Comparison of Pharmacokinetics and Vasodilatory Effect of Nebulized and Infused Iloprost in Experimental Pulmonary Hypertension: Rapid Tolerance Development

Aerosolized iloprost has been suggested for selective pulmonary vasodilatation in severe pulmonary hypertension, but its pharmacokinetic profile is largely unknown. In perfused rabbit lungs, continuous infusion of the thromboxane mimetic U46619 was employed for establishing stable pulmonary hypertension. Delivery of a total amount of 75, 300, and 900 ng of iloprost to the bronchoalveolar space by a 10 min-aerosolization maneuver caused a dose-dependent pulmonary vasodilatation. Similarly, dose-dependent appearance of iloprost in the recirculating perfusate was noted, with maximum intravascular concentrations of iloprost ranging at 140, 510, and 1163 pg/mL at the same time period. Comparing pharmacokinetics and pharmacodynamics in a more detailed fashion, the following aspects were of interest. (i) The bioavailability (i.e., the percentage of aerosolized iloprost appearing intravascularly) decreased from 76% at the lowest to 33% at the highest iloprost dosage. (ii) The pulmonary vasodilatory response commenced already during the nebulization maneuver and preceded the perfusate entry of iloprost. (iii) After 3-3.5 h, the pulmonary vasodilatory response to aerosolized iloprost had virtually completely leveled off, whereas approximately two-thirds of the maximum iloprost perfusate levels were still detectable. A corresponding loss of vasodilatory response was also noted in experiments with continuous iloprost perfusion for clamping of the intravascular concentration of this prostanoid. We conclude that aerosolized iloprost causes dose-dependent vasodilatation and iloprost entry into the vascular space in a pulmonary hypertension model. Limited bioavailability in the higher dose range may suggest active prostanoid transport processes, and the early pulmonary vasodilatory response appears to be independent of prostanoid entry into the vessel lumen. Surprisingly, rapid tolerance development to the vasodilatory effect of iloprost is noted, occurring even with fully maintained perfusate levels of this agent.

Effect of iloprost on plasma asymmetric dimethylarginine and plasma and platelet serotonin in patients with peripheral arterial occlusive disease

BACKGROUND

Iloprost, a prostacyclin analogue, is used in the treatment of peripheral arterial occlusive disease at Leriche-Fontaine stages III-IV, through intravenous infusion for at least 21 days. Recently, iloprost has been shown to be safe and effective in critical limb ischemia patients when administered per 7 days. We investigated in patients at Leriche-Fontaine stages III-IV the effect of 1-week treatment with iloprost on plasma asymmetric dimethylarginine (ADMA), plasma and platelet serotonin, and on clinical response.

METHODS AND RESULTS

Twenty-four critical limb ischemia patients (16 men and 8 women, mean age 76+/-9.7 years) were included in the study and treated with intravenous iloprost (titrated from 0.5 up to 1.5 ng/kg/min) for 16 h a day for seven consecutive days. Blood samples were drawn before infusion on days 1, 4 and 8 of treatment, under the same conditions. Clinical assessment was performed by clinical evaluation, ankle/brachial pressure index and treadmill exercise test. During treatment with iloprost patients clinically improved and plasma levels of ADMA significantly decreased (p<0.001). We also observed a significant increase of serotonin (p<0.01) in platelets and a significant decrease of serotonin (p<0.001) in plasma. Similar variations of ADMA and serotonin were found in two subgroups of patients, diabetics and non-diabetics.

CONCLUSIONS

One-week treatment with iloprost in critical limb ischemia patients induced changes of peripheral markers of endothelial dysfunction and atherosclerosis, such as ADMA and serotonin, associated to a clinical improvement.

Effects of nebulised iloprost on pulmonary function and gas exchange in severe pulmonary hypertension

Nebulised iloprost is established therapy of severe pulmonary hypertension; however, the effects on the bronchoalveolar compartment have not been investigated so far. We studied the short- and long-term effects of nebulised iloprost on pulmonary function tests and gas exchange in 63 patients with severe pulmonary hypertension (idiopathic n=17, chronic thromboembolism n=15, connective tissue disease n=12, congenital heart disease n=11, respiratory diseases n=8). Patients received iloprost in increasing dose up to 140 micro g iloprost/24h via an ultrasonic nebuliser. Short-term effects were assessed before and after every nebulisation: peak expiration flow decreased in mean by 1.9% (423+/-98 to 415+/-98) and percutaneous oxygen saturation increased in mean by 0.7% (90+/-6 to 91+/-5) post-nebulisation. There were no significant differences concerning underlying diagnosis or dose of nebulised iloprost. Within 3 months, 9 patients stopped treatment due to non-compliance with frequent nebulisations (n=3), or severe side effects (n=4); 2 patients with additional obstructive lung disease developed bronchoconstriction. Long-term effects were assessed by pulmonary function tests and gas exchange parameters at baseline and after 3 months treatment. There were no significant differences after 3 months therapy neither in FEV(1), FVC, TLC, residual volume nor in diffusions capacity, SO(2) at rest and during 6 min walking test, also in respect of the underlying diseases. However, there was a significant increase in 6 min walking distance (6 MWD) after 3 months (246+/-113 to 294+/-115 m, P<0.05). In conclusion, treatment with nebulised iloprost leads to functional improvement in severe pulmonary hypertension without systematic adverse short- and long-term effects on pulmonary function test or gas exchange. Patients with additional obstructive lung disease might develop bronchoconstriction. Severe side effects leading to discontinuation of treatment occurred in 9% of patients.

Iloprost inhalation solution for the treatment of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a condition that is characterised by increased pulmonary arterial pressure and vascular resistance that can lead to right ventricular failure and death. A variety of disturbances in pulmonary vascular endothelial and smooth muscle function are present in PAH, including reduced production of vasodilator and antiproliferative substances, such as nitric oxide and prostacyclin, and an overproduction of mitogens, such as endothelin. As a result of these observations, therapies have been developed for PAH that specifically target these pathogenic processes, including prostacyclin analogues and endothelin receptor antagonists. This article reviews iloprost inhalation solution, the most recently approved form of prostacyclin therapy that is delivered directly to the lungs by inhalation.

A randomized trial of intravenous iloprost (a stable prostacyclin analogue) versus lumbar sympathectomy in the management of Buerger's disease

AIM

The aim of this study was to compare the effects of iloprost and lumbar sympathectomy (LS) in the treatment of Buerger's disease.

METHODS

Two hundred patients with rest pain and/or ischemic ulcers were randomized to undergo LS or 28-day intravenous treatment of iloprost. The primary endpoint was complete healing without pain or major amputation at 4 and 24 weeks. The secondary endpoints were analgesic requirement, reduction in the ulcer size, 50% reduction of the ulcer, and shift in the modified SVS/ISCVS clinical status grading scale.

RESULTS

The comparison was carried out in 162 patients (iloprost: n=84; LS: n=78). Complete healing rate was 61.9% in the iloprost group, but 41% in the LS group at the 4th week (P=0.012); respective values for the 24th week were 85.3%, 52.3%, P<0.001. Analgesic requirement was lower in the iloprost group at the 4th and 24th weeks (P=0.01, and P=0.098, respectively). The size of the ulcers decreased more in the iloprost group than the LS group (P=0.044 and P=0.035 at 4th and 24th weeks); 50% reduction in the ulcer size in the iloprost group was greater than in the LS group (P=0.001 and P=0.009 at 4th and 24th weeks). SVS/ISCVS grading scale demonstrated a better clinical benefit in patients treated with iloprost (P<0.001 at 4th week, and P<0.001 and at 24th week).

CONCLUSIONS

The results of this independent study indicate that using iloprost relieves ischemic symptoms better than LS. In the era of stable prostacyclin analogues, there is no reliable evidence to support the use of LS in Buerger's disease.

[Medical therapy in critical lower limb ischemia when immediate revascularization is not feasible]

Revascularization by either bypass surgery or endovascular recanalization is considered the first-choice treatment in patients with critical limb ischemia (CLI). Only conservative options are left in CLI patients in whom successful revascularization strategies are not possible: in these patients, at present, prostanoids (iloprost and prostaglandin [PGE1]) represent the pharmacological treatment of choice. Iloprost resulted more effective than PGE1, in a 6 month follow-up, in both limb savage and in prevention of cardiovascolar death, either in diabetic or non diabetic patients with unreconstructable CLI. In our experience, in patients who have responded to a first cycle of therapy (early responders), performed for at least 2-3 weeks, cyclic annual further treatments with iloprost are usually able to stabilize arterial disease, with a regression to Fontaine II stage and, in absence of further arterial complications, with complete limb preservation for an unlimited period of time. In non-responder patients, who are not urgently supposed to undergo amputation, a second cycle of iloprost carried out within few months from the first one, is able to increase the percentage of responders to prostanoids (late responders). Vice versa, in non-responders to repeat prostanoid cycles, it is useful to verify the outcomes of further attempts at saving, the symptomatic limb by surgical or endovascular re-timing, spinal cord stimulation, gene or stem cell therapy. Our recent better outcomes are related to earlier microvascular diagnosis and to earlier, repeat, pharmacological treatments with iloprost. Transcutaneous oxygen and carbon dioxide monitoring improves the possibility of an earlier diagnosis of microvascular damages and categorizes CLI patients in responders and non-responders after prostanoid treatments.

Acute resynchronization with inhaled iloprost in a pregnant woman with idiopathic pulmonary artery hypertension

We describe the case of a pregnant woman with idiopathic pulmonary arterial hypertension, a responder in right heart catheterization, followed since the first trimester in outpatient consultations, admitted to hospital at 23 weeks gestation. She was treated with inhaled iloprost until delivery (at 34 weeks gestation) and continuous infusion of iloprost throughout the perioperative period and following days. This line of therapy has proved efficacious in previous cases. The authors present echocardiographic images that document acute changes in ventricular synchrony during inhalation of iloprost.

Parenteral therapy with lipo-ecraprost, a lipid-based formulation of a PGE1 analog, does not alter six-month outcomes in patients with critical leg ischemia

PURPOSE

Eicosanoids with vasodilating and angiogenic properties have been postulated to be effective therapies for critical leg ischemia (CLI) secondary to atherosclerotic peripheral arterial disease. The ability to deliver active drug to the site of action at adequate doses for sufficient duration has been a major limitation in the clinical development of such therapies. Lipo-ecraprost is a lipid-encapsulated prostaglandin E1 prodrug with the potential to deliver active prostaglandin to the site of critical arterial ischemia. The current trial was designed to test the hypothesis that lipo-ecraprost would improve amputation-free survival in patients with CLI who had no revascularization options.

METHODS

The study was randomized, multicenter, double blind, and placebo controlled. Patients who met clinical and hemodynamic criteria were randomized to receive placebo or lipo-ecraprost (60 microg) administered intravenously on each of 5 days per week, for a total of 8 weeks. The study's primary endpoint was the rate of a composite end point of death or amputation above the level of the ankle at 180 days (6 months).

RESULTS

The study was terminated on a recommendation from the Data and Safety Monitoring Board after the completion of a protocol-specified interim analysis for futility. At the time of termination, 383 of the planned 560 patients had been randomized, of which 379 received at least one dose of study medication and thus were included in the intention-to-treat population. Twenty-three patients were lost to follow-up and were not available for 6-month assessments. At 6 months of follow-up, there were 23 amputations in the 177 patients who received placebo, and 29 amputations in the 179 patients randomized to lipo-ecraprost. At 6 months, 10 deaths had occurred in the placebo group and 18 deaths had occurred in the lipo-ecraprost arm. Changes in lower-extremity hemodynamics over the 6-month study period did not differ between the placebo and lipo-ecraprost treatment arms.

CONCLUSION

Intensive treatment with lipo-ecraprost failed to modify the 6-month amputation rate in patients with CLI who were not candidates for revascularization.

Inhaled aerosolized iloprost in the evaluation of heart transplant candidates—experiences with 45 cases

PURPOSE

Pulmonary hypertension represents a significant predictor of postoperative right heart insufficiency and increased mortality in patients undergoing orthotopic heart transplantation. As the use of intravenous vasodilators is limited by their systemic effects, we evaluated the pulmonary and systemic hemodynamic effects of inhaled aerosolized iloprost in heart transplant candidates with elevated pulmonary vascular resistance.

METHODS

Forty-five male heart transplant candidates with dilated or ischemic cardiomyopathy were included in the study. After assessing baseline hemodynamics, 20 microg of aerosolized iloprost was administered by ultrasonic inhalation. All patients were breathing spontaneously.

RESULTS

Inhalation of iloprost reduced pulmonary vascular resistance index (395 +/- 205 vs 327 +/- 222 dyne.s.cm(-5).m(-2); P < 0.05) and mean pulmonary arterial pressure (28.7 +/- 10 vs 24.3 +/- 10 mm Hg; P < 0.05). An additional improvement of ventricular performance with an increase of cardiac index (2.7 +/- 0.7 vs 3.0 +/- 0.8 L.min(-1).m(-2); P < 0.05) and a decrease of pulmonary capillary wedge pressure (16.6 +/- 7.7 vs 13.4 +/- 7.3 mm Hg; P < 0.05) was accompanied by a slight decrease of systemic vascular resistance (1280 +/- 396 vs 1172 +/- 380 dyne.s.cm(-5); P < 0.05). However, the mean arterial pressure remained uninfluenced.

CONCLUSIONS

Inhaled aerosolized iloprost effectively reduces mean pulmonary arterial pressure and also induces an increase in cardiac index. Further advantages of iloprost inhalation are the lack of adverse reactions and ease of administration. Iloprost represents a useful drug to screen for vascular reactivity in cardiac transplantation patients.

Sildenafil Improves Dynamic Vascular Function in the Brain: Studies in Patients with Pulmonary Hypertension

BACKGROUND

Prostaglandins and nitric oxide play a pivotal role in the regulation of macro- and microcirculatory blood flow distribution. Interference with both mediator systems have been implicated in cerebrovascular dysfunction. Inhaled iloprost (long-acting prostacyclin analogue) and the phosphodiesterase-5 inhibitor sildenafil have recently shown efficacy in the treatment of chronic pulmonary hypertension. We investigated the impact of these agents on cerebral microcirculatory regulation in patients suffering from this disease.

METHODS

In 11 patients suffering from severe pulmonary hypertension, a functional transcranial Doppler test utilizing a visual stimulation paradigm was undertaken to measure the evoked flow velocity in the posterior cerebral artery. Measurements were performed in parallel to right heart catheterization and pharmacological testing of the pulmonary vasoreactivity. After assessment of baseline measurements, inhaled iloprost and oral sildenafil were given consecutively for testing of cerebral and pulmonary vascular function. The data gained from the Doppler measurements were compared to data from 22 healthy volunteers.

RESULTS

Both substances provoked a significant reduction of pulmonary arterial pressure and vascular resistance, accompanied by minor changes in systemic vascular resistance. In contrast to these superimposable hemodynamic profiles opposite effects were observed regarding cerebral vascular tone: cerebral microvascular reactivity, as assessed by attenuation and time rate parameters, was significantly improved by sildenafil, but slightly worsened by iloprost.

CONCLUSIONS

Sildenafil has beneficial effects on cerebral vascular reactivity indicative of an improvement in neurovascular coupling in patients with pulmonary hypertension. These results warrant further investigations of the influence of sildenafil on dynamic vascular function in the brain independent of the underlying disease.

Successful switch from long-term intravenous iloprost to non-invasive combination therapy in idiopathic pulmonary arterial hypertension

In Europe intravenous (IV) iloprost, an alternative to epoprostenol, is an accepted treatment option for severely compromised patients with idiopathic pulmonary arterial hypertension (IPAH). Once initiated, this therapy usually has to be continued lifelong or as bridging to transplantation. In our paper we describe two patients with IPAH in World Health Organisation (WHO) functional classes II and III while on treatment with continuous IV iloprost monotherapy or combination therapy with continuous IV iloprost plus oral bosentan, respectively. The duration of IV iloprost therapy was 4.5 and 2.5 years, respectively. Because of life-threatening or recurring catheter-related complications during long-term IV iloprost therapy, these patients were switched to non-invasive combination therapy consisting of oral bosentan plus aerosolized iloprost (patient 1) and oral bosentan plus aerosolized iloprost plus oral sildenafil (patient 2), respectively. After four weeks of additional bosentan therapy, stepwise reduction and discontinuation of IV iloprost were performed within eight hours in the patient in WHO class II, and within five days in the patient in WHO class III. Simultaneously, therapy with aerosolized iloprost was started in the first patient and with aerosolized iloprost plus sildenafil in the second patient. Both patients were safely switched from IV iloprost to non-invasive combination therapy while WHO classification of functional status remained unchanged for at least 12 and 14 months, respectively. These data suggest that selected patients with complications due to IV iloprost treatment can be safely switched to non-IV combination therapies.

[Severe refractory pulmonary hypertension after liver transplantation for hepatitis C liver cirrhosis]

BACKGROUND

We report the case of a 43-year-old male with liver cirrhosis based on a chronically active hepatitis C.

CASE REPORT

Before liver transplantation right-ventricular pressure values of 36 mmHg (+ central venous pressure) were measured whereas, after transplantation, he developed severe pulmonary hypertension with pressure values up to 90 mmHg. These elevated pressure values correlated inversely with graft function. Given the diagnosis of portopulmonary hypertension, we initiated treatment with intravenous epoprostenol and inhalative iloprost but both treatments were not tolerated because of systemic side effects. A combined heart-lung transplantation was considered but the patient died from insufficient cardiac function.

CONCLUSIONS

The case report discusses the present diagnostic and therapeutic state of the art in portopulmonary hypertension and reveals basic problems of the present screening strategy.

Evaluation of finger skin temperature in scleroderma patients cyclically treated with iloprost

OBJECTIVES

To evaluate by computerized digital thermometry (CDT) the effect of cyclic iloprost infusions on finger skin temperature (FST) in scleroderma patients.

METHODS

Twenty-two scleroderma outpatients (one man, 21 women, mean age 54.2 years) underwent three computerized digital thermometries, the first one 3 days before a 5-day cycle of iloprost infusion, the second the day of the fifth infusion soon after the end of the therapy and the third 1 month after. FST was evaluated under basal conditions, immediately after a cold test and after an 18 min recovery period. For comparison CDT was performed in 10 sex and age matched control subjects.

RESULTS

FST was lower in scleroderma patients before iloprost infusion than in the control group either after cold test either at the end of the recovery period while no difference was found before the cold test. Soon after iloprost infusion and 1 month later the FST at the end of the recovery period increased from the pre-treatment value of 27.8 +/- 5.3 to 30.4 +/- 3.5 degrees C and to 30.0 +/- 4.5 degrees C, respectively (P < 0.05 for both values). No substantial differences were found concerning FST before and at the end of the cold test.

CONCLUSION

Iloprost administration for 5 days allows to normalize the FST value after cold exposition not only immediately after the infusions but even at 1 month distance from the therapy. Despite its short half-life the effect of the drug on endothelium is protracted.

Inhaled iloprost as a long-term additional therapy to oral sildenafil in severe idiopathic pulmonary arterial hypertension

Idiopathic pulmonary arterial hypertension (IPAH) is an uncommon and devastating disease which, if untreated, progresses rapidly and leads to right heart failure and death. The course of the disease has been altered by advances in medical therapies. However, the effects of long-term alternative therapies and responses to each treatment protocols are not definite. We want to define an IPAH case, which had long-term temporary responses to the conventional therapy plus calcium channel blockers treatment and moreover compared the long-term clinical and physiologic effects of oral sildenafil mono therapy and additional inhaled iloprost therapy. Patients with IPAH may have response to a short-term vasodilatation therapy but they have to follow for the long-term results and may be of benefit from combination treatments.

Inhaled iloprost to control residual pulmonary hypertension following pulmonary endarterectomy

OBJECTIVE

Pulmonary endarterectomy (PEA) is the standard therapy for patients with chronic thromboembolic pulmonary hypertension (CTEPH). In the immediate postoperative period, persistent pulmonary hypertension increases the risk of acute respiratory or right heart failure. In pulmonary arterial hypertension, prostanoid inhalation has been found to improve pulmonary hemodynamics, right ventricular function, gas exchange, and clinical outcome. We report the results of a double-blinded randomized trial with the aerosolized prostacyclin analogue iloprost in patients with residual pulmonary hypertension after PEA.

METHODS

Twenty-two patients (age, 55+/-13 years; 8 females; propofol- and sufentanil-based anesthesia; pressure-controlled mechanical ventilation) were randomized to receive either a single dose of 25 microg aerosolized iloprost (iloprost group; n=11) or normal saline (placebo group; n=11) immediately after postoperative ICU admission. Primary endpoints were changes in gas exchange, pulmonary and systemic hemodynamics, and clinical outcome.

RESULTS

Iloprost significantly enhanced cardiac index (CI) and reduced mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance [PVR (dynscm(-5))] in contrast to placebo. Placebo: pre-inhalation 413+/-195 versus post-inhalation 404+/-196 at 30 min (p=0.051), 415+/-189 at 90 min (p=0.929). Iloprost: pre-inhalation 503+/-238 versus post-inhalation 328+/-215 at 30 min (p=0.001), 353+/-156 at 90 min (p=0.003). Blood oxygenation remained unchanged.

CONCLUSION

In addition to the effect of PEA, iloprost reduces residual postoperative pulmonary hypertension, decreases right ventricular afterload and may facilitate the early postoperative management after PEA.

[Portopulmonary hypertension]

Patients with portal hypertension may develop pulmonary complications such as hepatopulmonary syndrome (HPS) or portopulmonary hypertension (PPHT). PPHT is defined as elevated pulmonary pressure, elevated pulmonary vascular resistance, a normal pulmonary capillary wedge pressure, and portal hypertension in the absence of other known causes pulmonary hypertension. Various factors such as hyperdynamic circulation, volume overload, and circulating vasoactive mediators are suspected to be involved in the pathogenesis of PPHT. The prognosis of patients with severe PPHT is significantly reduced due to the risk of right heart failure. In patients with moderate to severe PPHT liver transplantation is associated with a significantly increased mortality. The chief symptom of PPHT may be dyspnoe in the presence of typical histomorphological alterations comparable with idiopathic pulmonary hypertension. Continuous intravenous application of prostacyclin is currently regarded as the treatment of choice for patients with severe PPHT. Inhaled prostacyclin or its analogue iloprost or oral treatment with the endothelin-receptor antagonist bosentan may be promising alternatives which should be further investigated in randomized controlled trials.

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.

Use of Long-Term Combined Therapy With Inhaled Iloprost and Oral Sildenafil in an Adult Patient With Eisenmenger Syndrome

Eisenmenger syndrome is characterized by elevated pulmonary vascular resistance and right-to-left shunting of blood through a systemic to pulmonary circulation connection. Treatment requires either lung transplantation with intracardiac repair or heart-lung transplantation. There are inadequate data regarding treatment alternatives when the patient is not a candidate for surgery. In this article, we report on the case of a 68-year-old woman with Eisenmenger syndrome related to congenital heart disease who was treated with inhaled iloprost and oral sildenafil for 2 years.

Combination therapy of prostacyclin for pulmonary hypertension in congenital heart disease

BACKGROUND

Pulmonary arterial hypertension (PAH) is a recognized complication of congenital heart disease. Despite differences in etiology and pathophysiology, successful therapy for idiopathic PAH may benefit in patients with congenital heart disease. We theorized that combination of oral and aerosolization prostacyclin will benefit this group of patients in long-term.

MATERIAL AND METHOD

The study design was single group and open label study with intention to treat for patients with congenital heart disease with pulmonary artery (PA pressure) more than 50% of systemic pressure. All patients were given a combination of orally given beraprost sodium and inhalation of iloprost for 12 months. Data were collected prospectively consisting of functional class, O2 saturation, 6-minute walk test and right ventricular systolic pressure (RVSP).

RESULTS

There were 23 patients with an average right ventricular systolic pressure (+/- SD) of 94.8 +/- 14.5 mmHg and with average age of 27.8 +/- 14.9 years (2.5 to 50 years). The average oxygen saturation was 87.9 +/- 7 %. There were 12 patients with post surgical repair or cardiac catheterization interventional procedure and 11 with and Eisenmenger's syndrome. There were significant improvement of 6-minute-walk test from an average of 268 +/- 70 meters to 308 +/- 57 meters at the end of 12 months. The functional class of patients was also improving. However, there were no significant different in oxygen saturation.

CONCLUSION

Combination therapy of oral and inhalation of aerosolized vasodilators is a fascinating concept in the therapy of pulmonary hypertension. Treated patients showed an improvement in exercise capacity and right ventricular systolic pressure without a worsening in oxygen saturation.

Inhalative Pre-Treatment of Donor Lungs Using the Aerosolized Prostacyclin Analog Iloprost Ameliorates Reperfusion Injury

BACKGROUND

Lung transplantation is effective for end-stage pulmonary disease, but its successful application is still limited by organ shortage and sub-optimal preservation techniques. Therefore, optimal allograft protection is essential to reduce organ dysfunction, especially in the early post-operative period. Intravenous prostanoids are routinely used to ameliorate reperfusion injury. However, the latest evidence suggests similar efficacy using inhaled prostacyclin. Thus, we evaluated the impact of donor pre-treatment using the prostacyclin analog, iloprost, on post-ischemic function of Perfadex-protected allografts.

METHODS

In Group 1, 5 pig lungs were preserved with Perfadex (PER group) solution and stored for 27 hours. In Group 2, 100 microg of iloprost was aerosolized over 30 minutes using a novel mobile ultrasonic nebulizer (Optineb) before identical organ harvest (PER-ILO group). After left lung transplantation and contralateral lung exclusion, hemodynamic variables, Po2/Fio2 and dynamic compliance were monitored for 6 hours and compared with sham-operated controls. Pulmonary edema was determined stereologically and by wet-to-dry (W/D) weight ratio. Statistical assessment included analysis of variance (ANOVA) with repeated measures.

RESULTS

Dynamic compliance and pulmonary vascular resistance (PVR) were superior in iloprost-treated compared with untreated organs (p < 0.05), whereas oxygenation was comparable between groups. W/D ratio revealed a significantly smaller amount of lung water in PER-ILO organs (p = 0.048), whereas stereologic data showed a trend toward less intra-alveolar edema.

CONCLUSIONS

Endobronchial application of iloprost in donor lungs before Perfadex preservation decreases post-ischemic edema and significantly improves lung compliance and vascular resistance. This innovative approach is easily applicable in the clinical setting and offers a new strategy for improvement of pulmonary allograft preservation.

[Treatment of therapy-resistant acral ulcers with iloprost]

Patients with systemic sclerosis (SSc) develop often acral ulcers which are resistant to therapy and may result in gangrene and amputation. We investigated the effects of iloprost infusion on the acral ulcers and necrosis in patients with five patients with SSc and one with mixed connective tissue disease who had been previously treated with various modalities without improvement. All patients had Raynaud phenomenon, acral ulcers and necrosis. Iloprost 25 microg per day was administered intravenously daily over six hours for ten consecutive days. Eight weeks later all patients were treated with a second iloprost therapy cycle for five days. Two patients with severe ulceration received a third cycle until remission occurred. In all cases acral ulcers healed completely and no patient relapsed during an observation period of 6 months.

Effect of prostaglandin I2 analogues on left ventricular diastolic function in vivo

The prostaglandin I2 analogues epoprostenol and iloprost increase left ventricular contractility. Therefore, we hypothesize that the prostaglandin I2 analogues epoprostenol and iloprost improve also left ventricular diastolic function. To test this hypothesis, the effects of epoprostenol and iloprost on left ventricular diastolic function were assessed in vivo and compared to two vasodilators sodium nitroprusside and adenosine, not formerly associated with changes of left ventricular contractility. Eleven pigs (25.9+/-2.8 kg, balanced anaesthesia) were exposed to the short-acting intravenous vasodilators sodium nitroprusside, adenosine and epoprostenol in a randomized cross over design. The long-acting iloprost was administered at the end of the protocol. The drugs are titrated to achieve a 25% reduction of diastolic aortic pressure. Active isovolumic relaxation properties of the left ventricle were assessed by the maximum velocity of left ventricular pressure drop. Passive phase of relaxation and filling was assessed by the determination of end diastolic compliance during a preload reduction manoeuvre. The maximum velocity of left ventricular pressure drop worsened during the infusion of sodium nitroprusside (baseline: -1950; sodium nitroprusside: -1293 mm Hg/s, p<0.05, Wilcoxon signed rank test versus vs. baseline) and adenosine (baseline: -2015; adenosine: -1345 mm Hg/s, p<0.05), but remained stable during the infusion of the prostaglandins (baseline: -1943; epoprostenol: -1785 mm Hg/s; baseline: -2042; iloprost: -1923 mm Hg/s). End diastolic compliance was not altered significantly by any vasodilator. Interstitial myocardial cAMP increased during the infusion of epoprostenol (7.60 to 13.87 fmol/ml, p<0.05) and tended to increase during the infusion of iloprost (7.56 to 11.66 fmol/ml, p=0.21). The prostaglandin I(2) analogues epoprostenol and iloprost preserved the early phase of active isovolumic relaxation, presumably mediated by myocardial cAMP, whereas sodium nitroprusside and adenosine impaired early active isovolumic relaxation. Passive relaxation and filling properties remained stable during the infusion of each applied vasodilator in the intact left ventricle in vivo.