Microbiological assessment of arterial allografts processed in a tissue bank.

The transmission of microbial infection through tissue allografts is one of the main risks that must be controlled in tissue banks. Therefore, microbiological monitoring controls and validated protocols for the decontamination of tissues during processing have been implemented. This study is based on the evaluation of data from microbiological cultures of arteries (mainly long peripheral arteries) processed in the tissue bank of Valencia (Spain). Donors' profile, pre- and post-disinfection tissue samples were assessed. The presence of residual antibiotics in disinfected tissues was determined and the antimicrobial potential of these tissues was tested. Our overall contamination rate was 23.69%, with a disinfection rate (after antibiotic incubation) of 87.5%. Most (76.09%) of the microbial contaminants were identified as Gram positive. Arterial allografts collected from body sites affected by prior organ removal showed higher risk of contamination. Only vancomycin was detected as tissue release. The antimicrobial effect on Candida albicans was lower than that for bacterial species. Risk assessment for microbial contamination suggested the donor's skin and the environment during tissue collection as the main sources for allograft contamination. Antibiotic-disinfected arterial allografts showed antimicrobial potential.

Prognostic Value of High-Sensitivity Troponin-T to Identify Patients at Risk of Left Ventricular Graft Dysfunction After Heart Transplantation.

Primary graft dysfunction after heart transplantation (HTx) has a very high mortality rate, especially if the left ventricle (PGD-LV) is involved. Early diagnosis is important to select the appropriate therapy to improve prognosis. The value of high-sensitivity troponin T (HS-TNT) measurement obtained at patient arrival at the intensive care unit was analyzed in 71 HTx patients. Mild or moderate PGD-LV was defined by hemodynamic compromise with one of the following criteria: left ventricular ejection fraction <40%, hemodynamic compromise with right atrial pressure >15 mm Hg, pulmonary capillary wedge pressure >20 mm Hg, cardiac index <2.0 L/min/m2, hypotension (mean arterial pressure <70 mm Hg), and need for high-dose inotropes (inotrope score >10) or newly placed intra-aortic balloon pump. The mean recipient age was 54 ± 12 years (73% men), and donor age was 47 ± 11 years. Ischemic time was 200 ± 51 minutes, and coronary bypass time was 122 ± 31 minutes. Nine (13%) HTx patients were diagnosed with PGD-LV post-HTx, 8 with biventricular dysfunction. Four patients died, 2 with PGD-LV (22%) and 2 without PGD (4%). Mean HS-TNT before HTx was 158 ± 565 ng/L, and post-HT was 1621 ± 1269 ng/L. The area under the curve (receiver-operator characteristic) of HS-TNT to detect patients at risk of PGD-LV was 0.860 (P < .003). A cutoff value of HS-TNT >2000 ng/L had a sensitivity of 75% and specificity of 87% to identify patients at risk of PGD-LV. Multivariate analysis identified HS-TNT >2000 ng/L (P < .02) and coronary bypass-time (P < .01) as independent predictors of PGD-LV. HS-TNT >2000 ng/L at intensive care admission after HT and prolonged coronary bypass time were the most powerful predictors of PGD-LV. HS-TNT may be helpful for early detection of HTx patients at risk of PGD-LV.

De Novo Anti-HLA Antibodies After Heart Transplantation Are Associated With Adverse Events in the Long-term Follow-up of Cardiac Transplant Recipients.

BACKGROUND AND OBJECTIVES: Long-term morbidity and mortality after heart transplantation (HTx) remain very high. Several reports have suggested that anti-HLA antibodies (anti-HLA-AB) detected after HTx might be associated with poor survival, but the implication of isolated anti-HLA-AB is still under debate. The aim of the study was to analyze the incidence of de novo anti-HLA-AB and whether they are associated with adverse events after HTx. METHODS: This retrospective study analyzed the presence of anti-HLA-AB assessed by fluorimetry (Luminex) and quantified by a single-antigen bead assay in 119 HTx patients. Mortality, graft dysfunction, antibody-mediated rejection (AMR), and cardiac allograft vasculopathy (CAV) were recorded. Cardiovascular mortality of patients with and without anti-HLA-AB was compared according Kaplan-Meier curves. Cox regression analyses were performed to identify predictors for global mortality and for a combined endpoint (cardiovascular mortality, AMR, and CAV). Mean age of recipients and donors was 49 ± 15 and 38 ± 14 years, 70% were men, 29% were urgent transplants, and mean ischemic time was 195 ± 56 minutes. RESULTS: Anti-HLA-AB were detected in 23 patients (19%). These patients had higher rates of AMR (39% vs 1%; P < .05) and cardiovascular mortality (17% vs 2%; P < .05). By multivariate analysis, anti-HLA-AB were the only predictor of the combined endpoint (hazard ratio 3.1; confidence interval 1.3 to 7.5; P = .01). Kaplan-Meier curves showed the worse cardiovascular survival of patients with anti-HLA-AB (72% vs 97%; P = .003). CONCLUSIONS: Presence of anti-HLA-AB identifies a group of HTx patients with worse prognosis. Better understanding of the immunologic relevance of anti-HLA-AB is expected to improve long-term survival after HTx.

Cancer Incidence in Heart Transplant Recipients With Previous Neoplasia History.

Neoplasm history increases morbidity and mortality after solid organ transplantation and has disqualified patients from transplantation. Studies are needed to identify factors to be considered when deciding on the suitability of a patient with previous tumor for heart transplantation. A retrospective epidemiological study was conducted in heart transplant (HT) recipients (Spanish Post-Heart Transplant Tumor Registry) comparing the epidemiological data, immu-nosuppressive treatments and incidence of post-HT tumors between patients with previous malignant noncardiac tumor and with no previous tumor (NPT). The impact of previous tumor (PT) on overall survival (OS) was also assessed. A total of 4561 patients, 77 PT and 4484 NPT, were evaluated. The NPT group had a higher proportion of men than the PT group (p < 0.001). The incidence of post-HT tumors was 1.8 times greater in the PT group (95% confidence interval [CI] 1.2-2.6; p < 0.001), mainly due to the increased risk in patients with a previous hematologic tumor (rate ratio 2.3, 95% CI 1.3-4.0, p < 0.004). OS during the 10-year posttransplant period was significantly lower in the PT than the NPT group (p = 0.048) but similar when the analysis was conducted after a first post-HT tumor was diagnosed. In conclusion, a history of PT increases the incidence of post-HT tumors and should be taken into account when considering a patient for HT.

Role of Vascular Disease in the Evolution of Heart Transplant Patients.

BACKGROUND: The clinical profile of heart transplantation (HT) recipients has changed in recent years. Nowadays, we have to deal with a higher number of co-morbidities, including peripheral vascular disease (PVD). Previous studies suggest an increase in post-HT morbidity and mortality associated with PVD, especially when it is symptomatic. Our study aims were to analyze the prognostic implications of the presence of PVD before transplantation and to determine the factors associated with its development after it. METHODS: HT patients (n = 217) who survived the first year after surgery were included in the study. Mean follow-up was 9 ± 5 years. RESULTS: There were no statistically significant differences in mortality rates between patients with PVD (before or after HT) and those without. One third of patients with PVD required surgery in the post-HT monitoring, either revascularization or amputation. Furthermore, the prevalence of PVD was doubled. Dyslipidemia before HT (odds ratio [OR]: 2.9, 95% confidence interval [CI]: 1.3-6.4; P < .01) and older recipient age (OR: 1.05, 95% CI: 1.01-1.09; P < .05) were independently associated with development of PVD by means of multivariate analysis. CONCLUSIONS: The presence of PVD must be evaluated individually in candidates for heart transplantation despite being a relative contraindication to it at the present time.

Cost-Effectiveness of Highly Sensitive Cardiac Troponin T to Rule Out Acute Rejection After Heart Transplantation.

BACKGROUND: Endomyocardial biopsy (EMB) remains the gold standard for detecting acute rejection (AR) after heart transplantation (HTx). Non-invasive detection of AR thus far remains a challenge. Several studies have demonstrated that highly sensitive cardiac troponin T (hs-cTnT) concentrations have a low positive predictive value for diagnosing AR. Nevertheless, hs-cTnT proved to be useful for ruling out AR after HTx. An hs-cTnT concentration <17 ng/L, a value close to that used for rule-in or rule-out myocardial infarction, was associated with a 100% negative predictive value of AR. However, the cost-effectiveness of a strategy with the use of hs-cTnT for ruling out AR in HTx patients remains to be proven. METHODS: The cost-effectiveness of hs-cTnT determination for ruling out AR was assessed, comparing the costs of hs-cTnT measurements in 305 blood samples obtained at the time of EMB. Eighteen samples were excluded because the EMB was not assessable. RESULTS: Hs-cTnT determination cost 16.00€ per sample, whereas EMB cost 1752.00€ per biopsy; cost estimations included direct and indirect (30%) charges. Thirty-nine (13.6%) of the 287 blood samples presented hs-cTnT concentrations <17 ng/L; in none of them was an AR >2R degree found in the EMB. The cost of the assessment in the 287 blood samples and biopsies was of 4592.00€ for hs-cTnT and 502,824.00€ for EMB. Hs-cTnT systematic measurement would have avoided 39 EMB, with a saving of 68,328.00€, which represents the 13.5% of the total budget expended in these cases. CONCLUSIONS: The use of hs-cTnT values to rule out the need of EMB for AR diagnosis after HTx appears to be a cost-effective procedure.

RAndomized Comparison of raDIal vs. femorAL Access for Routine Catheterization of Heart Transplant Patients (RADIAL-heart transplant study).

Although a transradial approach (TRA) is considered feasible in many clinical situations, no data are available in patients undergoing orthotopic heart transplantation (OHT). Our goal was to randomly compare TRA versus a transfemoral approach (TFA) in this clinical setting. This single-center, prospective, randomized trial was conducted from January to November 2006, and all OHT patients scheduled for a control coronary angiography were randomized to receive TRA or TFA. The primary endpoint was the amount of contrast used during the procedure. The participating interventional cardiologists were intermediate-volume radial operators, and this was their initial experience of TRA in OHT patients. The analysis was performed according to the intention-to-treat principle. Overall, 49 patients (mean age, 55 ± 13 years; 74% male) were included in the trial: 26 patients were assigned to TRA, and 23 were assigned to TFA. A higher amount of contrast (147 mL [range, 113-175 mL] vs 105 mL [range, 86-127 mL]; P = .009), a longer fluoroscopy time (9.2 minutes [range, 6-12 minutes] vs 3.5 minutes [range, 3-5 minutes]; P < .001), a trend toward increased number of catheters used for left ostium cannulation, and a higher crossover rate (19% vs 0%; P = .03) were associated with TRA compared with TFA. Furthermore, patients treated with TRA exhibit a shorter hospital stay (6 [range 4-8]) compared with the other group (26 [range 24-28]) (P < .001). There were no significant differences between the 2 groups regarding total procedural time, and no vascular complications were reported in either group. For these operators with their first experience of TRA in OHT patients, TFA seemed to be more efficient.

Chronic renal dysfunction in maintenance heart transplant patients: the ICEBERG study.

Chronic renal dysfunction (CRD) is a major complication after heart transplantation. We sought to describe the renal function over time, to assess the risk factors associated with CRD development, and to evaluate the clinical attitudes on diagnosis and treatment of CRD. A retrospective, cross-sectional, multicenter study was conducted in 13 outpatient clinics in Spain. A total of 244 heart recipients who survived more than 2 years after transplantation were included. Post-transplantation follow-up was 7.7 years (range: 2-22 years). CRD was diagnosed in 32.4% of patients at a mean of 3.3 years after transplantation. Serum creatinine increased 0.1 ± 0.2 mg/dL per year in CRD group compared with 0.0 ± 0.2 mg/dL per year in non-CRD group (P = .003) and glomerular filtration rate decreased -1.5 ± 4.3 mL/min/1.73 m(2) per year in CRD group versus -0.1 ± 4.8 mL/min/1.73 m(2) per year in non-CRD group (P = .027). After CRD diagnosis, major changes in immunosuppression based on calcineurin inhibitors reduction were instituted in 46.8% of patients. Multivariate model identified recipient age (P < .0001), female sex (P = .0398), and time since transplant (P < .0001) as predictors of CRD. In conclusion, the prevalence of CRD in long-term heart recipient survivors was quite high. CRD was associated with nonmodifiable factors (age, gender, and time since transplant).

Use of mTOR inhibitors in chronic heart transplant recipients with renal failure: calcineurin-inhibitors conversion or minimization?

BACKGROUND: In the last decade, mTOR inhibitors (mTOR-is) have become the cornerstone of the calcineurin inhibitor (CNI)-reduced/free regimens aimed to the preservation of post-transplant renal function. We compared utility and safety of the total replacement of calcineurin inhibitors with a mTOR-i with a strategy based on calcineurin inhibitor minimization and concomitant use of m-TOR-i. METHODS: In a retrospective multi-center cohort of 394 maintenance cardiac recipients with renal failure (GFR<60 mL/min/1.73 m(2)), we compared 235 patients in whom CNI was replaced with a mTOR-i (sirolimus or everolimus) with 159 patients in whom mTOR-is were used to minimize CNIs. A propensity score analysis was carried out to balance between group differences. RESULTS: Overall, after a median time of 2 years from mTOR-i initiation, between group differences for the evolution of renal function were not observed. In a multivariate adjusted model, improvement of renal function was limited to patients with mTOR-i usage within 5years after transplantation, particularly with the conversion strategy, and in those patients who could maintain mTOR-i therapy. Significant differences between strategies were not found for mortality, infection and mTOR-i withdrawal due to drug-related adverse events. However, conversion group tended to have a higher acute rejection incidence than the minimization group (p=0.07). CONCLUSION: In terms of renal benefits, our results support an earlier use of mTOR-is, irrespective of the strategy. The selection of either a conversion or a CNI minimization protocol should be based on the clinical characteristics of the patients, particularly their rejection risk.

Hemorragia masiva después de anticoagulación con bivalirudina en 2 casos de pacientes con trasplante cardiaco / Massive haemorrhage after bivalirudin anticoagulation in two heart transplant patients

La trombopenia inducida por heparina es una complicación autoinmunitaria frecuente. Se trata de un estado protrombótico debido a la formación de anticuerpos contra los complejos heparina/factor plaquetario 4. Ante esta situación es necesario el empleo de fármacos alternativos a la heparina para la anticoagulación durante la circulación extracorpórea. Se exponen 2 casos de trasplante cardiaco en los que se empleó bivalirudina como anticoagulante durante la circulación extracorpórea. En ambos pacientes se observó la aparición de complicaciones hemorrágicas severas. Es necesario mejorar el diagnóstico de la trombopenia inducida por heparina y desarrollar protocolos de empleo de nuevos fármacos alternativos a la heparina. Por ello revisamos los protocolos de actuación y las alternativas terapéuticas a la heparina(AU)

Heparin-induced thrombopenia is a common autoimmune complication. It is a prothrombotic state due to the formation of antibodies against heparin/platelet factor 4 complexes. In this situation drugs other than heparin must be used for anticoagulation during extracorporeal circulation (bypass) surgery. Two cases of heart transplantation are presented in whom bivalirudin was used as an anticoagulant during the cardiopulmonary bypass. Severe bleeding complications were observed in both patients. The diagnosis of heparin-induced thrombopenia needs to be improved, as well as the development of protocols for using new drugs other than heparin. For this reason, we have reviewed current protocols and alternative therapies to heparin(AU)

[Massive haemorrhage after bivalirudin anticoagulation in two heart transplant patients]. / Hemorragia masiva después de anticoagulación con bivalirudina en 2 casos de pacientes con trasplante cardiaco.

Heparin-induced thrombopenia is a common autoimmune complication. It is a prothrombotic state due to the formation of antibodies against heparin/platelet factor 4 complexes. In this situation drugs other than heparin must be used for anticoagulation during extracorporeal circulation (bypass) surgery. Two cases of heart transplantation are presented in whom bivalirudin was used as an anticoagulant during the cardiopulmonary bypass. Severe bleeding complications were observed in both patients. The diagnosis of heparin-induced thrombopenia needs to be improved, as well as the development of protocols for using new drugs other than heparin. For this reason, we have reviewed current protocols and alternative therapies to heparin.

Correlation of immunological markers with graft vasculopathy development in heart transplantation.

This study examined the imbalance between T effector cells (Th1 defined as CD3+ interferonγ+) and T regulatory cells (Treg defined as CD4+CD25(high)FoxP3+) as a valuable albeit limited marker of cardiac allograft vasculopathy (CAV) after heart transplantation (HTx). CAV remains, with neoplasms, the most important cause of death in patients surviving the first year after HTx. It is an immune-mediated pathology, although nonimmune factors may also play a role. The process included concentric fibrous intima hyperplasia that narrows the entire length of the affected arteries. Coronary angiography is the usual method of diagnosis. Because a transplanted heart is a denervated organ, CAV is not diagnosed until the disease reaches an advanced stage, in which case transplantation is the only option for treatment. Although the host's immune response against an allogeneic graft is the major cause of endothelial dysfunction, the objective of this study was to detect anti-allogeneic responses on peripheral blood, seeking to identify signs of CAV before classical methods to predict outcomes in HTx recipients. CD3, CD4, CD8, CD19, CD56, Th1, and the Treg mononuclear cell populations were studied in 37 de novo and 20 long-term (more than 3 years) HTx patients as well as 20 healthy volunteers using flow cytometry. A progressive increase in CD8 and Th1 percentages and decrease in the CD4 population were detected during follow-up. Although Th1 changes also reflect processes not related to CAV receiver operating characteristics analysis of Th1/Treg ratio showed an area under the curve of 0.976, with an estimated sensitivity of 100% and specificity of 90%. The positive prediction value was 58.8% and the negative prediction value, 100%. These results prove that the Th1/Treg ratio was an important marker to following host immune response after HTx. The results confirm the need to test other T lymphocyte subsets.

Assessment of immunological markers as mediators of graft vasculopathy development in heart transplantation.

Heart transplantation (HT) remains the treatment of choice for patients with end-stage heart failure. Cardiac allograft vasculopathy (CAV), a diffuse form of coronary atherosclerosis, is the major cause of death after the first year of HT. CAV is thought to be multifactorial in origin. Although nonimmune factors may play a role in CAV development, it is primarily an immune-mediated disease. CAV is diagnosed by routine annual coronary angiography, and usually when diagnosed, the disease is advanced. There is a need to develop noninvasive surrogate markers for early detection. For this purpose, careful immune monitoring and graft histologic assessment are mandatory. The main objective of this study was the assessment of immunologic markers as mediators of CAV development in HT. Flow cytometry was performed to assess peripheral blood mononuclear cell populations forming CD3, CD4, CD8, CD19, CD56, Th1 (CD3+IFNγ+) or Treg (CD4+CD25(high)FoxP3+) markers among 20 de novo HT recipients. The control group included 13 patients who were more than 2 years post-HT (four with and nine without CAV) as well as 20 healthy subjects. CAV-related events over 2 years' follow-up correlated with the Th1/Treg ratio. An increased Th1 lymphocyte percentage was detected over the follow-up. Patients with medium and high Th1/Treg ratios showed higher acute rejection scores as well as greater incidences of CAV. These results indicated that the Th1/Treg ratio may represent a valuable marker to monitor allospecific T-cell responses in peripheral blood. Changes in the Th1/Treg ratio may help in the early detection of patients at risk for CAV. More studies with longer follow-up are needed to confirm these preliminary results.

Temporal trends in the use of proliferation signal inhibitors in maintenance heart transplantation: a Spanish multicenter study.

Proliferation signal inhibitors (PSI; sirolimus, everolimus) are being increasingly used in heart transplantation. We performed an observational, retrospective, multicenter study in 9 Spanish centers seeking to describe the clinical context in which a PSI was used among maintenance heart recipients and its evolution over time. We collected a cohort of 548 patients in whom a PSI was prescribed from October 2001 to March 2009. The group was divided into 3 time periods. The use of PSI steeply increased in the 2005-2006 period, remaining stable thereafter. There were no significant differences over time with regard to age, gender, or time from transplantation to the introduction of the PSI. Everolimus usage overtook sirolimus from 2005 on; currently, >90% of the subjects with PSI indications are prescribed everolimus. Compared with earlier periods, patients in the more recent period (October 2006-March 2009) showed less vascular graft disease and better basal renal function, irrespective of the primary indication for the PSI prescription. Also, skin cancer overtook solid cancer as the main type of neoplasm in patients for whom malignancy was the primary indication for the use of the PSI. The actuarial incidence of PSI withdrawal owing to adverse effects did not change significantly over time.

Incidence and risk factors for nonmelanoma skin cancer after heart transplantation.

INTRODUCTION: The incidence of skin cancer in heart transplant (HT) patients is higher than in the general population, reversing the proportion of cutaneous squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) with a predominance of the former. The etiologic role of new immunosuppressants is not well known. We sought to ascertain the incidence of SCC and BCC in HT patients and the risk factors for its occurrence. PATIENTS AND METHODS: We report the incidence of all types of post-HT skin cancer, SCC, and BCC among adult HT patients in Spain (4089 subjects) as well as the influence of gender, age at heart transplant, immunosuppression, and sunlight exposure. RESULTS: The incidence rates of SCC and BCC, per 1000 persons/year, were 8.5 and 5.2, respectively. Males had a higher risk of SCC but not BCC. Induction therapy increased the risk of SCC and BCC. The relative risk of mycophenolate mofetil (MMF) was 0.3 (0.2-0.6; P<.0005) and azathioprine (AZA) 1.8 (1.2-2.7; P<.0032) for SCC, whereas tacrolimus and cyclosporine showed no difference. The relative risk of BCC was not affected by any immunosuppressant. CONCLUSION: Age at transplantation>45 years, induction therapy use, and high sunshine zone were risk factors for both SCC and BCC. Different immunosuppressive agents have different risks of nonmelanoma skin cancer, as AZA increases the risk of SCC and MMF is a protective factor. The relative risk of BCC was not affected by any immunosuppressor.

Steroid use in heart transplant patients in Spain in the current era: a multicenter survey.

OBJECTIVE: Steroid withdrawal (SW) from maintenance therapy in heart transplant patients is still a controversial subject. We designed a questionnaire to ascertain the attitudes and procedures of a number of Spanish heart transplant units (16) regarding the use/withdrawal of steroids as part of the immunosuppressive maintenance therapy. MATERIALS AND METHODS: We sent an 11-item questionnaire to the clinical director in charge of each unit. The questionnaire was completed and returned by 14 units. RESULTS: In 21.5% of the centers SW was performed in all patients, while 78.5% of the centers only performed SW in selected patients. In 57% of units SW was performed at 12 months posttransplantation and between 6 and 12 months in the rest. Fewer than 20% of patients were steroid-free in 46% of units while in 23% of units this proportion was >50%. In 11 units, the minimum prednisone dose administered was

Gastrointestinal complications in heart transplant patients: MITOS study.

INTRODUCTION: The most frequent immunosuppressive treatment complications in solid organ transplant recipients are gastrointestinal (GI) disorders. MATERIALS AND METHODS: An observational, cross-sectional study to evaluate the prevalence and management of GI complications in transplanted patients was conducted via a written questionnaire given to doctors at their practice. RESULTS: This study included 1788 patients; 181 corresponded to heart transplant recipients. The mean age for the heart transplant patients was 58.7 +/- 11.8 years. The mean time from the transplantation was 5.2 +/- 4.4 years. GI complications were seen in 38.7% of cases. Regarding the clinical management, in 72.9% of cases patients with GI complications received pharmacologic treatment, 86.3% with gastric protectors, 32.8% reduced the dose of some drug, 8.1% interrupted the drug temporarily, and 10.9% discontinued the drug permanently. The drug that was always discontinued was mycophenolate mofetil (MMF), and in 85.7% of cases in which the dose of an immunosuppressive drug was reduced, the reduced drug was also MMF. CONCLUSIONS: Almost 40% of heart transplant recipients suffered GI complications which affected daily activities in most cases. The most used strategy to manage these complications was based on a treatment with gastric protectors together with dose reduction and/or partial or definitive MMF discontinuation.