Jose A. Tallaj

Report from a consensus conference on antibody-mediated rejection in heart transplantation

BACKGROUND The problem of AMR remains unsolved because standardized schemes for diagnosis and treatment remains contentious. Therefore, a consensus conference was organized to discuss the current status of antibody-mediated rejection (AMR) in heart transplantation. METHODS The conference included 83 participants (transplant cardiologists, surgeons, immunologists and pathologists) representing 67 heart transplant centers from North America, Europe, and Asia who all participated in smaller break-out sessions to discuss the various topics of AMR and attempt to achieve consensus. RESULTS A tentative pathology diagnosis of AMR was established, however, the pathologist felt that further discussion was needed prior to a formal recommendation for AMR diagnosis. One of the most important outcomes of this conference was that a clinical definition for AMR (cardiac dysfunction and/or circulating donor-specific antibody) was no longer believed to be required due to recent publications demonstrating that asymptomatic (no cardiac dysfunction) biopsy-proven AMR is associated with subsequent greater mortality and greater development of cardiac allograft vasculopathy. It was also noted that donor-specific antibody is not always detected during AMR episodes as the antibody may be adhered to the donor heart. Finally, recommendations were made for the timing for specific staining of endomyocardial biopsy specimens and the frequency by which circulating antibodies should be assessed. Recommendations for management and future clinical trials were also provided. CONCLUSIONS The AMR Consensus Conference brought together clinicians, pathologists and immunologists to further the understanding of AMR. Progress was made toward a pathology AMR grading scale and consensus was accomplished regarding several clinical issues.

Cardiovascular Events in Patients With Fabry Disease: Natural History Data From the Fabry Registry

OBJECTIVES These analyses were designed to determine the incidence of major cardiovascular (CV) events and the natural history of CV complications in patients with Fabry disease. BACKGROUND Fabry disease, a genetic disorder caused by deficiency of alpha-galactosidase A activity, is associated with CV dysfunction. METHODS Major CV events (myocardial infarction, heart failure, or cardiac-related death) were analyzed in 2,869 Fabry Registry patients during the natural history period (i.e., before enzyme replacement therapy or among patients who never received therapy). Multivariate logistic regression analyses were performed to identify significant predictors of CV events. RESULTS Eighty-three of 1,424 men (5.8%) and 54 of 1,445 women (3.7%) experienced CV events at mean ages of 45 and 54 years, respectively. Heart failure was the most common first CV event, reported by 50 men (3.5%) and 33 women (2.3%). Hypertension and left ventricular hypertrophy were the risk factors most strongly associated with CV events. When these parameters were used as covariates in logistic regression analyses, the odds ratio (OR) for hypertension in men was 7.8 (95% confidence interval [CI]: 2.1 to 28.6, p = 0.0019), and the OR for hypertension in women was 4.5 (95% CI: 1.6 to 12.3, p = 0.0037). The OR for left ventricular hypertrophy was 4.8 in men (95% CI: 1.03 to 22.2, p = 0.0463) and 8.2 in women (95% CI: 2.6 to 26.0, p = 0.0003). CONCLUSIONS Major CV events occurred in approximately 5% of Fabry Registry patients during the natural history period. All patients with Fabry disease should be monitored for possible CV risk factors, particularly hypertension and left ventricular hypertrophy.

Treprostinil-Based Therapy in the Treatment of Moderate-to-Severe Pulmonary Arterial Hypertension: Long-term Efficacy and Combination With Bosentan

BACKGROUND Treprostinil, a long-acting prostacyclin analog, diminished the symptoms of pulmonary arterial hypertension (PAH) in controlled 12-week clinical efficacy studies. This retrospective, single-center, open-label study was designed to assess the efficacy of long-term, subcutaneously administered, treprostinil-based therapy alone or in combination with bosentan for the treatment of moderate-to-severe PAH. METHODS Thirty-eight patients with pulmonary hypertension treated with subcutaneous treprostinil were followed up for a mean (+/-SD) duration of 984+/-468 days (range, 165 to 1,847 days). Oral bosentan was added to the treprostinil regimen if patients remained in New York Heart Association (NYHA) functional class III or II with intolerable prostacyclin side effects that limited therapy. Hemodynamic studies, Borg dyspnea score evaluations, 6-min walk (6MW) tests, and NYHA functional class determinations were performed at approximately 6-month intervals. RESULTS Mean pulmonary artery pressure decreased from 59.7 to 50.5 mm Hg (p<0.001). Significant and sustained improvement in 6MW distance (p=0.022) and Borg dyspnea score (p=0.023) were observed. At the final observation, the mean dose of treprostinil was 37.8 ng/kg/min (range, 7.5 to 115 ng/kg/min). At baseline, 5% of patients were in NYHA functional class 2 or lower vs 58% at the last follow-up. Bosentan was added to the regimens of 19 patients. In those patients, significant additional improvement occurred in the pulmonary arterial pressure (p<0.001), 6MW distance (p=0.001), and Borg dyspnea scale (p=0.020) compared to baseline. CONCLUSIONS Long-term treatment with subcutaneous treprostinil-based therapy improved functional parameters and hemodynamics in patients with moderate-to-severe PAH. In patients requiring combination therapy, the addition of oral bosentan to treprostinil-based therapy was safe, well-tolerated, and associated with further clinical improvements.

β1-Adrenergic Receptor Blockade Attenuates Angiotensin II–Mediated Catecholamine Release Into the Cardiac Interstitium in Mitral Regurgitation

Background—This study tested the hypothesis that &bgr;1-adrenoreceptor blockade modulates the angiotensin II (Ang II)–evoked neural release of norepinephrine (NE) and epinephrine (Epi) into the cardiac interstitial fluid (ISF) space in experimentally induced mitral regurgitation (MR) in the dog. Methods and Results—Normal dogs (n=8) were compared with dogs with MR of 2 (n=8) and 4 (n=6) weeks’ duration and with dogs with MR treated with &bgr;1-receptor blockade (RB; extended-release metoprolol succinate, 100 mg QD; MR+&bgr;1-RB) that was started 24 hours after MR induction for 2 (n=6) and 4 weeks (n=8). Left ventricular end-diastolic dimension increased 20% as plasma Ang II levels increased >5-fold in both MR and MR+&bgr;1-RB dogs at 2 and 4 weeks. Ang II infusion into the left atrium produced increases in ISF NE and Epi in normal dogs, which were further increased in 2- and 4-week MR dogs but were restored to normal in 4-week MR+&bgr;1-RB dogs. Ang II infusion produced 4-fold increases in circulating NE and Epi in 2- and 4-week MR dogs that returned to normal in 4-week+&bgr;1-RB dogs. Left ventricular angiotensin-converting enzyme activity and ISF Ang II were increased in 4-week MR dogs but were decreased in 4-week MR+&bgr;1-RB dogs. Conclusions—&bgr;1-RB decreases renin-angiotensin system sympathostimulation and activation by attenuating the Ang II–mediated NE and Epi release into the cardiac ISF and circulation and by decreasing left ventricular angiotensin-converting enzyme expression in the early phases of volume overload.

Minimizing infection and rejection death: Clues acquired from 19 years of multi-institutional cardiac transplantation data

BACKGROUND The purpose of this study was to estimate the relationship of age, race and gender to rejection and infection across time with respect to age at time of transplant, year of transplantation and immunosuppressive era. METHODS The study group consisted of 10,131 patients from 29 institutions in the Cardiac Transplant Research Database (n = 7,368, from 1990 to 2008) and 32 institutions in the Pediatric Heart Transplant Study (n = 2,763, from 1993 to 2008). The probabilities of rejection death and infection death were estimated with a parametric time-related model and adjusted for gender, ethnicity, date of transplant and age. RESULTS Actuarial survival by age at transplant showed that, when compared with the majority of patients transplanted between the ages of 30 to 60 years, death due to rejection at 5 years was highest among those transplanted at 10 to 30 years of age (p < 0.0001) and lowest in those transplanted at >60 years of age. Death due to infection at 5 years was highest among patients >60 years of age. Risk factors for death from rejection included age (p < 0.0001), female gender (p = 0.0001), black race (p < 0.0001) and transplant date (p < 0.0001); for infection death, risk factors were age (p < 0.0001), date of transplant (p < 0.0001), age (p = 0.002) and black race (p = 0.01). Modeling with respect to age at time of transplant showed an inverse relationship between infection and rejection death. Among patients transplanted at >60 years of age, there was a steep increase in infection-related deaths and a decrease in rejection deaths. Risk for rejection was elevated among young adults 10 to 30 years of age at time of transplant, particularly for black females. CONCLUSION Death from rejection affects adolescents and young adults preferentially, especially black recipients, whereas death from infection preferentially affects patients >60 years of age. Relative risk of infection vs rejection death with respect to recipient age should be considered in therapeutic plans for recurrent rejection, particularly in adolescents and the elderly.

Clinical Characteristics and Outcomes of Intravenous Inotropic Therapy in Advanced Heart Failure

Background—Inotrope use in heart failure treatment was associated with improved symptoms, but worse survival in clinical trials. However, these studies predated use of modern heart failure therapies. This study evaluates contemporary outcomes on long-term inotropes. Methods and Results—We collected baseline and postinotrope data on 197 patients discharged on inotropes between January 2007 and March 2013. Baseline characteristics, hemodynamic and clinical changes on inotropes, and survival were evaluated. Patients initiated on inotropes had refractory heart failure, with median baseline New York Heart Association class IV, cardiac index of 1.7 L/min per m2, pulmonary capillary wedge pressure of 25.6 mm Hg, and left ventricular ejection fraction of 18.7%. Inotropes were used in patients listed for transplant or scheduled for left ventricular assist device (LVAD; 60 patients), in patients being evaluated for LVAD/transplant (20 patients), for stabilization pending cardiac resynchronization therapy/percutaneous coronary intervention (4 patients), in patients who were offered LVAD but chose inotropes (15 patients), and for palliation (98 patients). Milrinone was used in 84.8% and dobutamine in 15.2%. At the end of the study, 68 patients had died, 24 were weaned off inotropes, 23 were transplanted, 32 received LVADs, and 50 remained on inotropes. Patients who received inotropes for palliation or those who preferred inotropes over LVAD had median survival of 9.0 months (interquartile range, 3.1–37.1 months), actuarial 1-year survival of 47.6%, and 2-year survival of 38.4%. Of 60 patients who were placed on inotropes as a bridge to transplant/LVAD, 55 were successfully maintained on inotropes until transplant/LVAD. Conclusions—Survival on inotropes for patients who are not candidates for transplant/LVAD is modestly better than previously reported, but remains poor. Inotropes are effective as a bridge to transplant/LVAD.

Arrhythmias in Fabry Cardiomyopathy

Prior studies suggest that the incidence of ventricular arrhythmias is high in patients with Fabry cardiomyopathy. This study evaluated the incidence of significant arrhythmias in a series of patients with Fabry cardiomyopathy.

Octreotide in the management of recurrent gastrointestinal bleed in patients supported by continuous flow left ventricular assist devices.

Gastrointestinal (GI) bleeding is the most common cause of readmission in patients supported by continuous flow left ventricular assist devices (CF-LVAD). We describe our experience in the off-label use of octreotide in the management of recurrent GI bleed in this population. Of 116 patients implanted with a CF-LVAD at our institution, seven had recurrent GI bleeding unresponsive to conventional management and were started in chronic octreotide injections. Hospitalizations due to GI bleeding, number of packed red blood cells transfused, and number of endoscopic procedures were compared 3 months before and after octreotide treatment. In the overall cohort, there were no differences in these three endpoints. When one patient with differing characteristics was excluded from the analysis there was a trend (p = 0.06) to a reduction of hospitalizations due to GI bleeding, number of blood transfusions, and number of endoscopic procedures. Octreotide exhibit a favorable trend in the frequency of admissions, blood transfusions, and endoscopic procedures in most patients with recurrent GI bleed. Further prospective studies are needed to clarify its benefits in this population.

Balancing rejection and infection with respect to age, race, and gender: Clues acquired from 17 years of cardiac transplantation data

BACKGROUND Donor and recipient risk factors for rejection and infection have been well characterized. The contribution of demographic factors, especially age at the time of transplantation to morbidity and mortality due to rejection and infection, is much less well understood. METHODS Using parametric hazard analysis and multivariate risk-factor equations for infection and rejection events, we quantitatively determined the relationship of fundamental demographic variables (age, race and gender) to infection and rejection. These analyses were conducted with respect to date of transplant and age at the time of transplantation. The patient group consisted of all primary heart transplants performed at the University of Alabama at Birmingham during the years 1990 to 2007 (n = 526). RESULTS Risk factors for rejection within 12 months post-transplantation were date of transplant (p < 0.0001) and age at the time of transplantation (young adults 10 to 30 years of age, p < 0.0001). Risk factors for infection were date of transplant (p < 0.0001) and age at the time of transplantation (young children and older adults, p < 0.0001). There were three immunosuppressive eras in 1990 to 2007. Notably, although the proportion of patients experiencing rejection and infection events decreased during each successive immunosuppressive era, the relative relationship of infection to rejection, as well as age at the time of transplantation, remained similar into the most recent era. The maximal frequency of rejection events and rejection death occurred among patients transplanted at ages 10 to 30 years. Conversely, the frequency of infection events was minimal within the same group. In the oldest and youngest patients receiving transplants, infection was the predominant cause of death and rates of rejection events decreased. CONCLUSIONS These data show that evolving immunosuppressive strategies have successfully reduced rejection and infection frequencies, and those patients transplanted at 30 to 60 years of age have the lowest frequency of rejection/infection events. However, individuals transplanted at younger or older ages, especially non-white recipients in the 10- to 30-year age group, experience significantly more infection or rejection. Therefore, programs should increase the level of surveillance in these patients and consider modification of immunosuppressive regimens in order to lower the frequency of infection and rejection events.

Selection of patients and techniques of heart transplantation

Cardiac transplantation remains the primary therapeutic choice for most patients under 65 years of age with advanced heart failure who remain symptomatic despite maximal medical therapy. Cardiac transplantation should be reserved for those patients most likely to benefit in terms of both life expectancy and quality of life. The concept of survival benefit margin must be balanced with the principles of utility in the selection process. A critical component of outcomes research for advanced heart failure will be the generation of accurate data and analyses which predict long-term survival and quality of life with various therapeutic modalities. Patients with multiple comorbidities have inferior survival and might be considered for alternative therapies. We currently recommend the bicaval techniques as the transplant technique of choice except in small infants and children.