Triple vasodilator therapy in pulmonary arterial hypertension associated with congenital heart disease

OBJECTIVE

This study assessed the long-term effects of triple therapy with prostanoids on patients with pulmonary arterial hypertension associated with congenital heart disease (PAH-CHD), as there is limited information on the safety and efficacy of this treatment approach.

METHODS

A retrospective cohort study was conducted on patients with PAH-CHD who were actively followed up at our centre. All patients were already receiving dual combination therapy at maximum doses. Clinical characteristics, including functional class (FC), 6-minute walking test distance (6MWTD) and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, were documented before initiating triple therapy and annually for a 2-year follow-up period.

RESULTS

A total of 60 patients were included in the study, with a median age of 41 years and 68% being women. Of these, 32 had Eisenmenger syndrome, 9 had coincidental shunts, 18 had postoperative PAH and 1 had a significant left-to-right shunt. After 1 year of triple combination initiation, a significant improvement in 6MWTD was observed (406 vs 450; p=0.0027), which was maintained at the 2-year follow-up. FC improved in 79% of patients at 1 year and remained stable in 76% at 2 years. NT-proBNP levels decreased significantly by 2 years, with an average reduction of 199 ng/L. Side effects were experienced by 33.3% of patients but were mostly mild and manageable. Subgroup analysis showed greater benefits in patients without Eisenmenger syndrome and those with pre-tricuspid defects.

CONCLUSIONS

Triple therapy with prostanoids is safe and effective for patients with PAH-CHD, improving FC, 6MWTD and NT-proBNP levels over 2 years. The treatment is particularly beneficial for patients with pre-tricuspid defects and non-Eisenmenger PAH-CHD.

Impact of current targeted drug therapy on the prognosis of Eisenmenger syndrome: A large-scale retrospective analysis

BACKGROUND

Data regarding the prognosis of Eisenmenger syndrome (ES) and effect of targeted drugs are limited. This study aimed to analyze the prognosis and impact of targeted drug therapy on the survival rate of patients with ES in the Chinese population.

METHODS

The data of patients with ES referred to our hospital between January 2010 and December 2020 were retrospectively analyzed. Data included baseline demographics, echocardiographic parameters, and clinical diagnoses. All patients were followed up via telephone interviews in February 2022. The primary endpoint was mortality.

RESULTS

Overall, 1,021 patients with ES were included. The 1-, 3-, 5-, 7-, 10-, and 12-year survival rates were 91.6%, 84.2%, 80.7%, 73.8%, 71.4%, and 69.9%, respectively. Patients with atrial septal defects had the best prognosis than those with ventricular septal defects, patent ductus arteriosus, and complex congenital heart disease (CHD) (P < 0.0001). Patients who visited between 2016 and 2020 received increased targeted drug therapy and had a better prognosis than those who visited between 2010 and 2015 (all P < 0.05). Cox regression analysis revealed age, pulmonary arterial systolic pressure, post-tricuspid shunt CHD, targeted drugs, and year of the first hospital visit to be predictors of death (P < 0.05).

CONCLUSIONS

Survival rates associated with an increased use of combined targeted drugs significantly improved in patients with ES. However, numerous factors that predict increased mortality remain to be elucidated.

What is the position of pulmonary arterial hypertension-specific drug therapy in patients with Eisenmenger syndrome: A systematic review and meta-analysis

BACKGROUND

It is commonly reported a limitation of therapeutic strategy in Eisenmenger syndrome (ES) historically. This qualitative systematic review is conducted to evaluate the safety and efficacy of pulmonary arterial hypertension-specific drug therapy (PAH-SDT) for ES patients for a clinical therapeutic strategy based on evidence.

METHODS

PubMed, EMBASE, and the Cochrane Library databases have been systematically reviewed up to January 2019. Two reviewers independently conducted a literature search, quality evaluation, and data extraction. The occurrence of death, deterioration, and adverse events (AEs) has respectively been described as a count or percentage. Meta-analysis was conducted by Stata 15.1, and weighted mean differences (WMD) with 95% confidence intervals (CI) were recorded for continuous data. Randomized-effect model or fixed-effect model was applied according to the heterogeneity test.

RESULTS

Fifteen citations recruiting 456 patients associated with ES were eventually pooled, which involved 4 RCTs, 6 prospective studies, and 5 retrospective studies. Within the first year, it indicated PAH-SDT significantly ameliorated exercise capacity in 6-minute walk distance (6MWD) (I = 60.5%; WMD: 53.86 m, 95% CI [36.59, 71.13], P < .001), functional class (FC) (WMD = -0.71, 95% CI [-0.98, -0.44], P < .001) and Borg dyspnea index (WMD = -1.28, 95% CI [-1.86, -0.70], P < .001), in addition to hemodynamics, especially mean pulmonary arterial pressure by 5.70 mmHg (WMD = -5.70 mmHg, 95% CI [-8.19, -3.22], P < .001) and pulmonary vascular resistance by 4.20 wood U (WMD: -4.20, 95% CI [-7.32, -1.09], P = .008), but unsatisfactory effects in oxygen saturation at exercise (P = .747). In a prolonged medication, bosentan, a dual ERA, has been proved acting an important role in improving exercise tolerance of patients with ES (6MWD: I = 47.5%; WMD: 88.68 m, 95% CI [54.05, 123.3], P < .001; FC: I = 0.0%; WMD = -0.65, 95% CI [-1.10, -0.19], P = .006). While a nonsignificant change of 6MWD was noted in a long-term therapy of ambrisentan (P = .385). There existed rare evidence about the efficacy and safety of macitentan, phosphodiesterase-5 inhibitors (PDE5i), and prostanoids in a prolonged medication. Most AEs were recorded as mild to moderate with PAH-SDT, but about 4.3% individuals treated with endothelin receptor antagonists (ERAs) suffered from serious ones, and 3.9% suffered from death.

CONCLUSIONS

This systematic review and meta-analysis proved PAH-SDT as a safe and effective role in ES in an early stage. However, in a long-term treatment, bosentan has been supported for a lasting effect on exercise tolerance. A further multicenter research with a large sample about pharmacotherapy of ES is necessary.

The Effect of Endothelin Receptor Antagonists in Patients with Eisenmenger Syndrome: A Systematic Review

INTRODUCTION

The efficacy of endothelin receptor antagonists (ERAs) in the management of Eisenmenger syndrome (ES) remains controversial. The aim of this study is to systemically review the safety and effects of ERAs in improving the quality of life and basic cardiac functions of these patients.

METHODS

Twelve databases were searched, including PubMed, Web of Science, Scopus, Virtual Health Library, World Health Organization (WHO) Global Health Library, Google Scholar, POPLINE, Systems for Information of Grey Literature in Europe, New York Academy of Medicine, ClinicalTrials.gov, metaRegister of Controlled Trials and the WHO International Clinical Trials Registry Platform, through August 2016. We included randomized clinical trials addressing the effect of ERAs on cardiac functions in patients with ES. The quality of studies was assessed using the Cochrane Collaboration tool.

RESULTS

We included two trials represented by four papers, of which three papers reported the efficacy of bosentan against placebo and one paper reported the results of a combination of bosentan and sildenafil versus placebo and bosentan. One trial showed a significant effect of bosentan treatment over placebo on indexed pulmonary vascular resistance and mean pulmonary artery pressure, but a non-significant increase in 6-min walk distance and a non-significant effect on systemic pulse oximetry. The other trial reported the safe but non-significant effect of combination therapy of bosentan and sildenafil compared with bosentan and placebo.

CONCLUSIONS

This study demonstrated safety and improved hemodynamic effects of bosentan in ES, with a controversial effect on exercise capacity. Further randomized controlled trials with longer follow-up duration are needed to confirm these results.

Familial clustering of congenital deafness, patent ductus arteriosus, Eisenmenger complex, and differential cyanosis: A case report

RATIONALE

Few studies had reported syndromes that include patent ductus arteriosus (PDA) with Eisenmenger syndrome and congenital deafness clustered in male siblings without facial, skeletal, or mental abnormalities.

PATIENT CONCERNS

Two brothers, who were deaf and had PDA with Eisenmenger complex, were first seen at our Cardiology clinic at the ages of 25 and 41, respectively. They presented with progressive dyspnea on exertion. Upon physical examination, both brothers had clubbing and/or cyanotic toes, normal fingers, and without facial, skeletal, ophthalmological, or mental abnormalities.

DIAGNOSES AND INTERVENTIONS

Echocardiography and multidetector computed tomography revealed large PDAs in both brothers. Cardiac catheterization showed bidirectional shunting via the PDA.

OUTCOMES AND LESSONS

Familial clustering of Eisenmenger PDA and congenital deafness is rare. Further studies are warranted to define possible genetic links.

Long-term Behavior of Endothelial and Coagulation Markers in Eisenmenger Syndrome

The long-term behavior of endothelial markers was studied in patients with Eisenmenger syndrome who were subjected to conventional therapy (no vasodilators) and observed for 18 months. Biochemical markers were analyzed comparatively in patients with class II or III symptoms (group 1, n=10) and patients with class IV symptoms (group 2, n=7). Plasma von Willebrand factor antigen (vWF: Ag), thrombomodulin, tissue-type plasminogen activator (t-PA) and its inhibitor (PAI-1), and D-dimer were determined by immunoenzymatic assay at baseline, and at 6, 12, and 18 months. At baseline, the main clinical difference between groups was a decreased peripheral oxygen saturation in group 2 versus group 1 (77±5% and 86±4%, respectively, p=0.001). Basal vWF: Ag and t-PA were increased and thrombomodulin was decreased in both groups in comparison with controls (p<0.0001), while D-dimer was increased in group 2 only (p=0.0003). In response to treatment, there was a decrease in vWF: Ag in both groups (19% and 23%, respectively in groups 1 and 2, at 18 months vs. baseline, p<0.0001) and t-PA in group 1 (38% vs. baseline, p=0.0485). Plasma vWF: Ag tended to be higher in group 2 in comparison with group 1 during the whole follow-up. Levels of PAI-1 greater than 38.4 ng/mL (upper 90% limit for normals) and D-dimer greater than 500 ng/mL were detected in individual patients (both groups) during the follow-up period. Thrombomodulin remained decreased in both groups. Thus, severity of symptoms in the Eisenmenger syndrome appears to correlate with low oxygen saturation and higher vWF: Ag levels. Improvement of endothelial dysfunction may occur in response to treatment, although increased risk for thrombosis persists, in view of residual abnormalities.

Eisenmenger syndrome: recent advances in pharmacotherapy

Over the last decade advanced therapies for the management of pulmonary arterial hypertension have been introduced. These agents have also been effective in reducing pulmonary vascular resistance in patients with Eisenmenger syndrome. Specific guidelines focusing on modern therapies for Eisenmenger syndrome however do not exist to date. More recently, clinical trials in patients with Eisenmenger syndrome demonstrated a significant clinical improvement with favorable safety and tolerability profile. This review aims to summarize newly reported pharmacological agents used in patients with Eisenmenger syndrome.

Amiodarone-induced thyrotoxicosis in a case of Eisenmenger's syndrome

Eisenmenger's syndrome is a condition due to any congenital heart defect with an intracardiac left-to-right communication that leads to pulmonary hypertension with reversed right-to-left blood flow and secondary cyanosis. The main complications of Eisenmenger's syndrome are heart failure and arrhythmias. Amiodarone, the drug of choice for arrhythmia treatment in such patients, can cause a number of complications, including amiodarone induced thyrotoxicosis (AIT). Hereby, we present a 41-year-old patient with Eisenmenger's syndrome who developed AIT and was successfully treated with radioactive iodine therapy. The patient had an accompanying heart failure and had been treated with amiodarone due to chronic atrial fibrillation. Twenty months later he developed an AIT for which was treated with 814 MBq (22 mCi) radioactive iodine. Since 7 weeks later only a slight decline in thyroid hormones was observed, the patient was received a transient treatment with methimazole, which had to be withdrawn soon due to severe leucopenia. Because of the need to maintain amiodarone, a second ablative radioactive iodine dose was administered leading to complete clinical remission. In conclusion, this case demonstrates that even though amiodarone reduces iodine uptake to a very low level, the therapy with radioactive iodine can be still effective if it is given in a repeated dose to patients who require continuation of amiodarone.

Changes in exercise capacity and cardiac performance in a series of patients with Eisenmenger's syndrome transitioned from selective to dual endothelin receptor antagonist

BACKGROUND

Differences in clinical effects between selective and dual endothelin (ET) receptor antagonists (ERA) in patients with pulmonary arterial hypertension (PAH) are currently unknown. We aimed to assess prospectively how transition from selective (sitaxsentan) to dual (bosentan) ERA affected exercise capacity and cardiocirculatory performance in patients with Eisenmenger's syndrome.

METHODS

A series of seven stable patients with Eisenmenger's syndrome aged 40.0 (30.0-56.0) years old treated with sitaxsentan were assessed before and three months after transition to bosentan. Six minute walk test and magnetic resonance to assess LV and RV mass, volume and ejection fraction, and pulmonary flow, and laboratory tests were performed.

RESULTS

We observed an increase in LV mass [96.5 (66.0-116.0) vs. 123.0 (93.0-146.0)g; p=0.03], LV ejection fraction [55.0 (44.0-63.0) vs. 65.0 (58.0-70.0)%; p=0.02)], and pulmonary flow [64 (53.0-71.0) vs. 69.0 (55.0-84.0)ml/beat; p=0.046]. This was accompanied by an increase of oxygen saturation, elongation of 6MWD [435.0 (378.0-482.3) vs. 474 (405.0-534.7); p=0.02], decrease of NTproBNP level and increase of ET-1 level.

CONCLUSIONS

Three month follow-up of stable patients with Eisenmenger's syndrome transitioned from sitaxsentan to bosentan revealed improvement of exercise capacity despite significant elevation of ET-1 level. Concurrent increase of LV ejection fraction and pulmonary flow might have contributed to these favourable effects.

Acute and short-term hemodynamic effects of metoprolol in Eisenmenger syndrome: a preliminary observational study

BACKGROUND

Progressive heart failure and sudden cardiac death are the common causes of death in Eisenmenger syndrome. β-Bockers may be useful in Eisenmenger syndrome, but the safety and efficacy are not proven. The objective of the study was to evaluate the hemodynamic effects and safety of metoprolol in Eisenmenger syndrome.

METHODS

Fifteen patients of Eisenmenger syndrome with a mean age of 22.6 (±8.9) years were studied. Hemodynamic parameters were measured at baseline, after 15 mg of intravenous metoprolol and 6 weeks after oral metoprolol (25 mg/d for 2 weeks and 50 mg/d for 4 weeks).

RESULTS

Intravenous metoprolol was well tolerated, although there was a significant decrease in pulmonary and systemic blood flows. The calculated pulmonary vascular resistance index (23.3 ± 8.6 to 27.4 ± 10.6 Wood U, P = .005) and systemic vascular resistance index (34.9 ± 9.9 to 41.9 ± 13.5 Wood U, P = .005) increased significantly. After 6 weeks of oral metoprolol, the pulmonary artery mean pressure declined significantly (79.9 ± 12.9 to 73.4 ± 14.0 mm Hg, P = .04), which was associated with a slight decrease in mean aortic pressures as compared with baseline. The 6-minutes walk distance increased (401.2 ± 99.9 to 462.5 ± 81.7 m, P = .005).

CONCLUSIONS

Preliminary observations suggest that metoprolol is safe and well tolerated in selected patients with Eisenmenger syndrome. Acute hemodynamic worsening recovers in the short term, and the exercise capacity improves in most patients. Larger studies are warranted.

Eisenmenger syndrome and juvenile rheumatoid arthritis--a case of double diagnosis

An 8.5-year-old girl evaluated for central cyanosis, hypoxia and normocarbia was found to have aorticopulmonary window and pulmonary hypertension. The diagnosis of Eisenmenger syndrome (ES) was made and treatment with bosentan was started. Four months later she was diagnosed to have juvenile rheumatoid arthritis and naproxen treatment was started. The case was remarkable in that she showed clinical improvement with new generation treatment of ES although pulmonary arterial pressure did not decrease significantly and the diagnosis of juvenile rheumatoid arthritis was made during follow-up.

Therapeutic methods used in patients with Eisenmenger syndrome

Patients with Eisenmenger syndrome form a small percentage of congenital heart disease patients. The rarity of this syndrome, combined with its complex pathophysiology, account for the insufficient understanding of the principles underlying its proper treatment. The main clinical symptoms are: cyanosis due to secondary erythrocytosis, resulting in increased blood viscosity, iron deficiency anemia (enhanced by unnecessary phlebotomies), blood clotting disturbances, heart failure and serious supraventricular and ventricular arrhythmias. Recent decades have seen developments in pulmonary hypertension pathophysiology which have led to the introduction of new groups of drugs: prostacycline analogs (Epoprostenol, Treprostinil, Beraprost, Illoprost), phosphodiesterase inhibitors (Sildenafil, Tadalafil), endothelin receptor antagonists (Bosentan, Sitaxantan, Ambrisentan) and nitric oxide. These drugs should be administered to patients in III-IV NYHA class. Despite successful early results, the therapeutic effect on patients with Eisenmenger syndrome has not been conclusively established. Our therapeutic efforts should be directed mainly towards preventing complications. As a rule, we should avoid agents with no established therapeutic efficacy and try to alleviate symptoms without any additional risk, so as not to disrupt the existing clinical balance.

Longer-term bosentan therapy improves functional capacity in Eisenmenger syndrome: Results of the BREATHE-5 open-label extension study

BACKGROUND

Bosentan, an oral endothelin ET(A)/ET(B) receptor antagonist, improves hemodynamics and exercise capacity in patients with Eisenmenger syndrome but longer-term effects are unknown. This study investigated the efficacy and safety of bosentan up to 40 weeks in these patients.

METHODS

Following the 16-week, double blind, placebo-controlled BREATHE-5 study of bosentan in patients with Eisenmenger syndrome, an open-label extension (OLE) was performed. Patients who completed BREATHE-5 received bosentan for an additional 24 weeks (62.5 mg b.i.d. for 4 weeks, then 125 mg b.i.d.) and were analyzed in two groups; ex-placebo and ex-bosentan, according to BREATHE-5 treatment.

RESULTS

Thirty-seven patients with Eisenmenger syndrome who participated in BREATHE-5 were included in the OLE. At week 24, the 6-minute walk distance (mean+/-SE) increased from OLE baseline for the ex-placebo (+33.2+/-23.9 m) and ex-bosentan group (+6.7+/-10.0 m). The overall improvement from baseline of BREATHE-5 was +61.3+/-8.1 m (95% confidence interval: [44.7, 78.0]) for the ex-bosentan group. WHO functional class was improved in both groups. Bosentan did not reduce systemic arterial blood oxygen saturation; safety profile was comparable to previous trials.

CONCLUSIONS

In conclusion, these longer follow-up data support the efficacy and safety profile reported in the preceding BREATHE-5 study of bosentan treatment of Eisenmenger syndrome, challenging the notion that pulmonary vascular disease and severe functional impairment in these patients are not amenable to therapy.

Endothelin receptor antagonists improve exercise tolerance and oxygen saturations in patients with Eisenmenger syndrome and congenital heart defects

Patients with Eisenmenger syndrome experience substantial morbidity and decreased survival rates. In advanced cases, lung transplantation with cardiac repair or heart-lung transplantation is often the only option. The efficacy of endothelin receptor antagonists in Eisenmenger syndrome, which has similar pathophysiology to idiopathic pulmonary hypertension, remains unknown.We retrospectively studied adults with congenital heart disease and Eisenmenger syndrome who were treated with endothelin receptor antagonists. Analysis included chart reviews of clinical evaluations, oxygen saturation levels, functional class, 6-minute walk distances, and pulmonary artery pressures. In the 24 patients studied, Eisenmenger syndrome was caused by ventricular septal defect (6 patients), atrial septal defect (5), atrioventricular canal defect (3), complex congenital heart disease (9), and patent ductus arteriosus (1).Eisenmenger syndrome was treated with bosentan (21 patients) and sitaxsentan (3 patients). On average, therapy lasted 19 +/- 12 months. Subsequently, mean 6-minute walk distances improved from 226 +/- 159 m to 351 +/- 113 m (P = 0.004), and World Health Organization functional class improved > or =1 grade (P < 0.0001). Oxygen saturations increased on therapy from 80.5% to 87% (P < 0.0001). Pulmonary arterial systolic pressures decreased from 97 +/- 21 mmHg to 78 +/- 27 mmHg, and mean pressures from 59 +/- 16 mmHg to 47 +/- 17 mmHg (both P < 0.0001). Neither major complications from therapy nor changes in pulmonary capillary wedge pressure occurred.Endothelin receptor antagonists may play an important role in improving 6-minute walk distance, oxygen saturation, pulmonary artery pressures, and symptoms in adults who have congenital heart defects and Eisenmenger syndrome.

Role of oral sildenafil in severe pulmonary arterial hypertension: Clinical efficacy and dose response relationship

BACKGROUND

Sildenafil (phosphodiesterase type 5 inhibitor) has been shown to be effective in pulmonary arterial hypertension (PAH). We evaluated the efficacy and safety of oral sildenafil in patients of severe PAH with special emphasis on dose response relationship, time of onset of clinical response and its effects on different haemodynamic parameters.

METHODS

Forty-four patients of severe PAH of either idiopathic pulmonary arterial hypertension [23 (51.7%)] or Eisenmenger syndrome [21 (48.3%)] were studied. All patients underwent six-minute walk test (SMWT) and echocardiography, while some also underwent cardiac catheterization. Sildenafil was started after a test dose and was gradually increased up to a target dose of 300 mg/day. Patients were followed-up 2 weekly for 10 weeks and monthly thereafter for functional class assessment and SMWT. Echocardiography and cardiac catheterization were repeated after at least 1 month of achieving maximal sildenafil dose (target dose or maximally tolerated dose). Drug safety and tolerability were assessed by monitoring patients for adverse effects including fundus examination.

RESULTS

Mean follow-up duration was 18.7+/-8.8 months (range 7-30 months). Mean maximum dose achieved was 276.1+/-62.2 mg/day (range 75-300 mg/day). A significant improvement in NYHA class (2.54+/-0.5 vs. 1.31+/-0.4, p=0.0001) and in SMWT distance (247.4+/-74.7 vs. 366.3+/-93.8 m, p=0.0001) was noted. All patients reported "feeling better" within 2 weeks of starting 12.5 mg thrice a day sildenafil. Marked improvement was noticed at 150 mg/day dose. Some minor additional benefit was noticed with further increase in the dose up to 225 mg/day. No further benefit was noted in improvement of NYHA class and SMWT distance by further increasing the dose of sildenafil. Haemoptysis as well as chest pain, if present, were also improved. On follow-up cardiac catheterization, a significant reduction in mean pulmonary arterial pressure (from 67.0+/-10.2 to 56.9+/-9.5 mm Hg, p=0.001), PVRI (from 19.5+/-7.0 to 11.1+/-6.9 WU m2, p=0.0001) and PVR/SVR ratio (0.6+/-0.3 vs. 0.4+/-0.2, p=0.013) with increase in cardiac index (2.9+/-1.1 l/min vs. 3.7+/-1.1 l/min, p=0.008) was noted. Systemic as well as pulmonary arterial oxygen saturations also improved significantly. Sildenafil was generally well tolerated, except for rhinorrhoea in 2, bodyache in 1 and headache in 1 patient. No visual symptom or change in fundus examination was noted.

CONCLUSIONS

Oral sildenafil improves functional capacity, haemodynamic parameters and is safe in patients with severe PAH. Benefits start as early as 2 weeks. The effects are dose related. A target dose of 150 mg/day appears to be optimal. Being very effective, widely available, relatively inexpensive, and very easy to use and very well tolerated without any major side effect, sildenafil may qualify as a first line medication for these patients.

Effects of chronic sildenafil in patients with Eisenmenger syndrome versus idiopathic pulmonary arterial hypertension

BACKGROUND

To test the hypothesis that chronic sildenafil treatment has similar functional and hemodynamic effects in patients with severe pulmonary arterial hypertension due to Eisenmenger syndrome as those due to idiopathic pulmonary arterial hypertension without intracardiac shunts.

METHODS

A prospective open-label study was carried out to compare the effects of sildenafil on the pulmonary hemodynamics between two groups of patients with severe pulmonary hypertension and similar baseline functional capacity--Eisenmenger syndrome (ES group) (n=7) versus idiopathic pulmonary arterial hypertension (IPAH group) (n=6).

RESULTS

After 6 months of sildenafil, there was a significant improvement in the functional capacity, the arterial saturation and the pulmonary hemodynamics in the ES group, as shown by significant reduction in the systolic and mean pulmonary artery pressures and the pulmonary vascular resistance.

CONCLUSION

Sildenafil increases pulmonary blood flow and improves cyanosis in patients with Eisenmenger syndrome. Efficacy of sildenafil as treatment for idiopathic pulmonary arterial hypertension may be extended to patients with Eisenmenger syndrome.

Long-term safety, tolerability and efficacy of bosentan in adults with pulmonary arterial hypertension associated with congenital heart disease

OBJECTIVE

To examine long-term safety and efficacy of bosentan--an oral dual endothelin receptor antagonist--in patients with pulmonary hypertension associated with congenital heart disease or Eisenmenger's syndrome.

DESIGN

Retrospective study.

SETTING

Tertiary cardiology referral centre.

PATIENTS

All adult patients with pulmonary arterial hypertension associated with congenital heart disease treated with bosentan at the Royal Brompton Adult Congenital Heart Centre were included.

MAIN OUTCOME MEASURES

Oxygen saturation, functional (WHO) class, 6-minute walk test distance and liver enzymes were analysed.

RESULTS

Eighteen patients (14 female) with pulmonary arterial hypertension associated with congenital heart disease (15 patients with Eisenmenger's syndrome) with a mean (SD) age of 41 (9) years (range 23-69) were included. Median follow-up was 29 months (range 1-39). One patient died during follow-up. Patients tolerated bosentan well and no significant rise in liver transaminases was seen. Arterial oxygen saturation remained stable throughout follow-up. Mean (SD) functional class (p = 0.001) and the 6-minute walk test distance improved compared with baseline (284 (144) vs 363 (124) m, 380 (91) m and 408 (114) m at baseline, 0-6 months, 6-12 months and 1-2 years of treatment, respectively; p<0.05 for each).

CONCLUSIONS

Bosentan appears to be safe and well tolerated in adults with pulmonary arterial hypertension associated with congenital heart disease or Eisenmenger's syndrome during mid- to long-term follow-up. In addition, functional class and the 6-minute walk test distance improved and this effect was maintained for up to 2 years of bosentan treatment.

Treatment of patients with Eisenmenger's syndrome with Bosentan

We treated prospectively 14 patients with Eisenmenger's syndrome, with a mean age of 10 years, ranging from 3 to 18 years. Treatment continued for 12 months, and demonstrated a lasting symptomatic improvement, but no improvement in terms of mean saturation of oxygen over 24 hours. Exercise capacity, as judged by peak uptake of oxygen, worsened in the six patients able to perform a treadmill test. The symptomatic benefit from dual blockage of endothelin receptors in these patients may be due to mechanisms other than selective pulmonary vasodilatation alone.

Congenital Heart Disease Associated Pulmonary Arterial Hypertension

Pulmonary arterial hypertension associated with congenital heart disease, although common (15%-30%) in all-comers with congenital heart disease, is variable in terms of clinical manifestations, severity of associated pulmonary arterial hypertension, and response to therapy and outcomes (depending on lesion anatomy, pulmonary circulation flows and pressures, and presence and timings of surgeries). Evaluation includes imaging and catheterization. Surgical or another anatomic correction may be desirable after rigorous preinterventional assessment. Patients who are not surgical candidates or who fail to improve early or late after surgery may have the potential to respond to idiopathic pulmonary arterial hypertension therapies. Lung or heart/lung transplantation remains an option for selected recalcitrant patients.

Phosphodiesterase-5 Inhibitor in Eisenmenger Syndrome

Background— Phosphodiesterase-5 inhibitors produce a significant decrease in pulmonary vascular resistance in patients with idiopathic pulmonary arterial hypertension. We studied the effects of tadalafil, a phosphodiesterase-5 inhibitor, on short-term hemodynamics, tolerability, and efficacy over a 12-week period in patients of Eisenmenger syndrome having a pulmonary vascular pathology similar to idiopathic pulmonary arterial hypertension.

Methods and Results— Sixteen symptomatic Eisenmenger syndrome patients (mean age, 25±8.9 years) were assessed hemodynamically at baseline and 90 minutes after a single dose of tadalafil (1 mg/kg body weight up to a maximum of 40 mg). The same dose was then continued daily for 12 weeks, and the patients were restudied. There was a significant decrease in mean pulmonary vascular resistance immediately (24.75±8.49 to 19.22±8.23 Woods units; P <0.005) and at 12 weeks (19.22±8.23 to 17.02±6.19 Woods units; P =0.03 versus 90 minutes). Thirteen of 16 patients (81.25%) showed a ≥20% decrease in pulmonary vascular resistance and were defined as responders. The mean systemic oxygen saturation improved significantly both immediately (84.34±5.47% to 87.39±4.34%; P <0.005) and at 12 weeks (87.39±4.34% to 89.16±3.8%; P <0.02 versus 90 minutes) without a significant change in systemic vascular resistance. None of the patients had a fall in systemic arterial pressure, worsening of systemic oxygen saturation, or any adverse reactions to the drug. The mean World Health Organization functional class improved from 2.31±0.47 to 1.25±0.44 ( P <0.0001), and the 6-minute walk distance improved from 344.56±119.06 to 387.56±117.18 m ( P <0.001).

Conclusions— Preliminary evaluation of tadalafil has shown efficacy and safety in selected patients with Eisenmenger syndrome, warranting further investigation in this subgroup of patients.

Bosentan Therapy in Patients With Eisenmenger Syndrome

Background— Eisenmenger syndrome is characterized by the development of pulmonary arterial hypertension with consequent intracardiac right-to-left shunt and hypoxemia in patients with preexisting congenital heart disease. Because Eisenmenger syndrome is associated with increased endothelin expression, patients may benefit from endothelin receptor antagonism. Theoretically, interventions that have some effect on the systemic vascular bed could worsen the shunt and increase hypoxemia.

Methods and Results— The Bosentan Randomized Trial of Endothelin Antagonist Therapy-5 (BREATHE-5) was a 16-week, multicenter, randomized, double-blind, placebo-controlled study evaluating the effect of bosentan, a dual endothelin receptor antagonist, on systemic pulse oximetry (primary safety end point) and pulmonary vascular resistance (primary efficacy end point) in patients with World Health Organization functional class III Eisenmenger syndrome. Hemodynamics were assessed by right- and left-heart catheterization. Secondary end points included exercise capacity assessed by 6-minute walk distance, additional hemodynamic parameters, functional capacity, and safety. Fifty-four patients were randomized 2:1 to bosentan (n=37) or placebo (n=17) for 16 weeks. The placebo-corrected effect on systemic pulse oximetry was 1.0% (95% confidence interval, −0.7 to 2.8), demonstrating that bosentan did not worsen oxygen saturation. Compared with placebo, bosentan reduced pulmonary vascular resistance index (−472.0 dyne · s · cm −5 ; P =0.0383). The mean pulmonary arterial pressure decreased (−5.5 mm Hg; P =0.0363), and the exercise capacity increased (53.1 m; P =0.0079). Four patients discontinued as a result of adverse events, 2 (5%) in the bosentan group and 2 (12%) in the placebo group.

Conclusions— In this first placebo-controlled trial in patients with Eisenmenger syndrome, bosentan was well tolerated and improved exercise capacity and hemodynamics without compromising peripheral oxygen saturation.

Eisenmenger syndrome: medical prevention and management strategies

The original definition of Eisenmenger syndrome refers to an unrestrictive post-tricuspid valve congenital systemic-to-pulmonary shunt. When the pulmonary arterial systolic pressure becomes equal to the systemic arterial systolic pressure, the direction of the shunt becomes pulmonary-to-systemic. The latter leads to progressive cyanosis, and exercise intolerance is initially proportional to the degree of hypoxaemia. Later, congestive heart failure may occur . The management principle is to avoid any factors that destabilise this delicately balanced physiology. Until recently, this could only be achieved by symptomatic therapy; however, when patients are severely incapacitated, transplantation is needed. At present, new drugs, which are more selective pulmonary vasodilators, are available to interfere with the ongoing disease process to improve functional capacity and delay the decision for transplantation.

[The effect of an endothelin receptor antagonist in Eisenmenger syndrome: a single-center experience of 11 patients]

The Eisenmenger syndrome is a complication of congenital heart disease with significant left-to-right shunts, such as large ventricular septal defects, and corresponds to fixed pulmonary hypertension with shunt reversal. Bosentan, an inhibitor of endothelin A and B receptors, is a new molecule previously validated in the treatment of primary pulmonary hypertension. The authors report their monocentric experience of bosentan in 11 consecutive patients with the Eisenmenger syndrome treated for at least one year. This retrospective study comprised 7 females and 4 males with an average age of 34 years (range 17 to 51 years). The underlying lesion was ventricular septal defect (n = 4), atrial septal defect (n = 3), pulmonary atresia with septal defect (n = 4 of which 2 were treated palliatively). Before treatment, the patients were classified according to the NHYA functional class (I, II, IIIa and IIIb, IV or, respectively from 1 to 5) with a distribution in this series between Classes IIIa and IV (average 3.81 +/- 0.75) and from 3 to 10 on Borg's dyspnoea scale (average 6.54 +/- 2.29). The ambient oxygen saturation (SaO2) at rest was, on average 77 +/- 9%, the haemoglobin concentration 16.6 +/- 2.4 g/dl; hepatic transaminase levels were normal. The 6 minute walk test before treatment was 216 +/- 111 m with marked desaturation on exercise (49 +/- 18%). With Bosentan, patients were globally much better clinically with a decrease in dyspnoea, improvement in NHYA class and increased 6 minute walking perimeter. Improvement in NYHA class was observed from 3 months' treatment (3.0 +/- 0.8, p = 0.0002) and was sustained to one year (2.54 +/- 0.7, p< 0.001). An improvement of dyspnoea on Borg's scale was observed from the second month's treatment (5.56 +/- 1.65, p = 0.0201) and persisted throughout follow up to one year (3.81 +/- 1.32, p < 0.0001). Similarly, the 6 minute walking perimeter increased from the first control at 6 months (323 +/- 82 m, p < 0.0001) and at one year (322 +/- 62 m, p <0.0004). Finally, although a significant increase in SaO2 was observed at 6 months (p = 0.0032), this was hardly significant at one year (82 +/- 10 %, p = 0.0512). Transaminase levels did not rise significantly at the follow up visits (p = ns) and the haemoglobin concentration was unchanged. No patient died during the study period. This study showed a clear functional improvement in patients with Eisenmenger's syndrome treated with bosentan. The drug was well tolerated clinically with few adverse effects and a good safety margin of usage.

Beraprost therapy in children with pulmonary hypertension secondary to congenital heart disease

We present a report on children with severe pulmonary hypertension secondary to congenital heart disease who received 6 months of beraprost therapy. The children had an increase in intracardiac left-to-right shunt and a reduction of the pulmonary-to-systemic vascular resistance ratio, whereas the pulmonary artery pressure was not significantly changed.

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.

Pregnancy Outcome in Patients With Pulmonary Arterial Hypertension Receiving Prostacyclin Therapy

BACKGROUND

Pregnancy is contraindicated in cases of pulmonary hypertension, a highly morbid disease affecting young women of childbearing age.

CASES

We describe the pregnancies of 3 patients with pulmonary arterial hypertension (idiopathic, Eisenmenger syndrome, and related to systemic lupus erythematosus). They received epoprostenol and low-molecular-weight heparin throughout pregnancy. The patient with Eisenmenger syndrome started epoprostenol in gestational week 16. Cesarean delivery under general anesthesia was performed at 28-33 weeks of gestation; early delivery was necessary in the patient with Eisenmenger syndrome because of fetal growth restriction. All deliveries were uneventful, and birth weights were 1,700, 1,500, and 795 g. There were no postpartum complications.

CONCLUSION

Pregnancy in women with pulmonary hypertension should still be considered high risk for both mother and child, but stable patients on epoprostenol may successfully complete pregnancy.

Eisenmenger syndrome in the adult--experience with new drugs for the treatment of pulmonary hypertension

BACKGROUND

The last few years have seen significant progress in the treatment of advanced pulmonary arterial hypertension (PAH). The efficacy of new drugs has been proved mainly in idiopathic PAH or PAH associated with connective tissue diseases. As the pathophysiologic patterns are similar, it is reasonable to use these drugs also in Eisenmenger syndrome or in other congenital heart defects with PAH related to initial high pulmonary flow.

OBJECTIVES

To evaluate our early experience with new drugs for PAH in patients with Eisenmenger syndrome.

METHODS

A retrospective study of five patients, aged 28 to 51 years (39.6 +/- 9.94), four female, with Eisenmenger syndrome due to atrial septal defect (n = 2), patent ductus arteriosus (n = 2) or ventricular septal defect (n = 1), who began therapy with iloprost (n = 4, later associated with sildenafil in one patient) and bosentan (n = 1), between April 2001 and May 2003. The existence of severe and fixed PAH, with predominant right-to-left shunt, was confirmed by hemodynamic study in all cases. The patients were evaluated by clinical examination, Doppler echocardiography and the six-minute walk test before treatment and throughout follow-up (9 to 34 months, 19.8 +/- 9.04). Before treatment two patients were in NYHA class III and three in class III with periods in class IV. By Doppler echocardiography the right ventricle-right atrium (RV-RA) gradient was 74 to 111 mmHg (90.6 +/- 15.73) and the Tei index was 0.53 to 2.05 (1.13 +/- 0.62). In the six-minute walk test the distance was 214 to 500 meters (296.8 +/- 115.27).

RESULTS

All patients improved clinically, though three are still in class III. One patient is in class II and one patient died. At the latest evaluation the RV-RA gradient was 60 to 112 mmHg (84.8 +/- 19.11) and the Tei index was 0.5 to 1.33 (0.85 +/- 80.32). In the six-minute walk test a net increase in the distance covered was evident: 376 to 520 meters (420 +/- 57.89). The treatment was well tolerated in all cases, without serious adverse effects.

CONCLUSIONS

Though the number of patients was small, our initial experience with the new specific drugs for PAH in Eisenmenger syndrome showed promising results, with clinical and functional improvement and without adverse effects.

Safety and tolerability of bosentan in adults with Eisenmenger physiology

BACKGROUND

Bosentan, a dual-endothelin receptor antagonist, is an established treatment for pulmonary arterial hypertension. We hypothesized that bosentan is safe and well tolerated in patients with Eisenmenger physiology.

METHODS

In this pilot open-label study, we primarily examined safety and tolerability of oral bosentan. Patients were recruited from our adult congenital heart clinic following informed consent. Baseline and 3-month assessment included WHO functional class, resting oxygen saturations, 6-min walk test, transthoracic echocardiography and respiratory mass spectrometry. Patient clinical status and liver enzymes were closely monitored throughout.

RESULTS

All 10 study patients (42+/-4 years; eight female) tolerated bosentan well. No major adverse events or significant liver enzyme elevations were observed. All but one patient felt better; none felt worse. Four patients experienced transient leg oedema. Resting oxygen saturations (83+/-5 versus 80+/-5%; P=0.011) and the distance travelled in the 6-min walk test (348+/-112 versus 249+/-117 m; P=0.004) increased relative to baseline. Changes in echocardiographic parameters (maximum aortic forward flow velocity 1.3+/-0.1 versus 1.1+/-0.2 ms, P=0.013; pulmonary arterial acceleration time 66+/-10 versus 58+/-12 m/s, P=0.02) and pulmonary blood flow (3.45+/-1.2 versus 2.58+/-1.0 L/min, P=0.008) suggested improved pulmonary haemodynamics by study end. Other echocardiographic changes suggested improved right ventricular systolic function (septal amplitude 1.0 versus 1.1 cm, P=0.048; systolic tissue Doppler velocity 4.8 versus 2.3 cm s(-1), P=0.002) by study end.

CONCLUSIONS

Bosentan was safe and well tolerated in adults with Eisenmenger physiology both at initiation and after 3 months of oral therapy. Clinical status of patients and pulmonary haemodynamics appeared to improve, and this warrants further investigation.

Initial experience with bosentan therapy in patients with the Eisenmenger syndrome

Bosentan, an endothelin-1 antagonist that can be administered orally, has been shown to be effective in the treatment of idiopathic pulmonary arterial hypertension and may be of benefit to patients with the Eisenmenger syndrome. Nine patients with Eisenmenger's syndrome were treated with bosentan at a dose of 125 mg twice a day. After treatment with bosentan, 6 of 9 patients (67%) had an improvement in New York Heart Assocation classification of >/=1 grades (p = 0.03). Oxygen saturation levels increased from 79 +/- 5% to 88 +/- 6%, (p = 0.03). The side effects of bosentan therapy were minor; no significant changes in liver function tests were noted. These preliminary data suggest that oral administration of bosentan therapy for Eisenmenger's syndrome results in improved oxygenation and functional status with minimal side effects.

Management of Eisenmenger syndrome in pregnancy with sildenafil and L-arginine

BACKGROUND

Eisenmenger syndrome in pregnancy may be a life-threatening disease despite recent additions to the treatment options.

CASE

We present a woman with severe pulmonary hypertension due to Eisenmenger syndrome treated during pregnancy and delivery and postpartum with L-arginine and sildenafil to enhance the nitric oxide pathway. This combination was associated with significant improvement in the mother's clinical and hemodynamic condition and fetal well-being.

CONCLUSION

The concomitant use of sildenafil and L-arginine for the management of pulmonary hypertension in pregnancy, combined with multidisciplinary care, permitted a good outcome for the mother and her infant.

Successful management of pregnancy in a patient with eisenmenger syndrome with epoprostenol

Pregnancy in the setting of pulmonary hypertension and Eisenmenger physiology is associated with a substantial maternal and fetal risk. Such patients are advised against pregnancy. We report a case of a woman with an Eisenmenger atrial septal defect diagnosed during the last trimester of pregnancy. On presentation, she was critically ill and there was evidence of fetal distress. She was emergently treated with IV epoprostenol, and her status improved. She underwent cesarean section and delivered a male infant with Apgar scores of 8 and 9. Her dyspnea improved, and she was characterized as World Health Organization functional class II on a subsequent clinical visit. Although pregnancy should be discouraged in women with Eisenmenger syndrome, we have demonstrated that IV epoprostenol successfully treated a woman with Eisenmenger syndrome diagnosed in the third trimester.

Favorable response of Eisenmenger syndrome to inhaled nitric oxide during pregnancy

OBJECTIVE

Our goal was to evaluate the effectiveness of therapy with a specific pulmonary vasodilator, nitric oxide, in a woman with Eisenmenger syndrome during pregnancy.

STUDY DESIGN

Eisenmenger syndrome consists of a congenital communication between the systemic and pulmonary circulation with secondary pulmonary hypertension causing reversal of flow through the shunt. Maternal morbidity is approximately 50% with the greatest risk of death being in the peripartum period. Pharmacologic therapy to relieve worsening pulmonary hypertension is confounded by the undesired effects of vasodilators on the systemic circulation. Therapy with a specific pulmonary vasodilator, nitric oxide, was attempted.

RESULTS

A 27-year-old woman with Eisenmenger syndrome at 36 weeks' gestation was treated with inhaled nitric oxide during the second stage of labor and the postpartum period when she experienced progressive refractory hypoxemia. Administration of nitric oxide was followed by improved oxygenation and lowering of pulmonary artery pressures. A brief episode of methemoglobinemia responded to lowering of the nitric oxide concentration and administration of intravenous methylene blue. Nitric oxide was discontinued after 48 hours. The patient died 2 days later despite continued vasodilator therapy including intra-pulmonary artery prostacyclin.

CONCLUSION

Inhaled nitric oxide can be used to correct the hypoxemia of Eisenmenger syndrome. Nitric oxide inhalation is easily performed, and pulmonary vasodilatory effects commence within minutes after administration.

Viable but denervated right ventricular myocardium: a case of Eisenmenger reaction

We report on a 47-year-old woman who experienced an Eisenmenger reaction (mean pulmonary artery pressure: 86 mm Hg) induced by atrial septal defect. Radionuclide myocardial scans with 99mTc-MIBI and 123I-BMIPP showed increased uptake to the right ventricular myocardium, whereas the 123I-MIBG scan disclosed no uptake to the right ventricular myocardium. The scans showed no apparent abnormality in the left ventricular myocardium. These findings suggest that the right ventricular myocardium was viable but denervated due to severe pulmonary hypertension. The mechanism of right ventricular failure may be closely related to sympathetic denervation.

[Aerosolized prostacyclin for preoperative evaluation and post-cardiosurgical treatment of patients with pulmonary hypertension]

BACKGROUND

Inhaled nitric oxide (NO) has been shown to selectively lower pulmonary vascular resistance and is applied in patients with pulmonary hypertension (PHT). However, application and monitoring is complex and not always successful ("non-responders"). We evaluated the effect of aerolized prostacyclin (aePGI2) as a therapeutic alternate to NO.

PATIENTS AND METHODS

aePGI2 and NO were applied to patients with different causes of pulmonary hypertension (Group 1a: preoperative patients with intracardiac shunting defects and Eisenmenger's disease, n = 30; Group 1b: patients with primary or postoperative PHT, n = 13; Group 2: PHT immediately following surgery for congenital heart disease, n = 6).

RESULTS

Pulmonary vascular resistance could be lowered significantly (Group 1a: from 91% of systemic vascular resistance to 58% with NO and 53% with aePGI2; Group 1b: from 20.2 Wood Units*m2 to 13.4 and 11.3; Group 2: from 24.9 Wood Units*m2 to 9.5 and 10.5); cardiac index increased (Group 1b: from 2.96 to 3.55 and 3.96 l/min*m2, Group 2: from 1.57 to 1.89 and 2.00 l/min*m2).

CONCLUSIONS

The short-term application of aePGI2 shows a selective pulmonary vasodilation similar to NO. Given adequate monitoring, aePGI2 appears to be useful for the acute treatment of PHT.

[Comparative studies of hemodynamics under prostacyclin and nifedipine in patients with Eisenmenger syndrome]

In 10 patients 4-20 years of age with obstructive pulmonary vascular disease after Eisenmenger reaction pulmonary arterial and aortic pressure, pulmonary and systemic flow (Qp, Qs), and pulmonary and systemic vascular resistance (Rp, Rs) were determined before and during stepwise increasing doses of prostacyclin and nifedipine. Prostacyclin caused a significant decrease of pulmonary and systemic vascular resistance and a significant decrease of pressures in the aorta and the pulmonary artery, whereas no significant changes of hemodynamics were realized following nifedipine. The individual hemodynamic changes during prostacyclin were favorable in only two patients who demonstrated a marked decrease of Rp with no substantial change of Rs resulting in an increase in arterial oxygen saturation. In the other patients prostacyclin resulted in an adverse effect with a decrease of Rs exceeding that of Rp in 5 patients, a paradoxical increase of Rp in 1 patient, and a critical decrease of Qs with respective low central venous blood oxygen saturation and consequently low arterial oxygen saturation caused by a small right-to-left shunt in 2 patients. Nifedipine did not bring about a significant general change of hemodynamic parameters. The individual control showed no effect in 5 patients, an unfavorable effect by a decrease of Rs exceeding that of Rp in 2 patients, and a favorable net effect in only 3 patients, induced in 1 patient only after a very high dosage of nifedipine and leading to a certain increase of arterial oxygen saturation in only 1 other patient. From our results a beneficial effect of nifedipine in an average dosage on the hemodynamics of patients with Eisenmenger syndrome cannot be recognized.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term hemodynamic effects of nifedipine on congenital heart disease with Eisenmenger's mechanism in children

The hemodynamic effect of long-term nifedipine medication was studied in 10 children, 3-12 years of age, five with ventricular septal defect and five with complete atrioventricular septal defect; all had Eisenmenger's reaction, seven also had Down's syndrome. They underwent heart catheterization prior to and during 1-4 years of nifedipine therapy. Fick's principle was used to calculate the ratio of pulmonary arterial pressure to aortic pressure (PAP/PAO), the ratio of pulmonary flow to aortic flow (QP/QS), as well as the ratio of pulmonary vascular resistance to aortic vascular resistance (RP/RS). In the seven children under 8.8 years, nifedipine caused a significant drop in PAP/PAO (p less than 0.004), a slight increase in arterial O2 saturation, a significant increase in QP/QS (p less than 0.02), and a decrease in RP/RS (p less than 0.02). The nifedipine effect was age related. On nifedipine, breathing oxygen resulted in, independent of age, a significant increase in QP/QS (p less than 0.003) and a significant decrease in PAP/PAO (p less than 0.04) and in RP/RS (p less than 0.003). Direct O2 consumption measurements before and during oxygen breathing in six patients demonstrated no significant change in RP, RS, QP, or QS indices. Nifedipine had a relaxing effect on the pulmonary vascular bed, especially in the younger child with Eisenmenger's mechanism. On nifedipine therapy, O2 produced a more complex hemodynamic reaction that was not restricted to the pulmonary circulation alone.

Improvement of exercise capacity after nifedipine in patients with Eisenmenger syndrome complicating ventricular septal defect

We investigated the potential benefit of a preferential pulmonary vasodilatory effect of nifedipine in 4 patients with Eisenmenger syndrome complicating ventricular septal defect. First-pass radionuclide scan was performed at rest to measure intracardiac shunting before and after nifedipine. Two hours after 20 mg sublingual nifedipine, right-to-left shunt increased from 16.3 +/- 1.4 to 20.4 +/- 1.5% (p less than 0.05), but systemic arterial oxygen saturation (SAO2) remained steady. With 4 weeks of maintenance nifedipine therapy, resting intracardiac shunting and SAO2 were unchanged from baseline. Symptom-limited cycle ergometry was performed before and after maintenance nifedipine with placebo control. Exercise duration was prolonged (8.7 +/- 0.6 vs. 6.8 +/- 0.9 min; p less than 0.02) and SAO2 at each stage of exercise was consistently increased in all patients after nifedipine. Cardiac output and the SAO2 at peak exercise were similar. Thus, chronic nifedipine therapy increases SAO2 on exercise and improves maximal exercise capacity in patients with Eisenmenger syndrome, which is not predicted by study of resting intracardiac shunting after acute therapy.

Chronic alpha 1 blockade in a patient with Eisenmenger syndrome

In an 18-year-old male with Eisenmenger syndrome cyanosis and erythrocytosis were increasing. The erythrocytosis diminished following oral bunazosin and phlebotomy was not needed during the treatment. When bunazosin was stopped, the erythrocytosis increased, but when it was resumed, the erythrocytosis and general fatigue diminished.