Sex differences in left-ventricular strain in a murine model of coxsackievirus B3 myocarditis

Myocarditis is typically caused by viral infections, but most cases are thought to be subclinical. Echocardiography is often used for initial assessment of myocarditis patients but is poor at detecting subtle changes in cardiac dysfunction. Cardiac strain, such as global longitudinal strain (GLS) and global circumferential strain (GCS), represents an increasingly used set of measurements which can detect these subtle changes. Using a murine model of coxsackievirus B3 myocarditis, we characterized functional changes in the heart using echocardiography during myocarditis and by sex. We found that 2D GLS, 4D mode, and 4D strains detected a significant reduction in ejection fraction and GLS during myocarditis compared to baseline and in males compared to females. Furthermore, worse GLS correlated to increased levels of CD45+, CD11b+, and CD3+ immune cells. Our findings closely resemble published reports of GLS in patients with myocarditis indicating the usefulness of this animal model for translational studies of myocarditis.

Screening for peripartum cardiomyopathies using artificial intelligence in Nigeria (SPEC-AI Nigeria): Clinical trial rationale and design

BACKGROUND

Artificial intelligence (AI), and more specifically deep learning, models have demonstrated the potential to augment physician diagnostic capabilities and improve cardiovascular health if incorporated into routine clinical practice. However, many of these tools are yet to be evaluated prospectively in the setting of a rigorous clinical trial-a critical step prior to implementing broadly in routine clinical practice.

OBJECTIVES

To describe the rationale and design of a proposed clinical trial aimed at evaluating an AI-enabled electrocardiogram (AI-ECG) for cardiomyopathy detection in an obstetric population in Nigeria.

DESIGN

The protocol will enroll 1,000 pregnant and postpartum women who reside in Nigeria in a prospective randomized clinical trial. Nigeria has the highest reported incidence of peripartum cardiomyopathy worldwide. Women aged 18 and older, seen for routine obstetric care at 6 sites (2 Northern and 4 Southern) in Nigeria will be included. Participants will be randomized to the study intervention or control arm in a 1:1 fashion. This study aims to enroll participants representative of the general obstetric population at each site. The primary outcome is a new diagnosis of cardiomyopathy, defined as left ventricular ejection fraction (LVEF) < 50% during pregnancy or within 12 months postpartum. Secondary outcomes will include the detection of impaired left ventricular function (at different LVEF cut-offs), and exploratory outcomes will include the effectiveness of AI-ECG tools for cardiomyopathy detection, new diagnosis of cardiovascular disease, and the development of composite adverse maternal cardiovascular outcomes.

SUMMARY

This clinical trial focuses on the emerging field of cardio-obstetrics and will serve as foundational data for the use of AI-ECG tools in an obstetric population in Nigeria. This study will gather essential data regarding the utility of the AI-ECG for cardiomyopathy detection in a predominantly Black population of women and pave the way for clinical implementation of these models in routine practice.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT05438576.

Characteristics, Treatment Patterns, and Clinical Outcomes After Heart Failure Hospitalizations During the COVID-19 Pandemic, March to October 2020

OBJECTIVE

To compare clinical characteristics, treatment patterns, and 30-day all-cause readmission and mortality between patients hospitalized for heart failure (HF) before and during the coronavirus disease 2019 (COVID-19) pandemic.

PATIENTS AND METHODS

The study was conducted at 16 hospitals across 3 geographically dispersed US states. The study included 6769 adults (mean age, 74 years; 56% [5033 of 8989] men) with cumulative 8989 HF hospitalizations: 2341 hospitalizations during the COVID-19 pandemic (March 1 through October 30, 2020) and 6648 in the pre-COVID-19 (October 1, 2018, through February 28, 2020) comparator group. We used Poisson regression, Kaplan-Meier estimates, multivariable logistic, and Cox regression analysis to determine whether prespecified study outcomes varied by time frames.

RESULTS

The adjusted 30-day readmission rate decreased from 13.1% (872 of 6648) in the pre-COVID-19 period to 10.0% (234 of 2341) in the COVID-19 pandemic period (relative risk reduction, 23%; hazard ratio, 0.77; 95% CI, 0.66 to 0.89). Conversely, all-cause mortality increased from 9.7% (645 of 6648) in the pre-COVID-19 period to 11.3% (264 of 2341) in the COVID-19 pandemic period (relative risk increase, 16%; number of admissions needed for one additional death, 62.5; hazard ratio, 1.19; 95% CI, 1.02 to 1.39). Despite significant differences in rates of index hospitalization, readmission, and mortality across the study time frames, the disease severity, HF subtypes, and treatment patterns remained unchanged (P>0.05).

CONCLUSION

The findings of this large tristate multicenter cohort study of HF hospitalizations suggest lower rates of index hospitalizations and 30-day readmissions but higher incidence of 30-day mortality with broadly similar use of HF medication, surgical interventions, and devices during the COVID-19 pandemic compared with the pre-COVID-19 time frame.

Artificial intelligence-based risk stratification of atrial fibrillation among women with peripartum cardiomyopathy compared to other cardiomyopathies

Background

Atrial fibrillation (AF) is diagnosed in up to 50% of patients with heart failure. However, the prevalence of AF among patients with peripartum cardiomyopathy (PPCM) ranges from only 2–10%, with the lowest rates in Black women. An artificial intelligence enhanced electrocardiogram (AI-ECG) has previously been shown to be effective in detecting AF while in sinus rhythm, and for AF risk prediction in a population-based study.

Purpose

Our objective was to evaluate the use of an AI-ECG for AF risk stratification among women of reproductive age (18 to 49 years) with PPCM compared to other forms of cardiomyopathy.

Methods

We identified 59 reproductive age women with a diagnosis of PPCM between January 2007, and October 2018 and included matched controls in a 3:1 fashion. Matching was performed based on sex, age, race, and left ventricular ejection fraction. We excluded patients with a diagnosis of AF prior to cardiomyopathy diagnosis date. AI-ECG prediction probabilities were generated for ECGs performed within a 30-day window prior to the patient's first cardiomyopathy diagnosis date for the entire study cohort.

Results

A total of 236 patients were included in the final analysis (59 cases, 177 controls). Overall, the median age at cardiomyopathy diagnosis was 31.7 years (IQR: 18.5, 49.4), 76.3% were White, 8.5% were Black, and 15.3% represented other or unknown race. Over the period studied, 3.4% of women with PPCM developed AF compared to 5.6% of women with other cardiomyopathies. The frequency of positive AI-ECG predictions for AF was more common among women with other cardiomyopathies (40.7%) compared to women with PPCM (20.3%). The predicted odds ratio for AF development following a cardiomyopathy diagnosis based on AI-ECG results was 0.37 (95% CI: 0.18, 0.73) for PPCM compared to other cardiomyopathies (p=0.006).

Conclusion

We demonstrated that an AI-ECG model for AF prediction may play a potential role in arrhythmia risk stratification/prediction among young women with PPCM who have a demonstrable lower risk for AF compared to women with other cardiomyopathies. Mechanisms for lower AF risk among patients with PPCM remain unknown. Further studies evaluating mechanistic pathways will be essential.

Funding Acknowledgement

Type of funding sources: None.

Clinical Characteristics of Patients with Myocarditis following COVID-19 mRNA Vaccination: A Systematic Review and Meta-Analysis

COVID-19 mRNA vaccinations have recently been implicated in causing myocarditis. Therefore, the primary aim of this systematic review and meta-analysis was to investigate the clinical characteristics of patients with myocarditis following mRNA vaccination. The secondary aims were to report common imaging and laboratory findings, as well as treatment regimes, in these patients. A literature search was performed from December 2019 to June 2022. Eligible studies reported patients older than 18 years vaccinated with mRNA, a diagnosis of myocarditis, and subsequent outcomes. Pooled mean or proportion were analyzed using a random-effects model. Seventy-five unique studies (patient n = 188, 89.4% male, mean age 18–67 years) were included. Eighty-six patients had Moderna vaccines while one hundred and two patients had Pfizer-BioNTech vaccines. The most common presenting symptoms were chest pain (34.5%), fever (17.1%), myalgia (12.4%), and chills (12.1%). The most common radiologic findings were ST-related changes on an electrocardiogram (58.7%) and hypokinesia on cardiac magnetic resonance imaging or echocardiography (50.7%). Laboratory findings included elevated Troponin I levels (81.7%) and elevated C-reactive protein (71.5%). Seven patients were admitted to the intensive care unit. The most common treatment modality was non-steroid anti-inflammatory drugs (36.6%) followed by colchicine (28.5%). This meta-analysis presents novel evidence to suggest possible myocarditis post mRNA vaccination in certain individuals, especially young male patients. Clinical practice must therefore take appropriate pre-cautionary measures when administrating COVID-19 mRNA vaccinations.

Upregulation of Endothelin-1 May Predict Chemotherapy-Induced Cardiotoxicity in Women with Breast Cancer

As survival in breast cancer patients from newer therapies increases, concerns for chemotherapy-induced cardiotoxicity (CIC) have offset some of these benefits, manifesting as a decline in left ventricular ejection fraction (LVEF). Patients receiving anthracycline-based chemotherapy followed by trastuzumab are at risk for CIC. Previous research evaluating whether clinical biomarkers predict cardiotoxicity has been inconsistent. Recently, angiotensin II type 1 receptor (ATR1) and endothelin 1 (ET1) have been shown to play a role in breast tumor growth. We evaluated ATR1 and ET1 expression in breast cancer tissue and its association with CIC. A total of 33 paraffin-embedded breast tissue specimens from women with breast cancer treated with anthracycline-based chemotherapy and trastuzumab were analyzed by immunohistochemistry (IHC) and qRT-PCR. We found that ET1 expression was increased in patients with an LVEF ≤ 50% (p = 0.032) with a lower LVEF correlating with higher ET1 expression (r = 0.377, p = 0.031). In patients with a change in LVEF of greater than 10%, greater ET1 expression was noted compared to those without a change in LVEF (p = 0.017). Increased ET1 expression in breast tumor tissue is associated with reduced LVEF. Future studies need to examine whether ET1 may be a tissue biomarker that helps predict the risk of developing CIC in women with breast cancer.

Detecting cardiomyopathies in pregnancy and the postpartum period with an electrocardiogram-based deep learning model

Aims

Cardiovascular disease is a major threat to maternal health, with cardiomyopathy being among the most common acquired cardiovascular diseases during pregnancy and the postpartum period. The aim of our study was to evaluate the effectiveness of an electrocardiogram (ECG)-based deep learning model in identifying cardiomyopathy during pregnancy and the postpartum period.

Methods and results

We used an ECG-based deep learning model to detect cardiomyopathy in a cohort of women who were pregnant or in the postpartum period seen at Mayo Clinic. Model performance was evaluated using the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity. We compared the diagnostic probabilities of the deep learning model with natriuretic peptides and a multivariable model consisting of demographic and clinical parameters. The study cohort included 1807 women; 7%, 10%, and 13% had left ventricular ejection fraction (LVEF) of 35% or less, <45%, and <50%, respectively. The ECG-based deep learning model identified cardiomyopathy with AUCs of 0.92 (LVEF ≤ 35%), 0.89 (LVEF < 45%), and 0.87 (LVEF < 50%). For LVEF of 35% or less, AUC was higher in Black (0.95) and Hispanic (0.98) women compared to White (0.91). Natriuretic peptides and the multivariable model had AUCs of 0.85 to 0.86 and 0.72, respectively.

Conclusions

An ECG-based deep learning model effectively identifies cardiomyopathy during pregnancy and the postpartum period and outperforms natriuretic peptides and traditional clinical parameters with the potential to become a powerful initial screening tool for cardiomyopathy in the obstetric care setting.

Detecting cardiomyopathies in pregnancy and the postpartum period using ECG

Background

Cardiovascular disease (CVD) has been identified as a major threat to maternal health in the US and UK with cardiomyopathy being one of the most common acquired CVD in the pregnant and postpartum period. Diagnosing cardiomyopathy in pregnancy is challenging due to an overlap of cardiovascular symptoms with normal pregnancy symptoms.

Purpose

The purpose of this study was to evaluate the effectiveness of an ECG based deep learning model in identifying cardiomyopathy among pregnant and postpartum women.

Methods

We utilized an ECG based deep learning model to detect cardiomyopathy in a cohort of pregnant or postpartum women seen at multiple hospital sites. Model performance was evaluated using area under the curve (AUC), accuracy, sensitivity, and specificity. We compared the diagnostic probabilities of the deep learning model with natriuretic peptides and a multivariable model consisting of demographic and clinical parameters.

Results

1,807 women were included. 7%, 10% and 13% had LVEF ≤35%, &lt;45% and &lt;50% respectively. The ECG based deep learning model identified cardiomyopathy with an AUC of 0.92 for left ventricular ejection fraction (LVEF) ≤35%, 0.89 for LVEF &lt;45% and 0.87 for LVEF &lt;50%. For LVEF ≤35%, AUC was higher in Black (0.95) and Hispanic (0.98) women compared to white (0.91). Natriuretic peptides and the multivariable model had AUCs of 0.85 and 0.72 respectively.

Conclusions

A deep learning model effectively identifies cardiomyopathy in pregnant or postpartum women, outperforms natriuretic peptides and traditional clinical parameters with the potential to become a powerful initial screening tool for cardiomyopathy in the obstetric care setting.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): This study was made possible using resources supported by the Mayo Clinic Women's Health Research Center and the Mayo Clinic Building Interdisciplinary Research Careers in Women's Health (BIRCWH) Program funded by the National Institutes of Health (NIH), grant number K12 HD065987. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Stable and metastable hard-sphere crystals in fundamental measure theory

Using fully minimized fundamental measure functionals, we investigate free energies, vacancy concentrations, and density distributions for bcc, fcc, and hcp hard-sphere crystals. Results are complemented by an approach due to Stillinger, which is based on expanding the crystal partition function in terms of the number n of free particles while the remaining particles are frozen at their ideal lattice positions. The free energies of fcc and hcp and one branch of bcc agree well with Stillinger's approach truncated at n=2. A second branch of bcc solutions features rather spread-out density distributions around lattice sites and large equilibrium vacancy concentrations and is presumably linked to the shear instability of the bcc phase. Within fundamental measure theory and the Stillinger approach (n=2), hcp is more stable than fcc by a free energy per particle of about 0.001k(B)T. In previous simulation work, the reverse situation has been found, which can be rationalized in terms of effects due to a correlated motion of at least five particles in the Stillinger picture.

Relation of brain natriuretic peptide level to extent of left ventricular scarring in patients with chronic heart failure secondary to ischemic cardiomyopathy

Multiple factors influence brain natriuretic peptide (BNP) release in patients with heart failure. We hypothesized that extensive myocardial scarring could result in an attenuated BNP response. A total of 115 patients with New York Heart Association class III chronic heart failure and ischemic cardiomyopathy were evaluated for ischemia, hibernation, and myocardial scarring by dipyridamole-rubidium-positron emission tomographic scanning with fluorine-18, 2-fluoro-2-deoxyyglucose. Plasma BNP levels were determined within 2 weeks of the study. Left ventricular dimension and function were evaluated by echocardiography. Patients were categorized as having <33% myocardial scar (n=67) or>or=33% myocardial scar (n=48). BNP measurements were correlated with amount of myocardial scarring. Compared with patients with less scar, those with >or=33% scar had lower BNP levels (mean 317+/-364 vs 635+/-852 pg/ml, median 212 vs 357, p=0.016). Using multiple regression analysis, presence of scarring was associated with decreased BNP response (p=0.022). Further, patients with <33% scar in whom a higher BNP level was noted had more ischemia (51% vs 27%, p=0.01) and greater myocardial hibernation (22+/-14% vs 12+/-7%, p=0.02) compared with patients with >or=33% scar. In conclusion, in patients with chronic heart failure, a decreased BNP response indicated extensive myocardial scarring.

Myocardial degradation and left bundle branch block predict conversion to low ejection fraction in heart failure with preserved systolic function

The authors prospectively investigated whether left bundle branch block (LBBB) and myocardial degradation as indicated by elevated troponin T (tnT) predict the phenomenon of systolic conversion to low ejection fraction (EF <or=40%) in patients with nonsignificant coronary disease and heart failure with preserved systolic function (HFPSF) (initial EF >40%). Thirty consecutive patients with HFPSF were included and followed over a 4-year interval. A follow-up EF assessment was performed in 25 patients. Six of 15 patients with tnT >or=0.01 ng/mL demonstrated systolic conversion to low EF on follow-up, while none of the 10 patients with tnT <0.01 ng/mL experienced this phenomenon (P=.03). Five of the 6 converters presented with LBBB, while only 1 of the 19 nonconverters had this abnormality (P=.0007). Four of the 6 converters had an initial EF >50%. Myocardial degradation and LBBB predicted systolic conversion in HFPSF patients with nonsignificant coronary disease.

Thymoglobulin induction and steroid avoidance in cardiac transplantation: results of a prospective, randomized, controlled study

BACKGROUND

Chronic use of corticosteroids (CS) following transplantation is associated with significant long-term morbidities. Minimizing exposure to CS to improve long-term outcomes, without compromising allograft function, remains an important goal in transplantation.

OBJECTIVES

This single-center, prospective, randomized, open-label study was designed to evaluate the efficacy of Thymoglobulin as part of a CS-sparing regimen in cardiac transplantation.

METHODS

Thirty-two low-risk cardiac transplant patients were randomized in a 1:1 ratio to receive either a Thymoglobulin-based CS-avoidance regimen (CS-avoidance group; n = 16) or a long-term CS-based regimen with no antibody induction (control group; n = 16). Pulse CS therapy was used for the treatment of acute cellular rejection in both groups.

RESULTS

Baseline characteristics were similar between groups. At one yr, there was no significant difference in the mean incidence of acute cellular rejection (>or=3A) episodes between the CS-avoidance and control groups, 0.81+/-1.05 and 1.07+/-1.03, respectively. Importantly, the CS-avoidance patients had significant improvement in muscle strength and less bone loss compared with the control patients during the first six months post-transplant.

CONCLUSIONS

CS-avoidance regimen with Thymoglobulin induction appeared to be safe and effective in cardiac transplantation. Further studies are required to demonstrate the long-term safety and benefits of such a regimen.

Post-transplant ischemic injury is associated with up-regulated AlloMap gene expression

BACKGROUND

The AlloMap gene expression test is used for the non-invasive detection of rejection. However, the impact of early post-transplant ischemic injury on subsequent AlloMap gene expression analysis has not been evaluated before.

METHODS

Sixty seven heart transplant recipients, mean age 53 years, were evaluated at a mean 34 months post-transplant. AlloMap score was determined on the same day of heart biopsies. Nineteen patients had evidence of early post-transplant ischemic injury (Injury group). These were compared with the remaining 48 patients, Control group.

RESULTS

Using multiple regression model with a backward selection method, post-transplant ischemic injury was found to be associated with significant increased AlloMap score compared with controls (31.5 +/- 4.6 vs. 26 +/- 6.2, p < 0.001). The Injury group had increased transplant vasculopathy (KM 5-year freedom from vasculopathy: 34% vs. 52%, p = 0.015), than Controls.

CONCLUSIONS

Post-transplant ischemic injury is associated with up-regulated AlloMap gene expression, and hence, may provide another explanation for a high score in the absence of rejection.

Attrition From Heart Transplant Waiting List for Patients on Ventricular Assist Devices Is Not Affected by Desensitization Strategies

BACKGROUND

Ventricular assist device (VAD) patients, who are commonly sensitized, can be successfully transplanted using strategies aimed at diminishing antibody burden. However, the impact of these therapies on outcomes for VAD patients on the waiting list is ill-defined. The following study was conducted to ascertain the relationship between desensitization therapies and attrition rate from the waiting list for VAD patients.

METHODS

The VAD patients listed between July 1996 and June 2002 were used for this report. Transplant and inpatient pharmacy databases were queried for demographics, date of transplantation, degree of allosensitization, use of desensitization therapy, immunosuppressive strategies, and specific causes of death.

RESULTS

Among 232 patients listed for heart transplantation who required bridging to transplantation with a VAD, 79 (34%) died while on the waiting list. Common causes of death included multisystem organ failure in 32 (40.5%), sepsis in 19 (24.0%), and stroke in 10 (12.6%) patients. While nearly 50% of these patients were sensitized at listing, only 5 (6.3%) patients received desensitization therapy following VAD implantation. Therapies included mycophenolate mofetil in 3 (3.7%) and IVIG in 2 (2.5%) patients. Not a single patient underwent plasmapheresis or OKT3 therapy.

CONCLUSION

For patients bridged to heart transplantation with a VAD, attrition from the waiting list was associated with factors other than desensitization or induction regimens.

Coronary Angiography for Follow-up of Heart Transplant Recipients: Insights From TIMI Frame Count and TIMI Myocardial Perfusion Grade

BACKGROUND

The aim of this study was to evaluate the course of Thrombolysis in Myocardial Infarction (TIMI) frame count (TIMI FC) and myocardial perfusion grade (TIMI MPG) in heart transplant recipients and whether these parameters could predict mortality.

METHODS

Sixty-two heart transplant recipients were enrolled in this study. All patients had coronary angiography at baseline and at 1 year, which were evaluated for TIMI FC and TIMI MPG. Also, 50 vessels in 35 patients were analyzed with volumetric intravascular ultrasound (IVUS) at baseline and at 1 year. Rejection episodes and mortality were recorded during the follow-up period.

RESULTS

The mean follow-up interval was 51.5 +/- 17.2 months (range 12.2 to 78.4 months). TIMI FCs of all three coronary arteries and global TIMI FC (gTIMI FC) significantly increased from baseline during the first year (p < 0.0001). TIMI MPG deteriorated significantly (p < 0.0001 for left anterior descending and circumflex coronary arteries, p = 0.002 for right coronary artery). There was no correlation between changes in TIMI FC and progression of transplant vasculopathy as assessed by IVUS. Episodes of Grade > or = 3A rejection were significantly more frequent in the stable gTIMI FC group (p = 0.03). Mortality rate was significantly higher in the group with increasing gTFC (p = 0.02).

CONCLUSIONS

gTIMI FCs and TIMI FCs of coronary arteries increase, and TIMI MPG gradually deteriorates during the first year after transplantation. Mortality rate is significantly higher in patients whose gTIMI FC increases from baseline. Change in gTIMI FC is a simple quantitative predictor of long-term mortality in heart transplant recipients.

Heart transplantation: a magnified model of heart-brain interactions

The human heart transplant model unmasks the heart-brain link as an active process that is clinically demonstrated and confirmed at the tissue level. Further studies are needed to elucidate the relative contribution of each of these isolated observations to the pathogenesis of coronary allograft vasculopathy, which remains enigmatic. Recent studies have suggested that mTOR inhibitors may have the ability to attenuate this lethal process that limits the long-term survival of cardiac transplant recipients. The observations we have discussed here suggest that other targeted therapies, including glycoprotein IIb/IIIa inhibitors, tissue metalloproteinase inhibitors, and angiotensin receptor blockers, may facilitate the attenuation of cardiac transplant vasculopathy, but clinical trials are difficult to conduct in this relatively small population of patients. These observations may shed insight, however, into the pathophysiology of hypertension and its impact on the vascular system, as cardiac transplantation provides a setting in which heart-brain interactions are magnified and the pathophysiology occurs over years rather than decades.

Transplant vasculopathy is associated with increased AlloMap gene expression score

The AlloMap gene expression test is used for the non-invasive detection of rejection in heart transplant recipients. We evaluated the impact of transplant vasculopathy on AlloMap gene expression analysis. A total of 69 heart transplant recipients, mean age 53 years, were evaluated at a mean 35 months post-transplant. AlloMap score was determined on the same day of the endomyocardial biopsies. Twenty patients had evidence of vasculopathy by coronary angiography (vasculopathy group). These were compared to the remaining 49 patients (control group). The vasculopathy group had a longer mean follow-up duration (48.7 vs 28.8 months, p < 0.01), lower left ventricular ejection fraction (51% vs 60%, p < 0.01) and increased use of sirolimus (40% vs 16%, p = 0.034) compared with controls. Using the logistic regression model and bagging bootstrap approach to adjust for the time factor and potential confounders, the vasculopathy group had a significantly higher AlloMap score than the control group (32.2 +/- 3.9 vs 26.1 +/- 6.5, p < 0.001). There was a correlation of AlloMap score with time after transplantation (r = 0.31, p = 0.01). We found transplant vasculopathy to be associated with increased AlloMap score.

The Impact of Hypogammaglobulinemia on Infection Outcome in Patients Undergoing Ventricular Assist Device Implantation

BACKGROUND

Infection is a major comorbidity after ventricular assist device (VAD) placement. Defects in cellular immunity have been reported after VAD placement. However, to our knowledge, quantitative immunoglobulin G (IgG) level determination and the impact of hypogammaglobulinemia (HGG) on infections after VAD implantation have not been evaluated before.

METHODS

A total of 76 patients (mean age, 53 years) underwent VAD implantation as a bridge to transplantation and had IgG levels determined as a baseline before transplantation. Patients were divided into 2 groups according to IgG level: Control Group (n = 56, IgG > or = 700 mg/dl) and HGG Group (n = 20, IgG < 700 mg/dl). Infection outcome during the VAD course and after transplantation was analyzed in relation to the IgG level.

RESULTS

Baseline characteristics were similar in both groups. The incidence of bacteremia (14/20 [70%] vs 18/56 [32%], p = 0.0032) and major infection (19/20 [95%] vs 31/56 [56%], p = 0.0009) were significantly increased in the HGG Group compared with the Control Group. After transplantation, the episodes of rejection were similar in both groups and survival was similar. The HGG Group experienced more cytomegalovirus infections compared with the Control Group (9/20 [45%] vs 9/56 [16%], p = 0.009).

CONCLUSIONS

VAD patients with HGG are at increased risk of infections. After transplantation, these patients also experience increased cytomegalovirus infections. A randomized preemptive IgG replacement trial may be warranted in the future to determine if this intervention will alleviate the risk of infection.

The impact of donor gender on cardiac peri-transplantation ischemia injury

BACKGROUND

Cardiac allografts from female donors have been shown to be associated with increased risk of transplant vasculopathy. However, the influence of donor gender on peri-transplantation ischemic injury has not been evaluated.

METHODS

A total of 361 patients (mean age, 52 +/- 10 years) underwent cardiac transplantation between January 1998 and December 2002. Patients were divided into 4 groups according to their donor-recipient gender status: Group A, male-male, 156; Group B, male-female, 37; Group C, female-male, 114; and Group D, female-female, 54. Serial right ventricular endomyocardial biopsy specimens were evaluated for ischemic injury during the first 4 weeks after transplantation.

RESULTS

Patients were similar in baseline characteristics. An increased incidence of ischemic injury complicated by fibrosis (12.9%, p = 0.03) and subsequent development of transplant vasculopathy (Kaplan-Meier 6-year freedom from vasculopathy, 53.4%; p = 0.012) was noted in Group D. No survival difference was observed among the 4 groups, however. In Group D (F-F), 2 patients underwent retransplantation and 2 patients underwent revascularization.

CONCLUSIONS

The transplantation of a female cardiac allograft into a female recipient is associated with increased risk of ischemic injury complicated by fibrosis and subsequent transplant vasculopathy.

Improved Survival After Acute Myocardial Infarction Complicated by Cardiogenic Shock With Circulatory Support and Transplantation: Comparing Aggressive Intervention With Conservative Treatment

BACKGROUND

The prognosis for patients with myocardial infarction has steadily improved, but remains poor for those developing cardiogenic shock. Utilization of re-vascularization, mechanical circulatory support and transplantation in these patients may improve survival.

METHODS

We retrospectively analyzed the clinical outcome of 138 consecutive patients at the Cleveland Clinic from 1992 to 1998 who met the criteria for cardiogenic shock after acute myocardial infarction. All patients received intensive medical therapy and intra-aortic balloon pump support. Forty-three patients received intensive medical therapy (conservative group) and 95 patients were treated aggressively (aggressive group). The aggressive group comprised patients who were treated with percutaneous intervention/coronary artery bypass grafting (n = 77, re-vascularization group), and patients who received circulatory support/cardiac transplantation (n = 18).

RESULTS

The baseline demographics and angiographic and hemodynamic features were comparable for the two groups. The in-hospital mortality rate was significantly reduced in the aggressive group compared with the conservative group (54% vs 81%, p = 0.002). The in-hospital mortality rate of the circulatory support/transplant group was markedly reduced compared with the conservative group (33% vs 81%, p < 0.001), and was also significantly lower than that of the re-vascularization group (33% vs 63%, p= 0.03). The aggressive group had a markedly improved 5-year survival compared with the conservative group (30% vs 6.2%, p = 0.003).

CONCLUSIONS

These data suggest that an aggressive strategy, particularly left ventricular assist device support as a bridge to heart transplantation, may improve survival in post-myocardial infarction patients with cardiogenic shock.

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.

Peritransplant ischemic injury is associated with up-regulation of stromal cell-derived factor-1

OBJECTIVES

We evaluated chimerism and stromal cell-derived factor-1 (SDF-1) expression in response to peritransplant ischemic injury following human heart transplantation.

BACKGROUND

Myocardial ischemia has been shown to trigger mobilization of stem cells to the heart in animal experiments.

METHODS

Between January 1998 and April 2002, a total of 114 male recipients received hearts from female donors. Of these 114 recipients, 26 had evidence of ischemic injury on their initial heart biopsies (ischemia group). These were compared to the remaining 88 patients (control group). Heart biopsy specimens obtained initially at one week and at one year after transplant were evaluated from 20 matched patients of each group for the presence of Y chromosome-containing nuclei. The SDF-1 messenger ribonucleic acid (mRNA) and protein expression were also evaluated on initial heart biopsy specimens.

RESULTS

At one week, Y chromosome-containing nuclei were significantly increased in the ischemia group (0.68% vs. 0.04%; p < 0.0001) compared to the control group. These were positive for the stem cell factor receptor c-kit. A significant 3.3-fold increased mRNA expression (p = 0.001) and 2.8-fold increased protein expression (p = 0.01) of SDF-1 was noted in the ischemia group. At one year, Y chromosome was detected in 0.29% of cardiomyocyte nuclei in the ischemia group but none in the control group. The ischemia group had poorer survival and increased vasculopathy.

CONCLUSIONS

This is the first report to describe chimerism and up-regulation of SDF-1 in human heart transplantation in response to ischemic injury.

The effect of combined Angiotensin-converting enzyme inhibition and calcium antagonism on allograft coronary vasculopathy validated by intravascular ultrasound

BACKGROUND

Hypertension is a potential risk factor for allograft coronary vasculopathy. We evaluated the efficacy of angiotensin-converting enzyme (ACE) inhibitors and calcium antagonists, and their combined use, on the development of coronary vasculopathy in hypertensive heart transplant recipients.

METHODS

Eighty-two heart transplant recipients underwent serial intravascular ultrasound (IVUS) analysis at baseline (within 1 month) and at 1 year after transplantation and were evaluated for the development of coronary vasculopathy. Patients were divided into 4 groups. Nineteen normotensive recipients received no treatment, control (Group A). Hypertensive patients were treated with either ACE inhibitors (Group B, n = 37), calcium antagonists (Group C, n = 16), or both (Group D, n = 10).

RESULTS

We found a significant reduction in IVUS indices of coronary vasculopathy in heart transplant recipients who used a combination of an ACE inhibitor and a calcium antagonist compared with recipients who used either drug alone (p < 0.05). This synergistic efficacy was independent of the baseline indices evaluated in a multivariate regression analysis model and was noted despite comparable mean arterial pressure among the 3 hypertensive groups at 1 year, thus suggesting the presence of a synergistic anti-proliferative effect beyond the anti-hypertensive efficacy.

CONCLUSIONS

The combined use of an ACE inhibitor and a calcium antagonist is more effective than the individual use of either drug alone on the development of coronary vasculopathy in cardiac transplant recipients. Large randomized clinical trials are warranted to evaluate such a synergistic efficacy.

Survival Beyond 10 Years Following Heart Transplantation: The Cleveland Clinic Foundation Experience

BACKGROUND

Long-term survival after heart transplantation is a desirable although challenging goal.

METHODS

We analyzed clinical outcomes in the cohort of 170 patients who have undergone heart transplantation at The Cleveland Clinic Foundation and survived >10 years.

RESULTS

We found 10-year and 15-year survival rates of 54% and 41%, respectively, in these patients, but there was also a high incidence of complications, such as hypertension, renal dysfunction, transplant vasculopathy, and malignancy.

CONCLUSIONS

Long-term survival following cardiac transplantation is possible although complications are frequent. Beyond 10 years, malignancy is a major cause of death.

The Impact of CytoGam on Cardiac Transplant Recipients With Moderate Hypogammaglobulinemia: A Randomized Single-Center Study

BACKGROUND

We have previously shown that the preemptive use of cytomegalovirus (CMV) immunoglobulin (Ig) replacement (CytoGam) decreases the incidence of opportunistic infections in cardiac transplant recipients with severe hypogammaglobulinemia. However, the impact of Ig replacement in moderately hypogammaglobulinemic patients is unknown.

METHODS

Periodic monitoring of the IgG levels was done in 300 heart transplant recipients. Moderate hypogammaglobulinemia (IgG, 350-500 mg/dl) developed in 56 patients (18.6%). Thirty-three patients declined randomization but agreed to have their IgG levels monitored. Twenty-three patients were randomized to placebo (n = 10) or CytoGam (n = 13) at 105 +/- 63 days after transplantation.

RESULTS

The baseline characteristics were similar. A significant reduction in CMV infection was noted in the CytoGam Group compared with the Placebo Group (15.4% [2/13] vs 60% [6/10], p = .039). Among patients who declined randomization, CMV infection developed in 13 (39.4%) of 33, and 6 (46.1%) of the 13 progressed to severe hypogammaglobulinemia. A trend for reduction in the average episodes of > or =grade 2 rejection during the 6-month period after randomization was noted in the CytoGam group (0.4 +/- 0.6 vs 1.4 +/- 1.3, p = 0.065).

CONCLUSIONS

The preemptive use of CytoGam decreases the incidence of CMV infection in patients with moderate hypogammaglobulinemia. A larger randomized study is needed to substantiate these results.

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.

Systemic Activation of Integrin αVβ3 in Donors with Spontaneous Intracerebral Hemorrhage is Associated with Subsequent Development of Vasculopathy in the Heart Transplant Recipient

BACKGROUND

Recipients of hearts from donors with spontaneous intracerebral hemorrhage (ICH) are at increased risk of allograft vasculopathy compared with trauma donors. We have recently shown that the vitronectin receptor (integrin alpha(V)beta3) is upregulated in transplant vasculopathy. We hypothesized that donor ICH is associated with systemic activation of alpha(V)beta3 in the donor before transplantation.

METHODS

We evaluated mRNA expressions of alpha(V)beta3 (TaqMan PCR) in endomyocardial biopsy samples at 1-week post-transplant in 20 recipients from ICH donors and 20 recipients from trauma donors. To investigate whether systemic activation of alpha(V)beta3 was present in the donor before transplantation, alpha(V)beta3 expression was also evaluated in the corresponding donor spleen lymphocytes. All patients underwent serial coronary intravascular ultrasound to evaluate for coronary vasculopathy. The baseline characteristics were similar except for increased donor age in the ICH Group.

RESULTS

The ICH Group showed significant increased mRNA expression of alpha(V)beta3 in the heart biopsy samples (3.8-fold, p = 0.012) and in the corresponding donor spleen lymphocytes (3.5-fold, p = 0.014) compared with the Trauma Group. At 1 year, the ICH Group also showed increased progression of coronary vasculopathy. Multivariate regression analysis found that donor lymphocytic alpha(V)beta3 mRNA expression was independently associated with increased risk of vasculopathy (odds ratio, 1.9; 95% CI, 1.21-3.98, p = 0.03).

CONCLUSIONS

Our report demonstrates the presence of systemic activation of alpha(V)beta3 in donors with spontaneous intracerebral hemorrhage and its association with the subsequent development of allograft vasculopathy in the recipient.

The influence of donor gender on allograft vasculopathy: Evidence from intravascular ultrasound

BACKGROUND

Allograft vasculopathy is a major risk factor for mortality following cardiac transplantation. Several immune and nonimmune factors have been evaluated as risk factors for the development of coronary vasculopathy.

OBJECTIVE

We evaluated the influence of donor gender on the progression of coronary vasculopathy in heart transplant recipients.

METHODS

Eighty-nine heart transplant recipients (67 men, 22 women of mean age: 56 +/- 12 years) underwent serial volumetric intravascular ultrasound analysis (IVUS) at baseline (within 1 month) and at 1 year after transplantation. Patients were divided into four groups in relation to the donor-recipient gender status: female-female, n=17; female-male, n=28; male-female, n=5; male-male, n=39. Ultrasound images were recorded during an automated pullback and with an equal number of slices (average=22 per coronary vessel). The measured IVUS indices for the left anterior descending artery were: change in maximal intimal thickness, average intimal area, total plaque volume, and intimal index.

RESULTS

Patients were similar in baseline characteristics. At 1 year after transplantation, IVUS indices of coronary vasculopathy were significantly increased among recipients of female allografts (P <.05).

CONCLUSION

Heart transplant recipients of female allografts display increased coronary vasculopathy progression.

Donor intracranial bleeding is associated with advanced transplant coronary vasculopathy: Evidence from intravascular ultrasound

OBJECTIVES

We evaluated the impact of spontaneous intracranial bleeding (ICB) in the donor on transplant coronary vasculopathy using serial intravascular ultrasound examinations.

MATERIALS AND METHODS

Between January 1995 and December 2000, 72 recipients underwent cardiac transplantation from donors who had experienced spontaneous ICB (ICB group). Their findings using serial intravascular ultrasound analysis at baseline (within 1 month) and 1 year after transplantation were compared with 90 recipients who had undergone transplantation from trauma donors (trauma group).

RESULTS

Compared with the Trauma group, the ICB group showed increased coronary intimal thickness (0.55 +/- 0.33 vs 0.39 +/- 0.3 mm; P = .034), plaque volume (3.84 +/- 2.5 vs 2.28 +/- 1.65 mm(3); P = .015) and plaque burden (7.4 vs 2%) at 1 year after transplantation.

CONCLUSIONS

Donor spontaneous ICB is associated with significantly increased coronary vasculopathy.

The renin-angiotensin hypothesis for the pathogenesis of cardiac allograft vasculopathy

The precise molecular mechanism for the development of cardiac allograft vasculopathy (CAV) after heart transplantation is not known. We, thus, hypothesize that increased activity of renin-angiotensin system (RAS) is important for the progression of CAV. There is evidence to support this concept. RAS via its principal effector molecule, angiotensin II exerts multitude of actions on vascular structure and function including regulation of vasomotor tone, cell growth/apoptosis, fibrosis and inflammation, which are particularly relevant to the genesis of atherosclerotic lesions. Risk factors, which increase predisposition to CAD, are known to activate tissue RAS and thus influence its progression. Importantly, CAD risk factors are also associated with accelerated CAV progression after transplantation. Whereas angiotensin converting enzyme (ACE) gene polymorphism increases the predisposition, pharmacological inhibition of RAS seems to reduce the incidence of CAV. These observations may support our hypothesis, provide a plausible explanation for the molecular mechanisms underlying the development of accelerated CAV and has predictions that can be tested.

Cardiac angiotensin II receptors as predictors of transplant coronary artery disease following heart transplantation

AIMS

We tested the hypothesis that cardiac angiotensin II (Ang II) receptor gene transcription may predict the development of transplant coronary artery disease (TCAD) following heart transplantation.

METHODS AND RESULTS

We examined the gene transcripts of Ang II type 1 (AT1R) and type 2 receptors (AT2R) in endomyocardial biopsy specimens from 50 heart transplant recipients. The progression of TCAD was measured as change in maximal intimal thickness (CMIT) and change in plaque volume (CPV) by intravascular ultrasound (IVUS) examinations from baseline to one year after transplantation. The development of transplant vasculopathy was defined as a CMIT of > or = 0.3 mm over one year. The level of AT(1)R mRNA was associated with that of AT2R in transplanted hearts (regression coefficient=1.77, 95% CI 0.85-2.89, p<0.0001). AT1R and AT2R gene transcripts were univariate predictors of CMIT (AT1R: regression coefficient 0.10, 95% CI 0.06-0.14, p<0.0001; AT2R: regression coefficient 0.28, 95% CI 0.17-0.40, p<0.0001 ) or CPV (AT1R: regression coefficient 0.41, 95% CI 0.17-0.65, p<0.0001 ; AT2R: regression coefficient 1.25, 95% CI 0.49-2.01, p=0.002 ). By one year, 21 (46%) transplant recipients showed evidence of transplant vasculopathy and the rest did not. The vasculopathic group demonstrated a higher level of expression of cardiac AT1R than the non-vasculopathic group (3.7+/-2.9 vs 1.6+/-1.7 folds; p=0.006). The level of AT(1)R mRNA in transplanted heart was identified as a discriminator that predicted the development of transplant vasculopathy with a sensitivity of 75% and specificity of 83%.

CONCLUSIONS

Cardiac Ang II receptor gene transcripts are associated with the progression of TCAD following heart transplantation. Only AT1R gene transcripts predicted the development of transplant vasculopathy in this preliminary study. These findings potentially support a role of Ang II receptors in the progression of TCAD following cardiac transplantation.

Systemic up-regulation of angiotensin II type 1 receptor in cardiac donors with spontaneous intracerebral hemorrhage

Donor spontaneous intracerebral hemorrhage (ICH) is a potential risk factor for morbidity and mortality after cardiac transplantation. We hypothesized that donor ICH is associated with systemic up-regulation of angiotensin II receptor type 1 (AT1R). We evaluated mRNA expression of AT1R and AT2R in donor spleen lymphocytes and in heart biopsies from 20 recipients of hearts from donors with spontaneous ICH which were compared with 20 recipients from trauma donors. Heart biopsies showed 4.7-fold increased mRNA expression of AT1R (p < 0.0001) in the ICH group compared with the Trauma group. The ICH group also showed 2.6-fold (p < 0.01) increased mRNA expression of AT1R in the donor spleen lymphocytes, suggesting the presence of systemic activation before transplantation. At 1 year, the ICH group had increased coronary vasculopathy by vascular ultrasound. Using multivariate regression analysis, mRNA expression of AT1R in the donor spleen lymphocytes was found to be a strong independent predictor of transplant vasculopathy (odds ratio = 4.397, CI = 1.243-15.553, adjusted p = 0.02). This is the first report to describe splenic up-regulation of AT1R in the presence of spontaneous ICH and its association with subsequent development of transplant vasculopathy.

Encephalitis owing to human herpesvirus-6 after cardiac transplant

Human herpesvirus-6 (HHV-6), a beta herpesvirus closely related to cytomegalovirus (CMV), infects the majority of the population in childhood. Human herpesvirus-6 can be reactivated in the immunosuppressed patient. After bone marrow and orthotopic liver transplant, it has been linked to various clinical syndromes, including undifferentiated febrile illness, encephalitis, pneumonitis and bone marrow suppression. To date its infectious role after orthotopic heart transplant has not been well documented. We present the case of a 32-year-old cardiac transplant recipient who initially presented 8 weeks after his transplant with high fever and headache. He developed increasing confusion, pulmonary infiltrates and neutropenia. Cytomegalovirus viral loads were negative. Polymerase chain reaction (PCR) of blood and cerebrospinal fluid detected HHV-6 DNA, consistent with HHV-6-related encephalitis, pneumonitis and bone marrow suppression. He was treated with foscarnet with gradual improvement in clinical status. We review the literature on the significance of this virus post cardiac transplant.

Donor hepatitis-C seropositivity is an independent risk factor for the development of accelerated coronary vasculopathy and predicts outcome after cardiac transplantation

BACKGROUND

It is possible, but unproven, that hepatitis C (HCV) infection accelerates atherosclerosis. We evaluated the hypothesis that donor HCV seropositivity predicts mortality and the development of coronary vasculopathy in cardiac transplant recipients.

METHODS

Thirty-four cardiac transplant recipients who were seronegative for HCV at the time of transplantation received hearts from HCV-seropositive donors. We compared the mortality and the incidence of vasculopathy in this group of patients (study group) with a group of 183 successive heart transplant recipients (control group) with no evidence of HCV in the donor or in the recipient.

RESULTS

After transplantation, 75% of the HCV-seronegative patients who received hearts from HCV-seropositive donors had detectable and persistent viremia (presence of HCV-RNA by reverse-transcription polymerase chain reaction). After a mean follow-up of 4.2 +/- 1.9 years, mortality was 2.8-fold greater in the study group than in controls (95% confidence interval [CI], 1.3-5.7; p = 0.006). The risk of having any vasculopathy after a mean follow-up of 3.4 +/- 1.6 years and after adjustment for other significant risk factors was 3-fold greater (hazards ratio, 3.08; 95% CI 1.52-6.20; p = 0.001) in the HCV group compared with controls. The risk of developing advanced vasculopathy was much greater in the study group compared with controls (hazard ratio, 9.4; 97% CI, 3.3-26.6; p = < 0.0001). The risk of mortality (p = 0.005) and vasculopathy (p = < 0.0001) was greatest in patients with combined donor HCV seropositivity and the presence of antibodies against donor B cells by flow cytometry.

CONCLUSION

We conclude that donor hepatitis-C virus seropositivity is an independent risk factor for increased mortality and for the development of accelerated allograft vasculopathy after cardiac transplantation. These observations may have implications for the use of HCV-positive donors in heart transplant recipients.

Angiotensin II receptors from peritransplantation through first-year post-transplantation and the risk of transplant coronary artery disease

OBJECTIVES

We evaluated whether the angiotensin II (Ang II) receptors from perioperation through one-year post-transplantation predict the transplant coronary artery disease (TCAD) progression.

BACKGROUND

The role of Ang II receptors (type 1: AT(1)R; type 2: AT(2)R) in TCAD is uncertain.

METHODS

We investigated 28 heart donors and the corresponding recipients. The levels of AT(1)R and AT(2)R messenger ribonucleic acid (mRNA) were examined in lymphocytes from the donor spleen and in the donor heart at one-week and one-year posttransplantation to determine their association with the progression of TCAD, measured as changes in maximal intimal thickness (CMIT) and plaque volume (CPV) by intravascular ultrasound (IVUS) examinations.

RESULTS

The AT(1)R mRNA in lymphocytes from the donor spleen (CMIT: r = 0.73, p < 0.0001; CPV: r = 0.69, p < 0.0001) and in the donor hearts at one-week (CMIT: r = 0.52, p = 0.005; CPV: r = 0.56, p = 0.002) and at one-year (CMIT: r = 0.63, p < 0.0001; CPV: r = 0.43, p = 0.004) post-transplantation along with AT(2)R mRNA in the donor hearts at one-year post-transplantation (CMIT: r = 0.3, p < 0.0001; CPV: r = 0.53, p = 0.009) were univariate predictors, whereas AT(1)R mRNA in lymphocytes and in the donor hearts at one-year post-transplantation proved to be multivariate predictors of the progression of TCAD.

CONCLUSIONS

These data suggest a role for Ang II receptors in the pathogenesis of TCAD and support a novel concept that TCAD may have its origin in the donor per se and may be modulated by the recipient's inherent biological factors.

Does acute cellular rejection correlate with cardiac allograft vasculopathy?

BACKGROUND

Previous studies of the association between acute cellular rejection and cardiac allograft vasculopathy (CAV) have yielded conflicting conclusions. We explored a possible association between acute cellular rejection and the extent of CAV, and we found a potential confounding variable that may obscure such an association.

METHODS

We investigated 140 patients (mean age, 51 +/- 11 years) who underwent serial intravascular ultrasound examinations at baseline and at 1 year after heart transplantation to assess CAV as change in maximal intimal thickness (CMIT). Patients were classified according to the presence or absence of biopsy-proven myocardial fibrosis. We used a standard biopsy-scoring system and a novel biopsy-scoring system, developed in our institution, to assess acute cellular rejection. Using univariate analysis, we found that CMIT was not associated with acute cellular rejection in the overall patient population (n = 140). However, we observed a correlation between CMIT and acute cellular rejection (standard method, r = 0.30, p = 0.01; novel method, r = 0.51, p < 0.0001) in patients who had no evidence of ischemic injury or fibrosis in their biopsy specimens (n = 57). Step-wise multiple regression showed that the rejection score derived from our novel method was associated more closely with the CMIT than was that derived from the traditional method.

CONCLUSIONS

This data indicate that the presence of myocardial fibrosis masks an actuarial association between acute cellular rejection and the development of de novo allograft vasculopathy. As previously suspected, myocardial fibrosis is a marker for non-immune-mediated graft injury independently associated with an increased incidence of CAV.

Impact of donor spontaneous intracranial hemorrhage on outcome after heart transplantation

Donor cause of death has been suggested to have a significant impact on cardiac transplant morbidity and mortality. Our objective was to evaluate the impact of donor spontaneous intracranial bleeding on clinical outcome after heart transplantation. A group of 160 recipients underwent cardiac transplantation from donors with spontaneous intracranial bleeding (ICB group). These were compared with 197 recipients who were transplanted from trauma donors (Trauma group). A higher 4-year mortality rate was noted in the ICB group (24% vs. 14%, p=0.015). ICB as a cause of donor death was an independent predictor of recipient mortality (adjusted hazard ratio 2.02, 95% CI 1.27-3.40, p<0.0001). Compared with the Trauma group, the ICB group had an increased incidence of post-transplant graft dysfunction during the first week of transplant (10% vs. 3%, p=0.007), and higher incidence of interstitial myocardial fibrosis on their endomyocardial biopsies within 4 weeks of transplant (21% vs. 9%, p=0.0012). There was a trend towards an increased rate of allograft vasculopathy in the ICB group (competing risks adjusted hazard ratio 1.39, 95% CI 0.90-2.13, p = 0.14).

Donor spontaneous intracerebral hemorrhage is associated with systemic activation of matrix metalloproteinase-2 and matrix metalloproteinase-9 and subsequent development of coronary vasculopathy in the heart transplant recipient

BACKGROUND

Matrix metalloproteinase (MMP)-2 and MMP-9 have been shown to play a role in the progression of hemorrhagic stroke. We hypothesized that donor intracerebral hemorrhage (ICH) is associated with activation of the metalloproteinases before transplantation that play a key role in the subsequent development of transplant vasculopathy.

METHODS AND RESULTS

We evaluated mRNA expressions of MMP-2 and MMP-9 in donor spleen lymphocytes (before transplantation) and in heart biopsies at 1 week after transplantation in 20 recipients from ICH donors and 20 recipients from trauma donors. Patients underwent serial coronary intravascular ultrasound, and interstitial myocardial fibrosis was quantified at 1 year. The baseline characteristics were similar except for increased donor age in the ICH group. Heart biopsies from the ICH group showed significant increased expression of MMP-2 (17-fold, P<0.0001) and MMP-9 (20-fold, P<0.0001) compared with the trauma group. Furthermore, the ICH group showed 1.8-fold (P=0.016) increased mRNA expression of MMP-2 and 1.7-fold (P=0.015) increased mRNA expression of MMP-9 in the donor spleen lymphocytes, suggesting the presence of systemic activation of metalloproteinases before transplantation. At 1 year, the ICH group showed increased myocardial fibrosis and accelerated coronary vasculopathy. Using multivariate regression analysis, MMP-9 was found to be associated with increased risk for vasculopathy independent of donor age (OR, 2.41; P=0.01; 95% CI, 1.24 to 4.69).

CONCLUSIONS

This is the first report to describe systemic activation of MMP-2 and MMP-9 in donors with intracerebral hemorrhage and subsequent development of allograft vasculopathy.

Sustained apoptosis in human cardiac allografts despite histologic resolution of rejection1

BACKGROUND

We investigated the occurrence of apoptosis during and after resolution of cardiac allograft rejection. Apoptosis could play different roles in graft survival depending on the target cells; thus, we also determined the cell types involved.

METHODS

Endomyocardial biopsy specimens were evaluated during the first 6 months after transplantation as follows: group I, no current or prior rejection; group II, during an episode of moderate rejection; and group III, histologic resolution after an episode of moderate rejection.

RESULTS

Groups II and III showed significantly increased apoptotic activity, indicated by increased caspase-8 and caspase-3 activity; however, activated caspase-3 was undetectable in group I. Activated caspase-3 was detected only in groups II and III. Terminal deoxynucleotide transferase-mediated dUTP nick-end labeling was detected in groups II and III but not group I and predominantly in inflammatory cells.

CONCLUSIONS

Increased caspase activity and apoptosis of infiltrating cells not only occurs during acute cardiac allograft rejection but persists after histologic resolution. Thus, programmed cell death occurs beyond the period of histologic resolution and may play a role in regulation of the rejection process.