A Comprehensive and Contemporary Review on Immunosuppression Therapy for Heart Transplantation

Heart transplantation is the standard of therapy for patients with end-stage heart disease. Since the first human-to-human heart transplantation, performed in 1967, advances in organ donation, surgical techniques, organ preservation, perioperative care, immunologic risk assessment, immunosuppression agents, monitoring of graft function and surveillance of long-term complications have drastically increased recipient survival. However, there are yet many challenges in the modern era of heart transplantation in which immunosuppression may play a key role in further advances in the field. A fine-tuning of immune modulation to prevent graft rejection while avoiding side effects from over immunosuppression has been the vital goal of basic and clinical research. Individualization of drug choices and strategies, taking into account the recipient's clinical characteristics, underlying heart failure diagnosis, immunologic risk and comorbidities seem to be the ideal approaches to improve post-transplant morbidity and survival while preventing both rejection and complications of immunosuppression. The aim of the present review is to provide a practical, comprehensive overview of contemporary immunosuppression in heart transplantation. Clinical evidence for immunosuppressive drugs is reviewed and practical approaches are provided. Cardiac allograft rejection classification and up-to-date management are summarized. Expanding therapies, such as photophoresis, are outlined. Drug-to-drug interactions of immunosuppressive agents focused on cardiovascular medications are summarized. Special situations involving heart transplantation such as sarcoidosis, Chagas diseases and pediatric immunosuppression are also reviewed. The evolution of phamacogenomics to individualize immunosuppressive therapy is described. Finally, future perspectives in the field of immunosuppression in heart transplantation are highlighted.

Ultrafiltration versus diuretics for the treatment of fluid overload in patients with heart failure: a hospital cost analysis

Background: Heart failure (HF) is a common, serious disease in the US and Europe. Patients with HF often require treatment for fluid overload, resulting in costly inpatient visits; however, limited evidence exists on the costs of alternative treatments. This study performed a cost-analysis of ultrafiltration (UF) vs diuretic therapy (DIUR-T) for patients with HF from the hospital perspective. Methods: The model used clinical data from the literature and hospital data from the Healthcare Cost and Utilization Project to follow a decision-analytic framework reflecting treatment decisions, probabilistic outcomes, and associated costs for treating patients with HF and hypervolemia with veno-venous UF or intravenous DIUR-T. A 90-day timeframe was considered to account for hospital readmissions beyond 30 days. Sensitivity and scenario analyses were performed to gauge the robustness of the results. Results: Although initial hospitalization costs were higher, fluid removal by UF reduced hospital readmission days, leading to cost savings of $3,975 (14.4%) at the 90-day follow-up (UF costs, $23,633; DIUR-T costs, $27,608). Conclusions: UF is a viable alternative to DIUR-T when treating fluid overload in HF patients because it reduces hospital readmission rates and durations, which substantially lowers costs over a 90-day period compared to DIUR-T.

Cardiorenal syndrome type 4: insights on clinical presentation and pathophysiology from the eleventh consensus conference of the Acute Dialysis Quality Initiative (ADQI)

In developed countries, the continuing rise in the prevalence of hypertension, hyperlipidemia and diabetes has contributed to an overall increase in the incidence of both cardiovascular disease (CVD) and chronic kidney disease (CKD). The observation that even modest reductions in renal function correlate with increased CVD morbidity and mortality has led to the recognition that CKD is an independent risk factor for CVD. Conversely, there is a growing recognition that many pathologic conditions that contribute to CVD, including coronary artery disease, left ventricular hypertrophy and diastolic dysfunction, can accelerate the decline in renal function. In addition, physiologic mechanisms designed to compensate for reduced glomerular filtration rate including activation of the renin-angiotensin-aldosterone axis, the release of fibroblastic growth factor 23 and other mechanisms for calcium-phosphate homeostasis as well as and the pathophysiologic effects of uremic toxins can also directly contribute to CVD. The end result of the interaction between changes in pressure and volume overload and the physiologic compensation for the loss of function in both the heart and the kidney leads to accelerated decline in both organ systems. This complex physiologic and pathophysiologic interplay between the cardiovascular and renal systems is collectively referred to as the cardiorenal syndrome. The discussion which follows is aimed at outlining the pathophysiologic mechanisms linking advanced CKD (4 and 5) to the development of cardiac abnormalities which occur with unique frequency and severity in patients with severe impairment of renal function.

Pathophysiology of the cardiorenal syndromes: executive summary from the eleventh consensus conference of the Acute Dialysis Quality Initiative (ADQI)

Cardiorenal syndromes (CRS) have been recently classified into five distinct entities, each with different major pathophysiologic mechanisms. CRS type 1 most commonly occurs in the setting of acutely decompensated heart failure where approximately 25% of patients develop a rise in serum creatinine and a reduction of urine output after the first several doses of intravenous diuretics. Altered cardiac and renal hemodynamics are believed to be the most important determinants of CRS type 1. CRS type 2 is the hastened progression of chronic kidney disease (CKD) in the setting of chronic heart failure. Accelerated renal cell apoptosis and replacement fibrosis is considered to be the dominant mechanism. CRS type 3 is acutely decompensated heart failure after acute kidney injury from inflammatory, toxic, or ischemic insults. This syndrome is precipitated by salt and water overload, acute uremic myocyte dysfunction, and neurohormonal dysregulation. CRS type 4 is manifested by the acceleration of the progression of chronic heart failure in the setting of CKD. Cardiac myocyte dysfunction and fibrosis, so-called 'CKD cardiomyopathy', is believed to be the predominant pathophysiologic mechanism. Type 5 CRS is simultaneous acute cardiac and renal injury in the setting of an overwhelming systemic insult such as sepsis. In this scenario, the predominant pathophysiological disturbance is microcirculatory dysfunction as a result of acutely abnormal immune cell signaling, catecholamine cellular toxicity, and enzymatic activation which result in simultaneous organ injury often extending beyond both the heart and the kidneys. This paper will summarize these and other key findings from an international consensus conference on the spectrum of pathophysiologic mechanisms at work in the CRS.

Effect of nesiritide in patients with acute decompensated heart failure

BACKGROUND

Nesiritide is approved in the United States for early relief of dyspnea in patients with acute heart failure. Previous meta-analyses have raised questions regarding renal toxicity and the mortality associated with this agent.

METHODS

We randomly assigned 7141 patients who were hospitalized with acute heart failure to receive either nesiritide or placebo for 24 to 168 hours in addition to standard care. Coprimary end points were the change in dyspnea at 6 and 24 hours, as measured on a 7-point Likert scale, and the composite end point of rehospitalization for heart failure or death within 30 days.

RESULTS

Patients randomly assigned to nesiritide, as compared with those assigned to placebo, more frequently reported markedly or moderately improved dyspnea at 6 hours (44.5% vs. 42.1%, P=0.03) and 24 hours (68.2% vs. 66.1%, P=0.007), but the prespecified level for significance (P≤0.005 for both assessments or P≤0.0025 for either) was not met. The rate of rehospitalization for heart failure or death from any cause within 30 days was 9.4% in the nesiritide group versus 10.1% in the placebo group (absolute difference, -0.7 percentage points; 95% confidence interval [CI], -2.1 to 0.7; P=0.31). There were no significant differences in rates of death from any cause at 30 days (3.6% with nesiritide vs. 4.0% with placebo; absolute difference, -0.4 percentage points; 95% CI, -1.3 to 0.5) or rates of worsening renal function, defined by more than a 25% decrease in the estimated glomerular filtration rate (31.4% vs. 29.5%; odds ratio, 1.09; 95% CI, 0.98 to 1.21; P=0.11).

CONCLUSIONS

Nesiritide was not associated with an increase or a decrease in the rate of death and rehospitalization and had a small, nonsignificant effect on dyspnea when used in combination with other therapies. It was not associated with a worsening of renal function, but it was associated with an increase in rates of hypotension. On the basis of these results, nesiritide cannot be recommended for routine use in the broad population of patients with acute heart failure. (Funded by Scios; ClinicalTrials.gov number, NCT00475852.).

Burden of sodium abnormalities in patients hospitalized for heart failure

Hyponatremia presumably is associated with adverse clinical outcomes in patients with congestive heart failure (CHF), but risk thresholds and economic burden are less studied. The authors analyzed 115,969 patients hospitalized for CHF and grouped them by serum sodium levels (severe hyponatremia, ≤130 mEq/L; hyponatremia, 131-135 mEq/L; normonatremia, 136-145 mEq/L; hypernatremia, >145 mEq/L). Univariable and multivariable analyses on the associated clinical and economic outcomes were performed. The most common abnormality was hyponatremia (15.9%), followed by severe hyponatremia (5.3%) and hypernatremia (3.2%). Hospital mortality was highest for severe hyponatremia (7.6%), followed by hypernatremia (6.7%) and hyponatremia (4.9%) (P<.0001). Compared with normonatremia, risk-adjusted mortality was highest for severe hyponatremia (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.59-1.99), followed by hypernatremia (OR, 1.55; 95% CI, 1.34-1.80) and hyponatremia (OR, 1.29; 95% CI, 1.19-1.40; all P<.0001). Risk-adjusted hospital prolongation was greater for each level of sodium abnormality than for normonatremia, ranging from 0.42 (CI, 0.26-0.60) days for hypernatremia to 1.28 (CI, 1.11-1.47) days for severe hyponatremia. Risk-adjusted attributable hospital cost increase was highest for severe hyponatremia ($1132; CI, $856-$1425; all (P<.0001). Sodium abnormalities were common in patients hospitalized for CHF. Adverse outcomes resulted not only from severe hyponatremia, but also from mild hyponatremia and hypernatremia.

Early vasoactive drugs improve heart failure outcomes

Vasoactive therapy is often used to treat acute decompensated heart failure (ADHF). The authors sought to determine whether clinical outcomes are temporally associated with time to vasoactive therapy (vasoactive time) in ADHF. Using the Acute Decompensated Heart Failure (ADHERE) Registry, the authors examined the relationship between vasoactive time and inpatient mortality within 48 hours of hospitalization. Vasoactive agents were used early (defined as <6 hours) in 22,788 (63.8%) patients and late in 12,912 (36.2%). Median vasoactive time was 1.7 and 14.7 hours in the early and late groups, respectively. In-hospital mortality was significantly lower in the early group (odds ratio, 0.87; 95% confidence interval, 0.79-0.96; P=.006), and the adjusted odds of death increased 6.8% for every 6 hours of treatment delay (95% confidence interval, 4.2-9.6; P<.0001). Early vasoactive initiation is associated with improved outcomes in patients hospitalized for ADHF.

Characteristics of "Stage D" heart failure: insights from the Acute Decompensated Heart Failure National Registry Longitudinal Module (ADHERE LM)

BACKGROUND

An improved understanding of the characteristics, treatment, and outcome of patients with "Stage D" heart failure (HF) may improve patient outcomes. We conducted an analysis of the ADHERE LM to enhance this understanding.

METHODS

ADHERE LM is a multicenter registry designed specifically to prospectively collect observational data on chronic Stage D HF. The findings were analyzed and compared to data from ADHERE CM, a multicenter registry designed to prospectively collect data on the entire spectrum of acute decompensated HF. Descriptive statistics and Kaplan-Meier analysis were used to evaluate data from all 1433 patients in ADHERE LM.

RESULTS

Compared to patients with acute decompensated HF, patients with chronic Stage D HF tended to be younger (69.6 vs 72.8 years), males (65% vs 49%), with hyperlipidemia/dyslipidemia (65% vs 41%), and with coronary artery disease (73% vs 57%). In Stage D patients, use of intravenous diuretics (73%) and vasoactive agents (84%) was common. Kaplan-Meier-estimated 1-year survival was 71.9% (95% CI 69.3%-74.5%) and estimated 1-year freedom from hospitalization or death was 32.9% (95% CI 30.2%-35.6%).

CONCLUSIONS

Patients with Stage D HF are frequently males with dyslipidemia and coronary artery disease. Morbidity and mortality are high. Therapeutic decisions based on studies in HF patients with different characteristics may not be applicable; additional research is needed to determine optimal therapeutic regimens for these patients.

Coronary endothelial dysfunction after heart transplantation predicts allograft vasculopathy and cardiac death

BACKGROUND

Coronary endothelial dysfunction may be an early marker for cardiac allograft vasculopathy (CAV) in orthotopic heart transplant recipients. Using serial studies with intravascular ultrasound and Doppler flow-wire measurements, we have previously demonstrated that annual decrements in coronary endothelial function are associated with progressive intimal thickening. The present study tested whether endothelial dysfunction predicts subsequent clinical events, including cardiac death and CAV development.

METHODS AND RESULTS

Seventy-three patients were studied yearly beginning at transplantation until a prespecified end point was reached. End points were angiographic evidence of CAV (>50% stenosis) or cardiac death (graft failure or sudden death). At each study, coronary endothelial function was measured with intracoronary infusions of adenosine (32-microgram bolus), acetylcholine (54 microgram over 2 minutes), and nitroglycerin (200 microgram) into the left anterior descending coronary artery; intravascular ultrasound images and Doppler velocities were recorded simultaneously. Of the 73 patients studied, 14 reached an end point during the study (6 CAV and 8 deaths, including 4 with known CAV, 1 graft failure, and 3 sudden). On the last study performed, the group with an end point had decreased epicardial (constriction of 11.1+/-2.9% versus dilation of 1.7+/-2.2%, P=0.01) and microvascular (flow increase of 75+/-20% versus 149+/-16%, P=0.03) endothelium-dependent responses to acetylcholine compared with the patients who did not reach an end point. Responses to adenosine and nitroglycerin did not differ significantly.

CONCLUSIONS

Endothelial dysfunction, as detected by abnormal responses to acetylcholine, preceded the development of clinical end points. These data implicate endothelial dysfunction in the development of clinically significant vasculopathy and suggest that serial studies of endothelial function have clinical utility.

Hypotension, acidosis, and vasodilatation syndrome post-heart transplant: prognostic variables and outcomes

BACKGROUND

In recent years a syndrome characterized by hypotension, acidosis, and vasodilatation, which we have designated HAV syndrome, has been reported to occur more frequently after heart transplantation (HT), but its pathogenesis is unknown.

METHODS

We analyzed consecutive patients undergoing HT between January 1994 and June 1998 (aged 50 +/- 8 years; 87% male; 40% African American; ischemia time, 190 +/- 20 minutes; given triple immunosuppression without anti-lymphocyte antibodies) in 2 groups: 38 (54%) who developed HAV (systemic vascular resistance < or = 800 dines x sec x cm(-5) and serum bicarbonate < or = 20 mEq/liter) and 32 (46%) who did not. To identify causes of HAV, we compared 113 pre-HT donor and recipient variables, 28 peri-HT variables, and 46 post-HT variables between groups. We used Mann-Whitney, Fisher exact, and chi-squared tests to compare variables and to determine significance.

RESULTS

Univariate analysis showed that HAV patients had significantly greater recipient and donor weight (p = 0.000007 and 0.0017, respectively), longer ischemia times (p = 0.0052), pre-HT use of beta-blockers (p = 0.009), and longer waiting times for HT (p = 0.018). African-American patients had less HAV than Caucasians (p = 0.047). Patients with pre-HT mechanical circulatory assistance had less HAV than pharmacologically treated patients (p = 0.014). Multivariate analysis showed that recipient (p = 0.0004) and donor weight (p = 0.0394) and ischemia time (p = 0.0015) independently predicted HAV and correlated with HAV severity. Deaths at < or =30 days of HT occurred more in patients with (33%) than in those without (15%) HAV.

CONCLUSIONS

(1) Hypotension, acidosis, and vasodilatation after HT are associated with high mortality. (2) Recipient and donor weights and ischemia time are independent risk factors for HAV. (3) Pre-HT mechanical circulatory assistance and African-American race confer protection against HAV. (4) Because HAV risk factors can be altered, prevention may be possible. Further study is needed to identify the cellular and humoral mediators of HAV.

Assessing coronary blood flow dynamics with the TIMI frame count method: comparison with simultaneous intracoronary Doppler and ultrasound

This study compared the TIMI frame count (TFC), which has been proposed as a method for quantifying coronary blood flow, with coronary flow and microvascular function measured with intracoronary Doppler and intracoronary ultrasound. Coronary blood flow volume was calculated from coronary blood velocity (by intracoronary Doppler) and lumen area (by intracoronary ultrasound) in the LAD in 46 post-heart transplant patients at baseline and after intracoronary adenosine. TFC correlated significantly with average peak coronary blood velocity (r = -0.42; P = 0.004) and coronary lumen area (r = 0.39; P = 0.008), but not with coronary blood flow volume (r = -0.01; P = 0.96) or the coronary flow reserve response to adenosine (r = 0.09; P = 0.58). In conclusion, TFC is a simple method of assessing coronary blood velocity but not volumetric flow. While TFC does not predict coronary flow reserve, as a measure of velocity it does provide an assessment of basal microvascular tone, information that is complementary to that afforded by flow reserve measurements.

Improvement in quality of life outcomes 2 weeks after left ventricular assist device implantation

BACKGROUND

The successful use of left ventricular assist devices (LVADs) as a bridge to heart transplantation has prompted our examination of quality of life (QOL) outcomes. The purposes of this study are to describe QOL in patients 1 to 2 weeks after LVAD implantation and to compare QOL in a smaller cohort of patients from before to 1 to 2 weeks after surgery.

METHODS

Data were collected from a convenience sample of 81 patients who completed booklets of questionnaires that measure domains of QOL 1 to 2 weeks after LVAD insertion and from 30 of 81 patients who completed booklets at both the pre-implantation and post-implantation periods. Patients completed booklets of 6 to 8 self-reporting instruments, with acceptable reliability and validity. Data were analyzed using descriptive and comparative statistics (chi-square, Mann-Whitney U and Wilcoxon signed ranks tests) with p = 0.01 considered statistically significant.

RESULTS

One to 2 weeks after LVAD implantation, patients were quite satisfied with their lives, experienced moderately low amounts of stress, coped well, and perceived themselves as having good health and QOL, low symptom distress, and moderately low functional disability. Patients reported significantly better QOL, more satisfaction with health and functioning, and were significantly less distressed by symptoms from immediately pre-operatively to post-operatively. However, patients reported significantly more self-care disability and more dissatisfaction with socioeconomic areas of life from before to immediately after surgery. Psychological distress was low and did not change with time.

CONCLUSION

Given that QOL improved from before to after LVAD implantation, our findings provide a springboard for investigation of the impact of LVADs on long-term QOL outcomes.

Cardiac transplant outcome of patients supported on left ventricular assist device vs. intravenous inotropic therapy

BACKGROUND

Although the left ventricular assist device (LVAD) has been increasingly used as a bridge to transplant, its effect on post-transplant outcome is uncertain. We, therefore, designed this study using the Cardiac Transplant Research Database to compare patients supported on an LVAD before transplant with those treated with intravenous inotropic medical therapy.

METHODS AND RESULTS

Of the 5,880 patients transplanted between 1990 and 1997, a total of 502 received support from LVADs and 2,514 received intravenous inotropic medical therapy at the time of transplant. Kaplan-Meier analysis showed no significant difference in post-transplant survival between the LVAD and medical-therapy groups (p = 0.09). Results of a multivariate Cox regression analysis were consistent with that of the Kaplan-Meier analysis and did not identify LVAD as a significant risk factor for mortality. The percentage of patients who received LVADs as a function of total transplants increased from 2% in 1990 to 16% in 1997. Furthermore, although the number of extracorporeal LVADs remained relatively constant, the number of intracorporeal LVADs increased over time. Multivariate parametric analysis found that the risk factors for post-transplant death in the LVAD group were extracorporeal LVAD use (p = 0.0004), elevated serum creatinine (p = 0.05), older donor age (p = 0.03), increased donor ischemic time (p < 0.0001), and earlier year of transplant (p = 0.03).

CONCLUSIONS

Given a limited donor supply, the intracorporeal LVAD helps the sickest patients survive to transplant and provides post-transplant outcome similar to that of patients supported on inotropic medical therapy. Therefore, patients supported on LVADs before transplant may receive the greatest marginal benefit when compared with other transplant candidates.

Transplant Coronary Vasculopathy

Because the transplanted heart is denervated, classic angina as a symptom of allograft coronary vasculopathy rarely is perceived. Any cardiac transplant patients who presents with decreased exercise capacity, shortness of breath, or syncope should be assessed thoroughly. Unfortunately, the initial presenting symptom of transplant vasculopathy may be acute myocardial infarction, heart failure, or even sudden death. Patients should be evaluated on an annual basis for the presence of transplant coronary vasculopathy in addition to when clinical suspicion warrants. Coronary angiography has been the main modality of invasive assessment, although it is insensitive. Recently, intracoronary ultrasound has been used in conjunction with angiography to detect the first evidence of transplant vasculopathy, manifested as thickening of the intimal layer of the vessel wall due to smooth muscle cell proliferation, which ultimately leads to luminal narrowing. Patients with evidence of vasculopathy should undergo functional evaluation with dobutamine echocardiography to document ischemic burden. Preventive measures include traditional coronary risk factor modification. Patients are started on statins early in the post-transplantation period and hypertension is treated aggressively using calcium channel blockers and angiotensin-converting enzyme (ACE) inhibitors. Because of their deleterious metabolic effects, steroids may be withdrawn under close surveillance for rejection. After transplant vasculopathy has developed, it is difficult to treat and options are limited. Patients with discrete luminal obstructions may undergo angioplasty, stenting, or coronary artery bypass. However, these procedures are palliative, and the only definitive therapy is retransplantation.

Safety, tolerability, and efficacy of cyclosporine microemulsion in heart transplant recipients: a randomized, multicenter, double-blind comparison with the oil-based formulation of cyclosporine--results at 24 months after transplantation

BACKGROUND

The widespread use of cyclosporine has improved the survival of cardiac transplant patients as a result of reduced morbidity and mortality from rejection and infection. The original oil-based form of cyclosporine demonstrated unpredictable absorption resulting in an increased frequency of acute and chronic rejection in patients with poor bioavailability. The primary end. points of the present, prospective, randomized multicenter, double-blind trial were to compare the efficacy of the micro-emulsion form of cycolsporine (CsA-NL) with the oil-based formulation as determined by cardiac allograft and recipient survival and the incidence and severity of the acute rejection episodes and to determine the safety and tolerability of CsA-NL compared with Sandimmune CsA-(SM) in the study population. The 6-month analysis of the study showed reduced number of CsA-NL patients requiring antilymphocyte antibody therapy for rejection, fewer International Society of Heart and Lung Transplantation grade > or =3A rejections in female patients and fewer infections. Our report represents the final analysis of the results 24 months after transplantation.

METHODS

A total of 380 patients undergoing de novo cardiac transplants at 24 centers in the United States, Canada, and Europe were enrolled in this double-blind, randomized trial evaluating the efficacy and safety of CsA-NL versus CsA-SM. Acute allograft rejection was diagnosed by endomyocardial biopsy and graded according to the International Society of Heart and Lung Transplantation nomenclature. Kaplan-Meier analysis and Fisher's exact test were used for comparisons between groups.

RESULTS

After 24 months, allograft and recipient survival were identical in both groups. There were fewer CsA-NL patients (6.9%) requiring antilymphocyte antibody therapy for rejection than in the CsA-SM-treated patient group (17.7%, P=0.002). There were fewer discontinuations of study drug for treatment failures in the CsA-NL groups (7; 3.7%) compared with the CsA-SM group (18; 9.4%, P=0.037). The average corticosteroid dose was lower in the CsA-NL group (0.37 mg/kg/day) compared with the CsA-SM group (0.48 mg/kg/day, P=0.034) over the 24-month study period. Overall, there was no difference in blood pressure or creatinine between the two study groups.

CONCLUSIONS

The final results of this multi-center, randomized study of two forms of cyclosporine confirmed that there were fewer episodes of rejection requiring antilymphocyte antibodies and fewer study discontinuations for treatment failures in CsA-NL-treated patients compared to those treated with CsA-SM. The use of CsA-NL did not predispose these patients to a higher risk of adverse events.

Flow cytometric detection of HLA-specific antibodies as a predictor of heart allograft rejection

BACKGROUND

Historically, panel reactive antibody (PRA) analysis to detect HLA antibodies has been performed using cell-based complement-dependent cytotoxicity (CDC) techniques. Recently, a flow cytometric procedure (FlowPRA) was introduced as an alternative approach to detect HLA antibodies. The flow methodology, using a solid phase matrix to which soluble HLA class I or class II antigens are attached is significantly more sensitive than CDC assays. However, the clinical relevance of antibodies detected exclusively by FlowPRAhas not been established. In this study of cardiac allograft recipients, FlowPRA was performed on pretransplant sera with no detectable PRA activity as assessed by CDC assays. FlowPRA antibody activity was then correlated with clinical outcome.

METHODS

PRA analysis by anti-human globulin enhanced (AHG) CDC and FlowPRA was performed on sera corresponding to final cross-match specimens from 219 cardiac allograft recipients. In addition, sera collected 3-6 months posttransplant from 91 patients were evaluated. The presence or absence of antibodies was correlated with episodes of rejection and patient survival. A rejection episode was considered to have occurred based on treatment with antirejection medication and/or histology.

RESULTS

By CDC, 12 patients (5.5%) had pretransplant PRA >10%. In contrast, 72 patients (32.9%) had pretransplant anti-HLA antibodies detectable by FlowPRA (34 patients with only class I antibodies; 7 patients with only class II antibodies; 31 patients with both class I and class II antibodies). A highly significant association (P<0.001) was observed between pretransplant HLA antibodies detected by FlowPRA and episodes of rejection that occurred during the first posttransplant year. Fifteen patients died within the first year posttransplant. Of nine retrospective flow cytometric cross-matches that were performed, two were in recipients who had no pretransplant antibodies detectable by FlowPRA. Both of these cross-matches were negative. In contrast, five of seven cross-matches were positive among recipients who had FlowPRA detectable pretransplant antibodies. Posttransplant serum specimens from 91 patients were also assessed for antibodies by FlowPRA. Among this group, 58 patients had FlowPRA antibodies and there was a trend (although not statistically significant) for a biopsy documented episode of rejection to have occurred among patients with these antibodies.

CONCLUSIONS

Collectively, our data suggest that pre- and posttransplant HLA antibodies detectable by FlowPRA and not AHG-CDC identify cardiac allograft recipients at risk for rejection. Furthermore, a positive donor reactive flow cytometric cross-match is significantly associated with graft loss. Thus, we believe that detection and identification of HLA-specific antibodies can be used to stratify patients into high and low risk categories. An important observation of this study is that in the majority of donor:recipient pairs, pretransplant HLA antibodies were not directed against donor antigens. We speculate that these non-donor-directed antibodies are surrogate markers that correspond to previous T cell activation. Thus, the rejection episodes that occur in these patients are in response to donor-derived MHC peptides that share cryptic determinants with the HLA antigens that initially sensitized the patient.

Myocarditis

Myocarditis and its sequela, dilated cardiomyopathy (DCM), cause substantial morbidity and mortality, especially in children and young adults. Physicians should include myocarditis in the differential diagnosis of all patients who have new symptoms of heart failure, arrhythmia, or chest pain syndromes of unclear cause, and should strongly consider performing endomyocardial biopsy (EMB) to establish the diagnosis. It may be necessary to perform multiple or serial biopsies to increase sensitivity. Patients with myocarditis and symptomatic heart failure, chest pain, or arrhythmias need hospitalization for evaluation and treatment. Patients with symptomatic left ventricular dysfunction should be treated with conventional heart failure therapy, including angiotensin-converting enzyme (ACE) inhibitors, digitalis, diuretics, and beta-blockers. Patients with arrhythmias or syncope may require electrophysiologic evaluation. In addition to conventional therapy, physicians should consider a course of immunosuppressive therapy in selected patients. The clinical course, response to therapy, and left ventricular function need close monitoring. Patients with myocarditis and rapidly progressive heart failure or cardiogenic shock should be referred early to an advanced heart failure center for implantation of a ventricular assist device and consideration for cardiac transplantation.

Sudden death in heart failure patients: effects of optimized medical therapy

Although medical therapy, particularly with angiotensin-converting enzyme (ACE) inhibitors, has been demonstrated to prolong life in patients with chronic heart failure, the effect of standard medical therapy on sudden unexpected death in patients with heart failure is less well understood. Recent clinical trials have provided new insights into this growing problem. The impact of modern medical therapy for heart failure, including ACE inhibitors, beta-adrenergic antagonists, digoxin, calcium channel antagonists, and antiarrhythmic interventions will be discussed.

Chronic Heart Failure

Physicians must aggressively treat heart failure in the early stages to prevent disease progression and improve survival. Early treatment implies early diagnosis of left ventricular (LV) dysfunction, before the onset of symptoms. Patients with risk factors for the development of heart failure, especially coronary disease or hypertension, should undergo echocardiography to evaluate LV function. Patients with LV systolic dysfunction should be further evaluated to determine the type of cardiac dysfunction, uncover correctable etiologic factors, determine prognosis, and guide treatment. Angiotensin-converting enzyme (ACE) inhibitors and beta-adrenergic blocking drugs improve survival and are integral to the treatment plan. Physicians should prescribe an ACE inhibitor as initial therapy for all patients with LV systolic dysfunction unless there are specific contraindications. The combination of hydralazine and isosorbide dinitrate is an acceptable alternative therapy for patients who cannot take ACE inhibitors. Diuretics should be used if there are signs or symptoms of volume overload. Beta-adrenergic blocking drugs should be added to therapy in stable patients with mild to moderate heart failure after optimal treatment with ACE inhibitors, diuretics, or other vasodilators. Digoxin should be used routinely in patients with severe heart failure and should be added to therapy in patients with mild to moderate heart failure who remain symptomatic despite optimal doses of ACE inhibitors and diuretics. Spironolactone should be added, but electrolytes should be closely monitored. Warfarin anticoagulation should be considered in patients with a left ventricular ejection fraction (LVEF) of 35% or less. Until survival data exist, angiotensin receptor blockers (ARBs) should not be used as initial therapy or as sole therapy but can be used for ACE-intolerant patients or can be added to standard heart failure therapy. Outpatient use of intravenous inotropic therapy should be avoided. Patients with severe heart failure should have peak oxygen consumption measured to quantify functional impairment, determine prognosis, and identify the need for advanced heart failure therapy. Patients who remain symptomatic while receiving optimal standard therapy should be referred early to a specialized heart failure center.

Safety, tolerability and efficacy of cyclosporine microemulsion in heart transplant recipients: a randomized, multicenter, double-blind comparison with the oil based formulation of cyclosporine--results at six months after transplantation

BACKGROUND

The introduction of cyclosporine has resulted in significant improvement in the survival of cardiac allograft recipients due to decreased mortality from infection and rejection. The original oil-based cyclosporine formulation exhibits variable and unpredictable bioavailability that correlates with an increased incidence of acute and chronic rejection in those patients in whom this is most pronounced. The primary objectives of this prospective, multicenter, randomized, double-blind study in cardiac transplant patients were: to compare the efficacy of cyclosporine microemulsion (CsA-NL) with oil-based cyclosporine (CsA-SM) as measured by cardiac allograft and recipient survival and the incidence and severity of acute rejection episodes; and to assess the safety and tolerability of CsA-NL compared with CsA-SM in this population. This report represents the analysis of results 6 months after transplantation.

METHODS

A total of 380 patients undergoing their first cardiac transplant at 24 centers in the United States, Canada, and Europe were enrolled in this double-blind, randomized trial examining the safety and efficacy of CsA-NL versus CsA-SM. Rejection was diagnosed using endomyocardial biopsy and were graded according to standardized criteria of the International Society of Heart and Lung Transplantation (ISHLT). Clinical parameters were monitored during the study. Survival and freedom from were used for analysis as was Fisher's exact test for comparisons between groups.

RESULTS

At 6 months after transplantation, allograft and patient survival were the same for both groups. The frequency of ISHLT grade 3A or greater episodes in the two groups was identical. Fewer CsA-NL patients (5.9%) required antilymphocyte antibody (ATG or OKT-3) therapy for rejection compared with the CsA-SM-treated patients (14.1%, P=0.01). Females with ISHLT rejection grade > or = 3A treated with CsA-NL had a 46% lower incidence of rejection compared with the CsA-SM-treated group (31.3% vs. 57.6%, P=0.032). Fewer infections were seen in the CsA-NL. With the exception of baseline and 1 week posttransplant creatinines which were higher in the CsA-NL group, the overall creatinine was not significantly different between the two groups.

CONCLUSIONS

This multicenter, randomized study of cardiac transplant recipients documented less severe rejection (in particular those requiring antibody therapy) and a lower incidence of infection in CsA-NL-treated patients. Results from the female subgroup analysis suggest that the improved bioavailability of CsA-NL might reduce the frequency of rejection episodes in female patients. The use of CsA-NL was not associated with an increased risk of adverse events.

Asymmetry of right ventricular enlargement in response to tricuspid regurgitation

BACKGROUND

Analysis of right ventricular adaptation to tricuspid regurgitation was studied in 10 heart transplant recipients following inadvertent endomyocardial biopsy disruption of the tricuspid apparatus.

METHODS AND RESULTS

Echocardiography demonstrated progressive diastolic right ventricular cavity enlargement (19.5+/-5.0 to 30.3+/-5.4 cm(2), P<0.0002), with disproportionate elongation along the midminor axis (3.5+/-0.6 to 5. 0+/-0.5 cm, P<0.001). As the right ventricle remodeled to more spherical (and less elliptical) proportions, the end-diastolic right ventricular midminor axis/long axis ratio increased significantly from 0.52+/-0.10 to 0.68+/-0.07, P<0.005.

CONCLUSIONS

Ventricular enlargement due to right ventricular volume overload results in disproportionate dilation along the free wall to septum minor axis.

Are preoperative obesity and cachexia risk factors for post heart transplant morbidity and mortality: a multi-institutional study of preoperative weight-height indices. Cardiac Transplant Research Database (CTRD) Group

BACKGROUND

The relationship between pre-transplant body weight and post-transplant outcome has only recently been identified using a single, indirect measure of weight (percent ideal body weight [PIBW]). The literature is equivocal regarding which index is the better indicator of body weight. The purpose of this study was to determine (1) if pre-heart transplant body weight, measured by body mass index (BMI) and PIBW, is associated with post-heart transplant morbidity and mortality and (2) if patient gender, age, and etiology of heart disease affect this association.

METHODS

The sample included 4,515 patients who received a heart transplant from January 1, 1990-December 31, 1995 at 38 institutions participating in the Cardiac Transplant Research Database (CTRD). Patients were divided into groups according to their BMI and PIBW. Data were described using frequencies, measures of central tendency, Pearson correlation coefficients, stratified actuarial analyses and log rank tests for comparisons, and a multivariable risk factor analysis in the hazard domain.

RESULTS

For all patients (n = 4,515), being <80% or >140% of IBW before heart transplant was a risk factor for increased mortality after heart transplant. The association between pre-heart transplant PIBW and post-heart transplant survival was affected by gender, age, and etiology of heart disease. In males, a higher PIBW was a significant risk factor for death early after transplant (p = .0003). Although not significant, there was a trend for a higher PIBW being a risk factor for death in females throughout the post transplant period (p = .07). No differences in cause of death were found for PIBW and BMI. In male and female recipients <55 years, being overweight pre-heart transplant was a risk factor for infection. In patients with pre-transplant ischemic heart disease, the greatest risk for infection was found in patients who were >140% of IBW. Pre-heart transplant BMI and PIBW were not associated with acute rejection or cardiac allograft arteriopathy after transplant.

CONCLUSIONS

In conclusion, being cachectic or obese preoperatively is associated with decreased survival in all patients after heart transplantation. Being obese preoperatively is associated with increased infection after heart transplant in males and females <55 years and in patients with ischemic heart disease. Of the 2 indices of body weight used in this study, percent ideal body weight appears to be the better predictor of future morbidity and mortality following heart transplantation.

Simultaneous intracoronary ultrasound and Doppler flow studies distinguish flow-mediated from receptor-mediated endothelial responses

Abnormalities in vascular endothelial function, which occur early in atherosclerosis, may play an etiologic role in the development of the disease or represent a marker for the extent of atherosclerosis. Endothelial dysfunction, usually characterized by demonstration of decreased endothelium-dependent vasorelaxation, may be a sensitive and specific method to detect vascular disease in its earliest stages. In this context, separation of abnormalities in receptor-mediated and flow-mediated endothelium-dependent vasodilatory responses may allow for the most accurate characterization of endothelial dysfunction. In 35 patients undergoing routine annual cardiac catheterization after heart transplantation, changes in epicardial lumen area and coronary blood flow in response to intracoronary administration of adenosine, acetylcholine, and nitroglycerin were measured simultaneously using an intravascular ultrasound (IVUS) catheter positioned over a Doppler flow wire in the left anterior descending coronary artery. The combination of these techniques allowed for distinction between receptor-mediated and flow-mediated endothelium-dependent vascular responses. Peak flow with the endothelium-independent resistance vessel dilator adenosine occurred at 18+/-2 sec; the maximal lumen area response occurred later, at 43+/-11 sec (P < 0.001). Acetylcholine, an endothelium-dependent small- and large-vessel vasodilator, caused an immediate increase in both flow and lumen area, but a second peak of dilation was observed, and maximal area occurred 46 sec after maximal flow (54+/-14 vs. 100+/-26 sec, P < 0.001). Simultaneous IVUS and Doppler flow measurements after infusion of vasoactive agents allows for distinction between and evaluation of the relative contribution of agonist-mediated and flow-mediated responses, which may offer important and unique insights into coronary endothelial function.

Impact of rifampin on serum amiodarone concentrations in a patient with congenital heart disease

A 33-year-old woman with congenital heart disease and atrial and ventricular arrhythmias, managed over the long term with an implantable cardioverter defibrillator, epicardial pacing system, and amiodarone, experienced an increase in palpitations and a shock from her defibrillator. Evaluation revealed decreases in amiodarone and desethylamiodarone serum concentrations from previous levels. Rifampin had been added to her therapy 5 weeks earlier. Increases in amiodarone and desethylamiodarone concentrations were observed after an increase in the amiodarone dosage and discontinuation of rifampin. The time course suggested that the addition of rifampin led to reductions in serum concentrations of both the drug and metabolite.

Characteristics of the signal-averaged P wave in orthotopic heart transplant recipients

Rejection remains the Achilles heel of orthotopic cardiac transplantation (OHT). Reliable noninvasive markers of rejection are desirable for timely therapy and to reduce risks and costs. Changes in atrial electrophysiology may precede ventricular changes during acute rejection. Although P wave duration in the signal-averaged ECG reflects atrial conduction, the feasibility of such measurement and the range of its values in OHT patients in absence of rejection is uncertain. This study compared the filtered P wave duration in 15 hypertensive OHT patients free of rejection with that in 15 age-matched hypertensive controls. All OHT patients had biatrial anastomoses. Two electrophysiologists interpreted the tracings independently. Three tracings (2 OHT, 1 control) could not be interpreted by either reader. An adequate P wave signal-averaged ECG was obtained in the remaining patients, despite the frequent presence of dissociated P waves (recipient and donor atria) on standard ECG in OHT patients. There was good interobserver agreement in the measurement of filtered P wave duration (r = 0.91; P < 0.0001).

CONCLUSIONS

The filtered P wave duration was significantly shorter in the OHT patients (112 +/- 15 ms versus 128 +/- 14 ms; P = 0.008). Filtered P wave duration can be measured in most OHT. Filtered P wave duration is shorter in OHT patients than in hypertensive controls, possibly as a result of the reduced mass of the truncated donor atria. Further studies are needed to determine whether the signal-averaged P wave can be useful to predict acute cardiac rejection.

The use of APACHE II scores to select candidates for left ventricular assist device placement. Acute Physiology and Chronic Health Evaluation

BACKGROUND

The growth in left ventricular assist device (LVAD) use has been hampered by high morbidity and mortality rates and cost. The purpose of this study was to help improve patient selection for LVAD placement by determining whether the Acute Physiology and Chronic Health Evaluation II (APACHE II) scoring system, a multiparameter, physiology-based predictor of outcome, could be used to predict outcome after LVAD placement and thus help determine optimum timing of LVAD placement.

METHODS

This was a retrospective analysis of a prospective cohort observational study consisting of 2 groups: (1) 50 patients with severe heart failure who did not receive LVAD placement after initial evaluation and (2) 31 patients who did receive LVAD placement. Patients included in the study were in severe heart failure on the basis of 3 of the following: lung crackles, S3, peripheral edema, ejection fraction < 0.30, systolic blood pressure < 80 mm Hg, progressive prerenal azotemia, altered level of consciousness, gastrointestinal ischemia or congestion, or persistent although reversible pulmonary hypertension in spite of maximal medical therapy, including intravenous inotropes. The decision for LVAD placement was at the discretion of the attending physician.

RESULTS

Both LVAD- and non-LVAD-treated patients were similar in cause of heart failure, APACHE II scores, and other baseline laboratory parameters. Survival time with a log-logistic model was better for LVAD-treated patients, p=.0266. Although Kaplan Meier analysis showed a trend toward better survival rates in the LVAD-treated patient, the Cox proportional hazards revealed that LVAD-treated patients had better survival (relative risk ratio, 95% confidence interval=0.305, 0.110 to 0.892; p=.0219) after adjustment for APACHE II score. Each unit increase in APACHE II independently predicted death (relative risk ratios, 95% confidence interval=1.139, 1.055 to 1.231; p=.0009). Patients with medium APACHE II (11 to 20) scores in particular benefitted from LVAD treatment.

CONCLUSION

LVAD placement for severe heart failure (not restricted to cardiogenic shock) improves survival. APACHE II can aid in deciding the timing of LVAD placement in patients with heart failure who may not have attained conventional hemodynamic criteria for LVAD placement. Patients who had APACHE II scores between 11 and 20 derived the greatest benefit from LVAD placement.

Heart transplant coronary artery disease detected by coronary angiography: a multiinstitutional study of preoperative donor and recipient risk factors. Cardiac Transplant Research Database

BACKGROUND

Controversy exists regarding donor and recipient factors that promote the development and progression of coronary artery disease after heart transplantation and the likelihood of coronary artery disease causing death or retransplantation.

METHODS

To investigate this issue in a large cohort of patients, we analyzed 5963 postoperative angiograms performed in 2609 of the 3837 patients undergoing heart transplantation at 39 institutions between January 1990 and December 1994. Coronary artery disease was classified as mild, moderate, or severe on the basis of left main involvement, primary vessel stenoses, and branch stenoses. Coronary artery disease was considered severe if left main stenosis was > 70% or 2 or more primary vessels stenoses were > 70% or branch stenoses were > 70% in all 3 systems.

RESULTS

By the end of 5 years after heart transplantation, coronary artery disease was present in 42% of the patients, mild in 27%, moderate in 8%, and severe in 7%. Coronary artery disease-related events (death or retransplantation) had an actuarial incidence of 7% at 5 years and occurred in 2 of 3 of the patients with development of angiographically severe coronary artery disease. By multivariable logistic analysis, risk factors for donor coronary artery disease included older donor age (P < .0001) and donor hypertension (P=.0002). By multivariable analysis in the hazard function domain, risk factors identified for the earlier onset of allograft coronary artery disease included older donor age (P < .0001 ), donor male sex (P=.0006), donor hypertension (P=.07), recipient male sex (P=.02), and recipient black race (P=.01). The actuarial incidence of severe coronary artery disease was 9% at 5 years.

CONCLUSIONS

Angiographic coronary artery disease is very common after heart transplantation, occurring in approximately 42% of the patients by 5 years. Older donor age, donor hypertension, and male donor or recipient predict earlier onset of angiographic allograft coronary artery disease. Although severe angiographic allograft coronary artery disease occurs in only 7% of the patients at 5 years, its presence is highly predictive of subsequent coronary artery disease-related events or retransplantation.

Outpatient inotropic therapy in heart transplant candidates: should its use influence waiting list priority status?

BACKGROUND

The use of outpatient intravenous inotropic therapy in heart transplant candidates is contentious. In addition to concerns about morbidity and mortality rates, the current United Network for Organ Sharing (UNOS) heart allocation system presently grants no waiting list priority status benefit to candidates who receive intravenous inotropic therapy in the outpatient setting (UNOS status 2), whereas identical therapy given in an intensive care unit setting does increase priority status (UNOS status 1). The goal of this study was to determine whether an increase in UNOS waiting list priority status is justified in heart transplant candidates receiving outpatient intravenous inotropic therapy by comparing the waiting list mortality of UNOS status 2 candidates on such therapy with that of UNOS status 2 candidates maintained on oral heart failure agents alone.

METHODS

This is a retrospective analysis of the pretransplantation outcomes of heart transplant candidates initially listed as UNOS status 2, comparing 29 candidates receiving intravenous outpatient inotropic therapy (group 1) to 109 candidates maintained on oral heart failure agents alone (group 2).

RESULTS

The waiting list mortality was not significantly different between the two groups (group 1=7% vs group 2=20%, p=.18); however, group 1 patients had greater morbidity rates while awaiting transplantation than group 2 patients. A greater percentage of group 1 than group 2 patients clinically deteriorated to UNOS status 1 while awaiting transplantation (45% vs 11%), resulting in more group 1 patients undergoing transplantation overall, (59% vs 33%, p=.01) and more group 1 than group 2 patients undergoing transplantation at a higher priority status, UNOS status 1 (76% vs 33%, p=.003). Group 1 patients had more pretransplantation heart failure admissions (1.2 vs 0.6 admissions/total waiting period, p=.02) and longer hospital stays (26+/-39 vs 8.8+/-16 days, p=.03), spent a greater percentage of their total waiting time hospitalized (7% vs 2%, p=.003), and were more likely than group 2 patients to receive intravenous inotropic therapy during hospitalization (70% vs 25%, p=.001).

CONCLUSION

This study suggests that heart transplant candidates who require maintenance outpatient intravenous inotropic therapy represent a subgroup of UNOS status 2 candidates with greater waiting list morbidity, but no greater waiting list mortality than candidates who can be maintained on oral heart failure agents alone. However, the current UNOS heart allocation system provides for this increased illness acuity by assigning a higher priority status when necessary. A larger, prospective study is necessary to determine whether a true difference in waiting list mortality rates exists and if an increase in priority status is justified for UNOS status 2 candidates requiring maintenance inotropic therapy.

Discordant epicardial and microvascular endothelial responses in heart transplant recipients early after transplantation

BACKGROUND

Cardiac allograft vasculopathy represents the leading cause of death in heart transplant recipients who survive more than 1 year. Functional endothelial abnormalities are sensitive measures of the early development of cardiac allograft vasculopathy, but the relative importance of large and small coronary vessel abnormalities has not been evaluated. The purpose of the study was to distinguish between large and small coronary endothelial dysfunction in patients early after heart transplantation and to test the hypothesis that microvascular endothelial responses can be preserved in the presence of epicardial endothelial dysfunction.

METHODS

Changes in epicardial lumen area and coronary artery blood flow in response to intracoronary administration of adenosine, acetylcholine, and nitroglycerin were measured simultaneously by use of an intravascular ultrasound catheter positioned over a Doppler flow wire in the left anterior descending coronary artery. The combination of these techniques allowed distinction between large and small coronary vascular responses. In 19 patients studied early after transplantation, adenosine (16 and 32 microg), acetylcholine (5.4 and 54 microg), and nitroglycerin (200 microg) were infused, with continuous intravascular ultrasound imaging and Doppler velocity measurements.

RESULTS

Acetylcholine induced paradoxical epicardial vasoconstriction in 12 of 19 patients (73% +/- 6% of baseline); vasodilation occurred in 7 (108% +/- 3%). In spite of this constriction, coronary artery flow increased in all 19 patients, to the same extent in patients with constriction and those with dilation (239 +/- 26 vs 193 +/- 20, p = 0.38). Adenosine and nitroglycerin increased area (107% +/- 1% and 112% +/- 3%) and flow (258% +/- 17% and 197% +/- 11%) in all patients. None of the area or flow responses correlated with the degree of intimal thickening.

CONCLUSIONS

Acetylcholine increased coronary artery flow early after transplantation, indicating preserved microvascular responses in spite of epicardial vasoconstriction. Simultaneous measurement of area and velocity responses, by permitting evaluation of the relative contribution of epicardial and microvascular vessels, may offer unique insights into coronary endothelial function.

Echocardiography for hemodynamic assessment of patients with advanced heart failure and potential heart transplant recipients

OBJECTIVES

This study sought to assess the accuracy of Doppler echocardiographic techniques for the determination of right heart catheterization hemodynamic variables in patients with advanced heart failure and in potential heart transplant recipients.

BACKGROUND

Doppler echocardiographic techniques permit the noninvasive acquisition of hemodynamic variables traditionally used for the assessment of patients with advanced heart failure and potential heart transplant candidates. However, the accuracy of these techniques has not been sufficiently well documented for clinical application in individual patients.

METHODS

Echocardiographic data required for estimation of mean right atrial, pulmonary artery and mean left atrial pressures and cardiac output were obtained. Right heart catheterization was performed immediately after Doppler echocardiographic data were acquired, before any intervention that might have altered the subject's hemodynamic status.

RESULTS

A complete Doppler echocardiographic hemodynamic data set was acquired in 21 (84%) of 25 subjects. For all variables, invasive and noninvasive hemodynamic values were highly correlated (p < 0.001), with minimal bias and narrow 95% confidence limits. An algorithm constructed from the noninvasive hemodynamic variable values identified all patients with adverse pulmonary vascular hemodynamic variables (i.e., transpulmonary gradient > or = 12 mm Hg, pulmonary vascular resistance > or = 3 Wood units or pulmonary vascular resistance index > or = 6 Wood units x m2). This algorithm identified 12 (71%) of 19 patients for whom right heart catheterization was unnecessary.

CONCLUSIONS

Doppler echocardiographic estimates of hemodynamic variables in patients with advanced heart failure are accurate and reproducible. This noninvasive methodology may assist with monitoring and optimization of medical therapy in patients with advanced heart failure and may obviate the need for routine right heart catheterization in potential heart transplant candidates.

Role of maximal oxygen consumption in establishment of heart transplant candidacy for heart failure patients with intermediate exercise tolerance

Maximal exercise oxygen consumption (VO2max) was measured in patients with chronic congestive heart failure undergoing evaluation for heart transplantation. Although VO2max correlated with survival for the group as a whole, it did not demonstrate survival discrimination for patients in the intermediate range (VO2max = 12 to 17 ml/kg/min) and should therefore not be used as a benchmark test for determination of appropriateness for cardiac transplantation in this group of patients.

Effects of methotrexate on acute rejection and cardiac allograft vasculopathy in heart transplant recipients

BACKGROUND

In heart transplant recipients methotrexate has been shown to reverse recurrent/persistent acute rejection refractory to intensified conventional immunosuppression. This study sought to determine whether methotrexate produces a sustained decline of heart allograft rejection rates and renders rejection rates of patients with a history of recurrent/persistent rejection similar to those of heart transplant recipients without such history.

METHODS

Rejection, infection, and cardiac allograft vasculopathy were compared in 35 patients treated with methotrexate (12 +/- 9 mg/week for 34 +/- 54 weeks) and 236 patients never given methotrexate. Because the mean time from transplantation to initiation of methotrexate was 9.4 months, patients treated without methotrexate were analyzed for events < or = 9.4 versus > 9.4 months after heart transplantation.

RESULTS

Demographics, perioperative and maintenance immunosuppression, and postoperative follow-up time (58 +/- 32 vs 57 +/- 33 months) were similar in the two groups. Rejection rates decreased in both groups but remained significantly higher in the patients treated with methotrexate after initiation of therapy than in the patients treated without methotrexate more than 9.4 months after transplantation (0.15 +/- 0.16 vs 0.06 +/- 0.12 episodes/patient/month; p = 0.0014). Infection rates were higher in patients after methotrexate initiation than in patients treated without methotrexate more than 9.4 months after heart transplantation (0.17 +/- 0.24 vs 0.06 +/- 0.13 episodes/patient/month; p = 0.015). At the end of the follow-up period methotrexate- and non-methotrexate-treated groups did not differ in the percentage of patients with angiographically detectable cardiac allograft vasculopathy (17.1% and 21.2%, respectively) and survival (71.4% and 64.0%, respectively).

CONCLUSIONS

Even after reversal of rejection by methotrexate, patients requiring methotrexate for the treatment of persistent/recurrent rejection continued to have higher rejection rates than patients not requiring methotrexate. In spite of persistently higher rejection rates, patients treated with methotrexate did not have higher rates of cardiac allograft vasculopathy. This finding raises the question whether methotrexate provides a protective influence on the development of cardiac allograft vasculopathy in this high-risk group.

Infectious complications in left ventricular assist device recipients

The left ventricular assist device (LVAD) has revolutionized the care of patients with heart failure who are awaiting transplantation. Despite reports of significant infection rates associated with LVAD implantation, few data are available concerning the management of LVAD-related infections and their impact on transplantation. Eight (40%) of our first 20 LVAD recipients developed infections. LVAD-related bloodstream infection occurred in three (15%) patients; infection was due to Staphylococcus aureus in one case, coagulase-negative staphylococci in the second case, and S. aureus and Candida tropicalis in the third case. All three patients were treated with courses of antibiotics that were appropriate for prosthetic valve endocarditis and received antibiotics for at least 6 weeks. All infected patients underwent successful transplantation and had no evidence of recurrence of infection up to 16 months postoperatively. Our experience suggests that LVAD infections can be successfully treated without device removal and that cardiac transplantation can be performed in individuals with LVAD-related bloodstream infection.

Prominence of apolipoproteins B, (a), and E in the intimae of coronary arteries in transplanted human hearts: geographic relationship to vessel wall proteoglycans

BACKGROUND

Transplant arteriopathy (TA) is characterized by vessel wall thickening with prominent glycosaminoglycan and lipid deposits. In this light, we have recently demonstrated the distribution of proteoglycans in allograft coronary arteries. The aim of this study is to examine the distribution of apolipoproteins within allograft coronary arteries and to investigate their localization in relation to proteoglycans.

METHOD

Particular transverse sections of left and right epicardial coronary arteries from 46 human cardiac allografts, 11 normal hearts, and 11 hearts with native atherosclerosis were stained immunohistochemically for apolipoprotein B, apolipoprotein (a) (apo[a]), apolipoprotein E (apoE), biglycan, decorin, and versican by use of an automated immunostainer.

RESULTS

Apo(a) and apoE immunopositivity in TA was much more intense than that in native atherosclerosis, whereas the reverse was true for apoB. Prominent apoE deposits were evident circumferentially in endothelia and extracellularly in superficial intima of mildly diseased TA, as well as in deeper intima of severely diseased TA. Apo(a) had a staining pattern very similar to apoE except for a patchy deposition also seen in TA media. The intimal areas staining prominently with apoE or apo(a) in TA arteries corresponded very closely to the areas with proteoglycan deposits, especially versican.

CONCLUSION

The distinctive patterns of apolipoprotein accumulation in TA and native atherosclefosis appear to reflect different pathogenetic processes in the two conditions. The colocalization of proteoglycans and apolipoproteins in TA intima supports the hypothesis that interactions between proteoglycans and apolipoproteins influence lipid retention and overload in allograft coronary arteries.

Biglycan, decorin, and versican protein expression patterns in coronary arteriopathy of human cardiac allograft: distinctness as compared to native atherosclerosis

BACKGROUND

Histochemical staining has demonstrated previously dramatic deposits of glycosaminoglycans associated with prominent lipid accumulations in thickened vessel walls of allograft coronary arteries. In this study, we characterized the amount, distribution, and types of proteoglycan in the walls of coronary arteries from human cardiac allografts and from native atherosclerotic (NA) controls as part of a strategy to understand the pathogenesis of transplant arteriopathy (TA).

METHOD

We used polyclonal rabbit antibodies against human biglycan, decorin, and versican localize the proteoglycan molecules in standardized transverse sections of the proximal left anterior descending and right coronary arteries. Slides were scored in a blinded fashion for intensity of proteoglycan staining (0 to 6+) and for localization in the vessel walls.

RESULTS

Unique patterns of proteoglycan distribution were present in TA and NA. Biglycan was particularly prominent in intima and evolving atheromata in severely diseased TA coronary arteries, but not in NA. Decorin was present mainly in adventitia of all vessels and in the intima of NA. Prominent versican accumulation occurred in intima and media of TA coronaries, associated with smooth muscle cells and foam cells. There was a reciprocal pattern of biglycan and decorin staining. Versican colocalized with biglycan. Intimal biglycan and versican deposits were positively correlated to the extent of luminal narrowing in TA.

CONCLUSION

The distinctive staining patterns for biglycan, decorin and versican in both native and allograft disease indicate that the synthesis and distribution of these proteoglycans are regulated by different local mechanisms in different atheromatous diseases.

Preoperative obesity is associated with decreased survival after heart transplantation

BACKGROUND

It is difficult to assess candidacy of obese patients for heart transplantation because the effect of obesity before heart transplantation on posttransplantation outcome has not been examined. Therefore, the purpose of this study was to examine the impact of both preoperative weight and postoperative weight gain on outcome after heart transplantation.

METHODS

The retrospective sample included 193 consecutive patients undergoing transplantation between March 1984 and June 1991 (mean age 47 +/- 14 years, 75% male). Data were gathered from retrospective chart review. Percent ideal body weight was calculated for each patient. Patients were divided into three groups based on pretransplantation percent ideal body weight: < 90% ideal body weight (n = 30), 90% to 110% ideal body weight (n = 79), and > 110% ideal body weight (n = 84). Chi-square, analysis of variance, Kaplan-Meier survival distributions, and the Cox Proportional Hazards Model were used for analyses.

RESULTS

Patients > 110% ideal body weight tended to have more coronary artery disease and higher serum triglyceride levels and significantly higher cholesterol levels than patients < 90% ideal body weight. After heart transplantation, no significant differences were found among the three pretransplantation percent ideal body weight groups regarding acute rejection, infection, and allograft arteriopathy. Survival was significantly worse among patients who were overweight before surgery (p = 0.018). A multivariate survival analysis showed that percent ideal body weight was an independent predictor of survival after heart transplantation (p = 0.046).

CONCLUSIONS

Despite a similar incidence of infection and rejection after heart transplantation among the three percent ideal body weight groups, obesity before heart transplantation is associated with significantly decreased survival after heart transplantation.

Selection and treatment of candidates for heart transplantation

Improved outcome of heart failure in response to medical therapy, coupled with a critical shortage of donor organs, make it imperative to confine heart transplantation to patients who are most disabled by heart failure and who are likely to derive the maximum benefit from heart transplantation. Hemodynamic and functional indices of prognosis (such as peak exercise oxygen consumption) has improved the ability to identify adult patients who should be selected for heart transplantation. These patients should have a poor prognosis despite optimization of medical and surgical therapy. When deciding the impact of individual comorbid conditions on a patient's candidacy for heart transplantation, the detrimental effects of each comorbid condition on post heart transplantation outcome should be weighed. Evaluation of patients with severe heart failure should be done by a multidisciplinary team expert in the management of heart failure, performance of cardiac surgery in patients with low left ventricular ejection fractions, and transplantation. Potential heart transplantation candidates should be reevaluated on a regular basis to assess the continued need for heart transplantation.