Clinical, haemodynamic and echocardiographic features of early cardiac graft dysfunction

BACKGROUND

The main cause of early death after heart transplantation (HTx) is so-called early primary or secondary graft failure (GF). The risk of profound GF has not declined in the past decade, as the consequence of the liberalisation of donor acceptance criteria because of the scarcity of donors. It is therefore important to try to diagnose graft failure and recognise the mechanisms of early graft dysfunction.

AIM

To establish haemodynamic and echocardiographic criteria of early GF to define patients who should be considered for assist device support or re-transplantation.

METHODS

Between January 2000 and March 2009, 116 HTx patients were studied. On the basis of echocardiography and continuous invasive monitoring, three groups were identified: (1) The true graft failure group (GF) consisted of 46 patients; (2) The latent right ventricular (RV) dysfunction group (RV-D) consisted of 25 patients with small left ventricular (LV) chamber (〈 39 mm) and RV ejection fraction (RVEF) 〈 50%; (3) The control group consisted of 45 consecutive HTx patients without any haemodynamic complications.

RESULTS

Postoperatively, only the GF group required large doses of norepinephrine (〉 0.3 μmg/kg/min) and inhalative NO (40 ppm). Nevertheless, right and left filling pressures were significantly higher than in the controls (right 12 ± 3.6 vs. 9.0 ± 2 and left atrial pressure 13.0 ± 3.2 vs. 9.6 ± 2 mm Hg, both p 〈 0.001). Cardiac index was significantly smaller (2.9 ± 0.7 vs. 3.7 ± 0.9, p 〈 0.001) but neither pulmonary artery pressure (29.5 ± 6 vs. 29.7 ± 7 mm Hg) nor transpulmonary gradient (6 ± 5 vs. 5.1 ± 5 mm Hg) nor pulmonary vascular resistance (273 ± 97 vs. 287 ± 144 dyn × s × cm-5) differed significantly from those of the control group. In the GF group, LV end diastolic dimension (LVEDD) was significantly smaller and function poorer than in controls (39.8 ± 5 vs. 44.4 ± 5 mm, respectively, p = 0.001). RV function was also significantly worse (RVEF 42.2 ± 14% vs. 56.0 ± 9%), respectively, p = 0.001), whereas RV dimension did not differ significantly. Mechanical support after failure of the initial medical treatment was necessary in 37% of patients; 29 (63.0%) patients from the GF group died, the cause of death being sepsis with multi-organ failure. In the RV-D group, remodelling was quite similar but LVEF was excellent and maximal systolic velocity from the posterior wall was significantly higher than in GF. No death occurred.

CONCLUSIONS

True early GF represents a grave haemodynamic situation with high mortality. Bedside echocardiography helps to distinguish between latent RV dysfunction and true GF.

Utility of screening computed tomography of chest, abdomen and pelvis in patients after heart transplantation

INTRODUCTION

Malignancy is a late cause of mortality in heart transplant recipients. It is unknown if screening computed tomography scan would lead to early detection of such malignancies or serious vascular anomalies post heart transplantation.

METHODS

This is a single center observational study of patients undergoing surveillance computed tomography of chest, abdomen and pelvis at least 5 years after transplantation. Abnormal findings, included pulmonary nodules, lymphadenopathy and intra-thoracic and intra-abdominal masses and vascular anomalies such as abdominal aortic aneurysm. The clinical follow up of each of these major abnormal findings is summarized.

RESULTS

A total of 63 patients underwent computed tomography scan of chest, abdomen and pelvis at least 5 years after transplantation. Of these, 54 (86%) were male and 9 (14%) were female. Mean age was 52±9.2 years. Computed tomography revealed 1 lung cancer (squamous cell) only. Non specific pulmonary nodules were seen in 6 patients (9.5%). The most common incidental finding was abdominal aortic aneurysms (N=6 (9.5%)), which necessitated follow up computed tomography (N=5) or surgery (N=1). Mean time to detection of abdominal aortic aneurysms from transplantation was 14.6±4.2 years. Mean age at the time of detection of abdominal aortic aneurysms was 74.5±3.2 years.

CONCLUSION

Screening computed tomography scan in patients 5 years from transplantation revealed only one malignancy but lead to increased detection of abdominal aortic aneurysms. Thus the utility is low in terms of detection of malignancy. Based on this study we do not recommend routine computed tomography post heart transplantation.

Myelofibrosis on 18F-FDG-PET/CT in a case suspicious for post-transplant lymphoproliferative disorder

Recent studies have advocated the utility of fluorine-18 fluorodeoxyglucose-positron emission tomography (18)F-FDG-PET imaging in evaluation of various hematological disorders. We report a case of a 61-year-old man with clinical suspicion of post-transplant lymphoproliferative disorder (PTLD) where (18)F-FDG-PET/CT (computerized tomography) was helpful in identifying myelofibrosis. This paper aims to reveal the potential diagnostic value of PET/CT as an imaging modality in the evaluation of myelofibrosis.

Effect of respiration on the spectral Doppler wave of the right hepatic vein in right lobe living donor liver transplant recipients

OBJECTIVE

The purpose of this study was to evaluate the effect of respiration on the spectral Doppler wave of the right hepatic vein (RHV) in right lobe living donor liver transplant (LDLT) recipients.

METHODS

A spectral Doppler wave of the RHV was obtained from 23 consecutive right lobe LDLT recipients who had no complications and from 26 healthy subjects during free breathing, breath holding at expiration, and breath holding at inspiration. To assess the RHV flow quantitatively, the venous periodicity index (VPI) was calculated as follows: VPI=(V(F)-V(R))/V(F), where V(F) was the measured peak forward velocity, and V(R) was the measured peak reversed velocity. The mean VPIs of the RHV obtained in the 3 respiratory states were compared by repeated measures analysis of variance. Spectral Doppler waves of the RHV were categorized as triphasic with or without reversed flow, biphasic, or monophasic and were compared among the 3 respiratory states.

RESULTS

In both right lobe LDLT recipients and healthy subjects, the mean VPIs of the RHV obtained during breath holding at inspiration were significantly lower than those during free breathing (P<.001) and breath holding at expiration (P<.001). The wave pattern during breath holding at inspiration was monophasic in 7 (30.4%) right lobe LDLT recipients and 3 (11.5%) healthy subjects, whereas the monophasic pattern was not seen during free breathing or breath holding at expiration in any of these subjects.

CONCLUSIONS

Breath holding at inspiration significantly reduces the periodicity of RHV flow and can make otherwise pulsatile RHV flow monophasic in right lobe LDLT recipients without postoperative complications as well as in healthy individuals.

Cardiac CT of the transplanted heart: indications, technique, appearance, and complications

Effective antirejection therapy and infection control have significantly improved the long-term survival of heart transplant recipients, but coronary allograft vasculopathy remains an important limiting factor. Most heart transplant recipients undergo annual coronary angiography for the detection of allograft vasculopathy, which is often clinically silent. Angiography allows detection of vasculopathy only indirectly, with depiction of the lumen, and does not depict the wall thickening and intimal hyperplasia that typify this disease; the procedure also is invasive and is associated with a 1%-2% risk of complication. In contrast, electrocardiographically gated multidetector computed tomography (CT) can provide a comprehensive and noninvasive evaluation of the transplanted heart in a single study. Cardiac CT enables evaluation of the coronary artery lumen and wall and thus may be used for screening, diagnosis, grading, and follow-up of coronary allograft vasculopathy. It also may be used to detect other posttransplantation complications, such as malignancy and infection, and to assess cardiac and vascular anastomoses and cardiac function. However, special strategies may be needed to reduce the transplant heart rate so as to obtain images of diagnostic quality.

Intravascular ultrasound correlates with coronary flow reserve and predicts the survival in angiographically normal cardiac transplant recipients

OBJECTIVES

We aimed to determine whether epicardial and intramyocardial arteries were involved concordantly in early cardiac allograft vasculopathy.

METHODS

Thirty consecutive recipients who had received cardiac transplantation more than 1 year before and had a normal coronary angiogram were enrolled for intravascular ultrasound (IVUS), fractional flow reserve, coronary flow reserve and dipyridamole thallium-201 single photon emission computed tomography. Graft failure including cardiac death and retransplantation served as the primary outcome.

RESULTS

Plaque volume index and maximum area stenosis calculated from IVUS measurements correlated with coronary flow reserve deterioration in a subgroup of patients with normal fractional flow reserve (n = 13; r = -0.80, p = 0.001 and r = -0.91, p <0.0001, respectively). After follow-up for 18.4 +/- 7.6 months, maximum area stenosis was found to be an independent predictor of graft failure (hazard ratio 1.43, 95% confidence interval 1.08-1.89, p = 0.012).

CONCLUSION

In patients with physiologically normal epicardial coronary arteries, impairment of microvascular integrity correlates with the plaque burden measured by IVUS, suggesting the concordant involvement of both epicardial and resistant vessels in early cardiac allograft vasculopathy. Evident epicardial coronary narrowing on IVUS may predict graft failure in spite of normal coronary angiograms.

Echocardiography in the cardiac transplant recipient

Despite the widespread use of echocardiography in the cardiac allograft recipient, the clinical usefulness of this practice is not well defined. In this article, the authors review the spectrum of echocardiographic findings in the adult heart transplant patient. Appreciation of typical alterations from "normal" allows the transplant physician to identify clinically significant changes and to avoid unnecessary invasive procedures based on misinterpretation of these differences. Though abnormalities of systolic and diastolic function correlate with episodes of acute rejection, the primary diagnostic usefulness of echocardiography in acute rejection is guiding the endomyocardial biopsy. Additionally, echocardiography has found a role as a supplement to invasive angiography in the diagnosis of cardiac allograft vasculopathy.

Morphological and functional evaluation of murine heterotopic cardiac grafts using ultrasound biomicroscopy

This study investigated the use of an ultrasound biomicroscope (UBM) to observe murine heterotopic cardiac transplants. By using an UBM (30 MHz), cardiac isografts in eight mice were studied on days 1, 5, 14 and 50 posttransplantation. The same method was tested in allografts in two mice on days 1, 5, 7 and 9. Two-dimensional imaging delineated the graft structures with high spatial resolution. In isografts, M-mode recording showed gradually decreased left ventricular (LV) wall thickness and chamber dimension, but increased LV fractional shortening. Doppler sampling measured blood velocities from the ascending aorta, left coronary artery (LCA), aortic and mitral orifices of grafts. In isografts, LCA forward flow caused by native circulation to perfuse the graft myocardium increased from day 1 to 5, then moderately decreased by day 14 and stabilized thereafter. In allografts, LCA forward flow sharply decreased to almost zero between day 5-9. Therefore, UBM is a reliable method for following the survival status of cardiac grafts in mice.

The Emerging Role of Multi-Detector Computed Tomography in Heart Failure

BACKGROUND

Recent advances in cardiac multi-detector computed tomography (MDCT) technology now permits entire coronary tree evaluation in a single breath hold with submillimeter slice collimation and improved temporal resolution.

METHODS AND RESULTS

Besides excellent correlation with invasive angiogram for the detection of significant coronary occlusion, MDCT also provides reliable and reproducible data regarding various other cardiac anatomic and functional parameters that are pertinent to heart failure patients. These include left ventricular measurement (eg, ejection fraction, regional wall motion, dimensions, volumes), pulmonary vein anatomy and drainage, right ventricular function, and cardiac venous system, among many others. However, there are radiogenic and nonradiogenic risks associated with MDCT that should be considered before scanning the patients.

CONCLUSIONS

This review summarizes the existing literature of the various cardiac MDCT applications pertinent to heart failure patients.

Use of 3-Dimensional Color Doppler Echocardiography to Measure Stroke Volume in Human Beings: Comparison with Thermodilution

BACKGROUND

The availability of accurate noninvasive measurements of cardiac output (CO) would be useful in assessing disease severity and the effects of therapeutic interventions in many different clinical settings. Current noninvasive methods are limited by their dependence on geometric assumptions. We tested the feasibility of a new technique for CO measurements based on 3-dimensional color Doppler echocardiographic (3D-CD) imaging.

OBJECTIVE

We sought to compare the accuracy of CO determination in human beings as measured by 3D-CD and conventional 2-dimensional echocardiography (2DE) using thermodilution as the gold standard for comparison.

METHODS

Simultaneous 3D-CD, 2DE, and thermodilution data were acquired in 47 patients postcardiac transplantation with good acoustic windows who required routine hemodynamic evaluation with a pulmonary artery catheter. Data were stored on compact disc and analyzed offline using custom software. Echocardiographic data were compared against thermodilution using linear regression and Bland-Altman analysis.

RESULTS

Correlation coefficients for 3D-CD and 2DE of the left ventricular outflow tract were r = 0.94 and r = 0.78, respectively. Correlation coefficients for 3D-CD and 2DE of the mitral valve were r = 0.93 and r = 0.75, respectively. Compared with 2DE, 3D-CD demonstrated a smaller bias and narrower limits of agreement in the left ventricular outflow tract (-1.84 +/- 16.8 vs -8.6 +/- 36.2 mL) and mitral valve inflow (-0.2 +/- 15.6 vs 10.0 +/- 26 mL).

CONCLUSION

The 3D-CD determination of CO is feasible and accurate. Compared with previous noninvasive modalities, 3D-CD has the advantages of independence of geometric assumptions and ease of image acquisition and analysis.

Vascular Remodeling 1 Year After Cardiac Transplantation

BACKGROUND

The belief that vascular remodeling and intimal hyperplasia are causes of luminal narrowing in cardiac allograft vasculopathy (CAV) is controversial. This study evaluated the relationship of vascular remodeling and intimal hyperplasia to luminal narrowing 1 year after orthotopic heart transplantation.

METHODS

Intravascular ultrasound imaging was performed on 190 cardiac transplant recipients at baseline and again 1 year after transplantation as part of a randomized trial of mycophenolate mofetil (MMF) and azathioprine (Aza). Studies 1 year apart were matched at 625 sites. All sites were classified into positive, non-significant and negative remodeling patterns, depending on a change of +/-10% in external elastic membrane area. Of the 190 patients, 99 were randomized to receive MMF, and 91 to receive Aza.

RESULTS

A total of 625 sites were observed. Of these, 52% had no remodeling, 25% exhibited vessel dilation, and 23% had vessel shrinkage in the presence of variable intimal growth (Delta intimal area: 0.73 +/- 1.70 mm2, p < 0.0001; 1.23 +/- 2.02 mm2, p < 0.0001; and 0.20 +/- 1.40 mm2, p = 0.09, respectively). Sixty percent of the lumen loss was due to a decrease in external elastic membrane area and 40% to an increase in intimal area (p = 0.005). Compared with Aza-treated patients, the MMF-treated patients had a lower incidence of vessel shrinkage (17% vs 28%, p = 0.001), and a trend for smaller maximum intimal thickness (0.21 +/- 0.25 mm vs 0.29 +/- 0.31 mm, p = 0.052).

CONCLUSIONS

Positive remodeling is associated with intimal growth, but negative remodeling does not correlate with any specific change in intimal hyperplasia. Constrictive remodeling is more responsible than intimal hyperplasia for the luminal narrowing that occurs. MMF is more efficacious than azathioprine in preventing the development of CAV at 1 year, by reducing the degree and incidence of vessel shrinkage and the progression of intimal hyperplasia.

Pulse doppler and M-mode to assess viability of cardiac allografts using heterotopic femoral heart transplantation in rats

Noninvasive assessment of heterotopic heart transplants using Doppler echocardiography was first described in two patients by Allen at Stanford in 1981. Since then, numerous experiments studying heterotopic heart transplantation in humans and large animals have confirmed its utility by employing either an intra-abdominal or cervical model. In rats, however, prior research investigating intra-abdominal heterotopic hearts has showed echocardiography to be ineffective. We have recently developed a new technique for heterotopic femoral heart transplantation in rats, which employs the novel use of trans-femoral echocardiography. Therefore, our goal was to re-examine the efficacy of echocardiography for detection of graft rejection.

Detection of Heart Transplant Rejection in Adults by Echocardiographic Diastolic Indices: A Systematic Review of the Literature

BACKGROUND

Diastolic dysfunction is often used as a marker of allograft rejection in patients with cardiac transplantation. However, the strength of evidence to support this approach needs to be determined.

METHODS

We sought to review and evaluate the quality of the published data about the use of diastolic indices (DI) to predict a rejection episode. A MEDLINE search was performed to identify English-language articles published from 1967 to 2005 that used DI to predict rejection episodes. The references of each retrieved article were scanned to identify additional relevant articles. Studies showing the correlation between echocardiography findings and biopsy results were included. Articles were abstracted using a standardized instrument designed by the authors. Quality was assessed using standardized criteria. Discrepancies were adjudicated by consensus.

RESULTS

Nineteen studies met the inclusion criteria. Quality of studies varied widely. Thirteen studies explicitly stated having an independent blind comparison with a reference standard, 4 studies presented reproducibility information, no studies presented likelihood ratios, and only 11 of them provided sensitivity and specificity. Left ventricular diastolic indices evaluated included inflow Doppler early diastolic (E) wave pressure half-time (sensitivity 23%-87%, specificity 76%-98%) and isovolumetric relaxation time (sensitivity 28%-85%, specificity 80%-98%), as well as tissue Doppler early diastolic (E') wave (sensitivity 69%-76% and specificity 59%-88%) and late diastolic (A') wave (sensitivity 67%-82%, specificity 49%-53%).

CONCLUSION

Because of inconsistent quality of the studies and low sensitivities, the current literature does not support the use of DI by echocardiography as a screening test in the prediction of allograft rejection in the heart transplantation population. Larger controlled studies incorporating newer DI such as tissue Doppler are needed.

Longitudinal Assessment of Cardiovascular Exercise Performance After Pediatric Heart Transplantation

BACKGROUND

No existing longitudinal data document exercise performance after pediatric heart transplantation. We report the exercise performance findings from the longitudinal study of pediatric heart transplantation patients and the association of aerobic capacity with echocardiographic measures of graft function.

METHODS

We performed a retrospective analysis of 28 children after heart transplantation who underwent 87 exercise tests and echocardiograms. Subjects exercised using graded cycle or treadmill protocols. Maximal oxygen consumption (VO2), physical working capacity, peak heart rate, and anaerobic threshold were evaluated. To measure systolic and diastolic function, shortening fraction and mitral valve pressure half-time (PHT) respectively, were obtained by echocardiography.

RESULTS

The average age at transplantation was 10.9 +/- 5.6 years, at initial exercise test was 13.8 +/- 5.0 years, and at final exercise test was 15.8 +/- 5.2 years. Percent-predicted values at the initial exercise test were VO2, 59.3%; physical working capacity, 60.2%; and peak heart rate, 75.8%; these remained similarly decreased at the final exercise test. Shortening fraction and PHT were within normal limits, but PHT was significantly greater at final test (p < 0.05). The relationship of VO2% with time was statistically significant, described by a quadratic equation that included initial VO2% and time from heart transplantation. This relationship remained significant when the shortening fraction (p < .05) but not PHT was added as a covariate in the equation.

CONCLUSIONS

Exercise performance after pediatric heart transplantation is impaired and, despite an initial improvement, declines over time. This can be explained by increasing diastolic dysfunction independent of donor graft age. If confirmed, these findings point the direction to further research aimed at limiting this aerobic capacity decline after heart transplantation.

The potential clinical role of ultrasonic strain and strain rate imaging in diagnosing acute rejection after heart transplantation

BACKGROUND

There has been a continued search for a more sensitive noninvasive technique for detecting sub-clinical acute rejection in heart transplant recipients. Ultrasonic deformation imaging (strain/strain rate) is sensitive in detecting sub-clinical abnormalities in regional systolic function and could potentially be sufficiently sensitive to detect changes in deformation induced by graft rejection.

AIM

To assess the use of strain (S) and strain rate (SR) imaging as a noninvasive method for monitoring and diagnosing acute rejection in heart transplant recipients.

METHODS AND RESULTS

A prospective preliminary study was carried out involving 31 consecutive heart transplant patients who underwent a total of 106 routine follow up endomyocardial biopsy with correlative cardiac ultrasound data. To assess regional longitudinal deformation, ultrasonic S and SR data were acquired from the intraventricular septum, left ventricular (LV) lateral and right ventricular free walls (RVFW). For radial deformation, data were obtained from the LV posterior wall (LVPW). According to the International Society of Heart and Lung Transplantation criteria, 88 biopsies (Group 1) had grade 0 or IA rejection, and 18 biopsies (Group 2) had > or =grade IB rejection. Longitudinal peak systolic S and SR were decreased (p<0.05) in Group 2, compared to Group 1 in the RVFW basal and apical segments and the basal and mid segments of the LV lateral wall. Radial peak systolic S and SR were significantly lower (p<0.001) in Group 2, compared to Group 1.

CONCLUSIONS

S/SR imaging might be a good technique and an additional tool for detecting > or =IB grade of acute rejection. The myocardial deformation, as assessed by S/SR imaging could be of clinical value in monitoring and diagnosing acute rejection in heart transplant recipients and could improve patients' management by reducing the number of biopsies performed.

Value of radionuclide studies in cardiac transplantation

Effective noninvasive evaluation of acute and chronic allograft rejection remains an important challenge in patients with cardiac transplantation. Radionuclide studies have demonstrated utility because of their ease of use, giving relevant information about the pathophysiology of the transplanted heart, along with valuable diagnostic and prognostic indicators. This article focuses on reviewing the pathophysiological changes of the transplanted heart and implications for radionuclide studies.

Donor or Recipient Hepatitis B Seropositivity Is Associated With Allograft Vasculopathy

BACKGROUND

Increasing interest has focused on possible viral triggers of cardiac allograft vasculopathy. Although much interest has centered on cytomegalovirus, it has recently been noted that donor hepatitis C seropositivity is associated with risk for accelerated vasculopathy. The current study hypothesized that hepatitis B (HBV) might be associated with accelerated vasculopathy.

METHODS

Sixty-six patients who received heart transplants between September 1998 and July 2000 were analyzed by intravascular ultrasound within 6 weeks and again at 12 months after transplantation. These patients were divided into 2 groups: the HBV Group (n = 13) in which either the donor or recipient was seropositive for hepatitis B core antibody (HBcAb), and a Control Group (n = 53) in which neither donor nor recipient was positive for HBcAb.

RESULTS

Baseline characteristics of the 2 groups were similar. The HBV Group had significant increase in the change in average intimal area (1.59 +/- 1.4 vs 0.46 +/- 0.4 mm2, p = 0.01) per mm length of the vessel compared with controls. Allograft vasculopathy at 1 year (defined as largest maximal intimal thickness increase of > or =0.50 mm) occurred in 46% of the HBV group compared with 24% of the control group (p = 0.05). When measured as an average maximal intimal thickness increase of >0.30 mm, allograft vasculopathy at 1 year occurred in 31% of the HBV Group compared with 5% of Controls (p = 0.01).

CONCLUSIONS

These preliminary results suggest that HBV seropositivity in donor or recipient may be associated with an increased risk for cardiac allograft vasculopathy.

Dobutamine myocardial scintigraphy for the prediction of cardiac events after heart transplantation

BACKGROUND

The long-term outcome after heart transplantation (HTx) is essentially influenced by the occurrence and extent of cardiac allograft vasculopathy (CAV). Single photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) has been shown to be a useful and cost-effective non-invasive method in patients with known or suspected coronary artery disease, but its role in detecting CAV remains unclear.

AIM

To evaluate the accuracy and predictive value of dobutamine MPI in patients after HTx during a 12-month follow-up.

METHODS

Seventy-seven patients (60 males, 17 females) underwent a total of 216 dobutamine MPI examinations over a period of 5 years. Examinations were obtained an average of 89+/-42 months after orthotopic HTx according to a 1-day protocol using 99mTc-methoxyisobutylisonitrile (99mTc-MIBI) with and without attenuation correction. For the present study, findings from 77 MPI examinations (one MPI examination per patient) were analysed visually and semiquantitatively using a 20-segment model. Summed stress scores (SSS) and summed rest scores (SRS) were calculated and receiver operating characteristic (ROC) analysis was performed to detect optimum threshold values. Patients were followed up for 12 months and cardiac events were registered.

RESULTS

Cardiac events were observed in 10 of the 77 patients. Good interobserver agreement was found for global visual and SRS-/SSS-based analysis (kappa=0.74 and 0.66, respectively). SSS was superior to SRS in the detection of cardiac events. ROC analysis showed an optimized SSS threshold value of three. For predicting a cardiac event during the 12-month follow-up, global visual and semiquantitative analysis reached sensitivities of 90% and 90%, specificities of 72% and 88%, accuracies of 74% and 87%, positive predictive values of 32% and 53% and negative predictive values of 98% and 98%, respectively. The sensitivity, specificity, accuracy and positive and negative predictive values for MPI to detect clinically relevant coronary artery stenoses (> or =50%) at conventional coronary angiography were 83%, 87%, 86%, 56% and 96%, respectively.

CONCLUSIONS

Non-invasive dobutamine MPI reliably identifies patients at risk for subsequent cardiac events in cases of CAV, with a high negative predictive value of 98% and an accuracy of 87%.

The Efficacy of Real-time 3-Dimensional Echocardiography for Right Ventricular Biopsy

BACKGROUND

In recipients of cardiac transplant, repetitive right ventricular (RV) biopsies can result in decreased sample quality as a consequence of fibrosis from oversampling specific locations. Real-time 3-dimensional echocardiography (RT3D) is a new imaging modality that may precisely guide bioptome placement and, therefore, is a potential alternative to fluoroscopy (Fl). We sought to determine if a RT3D-guided biopsy procedure would result in a comparable or decreased incidence of fibrosis versus Fl.

METHODS

Fifteen patients underwent 32 RV biopsy procedures with an equal number by each technique. RT3D was performed from the apical 4-chamber position. Fl was performed with biplane images. With both RT3D and Fl, attempts were made to vary bioptome position with each sample. A pathologist determined the percent fibrosis, with a biopsy sample containing 50% or more fibrosis considered uninterpretable for rejection.

RESULTS

RT3D provided excellent visualization of the distal end of the bioptome within the right atrium and RV. A mean of 4.3 +/- 1.0 RV biopsy samples were collected per procedure with 64 samples obtained by Fl and 72 obtained by RT3D. In all, 13 samples (20.3%) by Fl versus 10 samples (13.9%) by RT3D (P = .45) contained fibrosis and 7 samples (10.9%) by Fl versus 4 samples (5.6%) were uninterpretable (P = .41). Two Fl- versus zero RT3D-guided procedures contained 75% or more uninterpretable samples (P = .47) and were, therefore, nondiagnostic. There were no complications.

CONCLUSIONS

RT3D is a new modality to facilitate accurate localization of the bioptome in patients undergoing transplant providing comparable quality RV samples to that of biplane Fl.

Relation of left ventricular diastolic function as measured by echocardiography and pulmonary capillary wedge pressure to rejection in young patients (< or = 31 years) after heart transplantation

To investigate the association of catheter-derived and newer echocardiographically derived measures of diastolic function with rejection in heart transplant recipients, 48 transplant recipients had Doppler and Doppler tissue imaging assessment along with catheter-measured pulmonary capillary wedge pressure (PCWP) at the time of endomyocardial biopsy. Of echocardiographic measures, propagation velocity (Vp), mitral E-wave velocity (E)/Vp, and E/annular mitral E-wave velocity (Em) were significantly associated with rejection (p <0.02), and an elevated PCWP was associated with rejection (p = 0.023) but with poor sensitivity. Weak but insignificant correlations with PCWP were found for E/Vp (r = 0.28) and E/Em (r = 0.37).

[Use of imaging in the evaluation of heart transplant recipients]

Common complications after heart transplantation include acute rejection and coronary allograft vasculopathy. In order to detect the presence of rejection, tissue Doppler imaging echocardiography provides high accuracy and allows to optimize the timing of endomyocardial biopsies, which remain the cornerstone in rejection diagnosis. Coronary allograft vasculopathy is often a diffuse disease so that it is difficult to recognize by imaging modalities, such as myocardial perfusion scintigraphy, which are based on intra-patient comparison of different areas. Quantitative assessment of the myocardial blood flow by positron emission tomography overcomes this issue. Dobutamine stress echocardiography provides accurate diagnosis as well as useful prognostic information. Nevertheless, intracoronary ultrasound is nowadays considered the gold standard for vasculopathy assessment, since it is able to detect a minimum intimal thickening which represents the early feature of disease. Magnetic resonance represents the most attractive approach, though it has not yet gained widespread clinical use.

Sonolucent space posterior to left atrium: unusual echocardiographic appearance in a cardiac transplant patient

The usual echocardiographic appearances of the atria in heart transplant patients are well known. We report a case of an 81-year-old man with a 16-year-old cardiac transplant who showed a "new" echocardiographic left atrial abnormality. Two-dimensional echocardiography showed a large sonolucent space behind the donor left atrium (DLA), which was at first perplexing. This space, the distorted and partly displaced recipient left atrium (RLA), could be shown to communicate with the donor left atrium, by the use of unconventional imaging and by optison opacification.

Pseudomyxoma Originating from the Interatrial Septum in a Heart Transplant Patient

This report describes the echocardiographic diagnosis of an intracardiac mass in a heart transplant patient. The typical morphology of the lesions, its attachment to the interatrial septum, and the absence of a nidus focus for thrombus formation led to the preoperative assumption that it was a myxoma. The mass was successfully excised at the time of operation and the patient had an uneventful recovery. Pathology findings revealed a thrombus. Thus, echocardiography may have limited specificity for the differentiation of intracardiac tumors and thrombus.

Bilateral Adrenocortical Uptake of Ga-67 SPECT During Septicemia in a Heart Transplant Patient

Gallium-67 scintigraphy is a valuable agent in the management of fever of unknown origin. The use of SPECT increases its sensitivity and may demonstrate unexpected findings. We report on a heart-transplanted 55-year-old man with postsurgical fever of unknown origin. Ga-67 SPECT showed bilateral abnormal adrenal gland uptake that disappeared after intensive antibiotic therapy as assessed by a new Ga-67 scintigraphy obtained 3 months later. Unilateral and bilateral adrenal uptake of gallium has been reported in several clinical settings, ranging from adrenocortical adenomas to malignant disease such as lymphoma or adrenal metastases. Only one similar case, septicemia with transient adrenal uptake of gallium, has been previously reported.

Smooth muscle cell proliferation index correlates with 111In-labeled antibody Z2D3 uptake in a transplant vasculopathy swine model

Transplant vasculopathy is a major cause of morbidity and mortality in heart transplantation. The proliferation of coronary vascular smooth muscle cells is a hallmark of transplant vasculopathy. The goal of this study was to detect coronary vascular smooth muscle cell proliferation in a swine model by imaging regions of uptake of a monoclonal antibody (Z2D3) labeled with 111In.

METHODS

Coronary-to-right carotid artery transplantation was performed in 10 Yucatan minipigs with coronary arteries from farm pigs as donors. In 5 of these experiments, the right carotid artery was also grafted to the left carotid artery as a homograft. In 1 farm pig, the left and right carotid arteries were switched. After 44 +/- 22 days (mean +/- SE), animals were injected with 5-bromo-2-deoxyuridine (BrDU) and 111In-Z2D3 F(ab')2. Approximately 24 h later, the pigs underwent planar and SPECT imaging. After the imaging session, the pigs were sacrificed and the vessels were removed. Ex vivo autoradiography of all grafts was performed. Next, the tissues were immersion fixed, paraffin embedded, sectioned, and stained for histologic or immunohistologic examination. Quantitative morphometry was performed. A smooth muscle cell proliferation index, calculated as (BrDU- and actin-stained cells/actin-stained cells) x 100, was correlated with in vivo and ex vivo radiotracer uptake.

RESULTS

Patency or neovascularization was demonstrated in 10 of 10 allografts and 5 of 6 homografts. Ten of the scans were positive for focal tracer uptake in the neck in the area corresponding to the graft site, and 6 were negative. Actin- and BrDU-stained cells were seen in the media of allografts and in the recanalized lumen of occluded homografts. A smooth muscle cell proliferation index of 30 was used as a cutoff for scan positivity, on the basis of previous work. Analysis by the chi2 test indicated significant concordance (P < 0.01). Ex vivo vessel count ratios were significantly correlated with the smooth muscle cell proliferation index (r2 = 0.528, P < 0.01).

CONCLUSION

The use of monoclonal antibody Z2D3 tagged with 111In allows the detection of proliferating smooth muscle cells and correlates with the intensity of cell proliferation. This diagnostic method could allow early noninvasive detection of transplant vasculopathy.

Tricuspid annuloplasty significantly reduces early tricuspid regurgitation after biatrial heart transplantation

BACKGROUND

The incidence of tricuspid annuloplasty (TR) observed early after cardiac biatrial implantation is unpredictable and in our experience not infrequently problematic. Although the bicaval method of implant may reduce the incidence of TR, its benefit has not been conclusively documented.

METHODS

In an attempt to reduce the incidence of TR observed early after cardiac transplantation, 25 consecutive patients undergoing cardiac transplantation received donor heart tricuspid annuloplasty (TA) with either a DeVega or Ring technique. Early transthoracic echocardiograms were analyzed and compared with an immediately prior and consecutive cohort of 25 patients undergoing transplantation without TA. The biatrial technique of cardiac transplantation with a Cabrol modification was used for donor heart implant in both groups. Echocardiograms obtained 5 days after cardiac transplantation were reviewed in blinded fashion. TR was scored 0 = none, 1 = mild, 2 = moderate, and 3 = severe.

RESULTS

Donor and recipient characteristics were not different between groups. No hospital deaths occurred in either group. Patients undergoing transplantation without TA had a higher TR score, 1.3 (range 0-3), than did patients with TA, 0.7 (range 0-1.5, p = 0.002). Moderate or severe TR was present in 8 of 25 patients without TA compared with 0 of 25 patients with TA (p = 0.004). No patients required permanent pacemaker.

CONCLUSIONS

TA can significantly reduce the incidence of early postoperative TR after biatrial cardiac transplant without adding to the complexity of operation.

A novel polymorphism of the gene encoding furin, a TGF-β1 activator, and the influence on cardiac allograft vasculopathy formation

BACKGROUND

Coronary vasculopathy (CV) is an important determinant of survival following cardiac transplantation. We have previously shown that G915C polymorphism of the Transforming Growth Factor-beta1 (TGF-beta1) gene strongly influences CV development. Furin is a proprotein convertase enzyme important in TGF-beta1 activation. We investigated for polymorphism within the promoter region of the gene for furin (fur). Allelic variation of the fur gene, in conjunction with TGF-beta1 polymorphism, was subsequently related to the development of CV.

METHODS AND RESULTS

The fur gene promoter region (position -1199 to +39) was analysed by SSCP and sequencing. A C/T single nucleotide substitution polymorphism at position -231* was identified. Using PCR the fur and TGFB1 genotypes were identified in 115 cardiac transplant recipients. CV was diagnosed at routine surveillance post-transplant coronary angiography. Fur polymorphism had no influence on vasculopathy development; median time to diagnosis, *C/C homozygotes, 2.27 years (2.10-4.32), *C/T heterozygotes 2.97 years (2.09-4.24), *T/T homozygotes 2.65 years (2.33-4.08), (P=0.95). Allelic variation did not influence Kaplan Meier actuarial analysis of disease onset (P=0.54). Ninety-three percent of recipients were high TGF-beta1 producers. We used fur polymorphism to substratify patients with the +915*G/G TGFB1 (high producing) allele. Fur polymorphism did not influence CV development within this TGF-beta1 high producer cohort, when analysed by time to first diagnosis and Kaplan Meier testing.

CONCLUSIONS

We have described a novel polymorphism at position -231* in the gene encoding furin. The fur -231* single nucleotide polymorphism in isolation, or in conjunction with TGFB1 polymorphism, is not useful as a genetic risk marker for cardiac transplant associated coronary vasculopathy.

Evaluation of myocardial performance index to predict mild rejection in cardiac transplantation

BACKGROUND

Early diagnosis of heart transplant rejection is mandatory, since even mild rejection can rapidly progress to more severe rejection. Noninvasive diagnosis of heart transplant rejection still remains a challenge.

HYPOTHESIS

The purpose of the study was to determine a possible association between myocardial performance index (MPI) and biopsy score of the heart transplant.

METHODS

This is a retrospective cohort analysis of 99 complete Doppler echocardiographic studies from 24 consecutive patients (23 men) performed within 24 h of endomyocardial biopsy. Mean age of the cohort was 50 +/- 9 years and mean time from transplantation was 19 +/- 21 months (1-81). All patients were in sinus rhythm. Myocardial performance index was calculated as the ratio of isovolumic contraction time plus isovolumic relaxation time divided by ejection time. Left ventricular dimensions, left ventricular mass, ejection fraction, and a number of Doppler indices (E-point velocity, A-point velocity, deceleration time, and deceleration slope) were also measured. The International Society for Heart and Lung Transplantation (ISHLT) grading system was used for the classification of endomyocardial biopsies.

RESULTS

Myocardial performance index was significantly prolonged (0.60 +/- 0.13, 0.68 +/- 0.08, 0.75 +/- 0.20, in biopsy scores 0, IA, and IB, respectively; p<0.001). Isovolumic contraction time was significantly prolonged; isovolumic relaxation time was not significantly changed. Ejection time and deceleration time were significantly shortened. Multivariate stepwise regression analysis revealed that MPI and deceleration time were the only independent predictors of biopsy score (r=0.48, F=10.53, p<0.0001).

CONCLUSION

Myocardial performance index seems to be a useful adjunct in the follow-up of cardiac transplant patients. These preliminary data suggest that a larger study may be indicated to clarify the relevance of myocardial performance index.

Diastolic performance assessed by tissue Doppler after pediatric heart transplantation

BACKGROUND

Diastolic performance, indexed by tissue Doppler imaging (TDI), has been reported to predict cellular rejection in adult heart recipients, but the predictive value of TDI after pediatric heart transplantation is unknown.

METHODS

TDI-derived diastolic performance was studied in 37 pediatric (median age 2.54 years) heart recipients in the absence and presence of rejection. Maximum velocities in diastole of the left ventricular posterior wall thinning (diastvelLVPWmax) and medial mitral valve annulus (MVA) were determined in 160 echocardiograms from recipients who experienced either no rejection (Group 1, n = 22) or >or=1 rejection episode(s) (Group 2, n = 14) during the study interval (2 years). There was 1 death in the immediate post-transplant period not included in the analyses.

RESULTS

The diastvelLVPWmax determined by TDI in Group 1 increased during the first 90 days post-transplant (r = 0.31; p = 0.05), was heart-rate-dependent (r = 0.591; p < 0.001), and was significantly lower than the veILVPWmax determined from digitized M-mode tracings (116 +/- 31 vs 135 +/- 44 mm/s; p < 0.05). In a sub-group of children transplanted during the study and followed for >or=1 year (n = 9), diastvelLPWmax, determined by TDI, was lower in infant recipients (n = 6; 106.5 +/- 22 mm/s) than in older recipients (n = 3; 135 +/- 36 mm/s; p = 0.015). With rejection, diastvelLVPWmax, determined by M mode (147 +/- 13 vs 104 +/- 11 mm/s; p < 0.05), was decreased compared with baseline recipient studies prior to rejection. In contrast, rejection did not significantly change diastvelLVPWmax, as determined by TDI. MVA E/A (peak early-to-late diastolic velocity ratio) was significantly decreased with rejection (1.37 +/- 0.23 vs 0.92 +/- 0.22; p < 0.05). As a single parameter, an MVA E/A <1.1 was predictive of rejection in 4 of 10 recipients with MVA E/A >or=1.1 pre-rejection.

CONCLUSIONS

TDI-derived diastvelLVPWmax varied with age at transplant, heart rate and time post-transplant. A decrease in TDI-derived MVA E/A, but not diastvelLVPWmax, can be of additional predictive value in non-invasive surveillance for rejection in pediatric heart recipients.

Myocardial performance index in pediatric patients after cardiac transplantation

BACKGROUND

Myocardial performance index (MPI) has been shown to be a reliable indicator of ventricular performance. This study determined MPI values in pediatric patients after cardiac transplantation without endomyocardial rejection.

METHODS

MPI was determined in 41 pediatric patients after cardiac transplantation, without evidence of microscopic rejection, and in 31 pediatric control subjects.

RESULTS

MPI in the transplantation group (0.41 +/- 0.12) was higher than in the control group (0.31 +/- 0.09; P =.0003). Isovolumic relaxation time and isovolumic relaxation time/ejection time were higher in the transplant group (55 +/- 20 milliseconds and 0.22 +/- 0.07, respectively) compared with the control group (41 +/- 10 milliseconds and 0.16 +/- 0.06, respectively; P =.0002). Isovolumic contraction time and isovolumic contraction time/ejection time were similar in the transplant group (48 +/- 23 milliseconds and 0.19 +/- 0.09, respectively) and control group (43 +/- 21 milliseconds and 0.16 +/- 0.08, respectively; P = not significant).

CONCLUSIONS

Pediatric patients after cardiac transplantation without endomyocardial rejection have a higher MPI compared with a normative pediatric control population. The difference appears to be related to abnormal diastolic function.

Mycophenolate mofetil for secondary prevention of cardiac allograft vasculopathy: influence on inflammation and progression of intimal hyperplasia

BACKGROUND

Cardiac allograft vasculopathy (CAV) remains the single most important complication impairing long-term survival after heart transplantation (HTx). Intimal hyperplasia as a response to immunologic and non-immunologic injury is involved in the pathogenesis. Because improved immunosuppressive properties with mycophenolate mofetil (MMF) have been shown within the first year, beneficial effects on intimal hyperplasia and systemic inflammation might be found late after HTx as well.

METHODS

After a baseline examination with intravascular ultrasound (IVUS, volumetric assessment) 30 patients (2.0 +/- 1.1 years post-HTx) were prospectively randomized to receive either MMF (2 g/day) or to continue with azathioprine (AZA) as part of a triple immunosuppression protocol with cyclosporine and prednisolone. Markers of systemic inflammation and changes in vascular geometry were evaluated by IVUS after 1 year of follow-up.

RESULTS

With regard to inflammation, significantly lower values were found for high-sensitive C-reactive protein (CRP) in the MMF group (AZA 1.8 +/- 1.2 mg/liter. vs MMF 1.0 +/- 4.1 mg/liter, p = 0.02). Tumor necrosis factor (TNF)-alpha, interleukin (IL)-10, IL-6 and transforming growth factor (TGF)-beta did not differ between the groups. IVUS revealed no significant differences between groups. There was a weak trend toward a larger increase in plaque volume (AZA 13 +/- 43 mm(3) vs MMF 27 +/- 41 mm(3), p = 0.33), whereas MMF-treated patients tended to show a small increase in vessel dimensions (AZA +10 +/- 63 mm(3) vs MMF +50 +/- 87 mm(3), p = 0.17).

CONCLUSIONS

Changing immunosuppression from a standard AZA-based regimen to MMF resulted in a decrease in systemic inflammatory activity as indicated by levels of high-sensitive CRP. However, progression of intimal hyperplasia did not differ significantly, and the weak trend toward vascular enlargement could indicate some influence on vascular geometry.

The role of echocardiography in evaluation of the cardiac transplant recipient

Echocardiography is an important tool in the management of cardiac transplant recipients. It provides comprehensive information about allograft structure and function without exposing the recipient to the risks associated with invasive investigations. Imaging can be performed in the early in-hospital phase and easily repeated during follow-up for the purposes of screening or for assessing the progression of specific pathology. When interpreting studies it is important to be aware that characteristic normal findings may be quite different from the non-transplant population. Endomyocar-dial biopsy remains the gold standard for the detection of acute allograft rejection. Doppler echocardiography has traditionally formed the basis for non-invasive diagnosis of this important complication but has recognised limitations. Advances in echocardiographic techniques indicate a potential important role for the reliable detection of rejection by this modality in the future. A range of other complications can be evaluated by echocardiography. There has been considerable recent interest in assessment of cardiac allograft vasculopathy by stress-imaging methods.

Usefulness of chronotropic incompetence to dipyridamole in predicting myocardial perfusion defects in heart transplant recipients

The aim of this report was to assess the relation between heart rate response to dipyridamole infusion and perfusion defects at quantitative sestamibi single-photon emission computed tomographic imaging. We demonstrated in 166 heart transplant recipients that chronotropic incompetence to dipyridamole is the only significant and independent predictor of perfusion defects.

Radioimmunometric assay of B-type natriuretic peptide (BNP) in heart transplantation: correlation between BNP determinations and biopsy grading of rejection

The aim of this study was to determine whether elevated brain natriuretic peptide (BNP) levels after heart transplantation are correlated with the severity of rejection by using endomyocardial biopsy (EMB) and echocardiographic parameters indicative of ventricular function of the transplanted heart. This was an observational study of 80 orthotopic heart transplant recipients (11 women and 69 men; mean age 53+/-11 years). BNP determinations were performed within 48 h of endomyocardial biopsy. The echocardiographic study and BNP determination were also performed in a group of healthy volunteers. We found significantly higher BNP mean levels in heart transplant patients than in healthy volunteers (volunteers, 16.7+/-16.2 pg.ml-1; transplant, 213.4+/-268.6 pg.ml-1; P<0.001). Transplant recipients with rejection grades 2, 3 and 4 on EMB had significantly higher BNP levels than those with rejection grades 0 and 1 (higher rejection grade, 162.5+/-168.4 pg.ml-1; lower rejection grade, 292+/-361.8 pg.ml-1; P<0.01). BNP values of patients with good left ventricular function (LVF) were significantly lower than in patients with mildly and moderately impaired LVF and patients with severely impaired LVF (good function, 199.76+/-233.6 pg.ml-1; mildly/moderately impaired LVF, 937+/-644.5 pg.ml-1; severely impaired LVF, 1038+/-491.2 pg.ml-1; P<0.001). It is concluded that BNP plasma levels are elevated in heart transplant patients compared to the normal population. The distribution of BNP levels in heart transplanted patients show a wide range. BNP elevation is greater in patients with higher rejection grades on EMB and greater impairment of left ventricular function.

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.

Aspects of human parasites in which surgical intervention may be important

Until recently, physicians and surgeons in developed countries only occasionally encountered patients with parasitic protozoan and helminthic infections. High-speed travel, immigration and the popularity of the tropics as vacation areas have increased the number of people at risk for parasitic disease. This chapter examines the significant literature on a select number of protozoan and helminthic parasites for which surgical intervention is important in the diagnosis, treatment or cure of the disease. Although traditional surgical approaches are covered, emphasis is placed on recent advances in the areas of transplantation and minimally invasive surgery. Combining the disciplines of parasitology and surgery, this chapter covers three protozoan and seven helminthic parasites for which surgery is a valid treatment option based on the frequency of cases reported in the literature. Following coverage of the selected parasites, a table is included listing additional helminths for which surgery contributes to patient management. Physicians in the USA, UK, and Europe need to be more aware of the presentation and treatment of parasitic infections. It is our sincere hope that this review accomplishes that goal, and ultimately benefits the patients we serve.

Is all intimal proliferation created equal in cardiac allograft vasculopathy? The quantity-quality paradox

BACKGROUND

Pre-angiographic detection of intimal proliferation using intravascular ultrasound in heart transplant recipients has focused investigators' attention on the prognostic utility of such early information. Not all heart transplant recipients who exhibit a "prognostically relevant" threshold of severe (>0.5 mm) intimal thickening experience cardiac events. We sought to contrast clinical characteristics of heart transplant recipients who have prognostically relevant, severe intimal proliferation and who experience cardiac events with those who remain event free.

METHODS

We prospectively followed an inception cohort of 54 consecutive heart transplant recipients with severe intimal proliferation (intimal thickness >0.5mm) of the coronary arteries after index intravascular ultrasound examination to assess the development of cardiac events (sudden cardiac death, myocardial infarction) and/or the necessity for coronary revascularization with percutaneous techniques (angioplasty, atherectomy, stent implantation) or surgical bypass.

RESULTS

Based on the occurrence of adverse cardiac events during the subsequent 24 months, we divided the study cohort into 2 groups: Group 1 (no event, n = 33) and Group 2 (cardiac event, n = 21). Both groups demonstrated similar intimal thickness at the index ultrasound (Group 1, 0.89 +/- 0.27 mm, vs Group 2, 0.94 +/- 0.36 mm; p = not significant). Those with cardiac events were more likely than those without events to have hyperlipidemia, to have greater exposure to cumulative and average daily prednisone, and to exhibit greater average biopsy rejection scores at follow-up.

CONCLUSIONS

These observations underscore the importance of the quality and not merely the quantity of intimal proliferation in determining occurrence of morbid cardiac events and further emphasize the interaction of immunologic and non-immunologic factors in determining event vulnerability in cardiac allograft vasculopathy.

[The role of intravascular ultrasound examination for assessment of graft vasculopathy]

Long-run development of heart transplanted patients is predominantly determined by the occurrence of graft vasculopathy. Due to the commonly diffuse and concentrical appearance of plaque in the coronary vessels, the disease defies, at least in the early stage, the conventionally used angiographic diagnostic procedures with radiocontrast agents. With the possibility to differentiate not only the lumen but also structures of the vessel walls and different tissue types, intracoronary ultrasound (IVUS) of coronary vessels yields entirely new insights in the development, the course and the prognostic importance of graft vasculopathy. Besides the extended scientific application in order to investigate the pathophysiology of graft vasculopathy and the assessment of therapeutic strategies, regular follow-ups with IVUS are nowadays used in many centers in routine care after heart transplant.

Quantitation of the regional blood flow in the interventricular septum using positron emission tomography and nitrogen-13 ammonia

The purpose of the present study was to evaluate the effect of spillover of activity from the right ventricle (RV) on quantitation of the regional myocardial blood flow in the septum. Thirty-one healthy volunteers, 31 patients with ischemic heart disease, 7 patients with severe congestive heart failure, and 6 heart transplant patients underwent positron emission tomography (PET) with nitrogen-13 ammonia. Quantitation of the regional myocardial blood flow in the septum was performed using both a conventional two-compartment model and a previously validated two-compartment model taking RV spillover into account. Unaccounted RV spillover resulted in significant underestimation of the regional myocardial blood flow in the septum. The amount of underestimation was primarily dependent on the magnitude of spillover and the dispersion between the right and the left ventricular input functions. In healthy volunteers, the flow error was small but significant: on average 6% (range 5%-29%, P<0.00001), compared with 27% (range 0%-88%, P<0.002) in the group of patients with severe congestive heart failure, who had the most considerable amount of RV spillover. In the group of patients with ischemic heart disease and the group of heart transplant patients the flow errors were 10% (range 0%-55%, P<0.00001) and 6% (range 1%-19%, P<0.01), respectively. It is concluded that flow quantitation in the septum is significantly affected by RV spillover, resulting in a considerable underestimation of the septal blood flow unless correction is performed.

C-reactive protein, arterial endothelial activation, and development of transplant coronary artery disease: a prospective study

BACKGROUND

Arterial endothelial expression and raised serum concentrations of the soluble form of intercellular adhesion molecule-1 (ICAM-1) are implicated in development of transplant coronary artery disease. We investigated whether C-reactive protein, known to stimulate ICAM-1, was associated with increased ICAM-1 concentration and subsequent development of coronary artery disease.

METHODS

With sandwich ELISAs, we measured C-reactive protein and soluble ICAM-1 in serial serum samples obtained during the first 3 months after transplantation in 109 heart-transplant patients. Matching endomyocardial biopsy samples were screened immunohistochemically for arterial endothelial ICAM-1. Serial coronary angiograms were assessed for development, severity, and progression of coronary artery disease.

FINDINGS

We showed a significant correlation (p=0.001) between raised concentrations of C-reactive protein and arterial endothelial ICAM-1 expression in endomyocardial biopsy samples. We also noted a significant relation between C-reactive protein and soluble ICAM-1 concentrations soon after transplantation (p=0.003). Early raised C-reactive protein concentrations were associated with development (p=0.004), increased severity (p=0.02), and enhanced rate of progression (p=0.01) of coronary artery disease, and with heightened frequency of ischaemic events (p=0.049) and graft failure (p=0.04).

INTERPRETATION

C-reactive protein concentration can be used to identify heart-transplant patients at increased risk of coronary artery disease and graft failure. Treatments directed at reduction of C-reactive protein concentration could improve patients' outcome.

The role of intraoperative transesophageal echocardiography in heart transplantation

The number of centers that perform heart transplants has increased rapidly in recent years. Although transthoracic and transesophageal echocardiography (TTE and TEE) are utilized frequently to diagnose and manage cardiac complications commonly found in this population postoperatively, little has been written about the routine use of intraoperative TEE. Intraoperative echo is ideally suited to identify acute complications during cardiac transplantation. This can include immediate signs of rejection, valvular abnormalities, and mechanical complications related to the surgical procedure. Many of these patients might require ventricular assist devices (VAD) to provide circulatory support, and intraoperative TEE can be used to verify correct positioning of the VAD hardware. In addition, many of the chronic complications that patients with heart transplants are at risk for may be serious yet asymptomatic. Therefore, a high quality, complete intraoperative echocardiographic study might serve as an important baseline to compare postoperative changes.