Combining inhaled iloprost with bosentan in patients with idiopathic pulmonary arterial hypertension

Addition of inhaled iloprost to bosentan may have beneficial effects in patients with idiopathic pulmonary arterial hypertension (IPAH). A multicentre, open, randomised, controlled trial was performed to assess the safety and efficacy of inhaled iloprost in patients with IPAH who had already been treated with bosentan. The trial was terminated early after a futility analysis predicted failure with respect to the predetermined sample size. At that time, 40 patients were randomised to receive either bosentan alone (control group) or bosentan plus inhaled iloprost (combination group) for a 12-week period. The primary end-point, change in 6-min walking distance, was not met (mean changes +1 m and -9 m in the control and combination group, respectively). These results may have been skewed by three outliers in the iloprost group who presented with severe clinical worsening. None of the secondary end-points including functional class, peak oxygen uptake, and time to clinical worsening differed significantly between groups. The current study failed to show a positive effect of adding inhaled iloprost to bosentan in idiopathic pulmonary arterial hypertension patients. Further studies involving larger sample sizes and long-term follow-up are needed to determine the efficacy of adding inhaled iloprost to bosentan in patients with idiopathic pulmonary arterial hypertension.

Goal-oriented treatment and combination therapy for pulmonary arterial hypertension

Combination therapy may improve outcome in patients with severe pulmonary arterial hypertension (PAH). PAH patients were treated according to a goal-oriented therapeutic strategy. Patients who did not reach the treatment goals with monotherapy received combination treatment according to a predefined strategy, including bosentan, sildenafil and inhaled iloprost. Intravenous iloprost and lung transplantation were reserved for treatment failures. End points were overall survival, transplantation-free survival, and survival free from transplantation and intravenous prostanoid treatment. Between January 2002 and December 2004, 123 consecutive patients with PAH were treated according to the novel approach. Survival at 1, 2 and 3 yrs was 93.0, 83.1 and 79.9%, respectively, which was significantly better than the survival of a historical control group, as well as the expected survival. Compared to the historical control group, the use of combination treatment also significantly improved the combined end point of death, lung transplantation and need for intravenous iloprost treatment. In conclusion, a therapeutic approach utilising combinations of bosentan, sildenafil and inhaled iloprost in conjunction with a goal-oriented treatment strategy provides acceptable long-term results in patients with severe pulmonary arterial hypertension, and reduces the need for intravenous prostaglandin treatment and lung transplantation.

Pulmonary arterial hypertension: pathobiology, diagnosis and treatment

Pulmonary arterial hypertension (PAH) is defined as a group of diseases characterized by a progressive increase of pulmonary vascular resistance leading to right ventricular failure. It includes a variety of pulmonary hypertensive diseases with different etiologies but similar clinical presentation. PAH is a disease of the small pulmonary arteries, characterized by progressive obliteration of the pulmonary vascular bed. Vasoconstriction, remodeling of the pulmonary vessel wall and thrombosis contribute to an increased pulmonary vascular resistance. Major advances in our understanding of the mechanism of disease development have been achieved over the past decade. Several of these new insights have led to the development and clinical application of novel treatments that includes new classes of drugs such as prostanoids, endothelin receptor antagonists and type 5 phosphodiesterase inhibitors.

Bosentan therapy for portopulmonary hypertension

The dual endothelin receptor antagonist bosentan has been approved in several countries for pulmonary arterial hypertension, and patients with portopulmonary hypertension (PPHTN) have not specifically been excluded. However, no data have been published on the efficacy and safety of bosentan in this patient population. Here, the first clinical experiences with bosentan in patients with Child A cirrhosis and severe PPHTN are reported. In total, 11 consecutive patients with cirrhosis and severe PPHTN in New York Heart Association Functional Classes III and IV were treated for >1 yr with bosentan. After 1 yr of treatment with bosentan, all patients showed improved symptoms and exercise capacity. The 6-min walking distance increased from 310+/-102 m at baseline to 388+/-81 m at 1 yr. Cardiopulmonary exercise testing disclosed a significant increase in peak oxygen uptake, from 12.6+/-3.5 to 16.6+/-2.8 mL.min(-1).kg(-1). Pulmonary vascular resistance fell from 944+/-519 to 635+/-321 dynes.s.L(-1). The medication was well tolerated by all patients, and there was no evidence of drug-related liver injury. In conclusion, bosentan proved to be efficacious and safe in a small number of patients with portopulmonary hypertension.

Acute liver failure: a message found under the skin

Acute liver failure is a rare syndrome with rapid progression and high mortality. It is characterised by the onset of coma and coagulopathy usually within six weeks but can occur up to six months after the onset of illness. Viral hepatitis, idiosyncratic drug induced liver injury, and acetaminophen ingestion are common causes. This report describes the case of a 35 year old man who presented with acute liver failure shortly after binge drinking. Repeated history taking disclosed a gluteal disulfiram implant that the patient had received to treat his alcohol dependence. The patient recovered with maximum supportive care after surgical removal but without liver transplantation. This case illustrates that only meticulous history taking will disclose the sometimes bewildering causes of acute liver failure.

Combination therapy with bosentan and sildenafil in idiopathic pulmonary arterial hypertension

It has been proposed that targeted treatments should be combined for patients with idiopathic pulmonary arterial hypertension (IPAH) responding insufficiently to monotherapy. This study followed the clinical course of nine patients with severe IPAH, in whom the endothelin receptor antagonist bosentan caused transient clinical improvement, eventually followed by a decline in exercise tolerance, who received adjunct treatment with the phospodiesterase-5-inhibitor sildenafil. Measurements included the 6-min walk distance (6MWD) and cardiopulmonary exercise testing (CPET). The 6MWD at baseline was 346+/-66 m and improved to 403+/-80 m 3 months after introduction of bosentan treatment. However, this effect was not sustained and, after an interval of 11+/-5 months, the walk distance had declined to 277+/-80 m. At this point, sildenafil was added to bosentan. Three months later, the 6MWD had increased to 392+/-61 m and the patients remained stable throughout the median follow-up of 9 months (range 6-12). Measurement of the maximum oxygen uptake during CPET confirmed these results. The combination of bosentan and sildenafil was well tolerated by all patients. These preliminary data suggest that combining bosentan and sildenafil may be safe and effective in patients with idiopathic pulmonary arterial hypertension.

Bosentan treatment in patients with primary pulmonary hypertension receiving nonparenteral prostanoids

Primary pulmonary hypertension (PPH) is a life-threatening disease. Nonparenteral prostanoids, i.e. aerosolised iloprost or oral beraprost sodium show beneficial therapeutic effects but are not sufficiently active in all patients with this devastating disease. The purpose of the present study was to determine whether the endothelin-receptor antagonist bosentan is safe and effective in patients with PPH already receiving nonparenteral prostanoids. The effect of bosentan as add-on medication was studied in 20 patients with PPH, who received either inhaled iloprost (n=9) or oral beraprost (n=11) for a median period of 16+/-13 months, by means of the 6-min walk test and cardiopulmonary exercise testing. After 3 months of administration of bosentan in addition to prostanoids, the walking distance in the 6-min walk test increased by 58+/-43 m. Cardiopulmonary exercise testing revealed an increase in maximal oxygen consumption from 11.0+/-2.3 to 13.8+/-3.6 mL x kg(-1) x min(-1) accompanied by significant improvements in anaerobic threshold, oxygen pulse and minute ventilation/carbon dioxide production slope. Peak systolic blood pressure increased from 120+/-17 to 139+/-21 mmHg. Combination treatment was well tolerated by all patients. It is concluded that the addition of the endothelin-receptor antagonist bosentan to inhaled iloprost or oral beraprost therapy appears to be safe for patients with primary pulmonary hypertension, resulting in a marked increase in exercise capacity. Therefore, rigorous studies should address whether combination treatment is more effective than either therapeutic intervention alone.

Effects of inhaled salbutamol in primary pulmonary hypertension

Although lung function is grossly normal in patients with primary pulmonary hypertension (PPH), mild-to-moderate peripheral airflow obstruction can be found in the majority of patients with this disease. Therefore, beta2-agonists may affect pulmonary function, blood gases and haemodynamics in patients with PPH. Pulmonary function testing, blood gas measurements and right heart catheterisation was performed in 22 patients with PPH and the acute effects of inhaled salbutamol (0.2 mg) were measured. Salbutamol caused an increase in the forced expiratory volume in one second (FEV1) from 2446+/-704 to 2550+/-776 mL. The mean expiratory flow at 50% of the vital capacity (MEF50) rose from 58+/-17 to 66+/-21% pred. The pulmonary artery pressures remained unchanged after inhalation of salbutamol, but the cardiac output increased significantly from 3.9+/-1.4 to 4.2+/-1.4 L x min(-1) accompanied by significant increases in stroke volume and mixed venous oxygen saturation as well as a significant decrease in pulmonary vascular resistance. The arterial oxygen tension rose from 9+/-2.4 kPa (68+/-18 mmHg) at baseline to 9.7+/-2.8 kPa (73+/-21 mmHg) after inhalation of salbutamol, the alveolo-arterial oxygen gradient values improved from 6+/-2.5 kPa (45+/-19 mmHg) to 5.1+/-2.9 kPa (38+/-22 mmHg), respectively. Inhaled salbutamol has beneficial acute effects on pulmonary function, blood gases and haemodynamics in patients with primary pulmonary hypertension.

Intravenous iloprost for treatment failure of aerosolised iloprost in pulmonary arterial hypertension

Treatment with aerosolised iloprost, a prostacyclin analogue, has beneficial effects in patients with pulmonary arterial hypertension (PAH). It is unclear if patients, whose clinical condition deteriorates under treatment with aerosolised iloprost, benefit from switching to continuous intravenous iloprost. The current authors report on 16 patients with severe PAH who received continuous intravenous iloprost after primary or secondary failure of treatment with aerosolised iloprost. Determinants of efficacy were survival, New York Heart Association (NYHA) class, and walking distance in the 6-min walk test. Of 93 patients with PAH treated with aerosolised iloprost, 16 required switching to intravenous iloprost for clinical deterioration. These patients had severe right heart failure with a cardiac index of 1.6+/-0.2 L x min(-1) x m(-2) and a mixed-venous oxygen saturation of 52+/-6%. Five of these patients showed no improvement and eventually died. Three patients had further deterioration in NYHA class and exercise capacity; two of them underwent lung transplantation; the third patient is still alive. Eight patients showed marked clinical improvement; one underwent lung transplantation and the others are currently alive and stable. In the latter group of patients, the walking distance in the 6-min walk test increased from 205+/-94 to 329+/-59 m. It was not possible to identify clinical or haemodynamic factors that would predict whether switching from inhaled to intravenous iloprost would have a beneficial effect. In patients with pulmonary arterial hypertension who deteriorated while being treated with aerosolised iloprost, switching to continuous intravenous iloprost caused substantial improvement in exercise capacity in eight of 16 patients but could not prevent progression of pulmonary hypertension in the remaining eight patients. Since it was impossible to predict the individual effects of this approach, intravenous prostaglandin treatment should be considered in pulmonary arterial hypertension patients who deteriorate while receiving iloprost aerosol.

Peripheral airway obstruction in primary pulmonary hypertension

BACKGROUND

As there is controversy about changes in lung function in primary pulmonary hypertension (PPH), lung mechanics were assessed with a focus on expiratory airflow in relation to pulmonary haemodynamics.

METHODS

A cross sectional study was performed in 64 controls and 171 patients with PPH (117 women) of mean (SD) age 45 (13) years, pulmonary artery pressure (PAPmean) 57 (15) mm Hg, and pulmonary vascular resistance 1371 (644) dyne.s/cm(5).

RESULTS

Mean (SD) total lung capacity was similar in patients with PPH and controls (98 (12)% predicted v 102 (17)% predicted, mean difference -4 (95% confidence interval (CI) -7.89 to -0.11); residual volume (RV) was increased (118 (24)% predicted v 109 (27)% predicted, mean difference 9 (95% CI 1.86 to 16.14); and vital capacity (VC) was decreased (91 (16)% predicted v 102 (10)% predicted, mean difference -11 (95% CI 15.19 to -6.80). RV/TLC was increased (117 (27)% predicted v 97 (29)% predicted, mean difference 20 (95% CI 12.3 to 27.8)) and correlated with PAPmean (r=0.31, p<0.001). In patients with PAPmean above the median of 56 mm Hg, RV/TLC was further increased (125 (32)% predicted v 111 (22)% predicted, mean difference -14 (95% CI -22.2 to -5.8)). Expiratory flow-volume curves were reduced and curvilinear in patients with PPH.

CONCLUSIONS

Peripheral airway obstruction is common in PPH and is more pronounced in severe disease. This may contribute to symptoms. Reversibility of bronchodilation and relation to exercise capacity need further evaluation.

Pulmonary hypertension in collagen vascular disease

Pulmonary hypertension is a serious but often overlooked complication in collagen vascular disease. The understanding of the development of pulmonary hypertension has increased substantially during the last years. Abnormal proliferation of pulmonary vascular cells is now being regarded as a predominant process leading to pulmonary vascular obliteration. Medical therapy focuses on prostacyclin treatment, which has been shown to improve exercise capacity and haemodynamic variables in patients with several collagen vascular diseases and pulmonary arterial hypertension. Continuous intravenous prostacyclin remains the standard treatment of associated pulmonary hypertension but less invasive alternatives such as subcutaneous treprostinil, oral beraprost or aerosolized iloprost, as well as, novel substances such as endothelin receptor antagonists may be appropriate for selected patients.

Evaluation of right ventricular performance with a right ventricular ejection fraction thermodilution catheter and MRI in patients with pulmonary hypertension

STUDY OBJECTIVES

We sought to compare catheter studies using a right ventricular ejection fraction (REF) catheter together with echocardiography and MRI in patients with pulmonary hypertension.

PATIENTS AND METHODS

We compared hemodynamic findings, echocardiography, and MRI studies in 16 patients with pulmonary hypertension. Six healthy volunteers served as control subjects for the MRI studies.

RESULTS

MRI imaging provided accurate assessment of cardiac output in all but two patients. As compared with MRI, the REF catheter constantly underestimated the REF and overestimated right ventricular volumes in patients with pulmonary hypertension. REF, end-systolic and end-diastolic right ventricular volumes, and right ventricular muscle mass, as determined by MRI, were almost identical in patients with preserved cardiac function and those with low-output failure. The only factor that was different in both groups was the severity of tricuspid regurgitation.

CONCLUSION

Right ventricular dimensions and muscle mass do not differ in patients with pulmonary hypertension who have low cardiac output and those who do not. According to our results, the major determinant of cardiac output in these patients appears to be the severity of tricuspid regurgitation. The REF catheter provides invalid data on right ventricular dimensions in patients with pulmonary hypertension.

[Long-term treatment of primary pulmonary hypertension with inhaled iloprost]

BACKGROUND

Continuous intravenous infusion of prostacyclin is an effective treatment for primary pulmonary hypertension. This approach, however, requires the insertion of a permanent central venous catheter with the potential risk of serious complications. Recently, administration of aerosolized iloprost, a stable prostacyclin analogue, has been introduced as an alternative therapy for severe pulmonary hypertension.

METHODS

We evaluated the effects of treatment with aerosolized iloprost over a one-year period on exercise capacity and hemodynamic variables in patients with primary pulmonary hypertension.

RESULTS

Twenty-four patients with primary pulmonary hypertension received aerosolized iloprost at a cumulative daily dose of 100 to 150 micrograms for at least one year. The mean (+/- SD) walking distance in the 6-min-walk test increased from 278 +/- 96 meters at base line to 363 +/- 135 meters after 12 months (P < 0.0001). During the same period, the mean pulmonary artery pressure declined from 59 +/- 10 mmHg to 52 +/- 15 mmHg (P = 0.006), the cardiac output increased from 3.8 +/- 1.4 l/min to 4.4 +/- 1.3 l/min (P = 0.02), and the pulmonary vascular resistance declined from 1.205 +/- 467 dynes.s.cm-5 to 925 +/- 469 dynes.s.cm-5 (P = 0.0003). Treatment was generally well tolerated and except for mild coughing, minor headache and jaw pain in some patients, no side effects occurred.

CONCLUSIONS

Long-term treatment with aerosolized iloprost is safe and has sustained effects on exercise capacity and pulmonary hemodynamics in patients with primary pulmonary hypertension.

Ultrasonic versus jet nebulization of iloprost in severe pulmonary hypertension

Inhalation of iloprost, a stable prostacyclin analogue, is a promising perspective in the treatment of pulmonary hypertension. In initial clinical studies, a conventional jet nebulizer system was successfully used to decrease pulmonary vascular resistance and pressure, requiring however, up to twelve inhalations of 12-15 min per day. The aim of this study was to investigate if the application of an equal dose of iloprost at a drastically reduced duration of inhalation with the use of a more efficient ultrasonic nebulizer, leads to comparable haemodynamic effects, without escalation of side effects. The physical features of the jet nebulizer system (Ilo-Neb) and the ultrasonic nebulizer (Multisonic Compact) were characterized by laser diffractometry and a Tc99m-tracer technique. Mass median aerodynamic diameters were 3.2 microm for the jet and 3.9 microm for the ultrasonic nebulizer. Total output (mean+/-SD) was 60+/-7 microL.min(-1) (jet) and 163+/-15 microL.min(-1)(ultrasonic), and efficiency of the devices was 39+/-3% (jet) and 86+/-5% (ultrasonic). Based on these data, a total inhalative dose of 2.8 microg iloprost was delivered by jet nebulization within 12 min and by ultrasonic nebulization within 4 min, in 18 patients with severe primary and secondary pulmonary hypertension (New York Heart Association class III and IV), in a randomized crossover design. Haemodynamics were assessed by right heart catheterization. Inhalation with the ultrasonic device and jet nebulizer, reduced mean+/-SEM pulmonary artery pressure from 54.3+/-2.1 to 47.1+/-2.0 and from 53.5+/-2.2 to 47.0+/-2.2 mmHg, respectively, and mean+/-SEM pulmonary vascular resistance from 1,073+/-109 to 804+/-87 and from 1,069+/-125 to 810+/-83 dyn.s.cm(-5), respectively. Both modes of aerosolization were well tolerated. In conclusion, due to the markedly higher efficiency and output of the ultrasonic device, wastage of drug is largely avoided and the duration of inhalation can be shortened to one-third, with comparable haemodynamic effects and without enforcing side effects.

Hemoptysis following left ventricular aneurysm repair: a misleading clinical sign

We report on a 66-year-old man with severe hemoptysis following coronary artery bypass grafting and repair of a left ventricular septal defect after acute myocardial infarction. Initial diagnosis was delayed by misleading clinical symptoms and radiologic studies. Due to subfebrile temperature and sputum culture positive for Pseudomonas aeruginosa, he had been treated with antibiotics before reoperation. At reoperation, replacement of all foreign material and reconstruction of the ventricular repair with bovine pericardium resulted in reinfection with the same organism despite prolonged antibiotic therapy after 6 months. Removal of the pericardial tissue with direct suture closure of the ventricles and interposition of omentum led to complete healing of the infection without reoccurrence after 2 years.

Azathioprine withdrawal in stable lung and heart/lung recipients receiving cyclosporine-based immunosuppression

BACKGROUND

Chronic rejection is the leading cause of graft failure after (heart-) lung transplantation. Therefore, many centers maintain a triple immunosuppressive cyclosporine-based regimen including azathioprine (AZA) during the long-term course after lung transplantation. However, an increased risk of malignancies has been attributed to prolonged immunosuppression, and there is evidence that less intensive immunosuppressive regimens are feasible in the long-term course after other solid organ transplantation. Therefore, we investigated the effects of AZA withdrawal in stable lung transplant recipients.

METHODS

A prospective study was performed to assess the effects of AZA withdrawal in patients who received a lung transplant more than 4 years ago with stable graft function defined by absence of rejection episodes for at least 2 years and no evidence of bronchiolitis obliterans.

RESULTS

A total of 24 patients qualified for the study and 7 discontinued AZA. Despite the small number of patients, termination of the study became necessary after 12 months because significantly more grafts showed deteriorating function after withdrawing AZA (4 of 7) compared to recipients continuing a triple therapy (1 of 17; P<0.05). In recipients with deteriorating graft function conventional treatment with high-dose corticosteroids and reinstitution of AZA failed to stop the development of obliterative bronchiolitis.

CONCLUSIONS

Our data reinforce the importance of a potent immunosuppressive regimen for the maintenance of stable graft function after lung transplantation.

Long-term treatment of primary pulmonary hypertension with aerosolized iloprost, a prostacyclin analogue

BACKGROUND

Continuous intravenous infusion of epoprostenol (prostacyclin) is an effective treatment for primary pulmonary hypertension. This approach requires the insertion of a permanent central venous catheter, with the associated risk of serious complications. Recently, aerosolized iloprost, a stable prostacyclin analogue, has been introduced as an alternative therapy for severe pulmonary hypertension.

METHODS

We evaluated the effects of aerosolized iloprost on exercise capacity and hemodynamic variables over a one-year period in patients with primary pulmonary hypertension.

RESULTS

Twenty-four patients with primary pulmonary hypertension received aerosolized iloprost at a daily dose of 100 or 150 microg for at least one year. The mean (+/-SD) distance covered in the six-minute walk test increased from 278+/-96 m at base line to 363+/-135 m after 12 months (P<0.001). During the same period, the mean pulmonary arterial pressure before the inhalation of iloprost declined from 59+/-10 mm Hg to 52+/-15 mm Hg (P=0.006), cardiac output increased from 3.8+/-1.4 liters per minute to 4.4+/-1.3 liters per minute (P=0.02), and pulmonary vascular resistance declined from 1205+/-467 dyn x sec x cm(-5) to 925+/-469 dyn x sec x cm(-5) (P<0.001). The treatment was generally well tolerated, except for mild coughing, minor headache, and jaw pain in some patients.

CONCLUSIONS

Long-term treatment with aerosolized iloprost is safe and has sustained effects on exercise capacity and pulmonary hemodynamics in patients with primary pulmonary hypertension.