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

Use of Extracorporeal Membrane Oxygenation for Primary Graft Dysfunction After Cardiac Transplantation: Results of an A Priori Ventless Approach

Primary graft dysfunction (PGD) after cardiac transplantation is a devastating complication with increasing frequency lately in the setting of donation after circulatory death (DCD). Severe PGD is commonly treated with extracorporeal membrane oxygenation (ECMO) using central or peripheral cannulation. We retrospectively reviewed the outcomes of PGD after cardiac transplantation requiring ECMO support at our center from 2015 to 2020, focused on our now preferential approach using peripheral cannulation without a priori venting. During the study period, 255 patients underwent heart transplantation at our center and 26 (10.2%) of them required ECMO for PGD. Of 24 patients cannulated peripherally 19 (79%) were alive at 30 days and 17 (71%) 1 year after transplant; two additional patients underwent central ECMO cannulation due to unfavorable size of femoral vessels and concern for limb ischemia. Successful decannulation with full graft function recovery occurred in 22 of 24 (92%) patients cannulated peripherally. Six of them had an indwelling intra-aortic balloon pump placed before the transplantation. None of the other 18 patients received a ventricular vent. In conclusion, the use of an a priori peripheral and ventless ECMO approach in patients with PGD after heart transplant is an effective strategy associated with high rates of graft recovery and survival.

Review of Postoperative Care for Heart Transplant Recipients

The early postoperative management strategies after heart transplantation include optimizing the function of the denervated heart, correcting the causes of hemodynamic instability, and initiating and maintaining immunosuppressive therapy, allograft rejection surveillance, and prophylaxis against infections caused by immunosuppression. The course of postoperative support is influenced by the quality of allograft myocardial protection prior to implantation and reperfusion, donor-recipient heart size matching, surgical technique of orthotopic heart transplantation, and patient factors (eg, preoperative condition, immunologic compatibility, postoperative vasomotor tone, severity and reversibility of pulmonary vascular hypertension, pulmonary function, mediastinal blood loss, and end-organ perfusion). This review provides an overview of the early postoperative care of recipients and includes a brief description of the surgical techniques for orthotopic heart transplantation.

Balancing the tug of war: intraoperative and postoperative management of multiorgan transplantation

PURPOSE OF REVIEW

Multiorgan heart transplants (MOHT) have steadily increased and account for approximately 4% of all heart transplants performed. Although long-term outcomes of MOHT are similar to heart transplant alone, perioperative management remains an issue with nearly double the rate of prolonged hospitalization. Better understanding of hemodynamic environments encountered and appropriate therapeutic targets can help improve perioperative management.

RECENT FINDINGS

Accurate and precise hemodynamic monitoring allows for early identification of complications and prompt assessment of therapeutic interventions. This can be achieved with a multimodal approach using traditional monitoring tools, such a pulmonary artery catheter and arterial line in conjunction with transesophageal echocardiography. Specific targets for optimizing graft perfusion are determined by phase of surgery and organ combination. In some circumstances, the surgical sequence of transplant can help mitigate or avoid certain detrimental hemodynamic environments.

SUMMARY

With better understanding of the array of hemodynamic environments that can develop during MOHT, we can work to standardize hemodynamic targets and therapeutic interventions to optimize graft perfusion. Effectively navigating this perioperative course with multimodal monitoring including transesophageal echocardiography can mitigate impact of complications and reduce prolonged hospitalization associated with MOHT.

Primary Graft Dysfunction After Isolated Heart Transplantation - Incidence, Risk Factors, and Clinical Implications Based on a Single-Center Experience

BACKGROUND

Since the international consensus on primary graft dysfunction (PGD) following heart transplantation (HT) was reported in 2014, few clinical studies have been reported. We aimed to analyze the incidence, predictive factors, and clinical implications of PGD following the International Society of Heart and Lung Transplant criteria in a single center.Methods and Results:This study enrolled 570 consecutive adult patients undergoing isolated HT between November 1992 and December 2017. Under a new set of criteria, PGD-left ventricle (PGD-LV) occurred in 35 patients (6.1%; mild, n=1 [0.2%]; moderate, n=14 [2.5%]; severe, n=20 [3.5%]), whereas PGD-right ventricle (PGD-RV) occurred in 3 (0.5%). Multivariable analysis demonstrated that preoperative admission (odds ratio [OR] 4.20; 95% confidence interval [CI] 1.24-14.26; P=0.021), preoperative extracorporeal membrane oxygenation (OR 4.03; 95% CI 1.75-9.26; P=0.001), and prolonged total ischemic time (OR 1.09; 95% CI 1.02-1.15; P=0.006) were significant predictors of moderate to severe PGD-LV. Moderate to severe PGD-LV was an independent and significant risk factor for early death (OR 55.64; 95% CI 11.65-265.73; P<0.001), with its effects extending up to 3 months after HT.

CONCLUSIONS

Moderate to severe PGD-LV, as defined by the new guidelines, is an important predictor of early mortality, with effects extending up to 3 months after HT. Efforts to reduce the occurrence of moderate to severe PGD-LV may lead to better outcomes.

Donor Left Ventricular Function Assessed by Echocardiographic Strain is a Novel Predictor of Primary Graft Failure After Orthotopic Heart Transplantation

OBJECTIVES

This study sought to determine the utility of donor left ventricular function assessment by echocardiographic left ventricular global longitudinal strain (LV GLS) in predicting primary graft failure (PGF) after orthotopic heart transplantation (HT).

DESIGN

Retrospective, observational study.

SETTING

Tertiary referral hospital.

PARTICIPANTS

Adult patients (>18 years) who underwent isolated HT.

INTERVENTIONS

Demographic, clinical, and echocardiographic data were collected on 100 patients who underwent HT between January 2010 and December 2019 at the authors' institution. The respective donor variables, as well as procedural factors, were reviewed and analyzed to assess their independent association with PGF. Standard donor echocardiographic measurements were supplemented by two-dimensional speckle-tracking echocardiography to obtain LV GLS. PGF was defined as per the International Society for Heart and Lung Transplantation 2014 consensus statement.

MEASUREMENTS AND MAIN RESULTS

PGF occurred in 40 of the 100 patients (40%). Initial univariate analysis found that RADIAL score, donor ejection fraction, and donor LV GLS were associated with PGF. However, in a multivariate Cox regression analysis, only RADIAL score and donor LV GLS remained significant predictors of PGF, with a p < 0.001. By receiver operating characteristic curve analysis, LV GLS at a cut-off value of -11.5% showed the greatest area under the curve (area under the curve = 0.889; 95% confidence interval, 0.826-0.952) and predicted PGF with 92.5% sensitivity and 65% specificity.

CONCLUSIONS

Impaired donor LV GLS was proven to be an independent predictor of PGF after HT.

Extracorporeal Membrane Oxygenation Support After Heart Transplantation in Children-Outcomes of a Single Center Cohort

OBJECTIVES

Extracorporeal membrane oxygenation is used for postcardiotomy low cardiac output but is less established following heart transplantation. We characterized outcomes for children supported with extracorporeal membrane oxygenation after heart transplantation.

DESIGN

Single-center retrospective study.

SETTING

Large pediatric cardiac referral center.

PATIENTS

All patients who received heart transplantation and were cannulated to extracorporeal membrane oxygenation between 1995 and 2016.

INTERVENTIONS

Primary outcome measure was mortality 12 months postextracorporeal membrane oxygenation. Patient characteristics were analyzed for association with outcome according to early graft failure (extracorporeal membrane oxygenation ≤ 7 d after heart transplantation), or late graft failure.

MEASUREMENTS AND MAIN RESULTS

There were 246 heart transplants during the study period and 50 extracorporeal membrane oxygenation runs in 44 patients. Median time from transplant to extracorporeal membrane oxygenation was 1 day (range, 0-11.7 yr), with early graft failure in 28 patients (median 1, range 0-2 d) and 22 extracorporeal membrane oxygenation runs in 20 late graft failure patients (median, 0.8 yr; range, 8 d to 11.7 yr), including four patients with prior extracorporeal membrane oxygenation for early graft failure. Twenty-six patients (59%) survived to hospital discharge, and survival 12 months postextracorporeal membrane oxygenation was 24 patients (55%), lower in those with late graft failure (40% vs 67%; p 0.02). Independent risk factors for 12-month mortality were congenital heart disease, higher pulmonary vascular resistance indexed to body surface area (> 2.2 Woods U/m), and higher creatinine. Higher panel reactive antibody levels were associated with 12-month mortality in the late graft failure group only.

CONCLUSIONS

Extracorporeal membrane oxygenation can be effectively used to rescue patients with graft dysfunction after heart transplantation but is associated with high early mortality. Factors associated with mortality within 12 months include presence of congenital heart disease, renal dysfunction, elevated pulmonary vascular resistance indexed to body surface area and in those supported with extracorporeal membrane oxygenation late after heart transplantation, significant human leukocyte antigen sensitization.

Current and Future Considerations in the Use of Mechanical Circulatory Support Devices: An Update, 2008–2018

Our review in the 2008 volume of this journal detailed the use of mechanical circulatory support (MCS) for treatment of heart failure (HF). MCS initially utilized bladder-based blood pumps generating pulsatile flow; these pulsatile flow pumps have been supplanted by rotary blood pumps, in which cardiac support is generated via the high-speed rotation of computationally designed blading. Different rotary pump designs have been evaluated for their safety, performance, and efficacy in clinical trials both in the United States and internationally. The reduced size of the rotary pump designs has prompted research and development toward the design of MCS suitable for infants and children. The past decade has witnessed efforts focused on tissue engineering–based therapies for the treatment of HF. This review explores the current state and future opportunities of cardiac support therapies within our larger understanding of the treatment options for HF.

Short-term mechanical circulatory support for severe primary graft dysfunction following orthotopic heart transplant

OBJECTIVES

Primary graft dysfunction (PGD) is a devastating complication and the most common cause of early death following a heart transplant. The goal of this study was to report our experience of using mechanical circulatory support to manage severe PGD.

METHODS

Following 208 heart transplants performed between January 2007 and May 2017, 14 (6.7%) patients presented with severe PGD. We provided haemodynamic support using the following approaches: a venoarterial extracorporeal membrane oxygenation device, left ventricular assist device, right ventricular assist device and biventricular assist device. Primary complications included severe PGD, which resulted in hospital deaths and late survival. The mean follow-up was 3.7 ± 2.7 years.

RESULTS

Fourteen (6.7%) heart transplant recipients presented with severe PGD. Seven patients received a venoarterial extracorporeal membrane oxygenation device; 1 patient received a left ventricular assist device; 4 patients received a right ventricular assist device; and 2 patients received a biventricular assist device. Mean device support and explantation times were 4.7 ± 2 and 6.3 ± 2 days, respectively. Weaning with cardiac recovery was successful in 57.1% of the patients. The hospital mortality rate was 50%. Postoperative causes of morbidity included renal failure that necessitated dialysis in 28.5%, surgical re-exploration due to postoperative bleeding in 57.1%, pneumonia in 28.5%, sepsis in 14.2%, sternal wound infection in 14.2% and mediastinitis in 7.1% of the patients, respectively. There were no deaths following hospital discharge or later follow-up appointments.

CONCLUSIONS

Mechanical support devices such as venoarterial extracorporeal membrane oxygenation specifically offer a reliable therapeutic approach. Recognizing the relatively high number of deaths in-hospital, patients who have cardiac recovery and a successful hospital discharge can expect a favourable late outcome.

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.

Anesthesia for Heart Transplantation

This article seeks to evaluate current practices in heart transplantation. The goals of this article were to review current practices for heart transplantation and its anesthesia management. The article reviews current demographics and discusses the current criteria for candidacy for heart transplantation. The process for donor and receipt selection is reviewed. This is followed by a review of mechanical circulatory support devices as they pertain to heart transplantation. The preanesthesia and intraoperative considerations are also discussed. Finally, management after transplantation is also reviewed.

Primary Cardiac Allograft Dysfunction-Validation of a Clinical Definition

Background

Heart transplantation is an established treatment for advanced heart failure. Primary allograft dysfunction (PGD) is reported in up to 40% of transplants and is associated with a poor outcome.

Methods

As part of Heart Evaluation and Retrieval for Transplantation study, an investigation of the assessment of donor hearts for transplantation, we proposed a clinical definition for cardiac PGD comprising severely impaired systolic function affecting one or both ventricles accompanied by hypotension, low cardiac output, and high filling pressures occurring in the first 72 hours (in the absence of hyper acute rejection and technical surgical factors, such as cardiac tamponade). Here, we examine the prospective application of this definition to 290 heart transplants. We compared the clinical outcome of PGD and non-PGD cases.

Results

Ninety-four of 290 transplants developed PGD (32.4%). Inotrope use (score) was higher in the PGD group at 24, 48, and 72 hours after transplantation (P < 0.01). In the PGD group, there was a greater requirement for, intra-aortic balloon pump (50% vs 15%, P < 0.01), mechanical support (27% vs 0%, P < 0.01), and renal replacement therapy (61% vs 26%, P < 0.01). Intensive care stay was longer for recipients with PGD (median 14 vs 5 days, P < 0.01) and early mortality was higher (37% vs 4% at 30 days, 42% vs 8% at 1 year, P < 0.01).

Conclusions

In conclusion, our definition of PGD could be applied in a national multicenter study, and the cases it defined had more frequent complications and higher mortality.

Classification of primary cardiac allograft dysfunction into three grades has been shown to be predictive of 30-day mortality in a prospective study of 290 heart transplants. This demonstrated that the classification system would be applicable for use in multicenter studies.

Experience of ECMO in primary graft dysfunction after orthotopic heart transplantation

BACKGROUND

Primary graft dysfunction is the main cause of early mortality after heart transplantation. Mechanical circulatory support has been used to treat this syndrome.

OBJECTIVE

Describe the experience with extracorporeal membrane oxygenation to treat post-transplant primary cardiac graft dysfunction.

METHODS

Between January 2007 and December 2013, a total of 71 orthotopic heart transplantations were performed in patients with advanced heart failure. Eleven (15.5%) of these patients who presented primary graft dysfunction constituted the population of this study. Primary graft dysfunction manifested in our population as failure to wean from cardiopulmonary bypass in six (54.5%) patients, severe hemodynamic instability in the immediate postoperative period with severe cardiac dysfunction in three (27.3%), and cardiac arrest (18.2%). The average ischemia time was 151 ± 82 minutes. Once the diagnosis of primary graft dysfunction was established, we installed a mechanical circulatory support to stabilize the severe hemodynamic condition of the patients and followed their progression longitudinally.

RESULTS

The average duration of extracorporeal membrane oxygenation support was 76 ± 47.4 hours (range 32 to 144 hours). Weaning with cardiac recovery was successful in nine (81.8%) patients. However, two patients who presented cardiac recovery did not survive to hospital discharge.

CONCLUSION

Mechanical circulatory support with central extracorporeal membrane oxygenation promoted cardiac recovery within a few days in most patients.

Extracorporeal membrane oxygenation: experience in acute graft failure after heart transplantation

INTRODUCTION

Acute graft failure is the leading cause of early mortality after heart transplantation (HTx). Extracorporeal membrane oxygenation (ECMO) is an efficient therapeutic option to treat various pathologies, unburden the left and right ventricle, and allow for functional recovery of the transplanted heart. We reviewed our ECMO experience and outcomes in HTx patients.

METHODS

Retrospectively, we analyzed all patients who received an orthotopic HTx (n = 298) in our department over a 15-yr period (1997 through 2011) to assess the incidence of post-HTx ECMO implantation, perioperative complications, early and one-yr mortality as well as causes of death.

RESULTS

ECMO therapy was utilized to treat graft failure in 28 patients (10.6%) with a mean duration of ECMO support of 4.2 d (six h to 9.4 d). Multivariate analysis revealed as independent predictors for mortality low cardiac output (p = 0.028; odds ratio (OR) = 11.3) and stroke (p = 0.008; OR = 19.7). Cumulative survival rates were 46.4 ± 9.4% within 30 d and 25.0 ± 8.2% at one yr. Causes of death were multiorgan failure (n = 9), sepsis (n = 9), lung failure (n = 2), and intracerebral bleeding (n = 2). ECMO was implanted due to primary graft failure (PGF, n = 16), sepsis (n = 4), and right heart failure (n = 6).

CONCLUSION

Temporary ECMO support for postoperative output failure is an acceptable option as a last resort for otherwise doomed patients with fatal graft failure after HTx. The small fraction of patients surviving appear to have a decent long-term prognosis.

Early postoperative complications after heart transplantation in adult recipients: asan medical center experience

BACKGROUND

Heart transplantation has become a widely accepted surgical option for end-stage heart failure in Korea since its first success in 1992. We reviewed early postoperative complications and mortality in 239 patients who underwent heart transplantation using bicaval technique in Asan Medical Center.

METHODS

Between January 1999 and December 2011, a total of 247 patients aged over 17 received heart transplantation using bicaval technique in Asan Medical Center. After excluding four patients with concomitant kidney transplantation and four with heart-lung transplantation, 239 patients were enrolled in this study. We evaluated their early postoperative complications and mortality. Postoperative complications included primary graft failure, cerebrovascular accident, mediastinal bleeding, renal failure, low cardiac output syndrome requiring intra-aortic balloon pump or extracorporeal membrane oxygenation insertion, pericardial effusion, and inguinal lymphocele. Follow-up was 100% complete with a mean follow-up duration of 58.4±43.6 months.

RESULTS

Early death occurred in three patients (1.3%). The most common complications were pericardial effusion (61.5%) followed by arrhythmia (41.8%) and mediastinal bleeding (8.4%). Among the patients complicated with pericardial effusion, only 13 (5.4%) required window operation. The incidence of other significant complications was less than 5%: stroke (1.3%), low cardiac output syndrome (2.5%), renal failure requiring renal replacement (3.8%), sternal wound infection (2.0%), and inguinal lymphocele (4.6%). Most of complications did not result in the extended length of hospital stay except mediastinal bleeding (p=0.034).

CONCLUSION

Heart transplantation is a widely accepted option of surgical treatment for end-stage heart failure with good early outcomes and relatively low catastrophic complications.

Extracorporeal rescue for early and late graft failure after cardiac transplantation: short result and long-term followup

Objectives. Graft failure after heart transplantation led to poor outcomes. We tried to analyze the outcomes of extracorporeal membrane oxygenation (ECMO) rescue in graft survival after transplantation. Methods. A retrospective review of 385 consecutive heart transplants revealed 46 patients of graft failure requiring ECMO rescue (48 episodes). The pretransplant and ECMO-related variables were evaluated. Results. The median age was 37.7 ± 18.8 years, and the median support time was 155 ± 145 hours. Success rate was 47.9% (23/48). Pretransplant ECMO use was 25% (12/48) and they had 58.3% mortality. The success rate in “early” graft failures was 51.4% (18/35) and 50% for “late” graft failure. The ischemic time with graft failure (178 ± 70 min) was significantly longer than that without graft failure. Preoperative status and the longer ischemic time may be the major factors for failure. Long-term 5-year survival demonstrated significant survival difference between graft failure and nongraft failure. No survival difference was shown between “early” and “late” graft failure. Conclusions. Graft failure still carried high mortality if advanced circulatory support was required. Early graft failure and late graft failure had similar outcomes. Further investigation of the risk factors shows that ECMO does play a role of rescue in catastrophic conditions.

Primary graft dysfunction does not lead to increased cardiac allograft vasculopathy in surviving patients

OBJECTIVE

Early injury is associated with the development of cardiac allograft vasculopathy in heart transplantation. We examined whether adult heart transplant recipients surviving primary graft dysfunction were more susceptible to the development of cardiac allograft vasculopathy than their nonprimary graft dysfunction counterparts.

METHODS

A total of 857 patients who underwent heart transplantation between January 1994 and December 2008 at our institution were reviewed. Primary graft dysfunction was defined as the need for extracorporeal membrane oxygenation, open chest, or intra-aortic balloon pump placement within 72 hours of transplantation. Cardiac allograft vasculopathy was defined as ≥50% coronary artery stenosis in any vessel. Allograft survival was defined by patient death or need for retransplantation.

RESULTS

Completed follow-up was available for 32 patients in the primary graft dysfunction group and 701 patients in the nonprimary graft dysfunction group. Mean recipient ages (56 years vs 55 years, respectively; P = .50) and ischemic times (220 minutes vs 208 minutes, respectively; P = .35) were similar. Donor age was significantly higher in the primary graft dysfunction group (38 years vs 32 years, P = .02). Five-year survivals for the primary graft dysfunction and nonprimary graft dysfunction groups were 46.9% versus 78.9% (P < .001). Conditional 5-year survivals in patients surviving the first year were 78.9% and 88.3% for the primary graft dysfunction and nonprimary graft dysfunction groups, respectively (P = .18). Within a 30-day postoperative period, there were more deaths in the primary graft dysfunction group (28.1% vs 2.3%, P < .0001) and more retransplants (6.25% vs 0%, P = .002). Of the patients surviving past 30 days, only 2 (8.7%) of the primary graft dysfunction patients developed cardiac allograft vasculopathy versus 144 (21.0%) in the nonprimary graft dysfunction group (P < .001).

CONCLUSIONS

Primary graft dysfunction was associated with lower 30-day, 1-year, and 5-year allograft survival rates. Surviving patients, however, did not show increased tendency toward cardiac allograft vasculopathy development.

Primary graft failure after heart transplantation

Primary graft failure (PGF) is a devastating complication that occurs in the immediate postoperative period following heart transplantation. It manifests as severe ventricular dysfunction of the donor graft and carries significant mortality and morbidity. In the last decade, advances in pharmacological treatment and mechanical circulatory support have improved the outlook for heart transplant recipients who develop this complication. Despite these advances in treatment, PGF is still the leading cause of death in the first 30 days after transplantation. In today's climate of significant organ shortages and growing waiting lists, transplant units worldwide have increasingly utilised "marginal donors" to try and bridge the gap between "supply and demand." One of the costs of this strategy has been an increased incidence of PGF. As the threat of PGF increases, the challenges of predicting and preventing its occurrence, as well as the identification of more effective treatment modalities, are vital areas of active research and development.

Left ventricular remodeling and myocardial recovery on mechanical circulatory support

BACKGROUND

Myocardial recovery after ventricular assist devices (VAD) is rare but appears more common in nonischemic cardiomyopathies (NICM). We sought to evaluate left ventricular (LV) end diastolic diameter (LVEDD) for predicting recovery after VAD.

METHODS AND RESULTS

NICM patients receiving long-term mechanical support between 1996 and 2008 were reviewed. Subjects were divided into 3 groups: mild, moderate, and severe dilation (Group A: LVEDD <6.0 cm [n = 22]; Group B: 6.0-7.0 cm [n = 32]; Group C: >7.0 cm [n = 48], respectively). Overall, recovery (successful explant without transplantation) occurred in 14 of 102 subjects (14%). Of these, 2 died and 2 required transplantation within 1 year. Recovery was more common in patients without LV dilation (Groups A/B/C = 32%/22%/0%, P < .001), as was sustained recovery (alive and transplant free 1 year after explant; A/B/C = 27%/10%/0%, P = .001). Of the recovery patients in Group A, 6/7 (86%) had sustained recovery versus 3/6 (50%) in Group B.

CONCLUSIONS

Recovery occurred in 32% of NICM patients without significant LV dilation at time of VAD, the majority of whom experienced significant sustained recovery. Recovery was not evident in those with severe LV dilation. Routine echocardiography at the time of implant may assist in targeting patients for recovery after VAD.

Ventricular assist device therapy

Ventricular assist devices are an important therapeutic option for advanced congestive heart failure. A left ventricular assist device (LVAD) can be implanted as a bridge to transplantation or for the purpose of destination therapy. LVADs improve end-organ function and reduce morbidity and mortality in appropriately selected patients. The development of axial flow pumps has overcome many of the limitations of the first-generation pulsatile flow LVADs. However, many complications of LVAD therapy remain. Treating these complications requires an understanding of LVAD physiology. Ongoing research is directed at reducing the incidence of many of these complications and may allow for wider use of LVADs.

Right ventricular failure following heart transplantation--recovery after extended mechanical support

Early graft failure, particularly right ventricular dysfunction, remains a significant determinant of early morbidity and mortality in heart transplant recipients. If conservative medical management fails to help recover cardiac allograft function, mechanical circulatory support either bridging to recovery or retransplantation remains the last option. We report on a 16-year-old patient with hypertropic nonobstructive cardiomyopathy who was weaned successfully from a right ventricular assist device (RVAD) after extended right ventricular mechanical support for three months following heart transplantation.

[Major complications in the recovery unit following heart transplant: incidence and risk factors]

OBJECTIVE

To assess the incidence of major complications in the postoperative recovery unit and to analyze the associated recipient, donor, and surgical risk factors.

MATERIAL AND METHODS

We studied a series of consecutive orthotopic heart transplants carried out in our hospital from 2001 through 2007. Patients who experienced major complications during their stay in the recovery ward were compared with those who did not. Exitus, primary graft failure, severe infection, and need for hemodialysis were considered major complications.

RESULTS

One hundred fifty-two patients were enrolled. The mean stay in the recovery unit was 3 days (range, 225-5 days). Thirty-nine patients (26%) developed major complications in the recovery unit and 113 did not. The complications were primary graft failure (20%), infection (12%), and acute renal failure (53%). Patients with and without major complications were significantly different with respect to mean (SD) age (55 [6] vs 50 [12] years, respectively; P=.001), presence of diabetes mellitus (41% vs 14%, P=.0001), classification in New York Heart Association functional class IV/IV status (54% vs 34%, P=.05), emergency transplantation (46% vs 18%, P=.001), mean cardiopulmonary bypass time (145 [66] vs 119 [35], P=.03), pretransplant use of an intra-aortic balloon pump (15% vs 6%, P=.04). Multivariate analysis demonstrated an association between major complications and emergency transplantation (OR, 5.67; P=.001), recipient age over 55 years (OR, 2.99; P=.027), and diabetes mellitus (OR, 2.86; P=.048).

CONCLUSIONS

The incidence of major complications in our postoperative recovery unit was 26%. The most common complications were primary graft failure, infection, and acute renal failure. Emergency transplantation, older age, and a diagnosis of diabetes mellitus in the recipient were predictors of complication.

Management of acute severe perioperative failure of cardiac allografts: a single-centre experience with a review of the literature

BACKGROUND

Early graft failure is associated with high mortality and is the main cause of death within the first 30 days after transplantation. The purpose of the present study was to examine the investigators' experience of severe perioperative acute graft failure and to review the literature.

METHODS

Nine of 385 cardiac transplants (2.3%) performed from 1984 through 2005 developed severe perioperative acute graft failure either in the operating room or within 24 h after cardiac transplantation. Four patients had primary graft failure, two had right heart failure secondary to pulmonary hypertension, one had hyperacute rejection, one had accelerated acute rejection and one possibly sustained a particulate coronary embolus intraoperatively.

RESULTS

All except the two patients who had right heart failure secondary to pulmonary hypertension received mechanical circulatory support. Three patients were supported with total artificial hearts, two patients received a left ventricular assist device, one patient was supported with extracorporeal life support followed by a right ventricular assist device when the left ventricle recovered, and one patient was supported for several hours with cardiopulmonary bypass. Three patients were retransplanted after mechanical circulatory support, but only one survived. Only one of the nine patients (11%) survived; this patient was supported with a total artificial heart followed by retransplantation.

CONCLUSION

The outcome of severe perioperative acute graft failure is very poor. Mechanical circulatory support and retransplantation are not as successful as in other situations. Due to the shortage of donors and poor outcomes, retransplantation for hyperacute rejection is not advisable.

Myocardial recovery using ventricular assist devices: prevalence, clinical characteristics, and outcomes

BACKGROUND

Ventricular assist devices (VADs) are important bridges to cardiac transplantation. VAD support may also function as a bridge to ventricular recovery (BTR); however, clinical predictors of recovery and long-term outcomes remain uncertain. We examined the prevalence, characteristics, and outcomes of BTR subjects in a large single center series.

METHODS AND RESULTS

We implanted VADs in 154 adults at the University of Pittsburgh from 1996 through 2003. Of these implants, 10 were BTR. This included 2/80 (2.5%) ischemic patients (supported 42 and 61 days, respectively). Both subjects had surgical revascularization, required perioperative left VAD support, and were alive and transplant-free at follow up (232 and 1319 days, respectively). A larger percentage of nonischemic patients underwent BTR (8/74, 11%; age 30+/-14; 88% female; left ventricular ejection fraction 18+/-6%; supported 112+/-76 days). Three had myocarditis, 4 had post-partum cardiomyopathy (PPCM), and 1 had idiopathic cardiomyopathy. Five received biventricular support. After explantation, ventricular function declined in 2 PPCM patients who then required transplantation. Ventricular recovery in the 6 nonischemic patients surviving transplant-free was maintained (left ventricular ejection fraction 54+/-5%; follow-up 1.5+/-0.9 years). Overall, 8 of 10 BTR patients are alive and free of transplant (follow-up 1.6+/-1.1 years).

CONCLUSIONS

In a large single center series, BTR was evident in 11% of nonischemic patients, and the need for biventricular support did not preclude recovery. For most BTR subjects presenting with acute inflammatory cardiomyopathy, ventricular recovery was maintained long-term. VAD support as BTR should be considered in the care of acute myocarditis and PPCM.

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.

Early Institution of Mechanical Support Improves Outcomes in Primary Cardiac Allograft Failure

BACKGROUND

Primary graft failure (PGF) is the leading cause of early mortality after cardiac transplantation, accounting for 27.1% of deaths within 30 days. PGF is defined as severe dysfunction of the cardiac allograft without any obvious anatomic or immunological cause. The purpose of this study was to analyze our last 9 years of experience with cardiac transplantation to determine predictors of PGF and the influence on survival of our policy of early institution of mechanical circulatory support (MCS) in these patients.

METHODS

Data on 214 consecutive cardiac transplants performed at The Alfred Hospital between January 1996 and August 2004 were reviewed. PGF was defined as right or left or biventricular failure manifesting as hypotension (systolic blood pressure <90 mm Hg), low cardiac output (cardiac index <2.0 liter/min/m2 and pulmonary capillary wedge pressure >20 mm Hg after coming off cardiopulmonary bypass despite inotropic support of up to 5 mug/min adrenaline and without any other obvious cause for the graft dysfunction.

RESULTS

PGF developed in 51 patients (24%). Significant factors in the development of PGF were long ischemic time, which became significant over 4 hours (odds ratio, 1.43; p = 0.01) and increased donor age (odds ratio, 1.027; p = 0.045). Fifteen patients required mechanical support, and of these, 10 survived to leave hospital.

CONCLUSIONS

PGF is the major cause of early mortality after cardiac transplantation. Significant risks for PGF are long allograft ischemic time and increased donor age. Once the patient has survived 30 days, however, the longer-term survival is not influenced by PGF. Our management strategy of early mechanical support has yielded good outcomes in this population with a high risk of early death.

Differential Exercise Performance on Ventricular Assist Device Support

BACKGROUND

Ventricular assist devices (VADs) are approved for destination therapy because they improve survival in end-stage heart failure (HF). VADs are powered pneumatically or electrically. Pneumatic and electric left ventricular assist devices (LVADs) and biventricular assist devices (BiVADs) provide excellent hemodynamic support at rest, but differences in their effects on exercise tolerance are unclear. We sought to evaluate the effect of devices with varying operating parameters on exercise capacity.

METHODS

Exercise physiology data obtained during maximal exercise with on-line gas-exchange analysis were collected for 38 consecutive VAD-implanted HF patients referred for exercise testing.

RESULTS

Electric LVADs were implanted in 18 patients, and pneumatic LVADs in 10 patients. Percent of predicted peak exercise oxygen consumption (VO2%) was significantly greater in pneumatic LVAD patients (52.1 +/- 11.1% vs 38.2 +/- 11.3%, p < 0.05). The 10 patients implanted with a pneumatically powered LVAD were compared to 10 patients implanted with a pneumatically powered BiVAD. LVAD-supported patients had a higher VO2% (52.1 +/- 11.1% vs 36.5 +/- 17.7%, p < 0.05).

CONCLUSIONS

HF patients supported with a pneumatic LVAD appear to have better exercise tolerance than those receiving an electric LVAD. Patients on LVAD support have better exercise tolerance than BiVAD-supported patients. This highlights the importance of right ventricular function to exercise tolerance in HF patients, and may have implications for future VAD design.

Cardiac transplantation

Cardiac transplantation is a proven, accepted mode of therapy for selected patients with end-stage heart failure, but the inadequate number of suitable donor hearts available ultimately limits its application. This chapter reviews adult cardiac transplantation, with an emphasis on the anesthetic considerations of the heart transplant operation itself.

Extracorporeal Membrane Oxygenation is Superior to Right Ventricular Assist Device for Acute Right Ventricular Failure After Heart Transplantation

BACKGROUND

Acute right ventricular failure after heart transplantation is a life-threatening condition, and sometimes the use of mechanical circulatory support is inevitable. The aim of this retrospective study was to investigate the effectiveness of two different mechanical circulatory support systems for this indication.

METHODS

From 1984 to 2003, 28 heart transplant recipients exhibited right ventricular failure resistant to drug therapy. Right ventricular assist device (n = 15) or extracorporeal membrane oxygenation (n = 13) was implanted to support the failing heart.

RESULTS

Overall in-hospital survival was 43%. In the right ventricular assist device group, only 2 patients (13%) could be weaned from mechanical circulatory support compared with 10 patients (77%) in the extracorporeal membrane oxygenation group (p = 0.001). Retransplantation was necessary in 6 patients in the right ventricular assist device group and in 1 patient in the extracorporeal membrane oxygenation group (p = 0.049). There was no difference in patient survival between groups, but graft survival was significantly better in the extracorporeal membrane oxygenation group (p = 0.005).

CONCLUSIONS

In view of these results, extracorporeal membrane oxygenation seems to be the better option as mechanical circulatory support for right ventricular failure in heart transplantation.