardiac operation, and 30 patients required preoperative mechanical support. Forty patients received hearts from donors who were 40 years old or older (range, 40 to 62 years). Ischemic time was greater than 240 minutes in 32 cases, and pulmonary vascular resistance was greater than 3 Wood units in 40 patients (range, 3.1 to 10.0 Wood units). Cyclosporine induction was used in 52 patients, whereas 128 recipients received polyclonal antibody prophylaxis. There were 25 hospital deaths. Recipient diagnosis, use of mechanical support, donor age, and the immune suppression protocol were related to hospital survival according to univariate analysis. Using multiple logistic regression, only the method of immune suppression induction and the use of mechanical assists were significant independent determinants of survival. In conclusion, we believe that extended ischemic times and donor age do not adversely affect the early success of transplantation, whereas induction with immune globulin may reduce early mortality. Patients requiring mechanical support before transplantation continue to be a challenge.

Successful use of undersized donors for orthotopic heart transplantation--with a caveat

Accepted clinical practice has been to require body weights to be within 20% as a criterion for matching donor to recipient for cardiac transplantation. From November 1989 through September 1993 we began accepting larger differences in body weight between donor and recipient with 80 orthotopic heart transplants performed. Twenty-eight of these transplants used undersized donors (donor-to-recipient body weight ratio [DRBW] of 0.6 to 0.8) with the remaining donors being either size matched (DRBW = 0.8 to 1.0) or oversized (DRBW > 1.0). Thirty-three of the 80 transplant recipients (41%) were classified preoperatively as United Network for Organ Sharing (UNOS) status I and the remaining patients were classified as UNOS status II. Hospital survival for status I recipients was 9 of 14 (64%) for undersized donors, 7 of 8 (87.5%) for sized-matched donors, and 11 of 11 (100%) for oversized donors (p < 0.05). Hospital survival for status II recipients was 12 of 14 (85.7%) for undersized donors, 24 of 24 (100%) for sized-matched donors, and 8 of 9 (88.8%) for oversized donors. Our data support the continued use of hearts from undersized donors in status II recipients. The use of hearts from undersized donors in status I recipients is associated with increased mortality compared with size-matched donors and must be undertaken with caution.

Cardiac transplantation after donor mitral valve commissurotomy

Cardiac transplantation has become a relatively common procedure, with its limiting factor being the lack of donor hearts. The donor pool can potentially be increased by reevaluating donor criteria and performing innovative procedures on the donor heart, such as coronary bypass and valve repair. We present a recent case of donor heart mitral valve commissurotomy with successful transplantation.

Cardiac allografts from high-risk donors: excellent clinical results

Rising waiting list mortality and increasing demand for donor organs have led to extension of traditionally accepted criteria for evaluation of cardiac grafts. From December 1985 to June 1992, 188 cardiac grafts were orthotopically transplanted into 178 recipients. Of these grafts, 38.3% (72/188) were defined as high-risk donors. Risk criteria included prolonged cardiopulmonary resuscitation, age greater than 40 years, high inotrope requirements, undersizing by more than 20% body weight, significant wall motion impairment by echocardiography, elevation of myocardial enzyme levels, and cold ischemia time greater than 4 hours. There were no recipient deaths attributable to primary graft failure in the perioperative period. Operative (30-day), 1-year and 5-year survival was 95.5%, 86.1%, and 77.3%, respectively, in the high-risk group compared with 93.7%, 86.0%, and 67.2%, respectively, in the low-risk donor cohort (p = 0.94). Comparison of duration of postoperative inotrope use, intensive care unit stay, total hospital stay, and in-hospital costs revealed no significant trends favoring either group in postoperative morbidity. Among long-term survivors, development of graft coronary disease was noted in 47.1% (24/51) of the high-risk donor group and only 17.4% (12/69) of the remaining group (p = 0.0005). Left ventricular ejection fractions in the high risk donor group were 0.58 +/- 0.01 at 2 years. Review of this series suggests that selective use of apparently compromised cardiac donors is compatible with excellent cardiac function and survival. Higher incidence of graft vasculopathy may cause significant morbidity during late follow-up.

The role of transesophageal echocardiography in cardiac donor screening

Transthoracic echocardiography has played a useful role in the screening of cardiac transplant donors. However, transthoracic echocardiograms may be suboptimal in many patients on ventilators. The role of transesophageal echocardiography in cardiac donor screening is unknown. Therefore we compared the potential benefit of transesophageal echocardiography combined with transthoracic echocardiography in 24 (16 men and 8 women) consecutive brain-dead patients with a mean age of 29 +/- 9 years (range 16 to 44 years), who were being considered as cardiac transplant donors. Transthoracic echocardiography was performed immediately before or after transesophageal echocardiography. Transthoracic echocardiography was technically difficult in 7 of 24 (29%) patients. Results of transesophageal echocardiography were abnormal in five of the seven patients and demonstrated left (n = 4) and right (n = 3) ventricular wall motion abnormalities and concentric left ventricular hypertrophy (n = 2). The four patients with wall motion abnormalities were eliminated as potential donors. In 16 of 17 patients with technically adequate transthoracic echocardiograms, transesophageal and transthoracic echocardiographic findings agreed and demonstrated normal hearts in 13 patients, left (n = 2) and right (n = 1) ventricular wall motion abnormalities in two patients, and isolated concentric left ventricular hypertrophy in one patient. In 1 of the 17 patients with a technically adequate transthoracic echocardiographic study, a bicuspid aortic valve was demonstrated by transesophageal echocardiography but not diagnosed by transthoracic echocardiography. Overall seven patients were eliminated as cardiac donors on the basis of transesophageal echocardiograms (n = 7), transthoracic echocardiograms (n = 2), or both.(ABSTRACT TRUNCATED AT 250 WORDS)

Successful transplantation of marginally acceptable thoracic organs

OBJECTIVE

This study evaluates the efficacy of personally inspecting marginal thoracic organ donors to expand the donor pool.

SUMMARY BACKGROUND DATA

The present donor criteria for heart and lung transplantation are very strict and result in exclusion of many potential thoracic organ donors. Due to a limited donor pool, 20-30% of patients die waiting for transplantation.

METHODS

The authors have performed a prospective study of personally inspecting marginal donor organs that previously would have been rejected by standard donor criteria.

RESULTS

Fourteen marginal hearts and eleven marginal lungs were inspected. All 14 marginal hearts and 10 of the marginal lungs were transplanted. All cardiac transplant patients did well. The mean ejection fraction of the donor hearts preoperatively was 39 +/- 11% (range 15-50%). Postoperatively, the ejection fraction of the donor hearts improved significantly to 55 +/- 3% (p < 0.002). Nine of the ten lung transplant patients did well and were operative survivors. Our donor pool expanded by 36% over the study period.

CONCLUSIONS

The present donor criteria for heart and lung transplantation are too strict. Personal inspection of marginal thoracic donor organs will help to maximize donor utilization.

Cardiac transplantation: surgical considerations and early postoperative management

The limited availability of donor hearts is the major constraint to the expanded application of cardiac transplantation. As many as 25% of potential recipients will die before a donor becomes available. Since 1986, hospitals that receive Medicare and Medicaid funds have been required to ask family members of all brain-dead patients who are potential donors whether they have considered organ donation. The United Network for Organ Sharing is responsible for the national organ procurement and transplantation network as well as the national organ transplantation scientific registry. The increasing occurrence of multiorgan donation is amplifying the demands for intensive-care management of donors. Donor and recipient are matched on the basis of ABO blood group and body size. The donor operation can be performed in any standard operating room. Although the maximal acceptable ischemic time for a donor heart is 4 to 6 hours, briefer preservation times result in better hemodynamic performance after transplantation and a significantly lower 30-day mortality. The technique of choice in most medical centers is orthotopic cardiac transplantation. Postoperatively, most patients remain in the intensive-care unit for 1 or 2 days and in the hospital for 1 to 2 weeks. Standard intensive-care procedures after transplantation, including nursing and cardiovascular management as well as the treatment of failure of the donor heart, are reviewed. A comprehensive educational program for patients and their families should optimize the outcome after heart transplantation. The overall charges for heart transplantation averaged $114,000 in 1987, 80% of which were hospital charges.(ABSTRACT TRUNCATED AT 250 WORDS)

Weight is not an accurate criterion for adult cardiac transplant size matching

Owing to the limited availability of donor hearts, standard donor criteria for heart size matching need to be reexamined. The current practice at most centers is to match the donor's body weight to within +/- 20% of the recipient's. Our hypothesis was that minimal differences exist in heart sizes of the adult donor population, and therefore, the donor pool could be expanded for any given patient. M-mode echocardiographic measurements of left and right ventricular internal dimensions, left ventricular mass, and percent fractional shortening were reviewed in 235 normal adult subjects (101 men, 134 women). Low correlation coefficients and a high degree of variance were consistently observed between cardiac parameters and body size. There were no significant differences in left ventricular internal dimension when women weighing 40 to 109 kg were compared with men statistically different among men weighing 50 to 99 kg. No difference was noted in right ventricular size among men and women. Echocardiography is a simple and accurate technique to assess cardiac dimensions. Body weight does not correlate well with adult cardiac size and should not be used as an exclusion criterion for a donor heart.

The limits of cardiac preservation with University of Wisconsin solution

Previous studies from this institution have suggested that University of Wisconsin solution is preferred for prolonged cardiac storage and preserves high-energy phosphates better than other storage fluids. University of Wisconsin solution contains adenosine (5 mmol/L), which may maintain the concentration of myocardial adenine nucleotides. Cultures of human adult myocytes were grown from left ventricular biopsy specimens obtained from patients undergoing coronary bypass procedures. Cells (seven to nine dishes per group) were rinsed of culture medium and stored at 0 degrees C in University of Wisconsin solution. Cells were analyzed for adenine nucleotide content after 1, 6, 12, and 24 hours of storage by high-performance liquid chromatography (units = nmol/microgram DNA) and compared with control samples (0 hour). Adenosine concentration increased from 0.03 +/- 0.02 (mean +/- standard deviation) to 1.77 +/- 1.03 by 1 hour (p less than 0.0001, analysis of variance) and remained increased thereafter. Adenosine was largely degraded to inosine (0 hours, 0.03 +/- 0.03; 6 hours, 0.88 +/- 0.56; p less than 0.001) and hypoxanthine (0 hours, 0.01 +/- 0.01; 6 hours, 0.15 +/- 0.09; p = 0.004). Measured levels of xanthine and uric acid were extremely low at all time intervals. Adenosine triphosphate levels were maintained at 1 hour (0 hours, 0.64 +/- 0.38; 1 hour, 0.67 +/- 0.45) but declined thereafter (6 hours, 0.21 +/- 0.21; 12 hours, 0.11 +/- 0.09; 24 hours, 0.04 +/- 0.03; p less than 0.0001). Levels of adenosine diphosphate (p = 0.007) and adenosine monophosphate (p less than 0.05) decreased to approximately 25% of original values by 24 hours.(ABSTRACT TRUNCATED AT 250 WORDS)

Prolonged preservation with University of Wisconsin Solution

Previous studies from this institution using human cell cultures have suggested that University of Wisconsin Solution may be preferred for prolonged cardiac storage. University of Wisconsin Solution (UWS) contains adenosine (5 mmole/liter) which could maintain adenine nucleotides better than other storage fluids. Human cardiomyocytes were isolated from left ventricular biopsies. Cells (seven to nine dishes/group) were rinsed of culture media and placed in one of four solutions: Stanford cardioplegia, phosphate-buffered saline, modified EuroCollins', or UWS. Metabolites were assessed using high-performance liquid chromatography (units = nmole/micrograms DNA) after 24 hr of storage at 0 degrees C and compared to baseline controls (BASE). Adenosine triphosphate (P less than 0.0001, ANOVA), adenosine diphosphate (P less than 0.0001), and adenosine monophosphate (P less than 0.01) decreased with each solution compared to BASE but were maintained best with UWS (P less than 0.05). Adenosine increased in the UWS cells only (BASE, 0.029 +/- 0.118; UWS, 1.836 +/- 1.110; P less than 0.0001, ANOVA). Adenosine in the UWS cells was largely degraded to inosine (UWS, 1.013 +/- 0.779; BASE, 0.034 +/- 0.032; P less than 0.0001) and hypoxanthine (UWS, 0.124 +/- 0.091; BASE, 0.005 +/- 0.005; P less than 0.001). University of Wisconsin Solution does preserve adenine nucleotides better than other storage fluids and may improve the clinical results of cardiac transplantation.