Risk factors for development of accelerated coronary artery disease in cardiac transplant recipients

Fibrotic plaques in heart transplanted patients and their association with insulin resistance syndrome and Lp(a)

BACKGROUND

Angiographic evidence of cardiac allograft vasculopathy (CAV_angio) is a major limiting factor to survival after heart transplantation (HTx). Prevention of CAV_angio is therefore most relevant. Whether modifiable risk factors could be targeted for the prevention of fibrotic plaques, that are common and related to CAV_angio, is not clear.

METHODS AND RESULTS

In a cohort of 74 consecutive HTx patients (median post-transplant interval 9.2 [4.1-15.5] years), we used the high resolution of optical coherence tomography (OCT) to quantify angulation parameters (maximal and mean arc) and plaque load (mean arc*relative plaque length) of fibrotic plaques. Mean arc was defined as the mean value of all angulation measurements per patient. We assessed the association between cardiovascular risk factors and OCT findings. Linear regression analysis showed a significant association of TG/HDL-c with mean fibrotic arc (12.7 [3.9-21.5], p = 0.006) and fibrotic plaque load (2298 [617-3979], p = 0.009) after adjustment for recipient age and sex. We used the median value of fibrotic plaque load to define high fibrotic plaque load. In binary logistic regression analysis, TG/HDL-c (odds ratio [OR] 1.81 with 95% CI [1.09-3.03], p = 0.02) and Lp(a) (OR 1.02 [1.00-1.05], p = 0.02) were associated with high fibrotic plaque load. Multivariable logistic regression analysis confirmed Lp(a) as significant predictor of high fibrotic plaque load (OR 1.03 [1.01-1.05], p = 0.02).

CONCLUSION

TG/HDL-c ratio, a surrogate of insulin resistance syndrome, and Lp(a) were significantly associated with fibrotic plaque in HTx patients. Insulin resistance syndrome and Lp(a) might therefore represent additional targets for CAV prevention.

Effect of Statin Intensity on the Progression of Cardiac Allograft Vasculopathy

Background: In the non-transplant population, hyperlipidaemia has shifted from targeting LDL goals to statin intensity-based treatment. It is unknown whether this strategy is also beneficial in cardiac transplantation. Methods: This single-centre retrospective study evaluated the effect of statin use and intensity on time to cardiac allograft vasculopathy (CAV) after cardiac transplantation. Kaplan–Meier and Cox proportional hazards regression survival methods were used to assess the association of statin intensity and median post-transplant LDL on CAV-free survival. Results: The study involved 143 adults (71% men, average follow-up of 25 ± 14 months) who underwent transplant between 2013 and 2017. Mean CAV-free survival was 47.5 months (95% CI [43.1–51.8]), with 29 patients having CAV grade 1 or greater. Median LDL was not associated with time to CAV (p=0.790). CAV-free survival did not differ between intensity groups (p=0.435). Conclusion: Given the non-statistically significant difference in time to CAV with higher intensity statins, the data suggest that advancing moderate- or high-intensity statin after cardiac transplantation may not provide additional long-term clinical benefit. Trial registration: Not applicable.

A randomized clinical study using optical coherence tomography to evaluate the short-term effects of high-intensity interval training on cardiac allograft vasculopathy: a HITTS substudy

Cardiac allograft vasculopathy (CAV) remains a leading cause of long-term mortality after heart transplantation. Both preventive measures and treatment options are limited. This study aimed to evaluate the short-term effects of high-intensity interval training (HIT) on CAV in de novo heart transplant (HTx) recipients as assessed by optical coherence tomography (OCT). The study population was a subgroup of the 81-patient HITTS study in which HTx recipients were randomized to HIT or moderate intensity continuous training (MICT) for nine consecutive months. OCT images from baseline and 12 months were compared to assess CAV progression. The primary endpoint was defined as the change in the mean intima area. Paired OCT data were available for 56 patients (n = 23 in the HIT group and n = 33 in the MICT group). The intima area in the entire study population increased by 25% [from 1.8±1.4mm² to 2.3±2.0mm² , p<0.05]. The change was twofold higher in the MICT group (0.6±1.2 mm² ) than in the HIT group (0.3±0.6 mm² ). However, the treatment effect of HIT was not significant (treatment effect = -0.3 mm² , 95% CI [-0.825 to 0.2 mm² ] p = 0.29). These results suggest that early initiation of HIT compared with MICT does not attenuate CAV progression in de novo HTx recipients. This article is protected by copyright. All rights reserved.

Listing criteria for heart transplantation in the Netherlands

The updated listing criteria for heart transplantation are presented on behalf of the three heart transplant centres in the Netherlands. Given the shortage of donor hearts, selection of those patients who may expect to have the greatest benefit from a scarce societal resource in terms of life expectancy and quality of life is inevitable. The indication for heart transplantation includes end-stage heart disease not remediable by more conservative measures, accompanied by severe physical limitation while on optimal medical therapy, including ICD/CRT‑D. Assessment of this condition requires cardiopulmonary stress testing, prognostic stratification and invasive haemodynamic measurements. Timely referral to a tertiary centre is essential for an optimal outcome. Chronic mechanical circulatory support is being used more and more as an alternative to heart transplantation and to bridge the progressively longer waiting time for heart transplantation and, thus, has become an important treatment option for patients with advanced heart failure.

Predictive value of achieved blood pressure for cardiac events in the long-term follow-up of heart transplant recipients

BACKGROUND

A low diastolic blood pressure (DBP) is associated with increased cardiovascular events in patients with coronary artery disease or chronic kidney disease.

AIM

The aim of this study was to assess the association of blood pressure with cardiac events during the long-term follow-up of heart transplant recipients.

PATIENTS AND METHODS

In this prospective cohort study, we performed ambulatory blood pressure monitoring and home blood pressure monitoring in 76 transplant heart recipients 13.5±6.6 years after transplantation. The patients were followed for 54±17 months after blood pressure monitoring.

RESULTS

Twenty-one patients had a cardiac event (cardiac death, acute coronary event, coronary revascularization procedure, and hospitalization for heart failure) during the follow-up. In the Kaplan-Meier survival analysis, we found that a DBP below the median value (<81 mmHg) was associated significantly with cardiac events (log-rank: P=0.01). In a multivariate model, plasma creatinine and left ventricular ejection fraction (LVEF), but not DBP, were associated significantly with cardiac events. Low DBP was associated significantly with LVEF less than 55% (P=0.004).

CONCLUSION

A DBP below the median value predicts cardiac events during the long-term follow-up of heart transplant recipients, but is not an independent predictor. The association between low DBP and low LVEF explains at least in part the predictive value of low DBP.

Indications for and outcomes of therapeutic plasma exchange after cardiac transplantation: A single center retrospective study

INTRODUCTION

Limited data are available describing indications for and outcomes of therapeutic plasma exchange (TPE) in cardiac transplantation.

METHODS

In a retrospective study of patients who underwent cardiac transplantation at Duke University Medical Center from 2010 to 2014, we reviewed 3 TPE treatment patterns: a Single TPE procedure within 24 h of transplant; Multiple TPE procedures initiated within 24 h of transplant; and 1 or more TPE procedures beginning >24 h post-transplant. Primary and secondary outcomes were overall survival (OS) and TPE survival (TS), respectively.

RESULTS

Of 313 patients meeting study criteria, 109 (35%) underwent TPE. TPE was initiated in 82 patients within 24 h, 40 (37%) receiving a single procedure (Single TPE), and 42 (38%) multiple procedures (Multiple TPE). Twenty-seven (25%) began TPE >24 h after transplant (Delayed TPE). The most common TPE indication was elevated/positive panel reactive or human leukocyte antigen antibodies (32%). With a median follow-up of 49 months, the non-TPE treated and Single TPE cohorts had similar OS (HR 1.08 [CI, 0.54, 2.14], P = .84), while the Multiple and Delayed TPE cohorts had worse OS (HR 2.62 [CI, 1.53, 4.49] and HR 1.98 [CI, 1.02, 3.83], respectively). The Multiple and Delayed TPE cohorts also had worse TS (HR 2.59 [CI, 1.31, 5.14] and HR 3.18 [CI, 1.56, 6.50], respectively). Infection rates did not differ between groups but was independently associated with OS (HR 2.31 [CI, 1.50, 3.54]).

CONCLUSIONS

TPE is an important therapeutic modality in cardiac transplant patients. Prospective studies are needed to better define TPE's different roles in this patient population.

The 2018 ISHLT/APM/AST/ICCAC/STSW recommendations for the psychosocial evaluation of adult cardiothoracic transplant candidates and candidates for long-term mechanical circulatory support

The psychosocial evaluation is well-recognized as an important component of the multifaceted assessment process to determine candidacy for heart transplantation, lung transplantation, and long-term mechanical circulatory support (MCS). However, there is no consensus-based set of recommendations for either the full range of psychosocial domains to be assessed during the evaluation, or the set of processes and procedures to be used to conduct the evaluation, report its findings, and monitor patients' receipt of and response to interventions for any problems identified. This document provides recommendations on both evaluation content and process. It represents a collaborative effort of the International Society for Heart and Lung Transplantation (ISHLT) and the Academy of Psychosomatic Medicine, American Society of Transplantation, International Consortium of Circulatory Assist Clinicians, and Society for Transplant Social Workers. The Nursing, Health Science and Allied Health Council of the ISHLT organized a Writing Committee composed of international experts representing the ISHLT and the collaborating societies. This Committee synthesized expert opinion and conducted a comprehensive literature review to support the psychosocial evaluation content and process recommendations that were developed. The recommendations are intended to dovetail with current ISHLT guidelines and consensus statements for the selection of candidates for cardiothoracic transplantation and MCS implantation. Moreover, the recommendations are designed to promote consistency across programs in the performance of the psychosocial evaluation by proposing a core set of content domains and processes that can be expanded as needed to meet programs' unique needs and goals.

Psychosocial Assessments and Outcomes in Organ Transplantation

A qualitative review was conducted to define the term psychosocial as applied to transplant patients and to summarize evidence regarding the role and impact of psychosocial assessments and outcomes across the transplant process. English-language case series and empirical studies from January 1970 through April 1990 that were abstracted in Medline and Psychological Abstracts or listed in publications' bibliographies were used as data sources. A qualitative analysis was performed to determine the depth of the case reports and whether the empirical reports obtained statistically reliable, clinically significant findings. The authors conclude that psychosocial assessments differ in content and application to candidate selection depending on the transplant program. Psychosocial status before transplant does not consistently affect medical outcomes after transplant. Psychosocial status generally improves with transplant, although difficulties are prevalent in psychological adjustment and in compliance with medical regimens. Psychiatric history can predict psychological outcomes after transplant but does not consistently predict compliance. Social supports and coping strategies strengthen psychosocial outcomes. Posttransplant psychosocial outcomes may predict physical morbidity and mortality.

Community-Based Weight Management in Long-Term Heart Transplant Recipients: A Pilot Study

Background

Heart transplant recipients often suffer from obesity, dyslipidemia, and hypertension thought to be related to triple-drug immunosuppression and poor adherence to diet and exercise. A lifestyle intervention that allows recipients to attend a community-based weight management program may improve health outcomes.

Objective

To determine (1) the effects of attending a community-based weight management program on weight, systolic and diastolic blood pressure, and the lipid profile; and (2) the feasibility of a community-based program for weight management.

Methods

Twenty-one patients (81% male; age 57 years, 99.7 months since transplantation) participated in a randomized clinical trial and received either weight management counseling (control) or a 6-month scholarship to a structured commercial program (treatment). Using simple analysis of covariance models, group differences were assessed and reported as marginal means.

Results

At baseline, there were no demographic differences between groups. There were no differences in outcome variables except weight (control, 102.1 kg vs treatment, 98.3 kg; P = .05). After 6 months, significant differences were found in weight (control, 100.5 kg vs treatment, 95.6 kg; P = .047) and high-density lipoprotein cholesterol (control, 40.6 mg/dL vs treatment, 49.1 mg/dL; P = .044). A marginally significant difference was found in systolic blood pressure (control, 138 mm Hg vs treatment, 121 mm Hg; P=.07). A decrease in diastolic blood pressure (6 mm Hg) was attributed to treatment effect ( P = .16). No differences were noted in total cholesterol, triglycerides, or low-density lipoprotein cholesterol.

Conclusions

The structured commercial program appears to be an effective, feasible alternative to usual care. Findings need to be confirmed in future research with a larger sample.

Cardiac allograft vasculopathy: diagnosis, therapy, and prognosis

Development of cardiac allograft vasculopathy represents the major determinant of long-term survival in patients after heart transplantation. Due to graft denervation, these patients seldom present with classic symptoms of angina pectoris, and the first clinical presentations are progressive heart failure or sudden cardiac death. Although coronary angiography remains the routine technique for coronary artery disease detection, it is not sensitive enough for screening purposes. This is especially the case in the first year after transplantation when diffuse and concentric vascular changes can be easily detected only by intravascular ultrasound. The treatment of the established vasculopathy is disappointing, so the primary effort should be directed toward early prevention and diagnosis. Due to diffuse vascular changes, revascularization procedures are restricted only to a relatively small proportion of patients with favorable coronary anatomy. Percutaneous coronary intervention is preferred over surgical revascularization since it leads to better acute results and patient survival. Although there is no proven long-term advantage of drug-eluting stents for the treatment of in-stent restenosis, they are preferred over bare-metal stents. Severe vasculopathy has a poor prognosis and the only definitive treatment is retransplantation. This article reviews the present knowledge on the pathogenesis, diagnosis, treatment, and prognosis of cardiac allograft vasculopathy.

Detection and grading of coronary allograft vasculopathy in children with contrast-enhanced magnetic resonance imaging of the coronary vessel wall

BACKGROUND

Coronary allograft vasculopathy is the leading cause of late death after heart transplantation in children. It is poorly detected by conventional angiography. Intravascular ultrasound is invasive and costly. This study shows that magnetic resonance imaging (MRI) late gadolinium enhancement (LGE) of the coronary vessel wall can detect and grade coronary allograft vasculopathy.

METHODS AND RESULTS

Twenty-four children (10 male; age range, 9-17 years) underwent coronary angiography, intravascular ultrasound, and MRI. Maximal intimal thickness and mean intimal index were recorded. MRI included coronary magnetic resonance angiogram and LGE vessel wall imaging with 1.5 T (n=12) and 3.0 T (n=12). Ten healthy control subjects also underwent LGE MRI. Mean time posttransplantation was 5.5 years (range, 0.25-14 years). Seven patients had Stanford grade IV coronary allograft vasculopathy on intravascular ultrasound, 3 of whom had angiographic disease. Maximal intimal thickness and mean intimal index were 0.73±0.50 mm and 20.9±10.6%, respectively. On MRI, mean diameter of enhancement of vessel wall was 6.57±4.91 mm, and mean enhancement index (indexed to vessel lumen size) was 1.10±1.72. The control group showed little or no LGE. Correlation of LGE with maximal intimal thickness using the Pearson coefficient was 0.80 (P<0.001) and with mean intimal index was 0.92 (P<0.001). An MRI diameter >7.5 mm gave 86% sensitivity and 93% specificity.

CONCLUSIONS

LGE scores correlate well with traditional intravascular ultrasound measures. These promising early results encourage larger-scale clinical studies to investigate whether LGE MRI will allow closer follow-up and better prevention of coronary allograft vasculopathy in children.

Cardiac allograft vasculopathy: current knowledge and future direction

Cardiac allograft vasculopathy (CAV) is a unique form of coronary artery disease affecting heart transplant recipients. Although prognosis of heart transplant recipients has improved over time, CAV remains a significant cause of mortality beyond the first year of cardiac transplantation. Many traditional and non-traditional risk factors for the development of CAV have been described. Traditional risk factors include dyslipidemia, diabetes and hypertension. Non-traditional risk factors include cytomegalovirus infection, HLA mismatch, antibody-mediated rejection, and mode of donor brain death. There is a complex interplay between immunological and non-immunological factors ultimately leading to endothelial injury and exaggerated repair response. Pathologically, CAV manifests as fibroelastic proliferation of intima and luminal stenosis. Early diagnosis is paramount as heart transplant recipients are frequently asymptomatic owing to cardiac denervation related to the transplant surgery. Intravascular ultrasound (IVUS) offers many advantages over conventional angiography and is an excellent predictor of prognosis in heart transplant recipients. Many non-invasive diagnostic tests including dobutamine stress echocardiography, CT angiography, and MRI are available; though, none has replaced angiography. This review discusses the risk factors, pathogenesis, and diagnosis of CAV and highlights some current concepts and recent developments in this field.

Smoking is a risk factor for graft failure and mortality after renal transplantation

BACKGROUND

Smoking in renal transplant recipients (RTR) is an acknowledged cardiovascular risk factor. It is, however, unclear whether smoking also increases the risk of graft failure (GF).

METHOD

In this study, we prospectively assessed the association of current smoking versus past and never smoking with GF and mortality in 604 RTR (age 51.5 ± 12.1 years, 55% male).

RESULTS

At inclusion, 133 (22%) were current smokers, 255 (42%) were past smokers and 216 (36%) never smoked. During follow-up of 5.3 (4.7-5.7) years, 41 (7%) RTR experienced GF and 95 RTR (16%) died. Current smoking RTR had higher risk for GF compared to never smoking RTR (hazard ratio, HR = 3.3, 95% CI 1.5-7.1, p = 0.002). Past smoking RTR had similar risk of GF as never smoking RTR (HR = 1.1, 95% CI 0.5-2.6, p = 0.7). Current smoking RTR and past smoking RTR were at higher risk for death than never smoking RTR (HR = 2.1, 95% CI 1.1-3.8, p = 0.016, and HR = 2.4, 95% CI 1.4-4.0, p = 0.001, respectively).

CONCLUSION

Smoking after renal transplantation is associated with risk for GF and mortality. Since past smoking is a risk factor for mortality but not for GF, smoking cessation may be beneficial to RTR in delaying GF in long term.

Long-term outcomes after percutaneous coronary intervention of left main coronary artery for treatment of cardiac allograft vasculopathy after orthotopic heart transplantation

The present study evaluated the safety and efficacy of percutaneous coronary intervention (PCI) of the unprotected left main coronary artery (ULMCA) for the treatment of cardiac allograft vasculopathy (CAV) in consecutive unselected patients with orthotopic heart transplantation (OHT). PCI in patients with OHT and develop CAV has been associated with greater restenosis rates compared to PCI in patients with native coronary artery disease. A paucity of short- and long-term data is available from patients with OHT who have undergone PCI for ULMCA disease. The present retrospective, multicenter, international registry included 21 patients with OHT and CAV who underwent ULMCA PCI from 1997 to 2009. Angiographic success was achieved in all patients. Drug-eluting stents were used in 14 of the 21 patients. No major adverse cardiac events or repeat OHT occurred within the first 30 days. At a mean follow-up of 4.9 ± 3.2 years, 3 patients (14%) had died, myocardial infarction had occurred in 1 patient (5%), and target lesion revascularization had been required in 4 patients (19%). Follow-up angiography was performed in 16 patients (76%), and restenosis was observed in 4 (19%). No stent thrombosis of the ULMCA was observed. One patient (5%) underwent coronary artery bypass grafting, and 5 patients (24%) underwent repeat OHT. In conclusion, the results of our study have shown ULMCA PCI to be safe and reasonably effective in patients with OHT and represents a viable treatment strategy for CAV in these patients.

Smoking after cardiac transplantation

Although smoking cessation is a prerequisite prior to listing for cardiac transplantation, some patients return to smoking after recovery. We have covertly assessed the smoking habits of our cardiac transplant recipients (with ethical approval) since 1993 by measuring urinary cotinine: a level of >500 ng/mL signifying continued tobacco use. We retrospectively analyzed survival, causes of death and the development of graft coronary artery disease (GCAD) with respect to the number of positive and negative cotinine levels. One hundred four of 380 (27.4%) patients tested positive for active smoking at some point posttransplant, and 57 (15.0%) tested positive repeatedly. Smokers suffered significantly more deaths due to GCAD (21.2% vs. 12.3%, p < 0.05), and due to malignancy (16.3% vs. 5.8%, p < 0.001). In univariate analysis, smoking after heart transplantation shortened median survival from 16.28 years to 11.89 years. After correcting for the effects of pretransplant smoking in time-dependent multivariate analysis, posttransplant smoking remained the most significant determinant of overall mortality (p < 0.00001). We conclude that tobacco smoking after cardiac transplantation significantly impacts survival by accelerating the development of graft vasculopathy and malignancy. We hope that this information will deter cardiac transplant recipients from relapsing, and intensify efforts in improving cessation rates.

Cardiac allograft vasculopathy and insulin resistance--hope for new therapeutic targets

Cardiac allograft vasculopathy (CAV) is a major cause of death in patients surviving more than 1 year after heart transplantation. An important cluster of CAV risk factors occurs as a consequence of insulin resistance and manifests as part of the metabolic syndrome. This article summarizes the pathologic features of CAV and reviews the contribution of the major components of insulin resistance in CAV development and progression. It focuses on the few studies that have analyzed the impact of the individual metabolic abnormalities and inflammation and on therapeutic strategies to minimize the clinical manifestation of insulin resistance after heart transplantation.

Guidelines for heart transplantation

Based on the changes in the field of heart transplantation and the treatment and prognosis of patients with heart failure, these updated guidelines were composed by a committee under the supervision of both the Netherlands Society of Cardiology and the Netherlands Association for Cardiothoracic surgery (NVVC and NVT).THE INDICATION FOR HEART TRANSPLANTATION IS DEFINED AS: 'End-stage heart disease not remediable by more conservative measures'.CONTRAINDICATIONS ARE: irreversible pulmonary hypertension/elevated pulmonary vascular resistance; active systemic infection; active malignancy or history of malignancy with probability of recurrence; inability to comply with complex medical regimen; severe peripheral or cerebrovascular disease and irreversible dysfunction of another organ, including diseases that may limit prognosis after heart transplantation.Considering the difficulties in defining end-stage heart failure, estimating prognosis in the individual patient and the continuing evolution of available therapies, the present criteria are broadly defined. The final acceptance is done by the transplant team which has extensive knowledge of the treatment of patients with advanced heart failure on the one hand and thorough experience with heart transplantation and mechanical circulatory support on the other hand. (Neth Heart J 2008;16:79-87.).

Cardiac allograft vasculopathy and insulin resistance--hope for new therapeutic targets

Cardiac allograft vasculopathy (CAV) is a major cause of death in patients surviving more than 1 year after heart transplantation. An important cluster of CAV risk factors occurs as a consequence of insulin resistance and manifests as part of the metabolic syndrome. This article summarizes the pathologic features of CAV and reviews the contribution of the major components of insulin resistance in CAV development and progression. It focuses on the few studies that have analyzed the impact of the individual metabolic abnormalities and inflammation and on therapeutic strategies to minimize the clinical manifestation of insulin resistance after heart transplantation.

Update on cardiac transplantation pathology

CONTEXT

The endomyocardial biopsy is the mainstay for monitoring acute allograft rejection in heart transplantation. Objective and accurate assessment of cellular and humoral types of rejection is important to optimize immunosuppressive therapy, avoid therapeutic complications, and improve patient outcome. The grading system for evaluation of heart transplant biopsies published in 1990 was revised in 2004 after more than a decade of implementation.

OBJECTIVE

In this review, we focus on a practical approach to the evaluation of human heart transplant biopsies as diagnostic surgical pathologic specimens. We discuss the revised International Society of Heart and Lung Transplantation working formulation.

DATA SOURCES

We reviewed pertinent literature, incorporating ideas and vast experience of participants in various work groups that led to the revision of the 1990 grading system.

CONCLUSIONS

The grading system for cellular rejection is presented with detailed light microscopic morphology and comparison of the 1990 and 2004 International Society of Heart and Lung Transplantation working formulations. We show how the pathologic recognition of cellular rejection and antibody-mediated rejection has evolved. We emphasize the interpretation of immunostains for complement components C4d and C3d in the diagnosis of antibody-mediated rejection. Evidence of regulation of complement activation in human heart transplant biopsies is presented in this context. We also discuss the pitfalls, caveats, and artifacts in the interpretation of allograft endomyocardial biopsies. Lastly, we discuss the pathology of human cardiac allograft vasculopathy in practical detail.

Rates and Risk Factors for Nonadherence to the Medical Regimen After Adult Solid Organ Transplantation

BACKGROUND

Despite the impact of medical regimen nonadherence on health outcomes after organ transplantation, there is mixed and conflicting evidence regarding the prevalence and predictors of posttransplant nonadherence. Clinicians require precise information on nonadherence rates in order to evaluate patients' risks for this problem.

METHODS

A total of 147 studies of kidney, heart, liver, pancreas/kidney-pancreas, or lung/heart-lung recipients published between 1981 and 2005 were included in a meta-analysis. Average nonadherence rates were calculated for 10 areas of the medical regimen. Correlations between nonadherence and patient psychosocial risk factors were examined.

RESULTS

Across all types of transplantation, average nonadherence rates ranged from 1 to 4 cases per 100 patients per year (PPY) for substance use (tobacco, alcohol, illicit drugs), to 19 to 25 cases per 100 PPY for nonadherence to immunosuppressants, diet, exercise, and other healthcare requirements. Rates varied significantly by transplant type in two areas: immunosuppressant nonadherence was highest in kidney recipients (36 cases per 100 PPY vs. 7 to 15 cases in other recipients). Failure to exercise was highest in heart recipients (34 cases per 100 PPY vs. 9 to 22 cases in other recipients). Demographics, social support, and perceived health showed little correlation with nonadherence. Pretransplant substance use predicted posttransplant use.

CONCLUSIONS

The estimated nonadherence rates, overall and by transplant type, allow clinicians to gauge patient risk and target resources accordingly. Nonadherence rates in some areas--including immunosuppressant use--appear unacceptably high. Weak correlations of most patient psychosocial factors with nonadherence suggest that attention should focus on other classes of variables (e.g., provider-related and systems-level factors), which may be more influential.

Cardiac Allograft Vasculopathy: An Update

Allograft vasculopathy remains the nemesis of long-term survival in heart transplantation. Possible modifying risk factors such as obesity, diabetes, and hypertension should continue to be pursued aggressively. All patients should receive statins. Clinical trials will provide the evidence needed to ascertain whether mammalian target of rapamycin inhibitors should be used in de novo cardiac transplant recipients to attenuate cardiac allograft vasculopathy (CAV). Intravascular ultrasound appears to play a key role in the diagnosis and evaluation of new treatments, and may indeed represent a surrogate marker that can be used to tailor management and improve outcomes. A better understanding of CAV is needed to develop targeted preventive therapies. Ongoing research in native atherosclerosis and vascular biology may provide answers within the next decade.

Graft Vascular Disease After Cardiac Transplantation and Its Relationship to Mean Acute Rejection Score

Context.—Graft vascular disease remains a significant source of morbidity and mortality in heart transplant patients. The influence of acute cellular rejection on the development of graft vascular disease is controversial.

Objective.—To determine the relationship between mean acute cellular rejection score and the presence of atherosclerosis or fibrointimal hyperplasia in cardiac allografts at autopsy.

Design.—This retrospective, autopsy-based study examined 27 heart transplant patients to evaluate for graft vascular disease. A rejection score for each patient was calculated as the average of all the rejection scores determined by endomyocardial biopsy. Gross and histologic examination of the heart was used to divide patients into 3 groups: no coronary artery disease, atherosclerosis, and fibrointimal hyperplasia. Mean rejection scores were calculated for each of these groups for all patients and patients who survived longer than 3 months. Mean rejection scores were compared by an analysis of variance and pairwise t tests.

Results.—Mean rejection scores demonstrated a trend of increasing value from no coronary disease (0.323) to atherosclerosis (0.569) to fibrointimal hyperplasia (0.835). Only fibrointimal hyperplasia had a significantly higher mean rejection score compared with patients with no coronary disease when examined in all patients (P = .01) and in patients who survived longer than 3 months (P = .049).

Conclusion.—This study showed that the development of coronary artery fibrointimal hyperplasia, but not atherosclerosis, was significantly related to mean acute rejection score.

Analysis of Immune Markers in Human Cardiac Allograft Recipients and Association With Coronary Artery Vasculopathy

BACKGROUND

Because coronary artery vasculopathy (CAV) is a common cause of late cardiac allograft loss in humans, there is a need to develop and test non-invasive surrogate markers capable of detecting and predicting this disease entity.

METHODS

We performed a cross-sectional analysis of immune-based surrogate markers in 65 primary cardiac allograft recipients with or without angiographically documented CAV. Anti-donor cellular immunity was determined by interferon gamma (IFN)-gamma enzyme-linked immunosorbent spot (ELISPOT) assays using donor HLA-derived peptides (indirect pathway), and anti-donor alloantibodies were detected by flow cytometry using HLA-coated beads.

RESULTS

Anti-donor cellular and humoral immunity were detected more frequently in patients with CAV (17 of 32, 53.1%) than in controls (4 of 33, 12.1%) (p < 0.001). Anti-donor cellular and humoral immunity were detected in different sub-groups of CAV patients; peripheral blood lymphocytes (PBLs) from only 1 of 32 CAV patients reacted to donor peptides with simultaneous detection of peripheral anti-donor alloantibodies.

CONCLUSIONS

Immune reactivity in cardiac transplant recipients with CAV differs significantly from those without CAV and the detected responses are heterogeneous in nature. Serial assessments of anti-donor immunity using different methods will be required to detect and possibly predict outcome in cardiac transplant recipients.

Impact of Pre-Operative Diabetes Mellitus Upon Early and Late Survival After Heart Transplantation: A Possible Era Effect

BACKGROUND

The effect of pre- or post-operatively acquired diabetes mellitus on survival after heart transplantation remains controversial. The influence of transplant era on diabetes-associated survival is unknown.

METHODS

A retrospective database analysis was performed on all cardiac transplant recipients followed up at our institution between 1986 and 2003. Diabetes mellitus was diagnosed based on oral glucose tolerance testing.

RESULTS

Survival was analyzed in 243 patients (80% male, mean age 52.2 years, mean follow-up 5.22 years). Kaplan-Meier survival analysis demonstrated significantly worse (p = 0.0001) survival both early (months 0 to 12) and late (>5 years) after transplantation in pre-operative diabetics (n = 53) compared with non-diabetics (n = 190). Pre-operative diabetes was identified as the only independent risk factor for decreased long-term (>1 year) survival (p = 0.004). In contrast, no effect on survival (p = 0.5) was demonstrated in patients becoming diabetic only after heart transplantation (n = 39). At 12 months post-transplant renal function was significantly impaired in diabetics (p = 0.025); acute rejection, cytomegalovirus (CMV) infection and transplant vasculopathy occurred with similar frequency. Causes of death were similar in diabetics and non-diabetics. Reduced long-term survival in pre-operative diabetics was seen in the early transplant era (1986 to 1994) (p < 0.0001), but not in the more recent era (1995 to 2003) (p = 0.5).

CONCLUSIONS

Pre-transplant but not post-transplant diabetes confers an adverse risk for survival (short and long term). Diabetes-associated long-term survival appears to have improved in the recent era, supporting continued transplantation in diabetics under close surveillance and aggressive medical management.

Tobacco and alcohol use in lung transplant candidates and recipients

Tobacco and alcohol use among lung transplant candidates and recipients is unknown. Our first goal was to describe tobacco and alcohol use before and after lung transplant in patients with cystic fibrosis (CF) and other pulmonary diseases (non-CF). Our second goal was to determine whether demographic variables, depression, anxiety and social support predicted tobacco and alcohol use. Self-report data from transplant candidates and recipients, and transplant nurse coordinator ratings of post-transplant smoking and drinking were utilized. Data from two samples were analyzed. Sample 1 comprised 219 patients being evaluated for lung transplant, and sample 2 comprised 45 transplant recipients who were 1-7 yrs post-transplant. The results from analyzing sample 1 indicated that 72% of non-CF patients and 16% of CF patients had a history of smoking cigarettes, and the majority of patients in both groups had consumed alcohol in the past. For CF patients, past smoking was related to higher depression scores, and past drinking was related to higher education and lower social support. For non-CF patients, a history of smoking was associated with being Caucasian and older. For CF patients, a history of drinking was associated with being older and less depressed, and for non-CF patients a history of drinking was associated with higher education and lower social support. Post-transplant 100% of recipients reported abstinence from tobacco, and over 60% reported abstinence from alcohol. Transplant coordinator ratings corroborated that no transplant recipients were using tobacco products or consuming alcohol in an excessive or problematic manner. For both groups, consuming alcohol after transplant was related to lower levels of social support. In conclusion, lung recipients remain abstinent from tobacco, and although over 30% of patients consume alcohol after transplant, it is not at problematic levels. Smoking and drinking behaviors were related to demographic variables, depression, and low social support.

Early and midterm risk of coronary allograft vasculopathy in patients bridged to orthotopic heart transplantation with ventricular assist devices

BACKGROUND

Coronary transplant vasculopathy (CAV) has been associated with both immunologic and nonimmunologic factors. The impact of preoperative ventricular assist device (VAD) support on the development of CAV has not been studied. To examine this, we obtained posttransplant coronary angiograms from a group of patients bridged with VAD and compared them to post transplant coronary angiograms of a non-VAD cohort.

METHODS

Adult patients undergoing orthotopic heart transplant between 1996-2000 were retrospectively studied and divided into VAD and non-VAD patients. Coronary angiograms were retrospectively reviewed and severity of coronary vasculopathy was categorized as trivial, mild, moderate, or severe. Other variables studied included recipient and donor demographics, cytotoxic panel reactive antibodies (PRA) against T-cell targets and flow cytometric crossmatching against donor T lymphocytes.

RESULTS

There was no significant difference between groups regarding demographics. However, VAD patients had a sixfold greater chance of having a T-cell PRA >10% at the time of transplant (p < 0.05), and a fourfold greater chance of having a positive cross match when compared to non-VAD patients (p < 0.05). There was no significant difference in the degree of CAV between groups. Normal coronary anatomy was present in 76% of VAD patients and 64% of non-VAD patients (p = 0.37). These results were similar at 2- and 3-year follow-up (76 vs. 74% and 80 vs. 62%, respectively).

CONCLUSION

Preoperative VAD use is associated with increased sensitization; however, these patients develop CAV at the same rate as those not bridged with a VAD.

Current understanding and management of allograft vasculopathy

Cardiac allograft vasculopathy (CAV) is the major obstacle to long-term survival after heart transplantation. It is a rapidly progressive, obliterative form of coronary vasculopathy distinct from classic atheromatous disease. The pathogenesis is most likely multifactorial and involves both alloantigen dependent and independent mechanisms. Since there is no definitive treatment for CAV and new immunosuppressive agents can only slow the progression of this disease, the prophylaxis and modification of numerous risk factors remains the foundation of posttransplant management in the heart transplant recipient. In this review, we discuss current understanding of the pathogenesis of CAV, novel diagnostic and therapeutic avenues and explore optimal approaches to risk factors modification.

Cigarette smoking in renal transplant recipients

Cigarette smoking may adversely influence patient and graft survival. In Europe and the United States the prevalence of cigarette smoking in dialysis patients is 35% to 40% and 25%, respectively. In Turkey, the estimated prevalence of cigarette smoking rate in the normal population is 26%. This study evaluated the rate of smoking in 63 cadaveric, and 158 living-related renal transplant recipients including (150 men, and 76 women of 38 +/- 12 years; range, 8 to 70) who were operated between 1986 and 2001. Demographic data were collected with a questionnaire delivered to patients during their routine outpatient visits. During this time period, 8 patients had died, 4 from hemophagocytic syndrome, 2 from cardiovascular disease, 1 from Kaposi sarcoma and 1 from a cerebrovascular accident. Twenty-three patients have lost their grafts. While at the time of transplantation 97 (42%) were smoking cigarettes, only 29 (12%) continued smoke after transplantation. Male gender significantly correlated with cigarette smoking (P =.000). Twelve smokers were single but 85 out of 97 were married, a statistically significant difference (P =.010). In contrast there was no significant relationship between pretransplant smoking and educational status (P =.354); graft loss and smoking (P =.129); or mortality and smoking (P =.224). There was a significant relationship between pretransplant and posttransplant smoking (P =.000). There was no relationship between pre- and post-transplant smoking and development of diabetes mellitus or hypertension. Interestingly the posttransplant serum albumin level was lower among smokers than nonsmokers (4.44 +/- 0.02 g/dL vs 4.30 +/- 0.02 g/dL; P =.019). There was a close relationship between transplantation duration and smoking.

Cardiac allograft vasculopathy after heart transplantation: risk factors and management

Cardiovascular disease post-transplant, particularly ischemic heart disease, is a significant problem for all transplant recipients. The major risk factors-smoking, obesity, diabetes, dyslipidemia and hypertension-are often more prevalent in heart transplant populations than in the general population. One of the main risk factors influencing graft loss and patient survival is cardiac allograft vasculopathy (CAV). Because CAV affects between 30% and 60% of cardiac transplant recipients within 5 years of surgery, prevention is a key focus for cardiac transplant teams today. CAV is caused by both immunologic mechanisms (e.g., acute rejection and anti-HLA antibodies) and non-immunologic mechanisms relating to the transplant itself or the recipient (e.g., donor age, hypertension, hyperlipidemia and pre-existing diabetes) or to the side effects often associated with immunosuppression with calcineurin inhibitors or corticosteroids (e.g., cytomegalovirus infection, nephrotoxicity and new-onset diabetes after transplantation). The calcineurin inhibitors, cyclosporine and tacrolimus, effectively prevent acute rejection, but do not prevent the development of CAV. CAV prevention will require a combined approach of new adjunct immunosuppressant agents (e.g., the proliferation signal inhibitors) and reduction in cardiovascular risk. Hypertension, hyperlipidemia and diabetes are also associated with the immunosuppression required to prevent organ rejection. Some studies have shown that hypertension is present more frequently in cyclosporine-treated patients than in tacrolimus-treated patients and that tacrolimus may be associated with a more favorable lipid profile. On the other hand, tacrolimus may be more diabetogenic than cyclosporine with current data suggesting a trend but no statistically significant supporting evidence. New-onset diabetes after transplantation is at times difficult to manage and may be an important determinant along with hypertension and hyperlipidemia of ischemic heart disease, cerebrovascular disease and peripheral vascular disease. The choice of calcineurin inhibitor for an immunosuppressive regimen in heart transplantation should consider the associated relative cardiovascular risks.

Immune and nonimmune predictors of cardiac allograft vasculopathy onset and severity: multivariate risk factor analysis and role of immunosuppression

We studied 361 patients, to evaluate risk factors for cardiac allograft vasculopathy (CAV) onset and severity/diffusion in heart transplantation (HT). Rejection scores (RS) on endomyocardial biopsy were calculated (first year and whole follow-up). CAV onset was defined as any lesion seen at yearly angiography. A CAV severity/diffusion index was calculated for each patient summing up the scores of all lesions. Cox multivariate analysis included: donor age, sex, and weight; recipient sex, age, pre-HT diagnosis, hypertension, diabetes and hyperlipidemia post-HT; number of treated rejections and RS; and immunosuppressive dosage at 3, 6, and 12 months. CAV frequency was 2% at 1 year, 22% at 5 and 39% at 10 years. Risk factors for CAV onset were older donor age [p < 0.0001, relative risk (RR) = 9.9], male donor (p < 0.001, RR = 3.2), high RS for severe (> or = 3A) grades (p < 0.02, RR = 2.01), high cyclosporine at 3 months (p < 0.02, RR = 1.9). Risk factors for CAV severity/diffusion were higher donor weight (p < 0.01, RR = 7.5), high prednisone dosage at 1 year (p < 0.0001, RR = 21.1), and coronary disease pre-HT (p < 0.002, RR = 9.7). High RS was an independent predictor for CAV onset, not severity/diffusion. This suggests an immune basis for CAV onset and nonimmune modulation for progression. High RS for severe grades may provide a predictor for patients at risk.

Plasma C-reactive protein as a marker of cardiac allograft vasculopathy in heart transplant recipients

OBJECTIVES

This study was initiated to determine whether heart transplant recipients (HTRs) with cardiac allograft vasculopathy (CAV) have increased levels of high-sensitivity C-reactive protein (hsCRP) and to examine whether an increase in hsCRP after heart transplantation predicts the development of CAV. Furthermore, the effect of pravastatin on plasma levels of hsCRP in HTRs was investigated.

BACKGROUND

The relationship between CAV and hsCRP, as well as the effect of statins on hsCRP in HTRs, has not been well established.

METHODS

On referral for their annual angiographic control study, 150 consecutive HTRs (mean 6.5 years since transplantation) were included. Plasma levels of hsCRP were measured before angiography and compared with patients with (n = 52) and without (n = 98) CAV. In 49 of these patients, we additionally analyzed hsCRP in blood samples stored from their six-month visit after the transplantation procedure. Furthermore, in a randomized, crossover study, hsCRP was analyzed in 17 male HTRs before and after six weeks of treatment with 20 mg pravastatin.

RESULTS

Median levels of CRP were elevated among patients with CAV compared with those with normal angiograms [3.86 (1.78 to 7.00) vs. 1.08 (0.72 to 2.13) mg/l, p < 0.001]. Prospectively evaluated hsCRP levels from six months to follow-up were significantly higher among those who developed CAV compared with those with normal angiograms [+2.76 (1.56 to 5.00) vs. +0.07 (-0.57 to 0.41) mg/l, p < 0.001]. On multivariate analysis, the increase in hsCRP was the only significant predictor of CAV. Six weeks of treatment with pravastatin significantly reduced hsCRP levels by 25%, without any relation to changes in lipid values.

CONCLUSIONS

Elevated plasma levels of CRP are associated with angiographic evidence of CAV, and the increase in hsCRP is a strong predictor of development of CAV. Statin treatment reduces levels of hsCRP and should be used in HTRs, regardless of their lipid levels.