Impact of donor left ventricular hypertrophy on survival after heart transplant.

Left ventricular hypertrophy (LVH) of the donor heart is believed to increase the risk of allograft failure after transplant. However this effect is not well quantified, with variable findings from single-center studies. The United Network for Organ Sharing database was used to analyze the effect of donor LVH on recipient survival. Three cohorts, selected in accordance with the American Society of Echocardiography guidelines, were examined: recipients of allografts without LVH (<1.1 cm), with mild LVH (1.1-1.3 cm) and with moderate-severe LVH (≥ 1.4 cm). The study group included 2626 patients with follow-up of up to 3.3 years. Mild LVH was present in 38% and moderate-severe LVH in 5.6% of allografts. Predictors of mortality included a number of donor and recipient characteristics, but not LVH. However, a subgroup analysis showed an increased risk of death in recipients of allografts with LVH and donor age >55 years, and in recipients of allografts with LVH and ischemic time ≥ 4 h. In the contemporary era, close to half of all transplanted allografts demonstrate LVH, and survival of these recipients is similar to those without LVH. However, the use of allografts with LVH in association with other high-risk characteristics may result in increased mortality.

Changes in gene expression in the intact human heart. Downregulation of alpha-myosin heavy chain in hypertrophied, failing ventricular myocardium.

Using quantitative RT-PCR in RNA from right ventricular (RV) endomyocardial biopsies from intact nonfailing hearts, and subjects with moderate RV failure from primary pulmonary hypertension (PPH) or idiopathic dilated cardiomyopathy (IDC), we measured expression of genes involved in regulation of contractility or hypertrophy. Gene expression was also assessed in LV (left ventricular) and RV free wall and RV endomyocardium of hearts from end-stage IDC subjects undergoing heart transplantation or from nonfailing donors. In intact failing hearts, downregulation of beta1-receptor mRNA and protein, upregulation of atrial natriuretic peptide mRNA expression, and increased myocyte diameter indicated similar degrees of failure and hypertrophy in the IDC and PPH phenotypes. The only molecular phenotypic difference between PPH and IDC RVs was upregulation of beta2-receptor gene expression in PPH but not IDC. The major new findings were that (a) both nonfailing intact and explanted human ventricular myocardium expressed substantial amounts of alpha-myosin heavy chain mRNA (alpha-MHC, 23-34% of total), and (b) in heart failure alpha-MHC was downregulated (by 67-84%) and beta-MHC gene expression was upregulated. We conclude that at the mRNA level nonfailing human heart expresses substantial alpha-MHC. In myocardial failure this alteration in gene expression of MHC isoforms, if translated into protein expression, would decrease myosin ATPase enzyme velocity and slow speed of contraction.

Left ventricular mass increases during cardiac allograft vascular rejection.

OBJECTIVES: This study evaluated whether left ventricular mass increases during cellular or vascular (humoral) cardiac allograft rejection. BACKGROUND: An increase in left ventricular mass during cellular cardiac allograft rejection has been described by other investigators, although controversy has existed over the validity of these findings. Left ventricular mass changes have not been evaluated in the setting of vascular (humoral) cardiac allograft rejection. METHODS: To determine the effect of allograft rejection on left ventricular mass, we retrospectively reviewed endomyocardial biopsy results and corresponding echocardiograms in 41 cardiac transplant recipients undergoing treatment for allograft rejection. Left ventricular mass was assessed by two-dimensional echocardiography using the method of Schiller. Maintenance immunosuppression included cyclosporine in all patients. RESULTS: Although significant changes in left ventricular wall thickness, mass and dimensions were not observed in patients experiencing moderate or severe cellular allograft rejection (International Society for Heart and Lung Transplantation grades III and IV, n = 27), marked changes were noted in patients with vascular (humoral) rejection (n = 14). Patients with vascular rejection demonstrated an echocardiographic mean (+/- SEM) increase in left ventricular wall mass (from 109 +/- 17 to 151 +/- 17 g), and left ventricular wall thickness (from 1.3 +/- 0.1 to 1.6 +/- 0.1 cm) during the rejection episode. Additionally, vascular rejection was associated with a trend toward an increase in left ventricular systolic dimension (from 2.6 +/- 0.1 to 3.0 +/- 0.2 cm) and a decrease in left ventricular fractional shortening and increased incidence of hemodynamic compromise with rejection (50% for vascular vs. 11% for cellular rejection). CONCLUSIONS: Left ventricular mass increases during episodes of vascular (humoral) rejection, but there is no significant change in left ventricular mass during cellular cardiac allograft rejection.

Carvedilol improves left ventricular function and symptoms in chronic heart failure: a double-blind randomized study.

OBJECTIVES: This study assessed the safety and efficacy of carvedilol in patients with heart failure caused by idiopathic or ischemic cardiomyopathy. BACKGROUND: Carvedilol is a mildly beta 1-selective beta-adrenergic blocking agent with vasodilator properties. Beta-blockade may be beneficial in patients with heart failure, but the effects of carvedilol are not known. METHODS: Sixty patients with heart failure (New York Heart Association functional classes II to IV) and left ventricular ejection fraction < or = 0.35 were enrolled in the study. All patients tolerated challenge with carvedilol, 3.125 mg twice a day, and were randomized to receive carvedilol (n = 36) versus placebo (n = 24). Study medication was titrated over 1 month from 6.25 to 25 mg twice a day (< 75 kg) or 50 mg twice a day (> 75 kg) and continued for 3 months. One placebo-treated and two carvedilol-treated patients did not complete the study. RESULTS: Carvedilol therapy resulted in a significant reduction in heart rate and mean pulmonary artery and pulmonary capillary wedge pressures and a significant increase in stroke volume and left ventricular stroke work. Left ventricular ejection fraction increased 52% in the carvedilol group (from 0.21 to 0.32, p < 0.0001 vs. placebo group). Carvedilol-treated patients also reported a significant lessening of heart failure symptoms (p < 0.05 vs. placebo group). Submaximal exercise duration tended to increase with carvedilol therapy (from 688 +/- 31 s to 871 +/- 32 s), but this change was not significantly different from that with placebo therapy by between-group analysis. Peak oxygen consumption during maximal exercise did not change. CONCLUSIONS: Long-term carvedilol therapy improves rest cardiac function and lessens symptoms in patients with heart failure.

Long-term (2 year) beneficial effects of beta-adrenergic blockade with bucindolol in patients with idiopathic dilated cardiomyopathy.

Beta-adrenergic blockade represents a promising therapeutic approach to idiopathic dilated cardiomyopathy. Bucindolol, a new beta-blocker, showed favorable effects in a short-term (3 month) trial in idiopathic dilated cardiomyopathy. To assess long-term response, 20 study patients (7 of 9 patients previously assigned to the placebo group and 13 of 14 patients previously assigned to bucindolol therapy) received long-term bucindolol therapy and were followed up for a mean of 23 +/- 4 months (range 17 to 30). The mean patient age was 49 years (range 29 to 66) and the median duration of disease was 11 months (range 1 to 190). Ten patients were in functional class II and 10 were in class III; 15 patients were men. At the end of the common follow-up time, all 20 patients were alive, 17 continued to receive bucindolol (mean dose 176 mg/day, range 25 to 200), and 2 underwent cardiac transplantation. Left ventricular ejection fraction increased from a baseline value of 25 +/- 8% to 35 +/- 13% (n = 19 pairs, p less than 0.001). Functional class improved in 12, was unchanged in 5 and deteriorated in 3 (p = 0.056). Exercise time was maintained (9.4 +/- 3.1 versus 9.1 +/- 3.5 min, n = 19, p = NS), as was maximal oxygen uptake (19.2 +/- 4.9 versus 18.8 +/- 5.7 ml/kg per min, n = 19, p = NS). Thus, long-term bucindolol therapy leads to substantial increases in ejection fraction and to improved functional class while stable exercise performance is maintained.(ABSTRACT TRUNCATED AT 250 WORDS)

Combined oral positive inotropic and beta-blocker therapy for treatment of refractory class IV heart failure.

OBJECTIVES: We sought to assess the effects of combined oral positive inotropic and beta-blocker therapy in patients with severe heart failure. BACKGROUND: Patients with severe, class IV heart failure who receive standard medical therapy exhibit a 1-year mortality rate >50%. Moreover, such patients generally do not tolerate beta-blockade, a promising new therapy for chronic heart failure. Positive inotropes, including phosphodiesterase inhibitors, are associated with increased mortality when administered over the long term in these patients. The addition of a beta-blocker to positive inotropic therapy might attenuate this adverse effect, although long-term oral inotropic therapy might serve as a bridge to beta-blockade. METHODS: Thirty patients with severe heart failure (left ventricular ejection fraction [LVEF] 17.2+/-1.2%, cardiac index 1.6+/-0.1 liter/min per m2) were treated with the combination of oral enoximone (a phosphodiesterase inhibitor) and oral metoprolol at two institutions. Enoximone was given at a dose of < or = 1 mg/kg body weight three times a day. After clinical stabilization, metoprolol was initiated at 6.25 mg twice a day and slowly titrated up to a target dose of 100 to 200 mg/day. RESULTS: Ninety-six percent of the patients tolerated enoximone, whereas 80% tolerated the addition of metoprolol. The mean duration of combination therapy was 9.4+/-1.8 months. The mean length of follow-up was 20.9+/-3.9 months. Of the 23 patients receiving the combination therapy, 48% were weaned off enoximone over the long term. The LVEF increased significantly, from 17.7+/-1.6% to 27.6+/-3.4% (p=0.01), whereas the New York Heart Association functional class improved from 4+/-0 to 2.8+/-0.1 (p=0.0001). The number of hospital admissions tended to decrease during therapy (p=0.06). The estimated probability of survival at 1 year was 81+/-9%. Heart transplantation was performed successfully in nine patients (30%). CONCLUSIONS: Combination therapy with a positive inotrope and a beta-blocker appears to be useful in the treatment of severe, class IV heart failure. It may be used as a palliative measure when transplantation is not an option or as a bridge to heart transplantation. Further study of this form of combined therapy is warranted.

Multicenter trial of sotalol for suppression of frequent, complex ventricular arrhythmias: a double-blind, randomized, placebo-controlled evaluation of two doses.

Sotalol is a unique beta-adrenergic blocking agent with additional actions characteristic of Vaughn-Williams class III antiarrhythmic agents in experimental models. To test the efficacy of sotalol to suppress ventricular arrhythmias, a 6 week parallel, placebo-controlled out-patient study of two doses (320 and 640 mg/day, in two divided doses) was performed in four hospitals in 56 patients with chronic premature ventricular complexes at a frequency of 30/h or more (mean +/- SE, 528 +/- 60/h) on 48 hour ambulatory electrocardiographic recording. During a placebo week, no change occurred in arrhythmia frequency (532 +/- 76/h). Subsequent sotalol therapy significantly reduced median arrhythmia frequency in patients receiving both low (n = 19) and high (n = 18) doses compared with that in patients receiving placebo (by 77 and 83%, respectively, versus 6%; p less than 0.001). Twenty-two (59%) of 37 sotalol-treated patients, 11 in each group, reached the prospectively defined criterion of efficacy (greater than or equal to 75% arrhythmia reduction) versus 2 (11%) of 19 placebo control patients (p less than 0.001). Sotalol reduced the median frequency of couplets by 94% (p less than 0.0001) and that of runs by 89% (p less than 0.0007). The electrocardiographic effects of sotalol included reductions in heart rate (by 17 to 27%) and increases in the QTc (by 6 to 9%) and PR (by 6%) intervals. Ejection fraction was unchanged. The most common adverse side effect was fatigue, but drug discontinuation was required in only three patients taking 640 mg/day. No proarrhythmic events or biochemical abnormalities were observed. In summary, sotalol displays significant antiarrhythmic activity of moderately high degree with good tolerance in doses of both 320 and 640 mg/day. Its antiarrhythmic actions are distinguished from those reported for other beta-blockers by its effects on the QTc interval and its moderately high degree of antiarrhythmic activity.

Influence of carvedilol on hospitalizations in heart failure: incidence, resource utilization and costs. U.S. Carvedilol Heart Failure Study Group.

BACKGROUND: Carvedilol reduces disease progression in heart failure, but to our knowledge, its effects on hospitalizations and costs have not been evaluated. OBJECTIVES: We examined the effects on hospitalization frequency and costs in the U.S. Carvedilol Heart Failure Trials Program. This program consisted of four concurrent, multicenter, double-blind, placebo-controlled studies involving 1,094 patients with New York Heart Association class II to IV heart failure, which treated patients with placebo or carvedilol for up to 15 months (median, 6.5 months). METHODS: Detailed resource utilization data were collected for all hospitalizations occurring between randomization and the end of follow-up. In-patient care costs were estimated based on observed levels of resource use. RESULTS: Compared with placebo, carvedilol reduced the risk of hospitalization for any reason by 29% (p = 0.009), cardiovascular hospitalizations by 28% (p = 0.034) and heart failure hospitalizations by 38% (p = 0.041). Carvedilol also decreased the mean number of hospitalizations per patient (for cardiovascular reasons 30% [p = 0.02], for heart failure 53% [p = 0.03]). Among hospitalized patients, carvedilol reduced severity of illness during hospital admission, as reflected by shorter length of stay and less frequent use of intensive care. For heart failure hospital admissions, carvedilol decreased mean length of stay by 37% (p = 0.03) and mean number of intensive care unit/coronary care unit days by 83% (p = 0.001), with similar effects on cardiovascular admissions. As a result, estimated inpatient care costs with carvedilol were 57% lower for cardiovascular admissions (p = 0.016) and 81% lower for heart failure admissions (p = 0.022). CONCLUSIONS: Carvedilol added to angiotensin-converting enzyme inhibition reduces hospitalization risk as well as severity of illness and resource utilization during admission in patients with chronic heart failure.

Long-term beta-blocker vasodilator therapy improves cardiac function in idiopathic dilated cardiomyopathy: a double-blind, randomized study of bucindolol versus placebo.

PURPOSE: Bucindolol is a potent nonselective beta-blocking agent with vasodilatory properties. In this study, we evaluated the effects of long-term bucindolol therapy in the treatment of heart failure from idiopathic dilated cardiomyopathy. PATIENTS AND METHODS: Patients were eligible for enrollment if they had symptomatic heart failure, idiopathic dilated cardiomyopathy, and left ventricular ejection fraction less than 0.40. All patients received an initial test dose of 12.5 mg bucindolol orally every 12 hours for two or three doses. Patients tolerating the test dose were randomly assigned (double-blind) to receive bucindolol or placebo in a 3:2 ratio. Study medication was begun at a dose of 12.5 mg orally every 12 hours and gradually increased over a 1-month period until either a maximum tolerated dose or a target dose of 100 mg every 12 hours was reached. Study medication was then continued for an additional 2 months. RESULTS: A total of 24 patients were enrolled into the study. Twenty-three patients tolerated bucindolol test challenge; 14 were randomized to receive bucindolol, and nine were randomly assigned to receive placebo. The placebo group (age 56 +/- 2 years) was significantly older than the bucindolol group (46 +/- 3 years), but by all other clinical and hemodynamic parameters the two groups were comparable. Twenty-two of 23 patients completed the study. Patients treated with bucindolol had significant improvements in clinical heart failure symptoms and in resting hemodynamic function, including an increase of left ventricular ejection fraction (0.26 +/- 0.02 to 0.35 +/- 0.09, p = 0.003), cardiac index (2.2 +/- 0.1 to 2.5 +/- 0.4 L/minute/m2, p = 0.014), and left ventricular stroke work index (25 +/- 3 to 35 +/- 7 g.m/m2, p = 0.002) and a decrease in pulmonary artery wedge pressure (17 +/- 3 to 10 +/- 5 mm Hg, p = 0.005) and heart rate (86 +/- 3 to 75 +/- 9 beats/minute, p = 0.012). Patients treated with bucindolol also had a significant increase in exercise left ventricular ejection fraction (0.26 +/- 0.03 to 0.32 +/- 0.14, p = 0.015) and reduction in questionnaire-measured symptoms (p = 0.007) and New York Heart Association functional class (p less than 0.001). However, total treadmill exercise duration and maximal oxygen consumption with exercise did not change. No changes in rest or exercise parameters were observed in the placebo-treated group. Central venous plasma norepinephrine concentration decreased significantly in the bucindolol-treated group (423 +/- 79 to 212 +/- 101 pg/mL, p = 0.010), but was unchanged in the placebo-treated group. CONCLUSION: Bucindolol is well tolerated in patients with idiopathic dilated cardiomyopathy and congestive heart failure, and therapy for 3 months is associated with improved resting cardiac function, improved heart failure symptoms, and a reduction in venous norepinephrine concentration.

Treatment of refractory cardiac allograft rejection with OKT3 monoclonal antibody.

OKT3 monoclonal antibody is a murine monoclonal antibody specific for the T lymphocyte T3 cell surface receptor that mediates antigen recognition. The use of OKT3 monoclonal antibody for the treatment of cardiac allograft rejection refractory to conventional therapy with high-dose steroids and antithymocyte globulin is described. Seven patients received 5 mg of OKT3 monoclonal antibody intravenously per day for 10 to 14 days. Diagnosis of moderate or severe rejection was made in all seven from right ventricular endomyocardial biopsy. Biopsy was repeated 48 to 72 hours and seven to 10 days after OKT3 monoclonal antibody was begun. With treatment, four patients had a complete response, with improvement on both early and late biopsy. Two patients had partial responses, with improvement on early biopsy followed by worsening rejection on late biopsy. One patient died of graft failure six hours after receiving OKT3 monoclonal antibody. Adverse events were common in the first two days of therapy but were well tolerated. It is concluded that OKT3 monoclonal antibody is useful in the treatment of refractory cardiac allograft rejection.

Age-associated decline in cardiac allograft rejection.

The influence of age on cardiac allograft rejection was studied in 57 consecutive recipients. Twenty-one subjects were 54 years of age or older (mean, 57.7 +/- 0.6 years [+/- SEM]; range, 54 to 63 years) and 36 subjects were 52 years of age or younger (mean, 39.9 +/- 1.8 years; range, 16 to 52 years; p less than 0.001). The older recipients had fewer rejection episodes during the first four months following cardiac transplantation (0.24 +/- 0.05 episodes per month versus 0.72 +/- 0.09 episodes per month; p less than 0.001) and during the total duration of follow-up (0.20 +/- 0.03 episodes per month versus 0.40 +/- 0.07 episodes per month; p = 0.045), and experienced their first rejection episode later (50.4 +/- 4.0 days versus 27.7 +/- 8.5 days; p = 0.008). Younger age was found to add significantly as a predictor of rejection in a multivariate analysis that controlled for sex, immunosuppressive agents, cause of heart failure, and pretransplantation lymphocyte cross-match status (r = 0.64, p less than 0.05). Decreased rejection frequency occurred without a concomitant increase in the serious infection rate (67 percent in both groups). The 12-month actuarial survival was 100 percent in the older group and 94 percent in the younger group (p = NS). Decreased rejection in the older recipients is likely a manifestation of an age-associated decline in immune function and might represent an advantage in transplantation for carefully selected older patients.

Increased risk of pneumococcal infections in cardiac transplant recipients.

We observed 5 episodes of pneumococcal infection among 129 cardiac transplant patients between March 1985 and December 1987, giving an estimated incidence of 36 cases per 1000 patient-years. Infections occurred a mean of 58 days after transplantation and included bacteremia with empyema, bacteremia alone, and pneumonia. All patients recovered from their infections. There was no correlation between infection and age, sex, immunosuppression, or rejection episodes. We also measured antibody levels to 12 pneumococcal antigens in 6 unvaccinated, uninfected patients before and after cardiac transplantation, to see if baseline antibody levels decreased. Protective levels of antibody were defined as greater than or equal to 300 ng of anticapsular antibody nitrogen per milliliter serum. Before transplantation patients had protective antibody levels to a mean of 8.7 +/- 1.2 pneumococcal serotypes; after transplantation, the number of presumably protective antibody levels decreased to 6.5 +/- 1.4 (P = 0.021). One of these patients subsequently developed pneumococcal pneumonia. Cardiac transplant patients are at increased risk of pneumococcal infections. Vaccinating transplant candidates prior to transplantation may provide protection after transplantation.

A prospective comparison of murine monoclonal CD-3 (OKT3) antibody-based and equine antithymocyte globulin-based rejection prophylaxis in cardiac transplantation. Decreased rejection and less corticosteroid use with OKT3.

To test the efficacy of murine monoclonal CD-3 antibody (OKT3) in early prophylaxis for cardiac allograft rejection, we conducted a 6-month trial, prospectively assigning 51 patients to receive either equine antithymocyte globulin-based (n = 25) or OKT3-based (n = 26) early prophylaxis. ATG patients received 8 days of ATG (10 mg/kg), with the first dose given preoperatively. OKT3 patients received 14 days of OKT3 (5 mg) beginning on the second postoperative day. Corticosteroid and azathioprine administration were similar during early prophylaxis. Cyclosporine was begun preoperatively in ATG patients and on the fourth postoperative day in OKT3 patients. In addition, patients in both groups were randomized to receive or not receive eight weekly administrations of vincristine (0.025 mg/kg). While infection rate (0.8 +/- 0.2 infections/patient in both groups [mean +/- SEM]) and mortality (1 patient in each group) did not differ, OKT3-based early prophylaxis delayed the first rejection episode (76 +/- 11 days vs. 36 +/- 8 days, P = 0.005) and decreased the risk of rejection during the 6-month follow-up (P less than 0.001, product-limit analysis). Overall, the OKT3 group manifested 1.5 +/- 0.2 episodes of rejection/patient compared with 2.2 +/- 0.2 episodes/patient in the ATG group (P = 0.036). Despite similar 6-month cumulative cyclosporine and azathioprine dosages, six month average corticosteroid administration was less in the OKT3 group (12.2 +/- 1.5 mg prednisone equivalent/m2/day versus 19.3 +/- 2.1 mg prednisone equivalent/m2/day, P = 0.008), fewer OKT3 patients subsequently required additional cytolytic therapy for rejection (2 [8%] versus 12 [48%], P = 0.001), and more patients in the OKT3 group were successfully weaned off maintenance corticosteroids (22 [88%] versus 11 [46%], P = 0.002). We conclude that, relative to an equine ATG-based protocol, OKT3-based early prophylaxis results in less rejection, permitting less chronic corticosteroid administration.

A randomized trial of the immunosuppressive efficacy of vincristine in cardiac transplantation.

We evaluated the efficacy of the addition of the lymphoblasticidal agent vincristine to standard immunosuppression in heart transplantation in a prospective randomized study of 92 patients (46 to receive and 46 to not receive vincristine) with a follow-up period of 12 months. Patients received either equine antithymocyte globulin for the first week or OKT3 monoclonal antibody (OKT3) for the first 10 or 14 days after transplantation. Six to eight doses of vincristine were given over 9-12 weeks, beginning 2 days after completion of ATG or OKT3. The number of rejection episodes in the first six months posttransplantation, the percentage of patients corticosteroid maintenance-free at one year, cumulative immunosuppressive drug doses, deaths, infections, and neuropathy were followed. The addition of vincristine resulted in more patients achieving corticosteroid maintenance-free status at one year (vincristine 68%, no vincristine 38%, P = 0.01). In comparing patients at relatively high risk for rejection (those younger than 55 years and all females) with those at relatively low risk (males older than 55 years), only the high-risk vincristine-treated patients showed significantly fewer rejection episodes and a higher corticosteroid maintenance status at one year (66% vs. 32%, P = 0.01). There were no significant differences in survival (vincristine 96%, no vincristine 98%), infection, or amounts of other immunosuppressive agents used. The major side effect was neuropathy, which occurred more frequently in the vincristine-treated group (43% vs. 18%, P less than .001). We conclude that vincristine acts as an immunosuppressive agent in cardiac transplantation, particularly in patients at higher risk for rejection.

Acute hemodynamic response to low dose enoximone (MDL 17,043): an oral dose-range study.

The efficacy of low dose oral enoximone (MDL 17,043) was evaluated in the treatment of congestive heart failure (CHF). Fourteen male patients with stable, moderately severe CHF (New York Heart Association functional class II or III) and mean left ventricular ejection fraction of 0.21 +/- 0.02 were randomized to receive 50, 75, 100, 150 or 200 mg of enoximone (mean dose 1.46 +/- 0.16 mg/kg). Hemodynamic data were measured before and during the first 24 hours of therapy. An oral dose was given in the first 24 hours, and then every 8 hours. Acute administration of enoximone resulted in significant improvement in cardiac index (2.07 +/- 0.18 to 2.36 +/- 0.16 liters/min/m2, p less than 0.05), mean pulmonary arterial pressure (35 +/- 4 to 30 +/- 4 mm Hg, p less than 0.02), mean pulmonary artery wedge pressure (22 +/- 3 to 18 +/- 2 mm Hg, p less than 0.05) and systemic vascular resistance (1,712 +/- 148 to 1,384 +/- 82 dynes s cm-5, p less than 0.02). Neither hypotension nor tachycardia was observed. Although there was a trend toward a dose-response relation, hemodynamic responses to doses less than 1.5 mg/kg and greater than 1.5 mg/kg were not significantly different. Clinical symptoms improved with long-term therapy, but left ventricular ejection fraction and exercise treadmill time did not change. In patients with moderate and severe CHF, low doses of enoximone result in significant acute hemodynamic improvement.

Circulating concentrations of proinflammatory cytokines in mild or moderate heart failure secondary to ischemic or idiopathic dilated cardiomyopathy.

Proinflammatory cytokines are capable of modulating cardiovascular function by a variety of mechanisms. These cytokines are elevated in patients with severe heart failure, but changes in mild or moderate heart failure have not been reported. Therefore, simultaneous arterial and coronary sinus concentrations of interleukin-1alpha, soluble interleukin-2 receptor, interleukin-6, and tumor necrosis factor-alpha were measured in 78 patients with New York Heart Association functional class II to IV heart failure and compared with 17 healthy volunteers. Concentrations of interleukin-1alpha, soluble interleukin-2 receptor, and interleukin-6 were determined by a "sandwich" enzyme-linked immunosorbent assay and tumor necrosis factor-alpha by tissue culture technique. There were no statistical differences in interleukin-1alpha, soluble interleukin-2 receptor, or tumor necrosis factor-alpha concentrations in mild to moderate heart failure versus control subjects. Interleukin-6 was significantly elevated, 75 +/- 16 versus 0.4 +/- 0.4pg/ml (p = 0.002). Cytokine concentrations did not differ by heart failure etiology. Paired arterial and coronary sinus concentrations were not significantly different. Soluble interleukin-2 receptor concentrations were significantly correlated with New York Heart Association functional class (r = 0.59, p = 0.04) and negatively associated with exercise tolerance time (r = -0.59, p = 0.007). Thus, interleukin-6 is significantly elevated in mild or moderate heart failure.

beta-adrenergic receptor regulation and left ventricular function in idiopathic dilated cardiomyopathy.

Alterations in the myocardial receptor-G protein-adenylate cyclase (RGC) complex and cardiac adrenergic neurons in the failing human heart result in subsensitivity to beta-adrenergic stimulation. Pharmacologic interventions such as beta blockade may modify critical components of the RGC complex and partially restore the sensitivity of the beta-adrenergic pathway. Among the receptors coupled to the stimulatory (Gs) protein are the beta 1 and beta 2 receptors. Because of differences in receptor population and agonist (i.e., norepinephrine) affinity, the beta 1-receptor is the predominate adrenergic subtype regulating contractility in the nonfailing myocardium. Down-regulation occurs in the myocardial beta-receptor component of the RGC complex with mild-to-moderate and severe left ventricular dysfunction. However, abnormalities of the RGC complex vary with the etiology of heart failure; beta 1-receptor down-regulation is greater in idiopathic dilated cardiomyopathy than in post-infarction cardiomyopathy, while beta-receptor uncoupling is greater in post-infarction disease. In chronic heart failure, the adrenergic nervous system is activated in the heart and kidney. There is evidence that an increased cardiac norepinephrine concentration contributes to the decrease in beta 1-receptor density in heart failure. However, norepinephrine exposure is not the only factor responsible for regulating beta-adrenergic receptors in heart failure. Chronic beta blockade may improve hemodynamic and clinical response in patients with idiopathic dilated cardiomyopathy by protecting the myocardium from the cardiotoxic effects of increased catecholamines and by up-regulating the beta 1 receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of carvedilol on left ventricular mass, chamber geometry, and mitral regurgitation in chronic heart failure.

We and others have previously shown that carvedilol improves left ventricular (LV) function and symptoms in chronic heart failure. This improvement in LV function has also been shown to be associated with an improvement in survival. This study evaluates the effect of carvedilol on LV mass, geometry, and degree of mitral regurgitation (MR). In 59 patients with symptomatic heart failure and LV ejection fraction <0.35, previously randomized to either treatment with carvedilol or placebo, we evaluated LV mass, geometry, and degree of MR over the time period of carvedilol treatment. LV mass decreased as early as 4 months into the treatment protocol and continued to decrease over a period of 1 year. LV geometry, defined by the length/diameter ratio, and severity of MR also improved with 4 months of therapy. Thus, compared with placebo treatment, carvedilol decreases LV mass while improving cardiac geometry and decreasing MR in patients with chronic heart failure. These changes occur in association with an improvement in LV systolic function. This process begins by 4 months of treatment and continues for 12 months.

Effects of carvedilol on right ventricular function in chronic heart failure.

This study investigated the effects of carvedilol on right ventricular (RV) volume and systolic function in chronic heart failure patients. Carvedilol treatment resulted in a significant improvement of RV ejection fraction and systolic performance, which paralleled the improvement of systolic function demonstrated in the left ventricle.

Effects of carvedilol on systolic and diastolic left ventricular performance in idiopathic dilated cardiomyopathy or ischemic cardiomyopathy.

Recent evidence has shown that improvement in left ventricular (LV) systolic function in patients with New York Heart Association class II to III heart failure occurs with beta-adrenergic blocking agents. However the specific effects on LV diastolic function have been subjected to only limited examination. This study investigated the effects of the combined beta blocker/vasodilator, carvedilol, on systolic and diastolic LV performance in dilated cardiomyopathy. Thirty-six patients with New York Heart Association II to III heart failure and LV ejection fraction < or = 0.35 were entered into either arm of this placebo-controlled, double-blind 4-month trial. Twenty-one subjects were entered into the carvedilol treatment arm and 15 patients were entered into the placebo arm in a 3:2 ratio. Carvedilol therapy resulted in a significant improvement in LV ejection fraction, from 0.22 +/- 0.02 to 0.30 +/- 0.02 when compared with the placebo group (0.19 +/- 0.02 to 0.21 +/- 0.02 at baseline and after 4 months of therapy, respectively; p = 0.0001). However, no significant change in radionuclide parameters of LV diastolic function, including peak filling rate or time to peak filling rate, was observed. LV end-diastolic volume index did not change with carvedilol therapy, whereas end-diastolic volume index increased in the placebo group, although the difference between groups at 4 months was significant (p = 0.02). In conjunction with these changes, end-systolic volume index was smaller at 4 months after carvedilol treatment compared with that of the placebo group (p = 0.04). Thus, these results demonstrate that in moderate chronic heart failure, systolic LV performance improves but diastolic LV function does not improve when compared with placebo after treatment with carvedilol.