Right ventricular dysfunction after cardiac transplantation: primarily related to status of donor heart

Epidemiology of perioperative RV dysfunction: risk factors, incidence, and clinical implications

In this edition of the journal, the Perioperative Quality Initiative (POQI) present three manuscripts describing the physiology, assessment, and management of right ventricular dysfunction (RVD) as pertains to the perioperative setting. This narrative review seeks to provide context for these manuscripts, discussing the epidemiology of perioperative RVD focussing on definition, risk factors, and clinical implications. Throughout the perioperative period, there are many potential risk factors/insults predisposing to perioperative RVD including pre-existing RVD, fluid overload, myocardial ischaemia, pulmonary embolism, lung injury, mechanical ventilation, hypoxia and hypercarbia, lung resection, medullary reaming and cement implantation, cardiac surgery, cardiopulmonary bypass, heart and lung transplantation, and left ventricular assist device implantation. There has however been little systematic attempt to quantify the incidence of perioperative RVD. What limited data exists has assessed perioperative RVD using echocardiography, cardiovascular magnetic resonance, and pulmonary artery catheterisation but is beset by challenges resulting from the inconsistencies in RVD definitions. Alongside differences in patient and surgical risk profile, this leads to wide variation in the incidence estimate. Data concerning the clinical implications of perioperative RVD is even more scarce, though there is evidence to suggest RVD is associated with atrial arrhythmias and prolonged length of critical care stay following thoracic surgery, increased need for inotropic support in revision orthopaedic surgery, and increased critical care requirement and mortality following cardiac surgery. Acute manifestations of RVD result from low cardiac output or systemic venous congestion, which are non-specific to the diagnosis of RVD. As such, RVD is easily overlooked, and the relative contribution of RV dysfunction to postoperative morbidity is likely to be underestimated.We applaud the POQI group for highlighting this important condition. There is undoubtedly a need for further study of the RV in the perioperative period in addition to solutions for perioperative risk prediction and management strategies. There is much to understand, study, and trial in this area, but importantly for our patients, we are increasingly recognising the importance of these uncertainties.

Primary isolated right ventricular failure after heart transplantation: prevalence, right ventricular characteristics, and outcomes

To determine the prevalence, right ventricular (RV) characteristics, and outcomes of primary isolated RV failure (PI-RVF) after heart transplant (HTX). PI-RVF was defined as (1) the need for mechanical circulatory support post-transplant, or (2) evidence of RVF post-transplant as measured by right atrial pressure (RAP) > 15 mmHg, cardiac index of < 2.0 L/min/m² or inotrope support for < 72 h, pulmonary capillary wedge pressure < 18 mmHg, and transpulmonary gradient < 15 mmHg with pulmonary systolic pressure < 50 mmHg. PI-RVF can be diagnosed from the first 24-72 h after completion of heart transplantation. A total of 122 consecutive patients who underwent HTX were reviewed. Of these, 11 were excluded because of secondary causes of graft dysfunction (GD). PI-RVF was present in 65 of 111 patients (59%) and 31 (48%) met the criteria for PGD-RV. Severity of patients with PI-RVF included 41(37%) mild, 14 (13%) moderate, and 10 (9%) severe. The median onset of PI-RVF was 14 (0-49) h and RV recovery occurred 5 (3-14) days after HTX. Severe RV failure was a predictor of 30-day mortality (HR 13.2, 95% CI 1.6-124.5%, p < 0.001) and post-transplant dialysis (HR 6.9, 95% CI 2.0-257.4%, p = 0.001). Patients with moderate PI-RVF had a higher rate of 30-day mortality (14% vs. 0%, p = 0.014) and post-operative dialysis (21% vs. 2%, p = 0.016) than those with mild PI-RVF. Among patients with mild and moderate PI-RVF, patients who did not meet the criteria of PGD-RV had worsening BUN/creatinine than those who met the PGD-RV criteria (p < 0.05 for all). PI-RVF was common and can occur after 24 h post-HTX. The median RV recovery time was 5 (2-14) days after HTX. Severe PI-RVF was associated with increased rates of 30-day mortality and post-operative dialysis. Moderate PI-RVF was also associated with post-operative dialysis. A revised definition of PGD-RV may be needed since patients who had adverse outcomes did not meet the criteria of PGD-RV.

Clamping of the Aortic Arch Vessels During Normothermic Regional Perfusion Does Not Negatively Affect Donor Cardiac Function in Donation After Circulatory Death

BACKGROUND

The hemodynamic effects of aortic arch vessel (AAV) clamping during normothermic regional perfusion (NRP) in donation after circulatory death is unknown. We investigated effects of AAV clamping during NRP compared with no clamping in a porcine model.

METHODS

In 16 pigs, hemodynamic parameters were recorded including biventricular pressure-volume measurements and invasive blood pressure. Additionally, blood gas parameters and inflammatory cytokines were used to assess the effect of AAV clamping. The animals were centrally cannulated for NRP, and baseline measurements were obtained before hypoxic circulatory arrest was induced by halting mechanical ventilation. During an 8-min asystole period, the animals were randomized to clamp (n = 8) or no-clamp (n = 8) of the AAV before commencement of NRP. During NRP, circulation was supported with norepinephrine (NE) and dobutamine. After 30 min of NRP, animals were weaned and observed for 180 min post-NRP.

RESULTS

All hearts were successfully reanimated and weaned from NRP. The nonclamp groups received significantly more NE to maintain a mean arterial pressure >60 mm Hg during and after NRP compared with the clamp group. There were no between group differences in blood pressure or cardiac output. Pressure-volume measurements demonstrated preserved cardiac function' including ejection fraction and diastolic and systolic function. No between group differences in inflammatory markers were observed.

CONCLUSIONS

AAV clamping did not negatively affect donor cardiac function or inflammation after circulatory death and NRP. Significantly less NE was used to support in the clamp group than in the nonclamp group.

Hemodynamic and Clinical Performance of Hearts Donated After Circulatory Death

BACKGROUND

Donor organ demand continues to outpace supply in heart transplantation. Utilization of donation after circulatory death (DCD) hearts could significantly increase heart donor availability for patients with advanced heart failure.

OBJECTIVES

The purpose of this study was to describe hemodynamic and clinical profiles of DCD hearts in comparison to standard of care (SOC) hearts donated after brain death (DBD).

METHODS

This single-center retrospective cohort study of consecutive heart transplant recipients analyzed right heart catheterization measurements, inotrope scores, echocardiograms, and clinical outcomes between DCD and DBD heart recipients.

RESULTS

Between April 2016 and February 2022, 47 DCD and 166 SOC hearts were transplanted. Median time from DCD consent to transplant was significantly shorter compared with SOC waiting list time (17 days [6-28 days] vs 70 days [23-240 days]; P < 0.001). Right heart function was significantly impaired in DCD recipients compared with SOC recipients 1 week post-transplant (higher median right atrial pressure (10 mm Hg [8-13 mm Hg] vs 7 mm Hg [5-11 mm Hg]; P < 0.001), higher right atrial pressure to pulmonary capillary wedge pressure ratio (0.64 [0.54-0.82] vs 0.57 [0.43-0.73]; P = 0.016), and lower pulmonary arterial pulsatility index (1.66 [1.27-2.50] vs 2.52 [1.63-3.82]; P < 0.001), but was similar between groups by 3 weeks post-transplant. DCD and SOC recipient mortality was similar at 30 days (DCD 0 vs SOC 2%; P = 0.29) and 1 year post-transplant (DCD 3% vs SOC 8%; P = 0.16).

CONCLUSIONS

DCD heart utilization is associated with transient post-transplant right heart dysfunction and short-term clinical outcomes otherwise similar to transplantation using DBD hearts.

Impact of bridging with left ventricular assist device on right ventricular function following heart transplantation

Aims

Patients awaiting orthotopic heart transplantation (OHT) can be bridged utilizing a left ventricular assist device (LVAD) that reduces left ventricular filling pressures, decreases pulmonary artery wedge pressure, and maintains adequate cardiac output. This study set out to examine the poorly investigated area of if and how pre‐treatment with LVAD impacts right ventricular (RV) function following OHT.

Methods and results

We prospectively evaluated 59 (LVAD n = 20) consecutive OHT patients. Transthoracic echocardiography (TTE) was performed in conjunction with right heart catheterization (RHC) at 1, 6, and 12 months after OHT. RV function TTE‐parameters included tricuspid annular plane systolic excursion (TAPSE), systolic tissue velocity (S′), fractional area change, two‐dimensional RV global longitudinal strain and longitudinal strain from the RV lateral wall (RVfree). At 1 month after OHT, the LVAD group had significantly better longitudinal RV function than the non‐LVAD group: TAPSE (15 ± 3 mm vs. 12 ± 2 mm, P < 0.001), RV global longitudinal strain (−19.8 ± 2.1% vs. −14.3 ± 2.8%, P < 0.001), and RVfree (−19.8 ± 2.3% vs. −14.1 ± 2.9%, P < 0.001). At this time point, pulmonary vascular resistance (PVR) was also lower [1.2 ± 0.4 Wood Units (WU) vs. 1.6 ± 0.6 WU, P < 0.05] in the LVAD group compared with the non‐LVAD group. At 6 and 12 months, no difference was detected in any of the TTE and RHC measured parameters between the two groups. Between 1 and 12 months, all parameters of RV function improved significantly in the non‐LVAD group but remained unaltered in the LVAD group.

Conclusions

Our results indicate that pre‐treatment with LVAD decreases PVR and is associated with significantly better RV function early following OHT. During the first year following transplantation, RV function progressively improved in the non‐LVAD group such that at 6 and 12 months, no difference in RV function was detected between the groups.

Right ventricular failure: a comorbidity or a clinical emergency?

There has been ample data providing a convincing perception about the underlying mechanism pertaining to left ventricle (LV) hypertrophy progressing towards LV failure. In comparison, data available on the feedback of right ventricle (RV) due to volume or pressure overload is minimal. Advanced imaging techniques have aided the study of physiology, anatomy, and diseased state of RV. However, the treatment scenario of right ventricular failure (RVF) demands more attention. It is a critical clinical risk in patients with carcinoid syndrome, pulmonary hypertension, atrial septal defect, and several other concomitant diseases. Although the remodeling responses of both ventricles on an increase of end-diastolic pressure are mostly identical, the stressed RV becomes more prone to oxidative stress activating the apoptotic mechanism with diminished angiogenesis. This instigates the advancement of RV towards failure in contrast to LV. Empirical heart failure (HF) therapies have been ineffective in improving the mortality rate and cardiac function in patients, which prompted a difference between the underlying pathophysiology of RVF and LV failure. Treatment strategies should be devised, taking into consideration the anatomical and physiological characteristics of RV. This review would emphasize on the pathophysiology of the RVF and the differences between two ventricles in molecular response to stress. A proper insight into the underlying pathophysiology is required to develop optimized therapeutic management in RV-specific HF.

Heart Transplantation From Brain Dead Donors: A Systematic Review of Animal Models

Despite advances in mechanical circulatory devices and pharmacologic therapies, heart transplantation (HTx) is the definitive and most effective therapy for an important proportion of qualifying patients with end-stage heart failure. However, the demand for donor hearts significantly outweighs the supply. Hearts are sourced from donors following brain death, which exposes donor hearts to substantial pathophysiological perturbations that can influence heart transplant success and recipient survival. Although significant advances in recipient selection, donor and HTx recipient management, immunosuppression, and pretransplant mechanical circulatory support have been achieved, primary graft dysfunction after cardiac transplantation continues to be an important cause of morbidity and mortality. Animal models, when appropriate, can guide/inform medical practice, and fill gaps in knowledge that are unattainable in clinical settings. Consequently, we performed a systematic review of existing animal models that incorporate donor brain death and subsequent HTx and assessed studies for scientific rigor and clinical relevance. Following literature screening via the U.S National Library of Medicine bibliographic database (MEDLINE) and Embase, 29 studies were assessed. Analysis of included studies identified marked heterogeneity in animal models of donor brain death coupled to HTx, with few research groups worldwide identified as utilizing these models. General reporting of important determinants of heart transplant success was mixed, and assessment of posttransplant cardiac function was limited to an invasive technique (pressure-volume analysis), which is limitedly applied in clinical settings. This review highlights translational challenges between available animal models and clinical heart transplant settings that are potentially hindering advancement of this field of investigation.

A Predictive Model for Intracardiac Pressures in Patients Free From Rejection or Allograft Vasculopathy After Pediatric Heart Transplantation

BACKGROUND

Despite the routine use of hemodynamic assessment in pediatric heart transplant (HT) patients, expected intracardiac pressure measurements in patients free of significant complications are incompletely described. A better understanding of the range of intracardiac pressures in these HT patients is important for the clinical interpretation of these indices and consequent management of patients.

METHODS

We conducted a retrospective chart review of pediatric HT recipients who had undergone HT between January 2010 and December 2015 at Lucile Packard Children's Hospital. We analyzed intracardiac pressures measured in the first 12 mo after HT. We excluded those with rejection, graft coronary artery disease, mechanical support, or hemodialysis. We used a longitudinal general additive model with bootstrapping technique to generate age and donor-recipient size-specific curves to characterize filling pressures through 1-y post-HT.

RESULTS

Pressure measurements from the right atrium, pulmonary artery, and pulmonary capillary wedge pressure were obtained in 85 patients during a total of 829 catheterizations. All pressure measurements were elevated in the immediate post-HT period and decreased to a stable level by post-HT day 90. Pressure measurements were not affected by age group, donor-recipient size differences, or ischemic time.

CONCLUSIONS

Intracardiac pressures are elevated in the early post-HT period and decrease to levels typical of the native heart by 90 d. Age, donor-to-recipient size differences, and ischemic time do not contribute to differences in expected intracardiac pressures in the first year post-HT.

Predicted heart mass-based size matching among recipients with moderate pulmonary hypertension: Outcomes and sex effect

BACKGROUND

There is a lack of evidence to guide appropriate donor sizing in recipients with moderate pulmonary hypertension (pHTN) awaiting heart transplantation (HTx). It is common practice to oversize donor hearts for such recipients to prevent post-operative right ventricular failure. Therefore, our objective was to determine if oversizing in pre-transplant moderate pHTN provides a survival advantage.

METHODS

The United Network for Organ Sharing database was analyzed to include HTx recipients from 1994 to 2016. Recipients were considered as having moderate pHTN if the pulmonary vascular resistance (PVR) was 2.5 to 5 Wood units (WU) or transpulmonary gradient (TPG) was 10 to 18 mm Hg. Heart size mismatch was determined using the predicted heart mass equations. A size mismatch of ≥15% in either direction was considered undersized or oversized, respectively. Ninety-day and 1-year survival were analyzed based on size matching via univariate and Cox regression analysis. Propensity matching was performed to specifically evaluate the effect of donor sex among male transplant recipients.

RESULTS

Among 29,441 HTx recipients, 10,666 had moderate pHTN by PVR criteria and 12,624 HTx patients had moderate pHTN according to TPG criteria. Among patients with a PVR of 2.5 to 5 WU, oversizing was not associated with lower mortality compared with matched hearts at 90 days (7.6% vs 7.4%; p = 0.75) and 1 year (12.1% vs 11.3%; p = 0.26). Conversely, undersizing the donor was associated with a higher 90-day (10.6% vs 7.6% vs 7.4%; p < 0.01) and 1-year (15.3% vs 12.1% vs 11.3%; p < 0.01) mortality than recipients receiving oversized or matched hearts, respectively. On Cox regression analysis, there was no benefit with oversizing at 90 days (hazard ratio [HR] 0.88; p = 0.23) and 1 year (HR 0.99; p = 0.90), whereas undersizing was associated with higher 90-day (HR 1.32; p = 0.02) and 1-year mortality (HR 1.23; p = 0.03) compared to size-matched controls. Among patients with moderate pHTN based on TPG of 10 to 18 mm Hg, neither undersizing nor oversizing was predictive of mortality at 90 days and 1 year according to Cox regression analysis. Propensity matching revealed that female-to-male transplantation had similar 1-year mortality to male-to-male transplantation, and there was no advantage to oversizing female donors for male recipients.

CONCLUSIONS

In this registry-based analysis, there was no benefit to oversizing donors for cardiac transplant recipients with moderate pHTN. Elimination of this restriction could increase the donor pool and reduce wait times for such recipients.

Right ventricular function during exercise in children after heart transplantation

Aims

Right ventricular (RV) dysfunction is a common problem after heart transplant (HTx). In this study, we used semi-supine bicycle ergometry (SSBE) stress echocardiography to evaluate RV systolic and diastolic reserve in paediatric HTx recipients.

Methods and results

Thirty-nine pediatric HTx recipients and 23 controls underwent stepwise SSBE stress echocardiography. Colour tissue doppler imaging (TDI) peak systolic (s') and peak diastolic (e') velocities, myocardial acceleration during isovolumic contraction (IVA), and RV free wall longitudinal strain were measured at incremental heart rates (HR). The relationship with increasing HR was evaluated for each parameter by plotting values at each stage of exercise versus HR using linear and non-linear regression models. At rest, HTx recipients had higher HR with lower TDI velocities (s': 5.4 ± 1.7 vs. 10.4 ± 1.8 cm/s, P < 0.001; e': 6.4 ± 2.2 vs.12 ± 2.4 cm/s, P < 0.001) and RV IVA values (IVA: 1.2 ± 0.4 vs. 1.6 ± 0.8 m/s2, P = 0.04), while RV free wall longitudinal strain was similar between groups. At peak exercise, HR was higher in controls and all measurements of RV function were significantly lower in HTx recipients, except for RV free wall longitudinal strain. When assessing the increase in each parameter vs. HR, the slopes were not significantly different between patients and controls except for IVA, which was lower in HTx recipients.

Conclusion

In pediatric HTx recipients RV systolic and diastolic functional response to exercise is preserved with a normal increase in TDI velocities and strain values with increasing HR. The blunted IVA response possibly indicates a mildly decreased RV contractile response but it requires further investigation.

Impact of gender on echocardiographic characteristics in heart transplant recipients

AIMS

Assessment following heart transplantation (HTx) is routinely performed using transthoracic echocardiography. Differences in long-term mortality following HTx related to donor-recipient matching have been reported, but effects of gender on cardiac size and function are not well studied. The aims of this study were to evaluate differences in echocardiographic characteristics of HTx recipients defined by gender.

METHODS AND RESULTS

The study prospectively enrolled 123 (n = 34 female) HTx recipients of which 23 recipients was donor-recipient gender mismatched. Patients were examined with 2-dimensional echocardiography using Philips iE33 ultrasound system. Data were analysed across strata based on recipient gender and gender mismatch. Male recipients had larger left ventricular (LV) mass, thicker septal wall (P<0·001) and larger absolute LV volumes (P<0·001). Mean LV ejection fraction (EF) was higher in females (P<0·05), but no differences in conventional parameters of right ventricular (RV) function were found. Ventricular strain was higher in females than in males: LV global longitudinal strain (P<0·01), RV global longitudinal strain (P<0·05) and RV lateral free wall (P<0·05). The male group receiving a female donor heart had comparable EF and strain parameters to the female group receiving a gender-matched heart.

CONCLUSION

We found that female recipient gender was associated with smaller chamber size, higher LV EF and better LV and RV longitudinal strain. Gender-mismatched male recipients appeared to exhibit function parameters similar to gender-matched female recipients. Our results indicate that the gender aspect, analogous to current reference guidelines in general population, should be taken into consideration when examining patients post-HTx.

Right Ventricular Dysfunction and Its Contribution to Morbidity and Mortality in Left Ventricular Heart Failure

PURPOSE

In patients with left-sided HF, there has been less emphasis on the pathophysiology of the RV in terms of diagnostic evaluation and treatment, versus focus on structural abnormalities of the LV. This review seeks to delineate the importance of RV dysfunction in terms of its contribution to symptomatic limitations and cardiovascular outcomes in patients with left-sided HF.

RECENT FINDINGS

Recent studies have demonstrated that RV dysfunction is common in both HFpEF and HFrEF, but more pronounced in HFrEF. LV dysfunction and atrial fibrillation are most commonly associated with RV dysfunction in left-sided HF. RV dysfunction may develop due to afterload-dependent and afterload-independent pathways. Regardless, RV dysfunction is strongly associated with functional limitations and worsened survival in patients with left-sided HF. In patients with HFpEF, a recent study showed that RV failure was the most common cause of overall mortality. Among LVAD patients and patients post-cardiac transplantation, RV dysfunction is also strongly associated with survival. Despite a number of previous and ongoing clinical trials that target the RV directly or decrease RV afterload in left-sided HF, there are no definitive therapies specifically targeting RV dysfunction in left-sided HF patients CONCLUSIONS: RV dysfunction is an important determinant of symptomatic limitations and cardiovascular outcomes in patients with left-sided HF. Further research is needed to developed pharmacotherapy that may target the RV specifically in left-sided HF patients.

Normal Reference Ranges for Transthoracic Echocardiography Following Heart Transplantation

BACKGROUND

Heart function following heart transplantation (HTx) is influenced by numerous factors. It is typically evaluated using transthoracic echocardiography, but reference values are currently unavailable for this context. The primary aim of the present study was to derive echocardiographic reference values for chamber size and function, including cardiac mechanics, in clinically stable HTx patients.

METHODS

The study enrolled 124 healthy HTx patients examined prospectively. Patients underwent comprehensive two-dimensional echocardiographic examinations according to contemporary guidelines. Results were compared with recognized reference values for healthy subjects.

RESULTS

Compared with guidelines, larger atrial dimensions were seen in HTx patients. Left ventricular (LV) diastolic volume was smaller, and LV wall thickness was increased. With respect to LV function, both ejection fraction (62 ± 7%, P < .01) and global longitudinal strain (-16.5 ± 3.3%, P < .0001) were lower. All measures of right ventricular (RV) size were greater than reference values (P < .0001), and all measures of RV function were reduced (tricuspid annular plane systolic excursion 15 ± 4 mm [P < .0001], RV systolic tissue Doppler velocity 10 ± 6 cm/sec [P < .0001], fractional area change 40 ± 8% [P < .0001], and RV free wall strain -16.9 ± 4.2% [P < .0001]). Ejection fraction and LV global longitudinal strain were significantly lower in patients with previous rejection.

CONCLUSION

The findings of this study indicate that the distribution of routinely used echocardiographic measures differs between stable HTx patients and healthy subjects. In particular, markedly larger RV and atrial volumes and mild reductions in both LV and RV longitudinal strain were evident. The observed differences could be clinically relevant in the assessment of HTx patients, and specific reference values should be applied in this context.

Low-Dose Donor Dopamine Is Associated With a Decreased Risk of Right Heart Failure in Pediatric Heart Transplant Recipients

BACKGROUND

Previous studies in adults have suggested that donor dopamine treatment may improve recipient outcomes in organ transplantation; in this analysis, we aimed to determine if donor dopamine reduces the incidence of postoperative right heart failure (RHF) in pediatric heart transplant recipients.

METHODS

Data for recipients aged 18 years or younger transplanted at our institution between January 1, 2000, and June 15, 2011, and their respective donors were obtained. The presence of postoperative RHF was assessed for in all subjects. Donor dopamine dose was stratified into 3 groups: none, low-dose (≤5 μg/kg per minute), and high-dose (>5 μg/kg per minute). Logistic regression was used to assess the relationship between donor dopamine dose and recipient RHF.

RESULTS

Of 192 recipients, 34 (18%) experienced postoperative RHF. There was no difference in baseline demographics between recipients with and without RHF. When controlling for pulmonary vascular resistance index, graft ischemic time, and cardiopulmonary bypass time, donor low-dose dopamine was independently associated with a decreased risk of RHF (odds ratio, 0.16; 95% confidence interval, 0.04-0.70; P = 0.02); however high-dose dopamine was neither associated with, nor protective of, RHF (odds ratio, 0.31; 95% confidence interval, 0.06-1.6; P = 0.16).

CONCLUSIONS

Despite advances in perioperative care of the recipient, RHF persists as a complication of pediatric heart transplantation. In this study, donor pretreatment with low-dose dopamine is associated with a decreased risk of postoperative RHF in pediatric heart recipients. Further studies into this association may be useful in determining the utility of empiric donor pretreatment with low-dose dopamine.

Heart Transplantation

Although the number of available donor hearts severely limits the epidemiologic impact of heart transplantation on patients with heart failure, patients with end-stage heart failure unresponsive to medical management currently have no other viable alternatives. Destination therapy with a ventricular assist device is the closest toward approaching clinical reality but has been plagued with problems of infection and stroke. The purpose of this review is to summarize recent developments in the field that may broaden the clinical impact of heart transplantation. For example, novel methods of cardiac preservation are being designed to safely evaluate and utilize “extended criteria” donors. Surgical techniques and medical management have reduced the incidence of postoperative right heart failure, and immunosuppressive regimens promise to limit chronic graft vascular disease.

Roles of inflammation and apoptosis in experimental brain death-induced right ventricular failure

BACKGROUND

Right ventricular (RV) dysfunction remains the leading cause of early death after cardiac transplantation. Methylprednisolone is used to improve graft quality; however, evidence for that remains empirical. We sought to determine whether methylprednisolone, acting on inflammation and apoptosis, might prevent brain death-induced RV dysfunction.

METHODS

After randomization to placebo (n = 11) or to methylprednisolone (n = 8; 15 mg/kg), 19 pigs were assigned to a brain-death procedure. The animals underwent hemodynamic evaluation at 1 and 5 hours after Cushing reflex (i.e., hypertension and bradycardia). The animals euthanized, and myocardial tissue was sampled. This was repeated in a control group (n = 8).

RESULTS

At 5 hours after the Cushing reflex, brain death resulted in increased pulmonary artery pressure (27 ± 2 vs 18 ± 1 mm Hg) and in a 30% decreased ratio of end-systolic to pulmonary arterial elastances (Ees/Ea). Cardiac output and right atrial pressure did not change. This was prevented by methylprednisolone. Brain death-induced RV dysfunction was associated with increased RV expression of heme oxygenase-1, interleukin (IL)-6, IL-10, IL-1β, tumor necrosis factor (TNF)-α, IL-1 receptor-like (ST)-2, signal transducer and activator of transcription-3, intercellular adhesion molecules-1 and -2, vascular cell adhesion molecule-1, and neutrophil infiltration, whereas IL-33 expression decreased. RV apoptosis was confirmed by terminal deoxynucleotide transferase-mediated deoxy uridine triphosphate nick-end labeling staining. Methylprednisolone pre-treatment prevented RV-arterial uncoupling and decreased RV expression of TNF-α, IL-1 receptor-like-2, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and neutrophil infiltration. RV Ees/Ea was inversely correlated to RV TNF-α and IL-6 expression.

CONCLUSIONS

Brain death-induced RV dysfunction is associated with RV activation of inflammation and apoptosis and is partly limited by methylprednisolone.

Cardiac Allograft Function During the First Year after Transplantation in Rejection-Free Children and Young Adults

Background—

Allograft dysfunction is a common finding early after heart transplant (HT). We sought to assess the recovery of left (LV) and right ventricular (RV) function during the first year after HT in children and young adults using pulsed-wave tissue Doppler imaging.

Methods and Results—

We analyzed serially performed echocardiography in 44 pediatric HT recipients (median age: 7.3 years at HT) who remained rejection-free during the first year post-transplant. Age-based normative values for systolic ( S ′), early-diastolic ( E ′), and late-diastolic ( A ′) velocities obtained using pulsed-wave tissue Doppler imaging in 380 healthy children were used to transform patient data into z scores. Pulsed-wave tissue Doppler imaging studies ≤10 days post-HT demonstrated biventricular systolic and diastolic dysfunction with most prominent impairment in RV systolic function ( S ′ z score −2.7±0.8), RV early-diastolic filling ( E ′ z score −2.3±1.1), and LV early-diastolic filling ( E ′ z score −2.3±1.1). LV systolic function ( S ′ z score) and late-diastolic filling ( A ′ z score) improved to normal in 11 to 30 days, LV early-diastolic filling ( E ′ z score) in 4 to 6 months, and RV early-diastolic filling in 6 to 9 months ( P <0.001 for all on longitudinal analysis). However, RV systolic function (RV S ′ z score −1.2±1.1) remained impaired 1-year post-transplant. Analysis of serial cardiac catheterization studies showed that RV and LV filling pressures were elevated early post-HT and declined gradually during the first year post-transplant.

Conclusions—

Pediatric HT recipients have biventricular dysfunction using pulsed-wave tissue Doppler imaging early after HT with most significant impairment in RV systolic function and RV and LV early-diastolic filling. Although other aspects of LV and RV function normalize in 6 to 9 months, RV systolic function remains abnormal 1 year-post-transplant.

Frequency, time course, and possible causes of right ventricular systolic dysfunction after cardiac transplantation: a single center experience

BACKGROUND

The frequency and causes of right ventricular (RV) systolic dysfunction early after cardiac transplantation are not well defined.

METHODS

We investigated the prevalence and causes of RV dysfunction in 27 heart transplant recipients, as measured by lateral tricuspid annular plane excursion (TAPSE) and fractional area change (FAC) at a mean of 15 ± 11 days after transplant. Tissue Doppler imaging was used to assess systolic time velocity integral (TVI) of the RV basal free wall. A subset of 22 patients had follow-up TAPSE measurement at 406 ± 121 days.

RESULTS

RV systolic dysfunction, defined as TAPSE > 2 standard deviation (SD) below values in a control group, was present in 100% (27/27) of patients (P < 0.05). FAC was also significantly lower in patients compared with controls (P < 0.0001). TVI confirmed the presence of RV dysfunction in all 16 patients with both TAPSE and TVI (P < 0.05). Ischemic time (P = 0.017) and posttransplant tricuspid regurgitation (P = 0.024) were independent predictors of early RV dysfunction (r = 0.753). On follow-up, RV function improved in 15 of 22 patients but all patients remained with TAPSE > 2 SD below controls.

CONCLUSION

This study showed that 100% of patients had reduced RV function early after transplant. Two thirds of patients had partial recovery of RV function during the first year. In all patients, however, RV function remained significantly lower than in controls.

Left Ventricular Circulatory Support as Bridge to Heart Transplantation in Chagas' Disease Cardiomyopathy

This study was performed to assess the safety and feasibility of the implantation of ventricular assist devices (VADs) as a bridge to heart transplantation in patients with advanced biventricular failure due to Chagas' disease. Six patients were submitted to paracorporeal left VAD implantation, while right ventricular dysfunction was managed clinically. The mean time of circulatory support was 27 days. Two patients were bridged to heart transplantation successfully, while the other four patients died under assistance with complications that correlated with the final situation of multiple organ failure. Nevertheless, persistent right ventricular dysfunction was observed only in one patient who survived more than 15 days, despite the general significant preoperative compromise of the right ventricle. This paradoxical observation indicates that left VAD implantation may be regarded as a valuable treatment option for patients with Chagas' disease cardiomyopathy who evolve with decompensated heart failure or cardiogenic shock.

Medical management to optimize donor organ potential: review of the literature

PURPOSE

Over the past two decades, the demand for donor organs continues to outpace the number of organs available for transplantation. Parallel with this has been a change in the demographics of organ donors with an increase in older donors and donors with marginal organs as a proportion of the total organ donor pool. Consequently, efforts have been made to improve the medical care delivered to potential organ donors to improve the conversion rate and graft survival of available organs. The purpose of this literature review is to provide updated recommendations for the contemporary management of organ donors after the neurological determination of death in order to maximize the probability of recipient graft survival.

SOURCES

A comprehensive review of the literature obtained through searches of MEDLINE/PubMed, and personal reference files.

PRINCIPAL FINDINGS

Contemporary management of the organ donor after neurological determination of death includes therapies to prevent the detrimental effects of the autonomic storm, the use of invasive hemodynamic monitoring and aggressive respiratory therapy including therapeutic bronchoscopy in marginal heart and lung donors, and the use of hormonal therapy including vasopressin, corticosteroids, triiodothyronine or thyroxine, and insulin for the pituitary failure and inflammation seen in brain dead organ donors. The importance of normalizing donor physiology to optimize all available organs is stressed.

CONCLUSION

Aggressive hemodynamic and respiratory management of solid organ donors, coupled with the use of hormonal therapy improves the rate of conversion and graft survival in solid organ recipients.

Brain death leads to abnormal contractile properties of the human donor right ventricle

OBJECTIVES

Experimental and clinical data suggest that brain death predominantly affects the right ventricle. We aimed to investigate right ventricle function after brain death and during clinical transplantation with load-independent methods.

METHODS

Patients with and without brain death were enrolled. A total of 33 consecutive heart donors (5 live, "domino" donors) and 10 patients undergoing coronary surgery (coronary artery bypass graft controls) were studied with pressure-volume loops in the right ventricle. Contractile reserve was measured with dopamine stimulation.

RESULTS

Brain-dead donors had a higher mean cardiac index than coronary artery bypass graft controls (3.3 vs 2.8 L/min/m2), but impaired load-independent indices. Despite increased right ventricle stroke volume, the ejection fraction and slope of the end-systolic pressure-volume relationship were significantly reduced in brain-dead donors compared with controls. Diastolic abnormalities were also manifest as increased end-diastolic volume index and prolonged Tau (P < .05). Dopamine improved cardiac output, but without influencing end-systolic pressure-volume relationship, or Tau, and at the expense of further increased right ventricle end-diastolic volume. Before explantation, a significantly higher diastolic volume was also seen in hearts that developed postoperative dysfunction compared with organs without this complication (114.4 vs 77.2 mL/m2, P = .02).

CONCLUSIONS

Brain death leads to right ventricle dysfunction, which may go undetected with conventional techniques. Right ventricle dilatation could represent an early marker of failure. Refinement of selection criteria to include load-independent indices of performance may be desirable to help expand the donor pool.

Normalization of Right Ventricular Performance and Remodeling Evaluated by Magnetic Resonance Imaging at Late Follow-up of Heart Transplantation: Relationship Between Function, Exercise Capacity and Pulmonary Vascular Resistance

BACKGROUND

Right ventricular (RV) dysfunction remains one of the most prominent complications during the period immediately after heart transplantation (HT); however, late adaptation of the RV has not been well described. The aim of our study was to evaluate RV function and remodeling using magnetic resonance imaging (MRI) and to correlate it with exercise capacity and also with hemodynamic data obtained before HT.

METHODS

We prospectively evaluated RV function of 25 heart-transplanted patients, without cardiac allograft vasculopathy, who were documented by negative dobutamine stress echocardiography during late follow-up (Group 1, 6 +/- 4.3 years) using MRI. We then compared Group 1 with a control group consisting of 10 patients, who were < or =1 year post-HT (Group 2), hemodynamically stable, and with the same pre-operative hemodynamic features as Group 1. Their pulmonary arterial systolic blood pressure (PSBP) varied from 17 to 67 mm Hg (43.2 +/- 15.3) and pulmonary vascular resistance (PVR) from 1.0 to 5.4 Wood units (2.5 +/- 1.12). The following parameters were studied: RV end-diastolic volume (EDV) and systolic volume (ESV); stroke volume (SV); ejection fraction (EF); and mass (M). We also evaluated the VO2 peak and slope VE/VCO2 values during a treadmill test. Data were analyzed and correlated with the hemodynamic values of PVR and PSBP obtained pre-HT.

RESULTS

In Group 1, treadmill evaluation data showed exercise VO2 peak (19.9 +/- 3.19 ml/kg/min) and slope VE/VCO2 (36.9 +/- 4.5) values comparable to those of sedentary individuals; RV variables according to MRI were within normal ranges, with the following mean values for Groups 1 and 2, respectively: RVEDV, 99.6 +/- 4.0 ml vs 127 +/- 16 ml (p = 0.03); RVESV, 42 +/- 2 ml vs 58.5 +/- 9 ml (p = 0.01); RVSV, 57 +/- 3 ml vs 71 +/- 10 ml (p = 0.1); RVEF, 58 +/- 1.4% vs 54 +/- 3.8% (p = 0.29); and RVM, 43.4 +/- 1.9 g vs 74 +/- 8.8 g (p = 0.001). There was no correlation between hemodynamic pulmonary values before HT or any other index of late RV performance, including RV remodeling and hypertrophy, in our study population (p = not significant).

CONCLUSIONS

In contrast to what we would expect for heart transplant patients at late follow-up, the RV may adapt to pulmonary pressure and resistance, with reverse remodeling characterized by volume and mass reduction, leading to normalization of RV function despite abnormal hemodynamic pulmonary values being measured before HT. There was no influence on the low exercise capacity observed in these patients, in the absence of cardiac allograft vasculopathy.

Endothelial activation in the transplanted human heart from organ retrieval to 3 months after transplantation: an observational study

BACKGROUND

Endothelial activation in the donor heart has been described variably after brain death and transplantation. We aimed to characterize the time course of endothelial activation in right ventricle (RV) and left ventricle (LV) during the acute phase of clinical transplantation.

METHODS

We studied biopsy specimens from the RVs and the LVs of 40 donor hearts: at initial assessment of the donor, at end-ischemia, and after 10 minutes of reperfusion. We also included follow-up RV biopsy specimens at 1 week, 1 month, and 3 months after surgery. Six of the patients had cystic fibrosis and were domino donors.

RESULTS

P-selectin and vascular cell adhesion molecule 1 (VCAM-1), but not E-selectin were up-regulated in brain-dead and in domino donors vs controls. Unused donor hearts (n = 6) had significantly less up-regulation of P-selectin and of VCAM-1. We found no difference between the RV and the LV during surgery, but we did see important time-dependent variations. P-selectin was present in 85% of vessels throughout transplantation and decreased to approximately 60% after transplantation (p < 0.001). We initially detected VCAM-1 in 20% of vessels, which decreased to 5% during storage, then increased to 47% at reperfusion, and gradually decreased thereafter (p < 0.001). E-selectin expression increased progressively from 15% initially to 45% at reperfusion and then decreased after surgery (p = 0.001). Thrombomodulin expression was decreased at baseline, and the decrease was accentuated afterward (p = 0.02). Patients with donor organ failure did not have a specific pattern of endothelial activation.

CONCLUSION

Cardiac transplantation is associated with marked endothelial activation, with no difference between the two ventricles. The changes persist in the post-operative period, even in the absence of acute rejection.

Noradrenaline Use in the Human Donor and Relationship with Load-Independent Right Ventricular Contractility

BACKGROUND

Experimental and clinical studies suggest that brain death (BD)-associated cardiac dysfunction is related to the neurohormonal storm and subsequent exposure to intravenous catecholamines. We aimed to describe the relationship between empirical noradrenaline treatment and donor heart function, described for the first time with load-independent indices of right ventricular contractility.

METHODS

Twenty-seven BD patients were divided in three groups based on noradrenaline at time of offer, started by the donor hospital: group 1=no noradrenaline (n=11); group 2=low dose (n=8); group 3=high dose (n=8). After protocol-guided optimization by our retrieval team using a Swan-Ganz catheter, pressure-volume data were obtained from the right ventricle. Ten patients undergoing coronary revascularization served as controls.

RESULTS

Twenty hearts were transplanted, seven of them as heart and lung blocks. Right ventricular end-systolic elastance (E(es)) was lower in BD donors compared with controls (mean 0.28 vs. 0.46 mm Hg/mL, P< or =0.01). There was no difference in terms of Swan-Ganz derived data between the BD subgroups, but E(es) was lower in groups 2 and 3 (P=0.04). Eight patients died within a year (four from graft failure), and they had a donor heart E(es) significantly lower than that of survivors (mean 0.20 vs. 0.33 mm Hg/mL, P=0.01).

CONCLUSION

Hearts from BD donors have subclinical right ventricular impairment in contractility. E(es), a load-independent measure of contractile function, seems to be inversely correlated with empirical use of noradrenaline in the donor and with recipient survival at 1 year. This has implications for refining donor selection and management.

Changing donor and recipient demographics in a heart transplantation program: influence on early outcome

BACKGROUND

The purpose of this study was to investigate whether broadening acceptance criteria for donor hearts and changing recipient demographics resulted in an increased perioperative morbidity and mortality in a heart transplant program.

METHODS

Donor and recipient data of 137 consecutive heart transplants performed from 1987 to 2001 were retrospectively analyzed and divided into three equal eras, each of 5 years: 1987 to 1991, 1992 to 1996, and 1997 to 2001. Multivariate analyses of recipient and donor demographics and operative factors were performed to identify the predictors of low cardiac output, intraaortic balloon pump utilization, 30-day mortality, and duration of intensive care and hospital stay.

RESULTS

Significant increases in number of female recipients (p = 0.025), cardiopulmonary bypass (p < 0.001), recipient cross-clamp (p < 0.001), donor age (p = 0.009), donor ischemic times (p < 0.001), use of cardioplegia (p < 0.001) and the bicaval technique (p < 0.001), brain death to retrieval time (p = 0.006), and need for postoperative dialysis were observed for the three study periods, whereas length of intensive care and hospital stay decreased. Female donor (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.0 to 5.7) was identified as a risk factor for low cardiac output. Female donor (OR, 3.7; 95% CI, 1.3 to 10.7), donor cardiac arrest (OR, 6.4; 95% CI, 1.6 to 25.9), and cardiopulmonary bypass time more than 2 hours (OR, 7.6; 95% CI, 2.1 to 28.1) were associated with increased intraaortic balloon pump utilization. Intensive care stay was prolonged by the biatrial technique (OR, 3.9; 95% CI, 1.3 to 11.9) and reduced by the use of cardioplegia (OR, 0.3; 95% CI, 0.1 to 0.9), longer cardiopulmonary bypass (OR, 0.2; 95% CI, 0.1 to 0.6) and aortic cross-clamp times (OR, 0.1; 95% CI, 0.03 to 0.6).

CONCLUSIONS

Although a number of significant changes were observed during the study period, no donor, recipient, or operative factors influenced 30-day mortality. This study justifies our current donor and recipient selection policies.

Analyse des critères qui participent à la décision de prélèvement cardiaque chez les patients en état de mort encéphalique

OBJECTIVES

The number of cardiac transplantation procedures does not increase because of the lack of donor hearts despite an increase in the number of brain-dead organ donors. The criteria used to select a donor heart are not formally standardized. The aim of the present study was to analyze the criteria that contribute to the selection of a donor heart.

TYPE OF STUDY

Descriptive, retrospective study.

PATIENTS AND METHOD

Clinical parameters, the initial causes that lead to brain death, maximum doses of catecholamines, several biochemical markers of myocardial ischaemia/necrosis as well as several echocardiography criteria were extracted from a prospectively collected database. Univariate and multivariate (logistic regression) analyses were performed with the "harvested heart" as dependent variable and the above-cited independent variables.

RESULTS

One hundred and eighty consecutive brain-dead patients admitted from 1st October 1998 to 31st December 2000 out of which 112 gave at least one organ were analyzed. Among these 112 patients, 59 (39 males and 20 females) were pre-selected as potential heart donors. Only 44 hearts were harvested. Logistic regression analysis showed that harvesting of the heart was more probable if the donor were a male, had no left ventricle systolic wall motion abnormalities, had low doses of norepinephrine and low serum troponin Ic concentrations.

CONCLUSION

After an initial phase of selection, the final decision to harvest a heart is based on several criteria. These results should be an incentive to conceive a score that could allow a more formal decision process for heart harvesting.

Reduction of tricuspid annular doppler tissue velocities in pediatric heart transplant patients

BACKGROUND

Orthotopic heart transplantation is a life-saving therapy for children with end-stage heart disease. However, 50% of these transplanted children die or require re-transplantation 12 years later. Progressive deterioration of cardiac function is a common feature of long-term survivors; however, quantitative evaluation of the state of the right ventricle has been lacking. Tissue Doppler imaging (TDI) has been used to measure alterations in right ventricular (RV) function in other illnesses. The purpose of this study was to quantitate abnormalities in tricuspid annular systolic and diastolic velocities as an indicator of RV dysfunction, and to evaluate if time since transplantation and the presence of tricuspid regurgitation are associated with quantitative changes in tricuspid annular velocities in pediatric heart transplant recipients.

METHODS

TDI was performed and velocities recorded during systole and early and late diastole at the tricuspid annulus, septum and mitral annulus in transplanted patients and in a control group with normal hearts. Pulsed wave Doppler mitral and tricuspid inflows were also measured and the severity of tricuspid regurgitation was estimated using color flow mapping. Patients with biopsy evidence of active cellular rejection or left ventricular ejection fraction of <60% were excluded from study.

RESULTS

Thirty-five patients were divided into a normal heart group (n = 14) and a transplant group (n = 21), aged from 1 to 23 years. Systolic and early diastolic velocities at the tricuspid annulus and septum in the transplant group were reduced significantly compared with the normal group (p < 0.05): tricuspid annular systolic, 5.8 +/- 1.4 vs 9.4 +/- 1.7 cm/sec; early diastolic, -6.4 +/- 2.6 vs -9.7 +/- 2.6 cm/sec; septum systolic, 3.9 +/- 1.5 vs 5.8 +/- 1.4 cm/sec; and early diastolic, -6.3 +/- 2.4 vs -9.1 +/- 2.5 cm/sec. Patients were divided into early (<5 years) and late (>5 years) term groups since transplantation. Tissue velocities at the tricuspid annulus in the late term group had further reduction in systole, 4.9 +/- 1.4 vs 6.4 +/- 1.1 cm/sec, and early diastole, -5.3 +/- 1.5 vs -7.1 +/- 2.9 cm/sec (p < 0.05). Patients with severe tricuspid regurgitation had systolic and early diastolic velocities at the tricuspid annulus that were further reduced. Left ventricular mitral inflow Doppler early/late diastolic ratios became significantly different from the normal group 5 years after transplantation (p < 0.05).

CONCLUSIONS

TDI demonstrated that tricuspid annular systolic and early diastolic velocities were abnormal in children after transplantation and became significantly more abnormal with prolonged time after transplantation. These alterations were not dependent on the presence of severe tricuspid regurgitation but appeared to be exacerbated by its presence. Evidence of diastolic left ventricular dysfunction was not detected before 5 years after transplantation in this unselected group. A prospective study may be required to define the evolution and progression of right and left ventricular dysfunction in children after heart transplantation.

Ventricular adrenomedullin is associated with myocyte hypertrophy in human transplanted heart

Adrenomedullin (ADM) is a vasoactive and natriuretic peptide. While it is known that ADM is increased in failing human ventricles, the expression of ADM in human ventricular allografts remains unknown. The present study was designed to investigate tissue localization and intensity of ADM expression in ventricular biopsy specimens and to characterize ventricular ADM in human cardiac allografts. Thirty-three post-transplant endomyocardial biopsy specimens were examined immunohistochemically. The average score (range: 0-4) of ADM immunoreactivity (IR) was 2.4+/-0.9 (mean+/-standard deviation). Right ventricular (RV) systolic pressure was significantly increased with high ADM-IR (p=0.048) and the ADM-IR positively associated with myocyte size (r(2)=0.23, p=0.010). In contrast, ADM-IR was not associated with systemic blood pressure, serum creatinine, cyclosporine concentration, cardiac fibrosis, or allograft rejection. The present study shows that ADM-IR is present in human ventricular endomyocardium after transplantation, and ADM-IR is associated with the magnitude of RV pressure and myocyte size, suggesting an important role for ventricular ADM in the counteraction against overload as well as in the progress of myocyte hypertrophy after heart transplantation.

The energy metabolism in the right and left ventricles of human donor hearts across transplantation

OBJECTIVE

Brain death appears to predominantly affect the right ventricle (RV) and right ventricular failure is a common complication of clinical cardiac transplantation. It is not clear to what extent myocardial energy stores are affected in the operative sequence. We aimed to describe the time-dependent variation in high energy phosphate (HEP) metabolism of the two ventricles, and the relationship with endothelial activation and postoperative functional recovery.

METHODS

Fifty-two human donors had serial biopsies from the RV and the left ventricle (LV) at (1) initial evaluation, (2) after haemodynamic optimisation, (3) end of cold ischaemia, (4) end of warm ischaemia, (5) reperfusion, and (6) at 1 week postoperatively. HEP was measured by chemiluminescence in biopsies 1-5 and adhesion molecules (P-selectin, E-selectin, VCAM-1) and thrombomodulin were analysed by immunohistochemistry in biopsies 5-6. Seventeen donors and five recipients had RV intraoperative pressure-volume recordings by a conductance catheter. Six patients served as live controls.

RESULTS

Brain death did not affect HEP metabolism quantitatively. There was no difference between the RV and LV at any time point, but significant time-dependent changes were observed. The RV was prone to HEP depletion at retrieval, with ATP/ADP falling from 3.89 to 3.13, but recovered during cold ischaemia. During warm ischaemia the ATP/ADP ratio fell by approximately 50%, from 5.48 for the RV and 4.26 for the LV, with partial recovery at reperfusion (P<0.005). Hearts with impaired function in the recipient showed marked variations in HEP levels at reperfusion, and those organs with RV dysfunction failed to replenish their energy stores. However, these organs were not different from normally functioning allografts in terms of endothelial activation and clinical risk factors. There was poor correlation between pressure-volume and HEP data in either donor or recipient studies. Hearts followed-up with HEP and pressure-volume studies showed improvement in the recipient, despite functioning against a higher pulmonary vascular resistance.

CONCLUSIONS

HEP are preserved over a wide range of contractile performance in the donor heart, with no metabolic difference between the two ventricles. No correlation with endothelial activation was seen either. Preservation efforts should be directed to the vulnerable periods of implantation and reperfusion.

Long-term results of cardiac transplantation from live donors: the domino heart transplant

BACKGROUND

Hearts explanted from the recipients of heart-lung transplants provide a unique source of transplants from live donors. This article presents long-term results with this procedure at our center.

METHODS

We performed a retrospective chart review of domino transplantations performed in our institution between 1989 and 1998.

RESULTS

We analyzed 131 domino transplants (123 orthotopic, 8 heterotopic). Domino hearts were from patients with cystic fibrosis (69%), primary pulmonary hypertension (15%), and other diagnoses (16%). The mean recipient pulmonary vascular resistance (PVR) was 3.1 Wood units, 25% of patients having values >4 Wood units. Thirty-day mortality was 13%. The 1-, 5-, and 10-year graft survival was 75% (70% confidence interval [CI], 65-74), 70% (70% CI, 65-74), and 58% (70% CI, 52-64), respectively. Patients with PVR >4 Wood units had 1-year survival (76%; 70% CI, 69-84) similar to that of patients with PVR of < or =4 units (74%; 70% CI, 69-80). Recipients of hearts from patients with cystic fibrosis survived longer (5-year survival, 76%; 70% CI, 71-82) vs 65% for non-cystic fibrosis hearts (70% CI, 57-74) p = 0.09). One-year survival was decreased after transplantation of hearts from female donors (66%; 70% CI, 60-72)) compared with hearts from male donors (85%; 70% CI, 79-90); p = 0.06). Late deaths caused by coronary artery disease and malignancy were uncommon.

CONCLUSION

Although the rate of early mortality after domino transplantation was slightly higher than after cadaveric transplantation, we noted a remarkably low long-term attrition rate in recipients of domino grafts, up to 10 years. In addition, successful transplantation of patients with high PVR supports the hypothesis that heart-lung recipients may provide superior donor hearts for this patient group, many of whom traditional listing criteria would exclude.

Brain death does not affect hepatic allograft function and survival after orthotopic transplantation in a canine model

BACKGROUND

Brain death has been shown to decrease graft function and survival in rodent models. The aim of this study was to evaluate how brain death affects graft viability in the donor and liver tolerance to cold preservation as assessed by survival in a canine transplant model.

METHODS

Beagle dogs were used for the study. Non-brain dead (BD) donors served as controls. Brain death was induced by sudden inflation of a subdural balloon catheter with continuous monitoring of arterial blood pressure and electroencephalographic activity. Sixteen hours after confirmation of brain death, liver grafts were retrieved. All livers were flushed in situ and preserved for 24 hr in cold University of Wisconsin solution before transplantation. Recipient survival rates, serum hepatic enzyme levels, coagulation, and metabolic parameters of the recipients were analyzed.

RESULTS

No significant changes were observed in serum aminotransferases (alanine and aspartate transaminases) and lactate dehydrogenase levels in the BD donor. After preservation, control (n=6) and BD livers (n=5) showed full functional recovery after transplant with 100% survival in both groups at day 7. There was no significant difference in peak serum alanine, aspartate transaminases, and lactate dehydrogenase after transplantation in recipients who received a liver from BD donor compared to control group. BD livers were functionally as capable as control livers in correcting metabolic acidosis during the first 24 hr posttransplantation. Coagulation profiles (index normalized ratio, activated partial thromboplastin time) after reperfusion were similar between groups.

CONCLUSION

In contrast to previous reports in rodent models, our study shows that brain death does not cause significant liver dysfunction in the donor before organ removal. Donor brain death and prolonged liver graft preservation do not interact significantly to impair liver function and survival after transplantation.

The paradox of survival results after heart transplantation for cardiomyopathy caused by Trypanosoma cruzi. First Guidelines Group for Heart Transplantation of the Brazilian Society of Cardiology

BACKGROUND

Donor supply limits heart transplantation (HT) and relative priority should be given to cases with greater chances of success. The objectives of this multicenter study were (1) to determine the survival rate after heart transplantation for patients with Chagas' heart disease (ChHD) in comparison with other causes; and (2) to identify the causes of death specifically due to reactivation of the Trypanosoma cruzi infection.

METHODS

We studied 720 patients who had undergone orthotopic heart transplantation and were followed in 16 heart transplantation centers. The etiology was idiopathic dilated cardiomyopathy in 407 patients, ischemic cardiomyopathy in 196 patients, and ChHD in 117 patients.

RESULTS

Follow-up was 2.87 +/- 3.05 years (from 1 month to 13.85 years). Survival of ischemic recipients at 1, 4, 8, and 12 years was 59%, 44%, 34%, and 22%, respectively; for idiopathic dilated cardiomyopathy it was 69%, 57%, 40%, and 32%; and for ChHD it was 71%, 57%, 55%, and 46% (p < 0.027). In ischemic recipients the most frequent causes of death were infection (15.3%), acute graft failure (13.3%), and graft coronary artery disease/sudden death (7.7%). In idiopathic dilated cardiomyopathy the causes were infection (11.1%), rejection (9.6%), and acute graft failure (9.1%). In ChHD the causes were infection (10.3%), rejection (10.3%), and neoplasm (4.3%). In ChHD, reactivation of the cruzi infection was the cause of death in 2 patients.

CONCLUSIONS

The survival results after heart transplantation are paradoxical according to the usually high expected death rates for Chagas' disease. Heart transplantation for ChHD should be regarded as a valuable treatment option.

The Brazilian experience with heart transplantation: a multicenter report

BACKGROUND

The results of heart transplantation in developing countries are influenced by the high incidence of marginal donors and the large number of recipients with characteristics of alternative list. The purpose of this multicenter report was to determine the rate of survival after heart transplantation in a developing country. Also we studied the causes of death, the results based on the year of transplant, the influence of gender and age, the numbers of transplants per year, and the etiology of the cardiomyopathy causing the heart failure.

METHODS

We studied 792 (632 male) patients who underwent orthotopic heart transplantation at 16 centers. The mean age of the patients was 42 +/- 16 years. Etiology included idiopathic dilated cardiomyopathy in 407 patients, ischemia in 196 patients, Chagas disease in 117 patients, and various other in 72 patients. Cyclosporine was the cornerstone of the immunosuppression administered.

RESULTS

Survival for the entire population at 3 months and 1, 4, 8, and 12 years was 72%, 66%, 54%, 40%, and 27%, respectively. There was an improvement in survival from 1991 to 1995 compared with before 1991. Age and gender did not influence the results. Unexpected early mortality was observed, but the late results were satisfactory. The most prevalent causes of death were infection in 23%, acute graft failure in 19%, and rejection in 18%.

CONCLUSIONS

Heart transplantation has become feasible in developing countries and the survival rate has improved without the influence of gender and age recipients. A chagasic etiology was found to be the third-leading indication for heart transplantation. The impact of increment of donors with appropriate care for reduction of marginal donors, perhaps associated with better recipient selection and postoperative care, should be investigated for improving early results.