Effects of bosentan on the skin lesions: an observational study from a single center in Japan

Prevalence of and factors independently associated with digital ischemic complications in patients with systemic sclerosis

Objective

To investigate the prevalence of and independent predictors for digital ischemic complications in patients with systemic sclerosis.

Method

Patients enrolled in the Siriraj Systemic Sclerosis Cohort registry during 2013-2019 were classified as having or not having digital ischemic complications at the baseline and 1-year timepoints.

Results

A total of 171 patients with systemic sclerosis were included. The prevalence of digital pulp loss, digital pitting scar, digital ulcer, and digital amputation at baseline and 1 year was 41.5%, 39.8%, 3.5%, 7.6% and 37.4%, 43.9%, 14.1%, 6.4%, respectively. Over half (58.5%) of overall systemic sclerosis had developed new digital ischemic complications during the 1-year follow-up. Those with digital ischemic complications at baseline were at high risk for developing new digital ischemic complications (odds ratio: 15.9). Diffuse cutaneous systemic sclerosis is associated with digital ischemic complications (odds ratio: 6.0), digital pitting scar (odds ratio: 4.9), and digital pulp loss (odds ratio: 6.4). Tendon friction rub is associated with digital pitting scar (odds ratio: 5.0). Salt-and-pepper skin appearance is associated with digital pulp loss (odds ratio: 3.0) and digital ulcer (odds ratio: 6.9). Disease duration > 3 years is associated with digital ulcer (odds ratio: 4.4). Male gender is associated with digital ulcer (odds ratio: 5.4).

Conclusion

Digital pulp loss, digital pitting scar, digital ulcer, and digital amputation were common manifestations of digital ischemic complications, and diffuse cutaneous systemic sclerosis was the strongest of the six independent predictors.

Effectiveness of bosentan in the treatment of systemic sclerosis-related digital ulcers: Systematic review and meta-analysis

Background

The aim of the present systematic review and meta-analysis was to evaluate the therapeutic efficacy of bosentan, a dual endothelin receptor antagonist, for systemic sclerosis (SSc) patients with digital ulcers (DUs).

Materials and Methods

A systematic search of MEDLINE, Embase, Web of Science, and Scopus was done using appropriate keywords till September 2021. Weighted mean difference (WMD) as the effect of therapeutic efficacy of bosentan on continuous outcomes was an estimate. Furthermore, the pooled prevalence of diffuse SSc and limited SSc was computed. Fixed or random effects models when appropriate were used for data synthesis.

Results

Totally, 469 patients, with a mean age ranging from 48.1 to 63.7 years, from 8 studies were included in the systematic review and meta-analysis. The pooled frequency of diffuse SSc and limited SSc was 56% (95% confidence interval [CI]: 39%, 73%) and 44% (95% CI: 27%, 61%). The pooled prevalence of new DUs following bosentan treatment was 21% (95% CI: 10%, 33%). The results of the meta-analysis showed a pooled mean decrease of WMD: -0.09 (95% CI: -0.020, 0.02, P = 0.10), WMD: -2.82 (95% CI: -5.91, 0.27, P = 0.07), and WMD: -6.65 (95% CI: -9.49, -3.82, P < 0.001) in mean SSc-Health Assessment Questionnaire, pain, and Rodnan score, respectively. Our meta-analysis also indicated a significant pooled decrease in the number of new DUs in SSc patients compared to placebo subjects (WMD: -0.89 [95% CI: -1.40, -0.37; P = 0.001]) and baseline values (WMD: -1.34 (95% CI: -1.95, -0.73; P < 0.001).

Conclusion

Bosentan possibly is an efficacious treatment option for SSc-related DUs. Although further large-scale randomized clinical trials are required to confirm the preliminary finding and underlying mechanisms of action.

Raynaud's Secondary to Granulomatosis With Polyangiitis

Raynaud's phenomenon (RP) is an episodic digital vasospastic condition that is prevalent among 5% of the population. The symptoms range from reversible pallor to ischemia and gangrene. RP can be primary or secondary. We discuss a case of severe RP secondary to granulomatosis with polyangiitis (GPA) that presented with ischemia and gangrene. Studies show that approximately <1% of GPA cases have similar presentations. Early diagnosis and management are essential to halt the progression of ischemia. Calcium channel blockers are the first-line medications used in RP. Phosphodiesterase type 5 inhibitors, endothelin receptor antagonists, and prostacyclin analogs are proven to be effective in cases of severe RP. Sympathectomy and amputation are considered as the extreme options in patients with refractory symptoms.

Pharmacotherapy Options in the Management of Raynaud's Phenomenon

Purpose of review

Multiple classes of medications have been studied for the treatment of Raynaud's phenomenon (RP) with or without digital ischemia. The goal of this review is to discuss the outcomes of recent studies and to report on our approach to the management of RP in light of the available evidence.

Recent findings

Comparing treatments for RP remains a challenge as efficacy endpoint vary widely among trials. While calcium channel blockers are used first-line in the pharmacologic management of RP, phosphodiesterase 5 inhibitors have also been shown to be beneficial in reducing symptoms. In the setting of digital ischemia, administration of intravenous prostanoids is the standard of care. Bosentan has shown benefit in the prevention of future ulcers in patients with scleroderma. Botulinum toxin therapy was ineffective in a clinical trial involving scleroderma patients; more controlled studies are needed in other subsets of patients. Digital sympathectomy may be beneficial in cases of critical digital ischemia, though recurrence of symptoms is common.

Summary

Comparative effectiveness studies are needed to determine which therapeutic interventions are most beneficial in patients with RP. Based on the available evidence, we start with CCBs and add a phosphodiesterase inhibitor if symptoms are not controlled, or intravenous prostacyclin in the setting of severe critical digital ischemia. We may additionally add an endothelial receptor antagonist in cases of recurrent digital ulcers. A surgical sympathectomy may be used in refractory cases of digital ischemia. A digital block may also be a less invasive, but temporary, intervention allowing for titration of medical therapy.

Raynaud's Phenomenon: A Brief Review of the Underlying Mechanisms

Raynaud’s phenomenon (RP) is characterized by exaggerated cold-induced vasoconstriction. This augmented vasoconstriction occurs by virtue of a reflex response to cooling via the sympathetic nervous system as well as by local activation of α_2C adrenoceptors (α_2C-AR). In a cold-initiated, mitochondrion-mediated mechanism involving reactive oxygen species and the Rho/ROCK pathway, cytoskeletal rearrangement in vascular smooth muscle cells orchestrates the translocation of α_2C-AR to the cell membrane, where this receptor readily interacts with its ligand. Different parameters are involved in this spatial and functional rescue of α_2C-AR. Of notable relevance is the female hormone, 17β-estradiol, or estrogen. This is consistent with the high prevalence of RP in premenopausal women compared to age-matched males. In addition to dissecting the role of these various players, the contribution of pollution as well as genetic background to the onset and prevalence of RP are also discussed. Different therapeutic approaches employed as treatment modalities for this disease are also highlighted and analyzed. The lack of an appropriate animal model for RP mandates that more efforts be undertaken in order to better understand and eventually treat this disease. Although several lines of treatment are utilized, it is important to note that precaution is often effective in reducing severity or frequency of RP attacks.

Management of digital vasculopathy in systemic sclerosis: benefits of multiple courses of endothelin-1 receptor antagonists

Two patients with scleroderma and recurrent digital ulcers (DUs) were treated with bosentan for 6 months. Treatment was associated with a reduction in the number of new DUs; however, DUs recurred on treatment discontinuation. This case report illustrates the positive response of digital vasculopathy to bosentan and describes the benefits of multiple bosentan treatment courses in these patients.

Low occurrence of digital ulcers in scleroderma patients treated with bosentan for pulmonary arterial hypertension: a retrospective case-control study

Digital ulcers (DU) are one of the most common and debilitating manifestations of vasculopathy in systemic sclerosis (SSc). Their prevention is important in order to improve patients' outcome and as a result of the economic impact they have on society. Randomised controlled studies have demonstrated that bosentan, an endothelin receptor antagonist, reduces the appearance of new DU. The aim of this retrospective study was to evaluate the occurrence of DU in a group of patients receiving long-term bosentan treatment for pulmonary arterial hypertension associated with SSc (PAH-SSc). Patients with PAH-SSc and treated with bosentan for at least 6 months (n = 30) were evaluated. Thirty patients with SSc not treated with bosentan, but matched for sex, age, disease duration and cutaneous form of SSc, were considered as a control group. The occurrence of DU, defined as loss of tissue of varying degrees in the epidermis, dermis and subcutaneous tissue, was determined in the bosentan-treated and untreated groups. Mean duration of bosentan treatment was 3.6 years. DU were detected in six patients in the bosentan-treated group (20.0 %) and 16 patients (53.3 %) in the untreated group (p = 0.0015). There were no significant differences in demographic or clinical characteristics between patients with or without DU at study end. The occurrence of DU in patients with PAH-SSc receiving long-term bosentan treatment was significantly lower than in untreated patients. The results from this long-term observational study provide valuable information on management of patients with PAH-SSc.

Treatment of thromboangiitis obliterans (Buerger's disease) with bosentan

BACKGROUND

This study assessed the effectiveness and safety of bosentan when administered to thromboangiitis obliterans (Buerger's disease) patients.

METHODS

A clinical pilot study was designed in which patients with ulcer and/or pain at rest were treated with bosentan p.o. at a dose of 62.5 mg twice daily during the first month, which was thereafter up-titrated to 125 mg twice daily. The study endpoints were clinical improvement rate, major or minor amputation rate, haemodynamic changes, changes in endothelial function and angiographic changes.

RESULTS

Seven out of 12 patients were male (58%). Median age was 39 years (range 29-49). The median follow-up was 20 months (range 11-40). All patients were smokers. With bosentan treatment, new ischaemic lesions were observed in only one patient. Overall, clinical improvement was observed in 12 of the 13 extremities (92%). Only two out of 13 extremities underwent amputation (one major and one minor) after bosentan treatment. After being assessed by digital arteriography with subtraction or angio-magnetic resonance imaging, an increase of distal flow was observed in 10 out of the 12 patients. All patients experienced a statistically significant improvement in their BAFMD values (mean: 1.8 at baseline; 6.6 at the end of the treatment; 12.7 three months after the end of the treatment; p < 0.01).

CONCLUSION

Bosentan treatment may result in an improvement of clinical, angiographic and endothelial function outcomes. Bosentan should be investigated further in the management of TAO patients. Larger studies are required to confirm these results.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01447550.

Endothelin Receptor Antagonists for the Treatment of Raynaud's Phenomenon and Digital Ulcers in Systemic Sclerosis

Systemic sclerosis is a connective tissue disease characterized by fibrosis of the skin, internal organs, and widespread vasculopathy. Raynaud's phenomenon and digital ulcers are vascular manifestations of this disease and cause significant morbidity. Current treatments are only moderately effective in reducing the severity of Raynaud's in a portion of patients and typically do not lead to substantial benefit in terms of the healing or prevention of digital ulcers. Several studies have evaluated the efficacy of targeting the vasoconstrictor endothelin-1 for the treatment of systemic sclerosis-associated vascular disease. The purpose of this paper is to summarize the published studies and case reports evaluating the efficacy of endothelin receptor antagonists in the treatment of Raynaud's phenomenon and digital ulcers associated with systemic sclerosis.

Bosentan in clinical practice for treating digital and other ischemic ulcers in Spanish patients with systemic sclerosis: IBER-DU cohort study

OBJECTIVE

To describe treatment outcomes and safety experience with bosentan in patients with systemic sclerosis (SSc) and digital ulcers (DU), in a clinical setting in Spain.

METHODS

This was a multicenter, noninterventional retrospective cohort study. Data were collected retrospectively from patients with DU, with or without pulmonary arterial hypertension (PAH), who were initiating bosentan therapy in 2003 (n = 26) or 2004 (n = 41) and followed until May 2005. Data were obtained from centers prescribing bosentan. Relevant measures included number of DU, occurrence of new DU, overall DU clinical status (improved, stabilized, worsened), and bosentan-associated adverse events.

RESULTS

Sixty-seven patients with SSc and DU or other ulcers were included. PAH was also present in 12 patients (18%). At the start of bosentan treatment, the median number of DU per patient was 3.0. The median change in number of DU was -3.6 and -5.0 at 12 and 24 months, respectively. Sixty-eight percent of the patients did not develop any new DU at 12 months. DU clinical status was reported at 12 months for 22 patients: 18 patients (81.8%) improved and 4 (18.2%) stabilized. The median treatment duration was 13.0 months. The main adverse event was increase of aminotransferase, observed in 5 patients (7%), leading to discontinuation of treatment in 3 patients (4.4%).

CONCLUSION

Previously reported results of bosentan efficacy in DU management are reproducible in clinical practice. This efficacy is maintained in the longterm followup. Bosentan treatment was well tolerated and adverse events were comparable with those observed in previous reports.

Bosentan treatment for Raynauds phenomenon and skin fibrosis in patients with Systemic Sclerosis and pulmonary arterial hypertension: an open-label, observational, retrospective study

Raynaud?s phenomenon (RP) and cutaneous fibrosis are the distinctive manifestations of scleroderma, in which Endothelin-1 plays a fundamental pathogenetic role. Bosentan, an Endothelin-1 receptor antagonist used for the treatment of pulmonary arterial hypertension, retards the beginning of new sclerodermic digital ulcers (DU). This open-label, observational, retrospective study verified the effect of Bosentan on RP and skin fibrosis in sclerodermic outpatients affected by pulmonary arterial hypertension without DU. Fourteen subjects (13 women, 1 man; mean age 60 ± 7.5 years; ten with limited and four with diffuse scleroderma) were observed at baseline (T0) and after four (T1), twelve (T2), twenty-four (T3) and forty-eight (T4) weeks during treatment with Bosentan. They were evaluated for daily quantity and duration of RP attacks and skin thickness (using modified Rodnan total skin score, MRSS). Videocapillaroscopic evaluation was performed at T0 and T4. Bosentan decreased significantly the number and duration of RP attacks, beginning at T2 (p<0.05). Videocapillaroscopy showed significant improvement of microcirculatory patterns at T4 (p<0.05). MRSS decreased throughout the study, reaching the statistical significance at T3 and T4 (p<0.01) in the whole cohort. The present data suggest that Bosentan is effective in stabilizing the microcirculation involvement and in improving skin fibrosis irrespective of scleroderma patterns.

Effect of bosentan on skin fibrosis in patients with systemic sclerosis: a prospective, open-label, non-comparative trial

OBJECTIVES

To assess the effect of the ET-receptor antagonist bosentan on skin fibrosis and functionality in patients with SSc.

METHODS

In this prospective, open-label, non-comparative trial, a total of 10 patients with SSc received 62.5 mg of bosentan twice daily for 4 weeks and then 125 mg twice daily for 20 weeks. The primary endpoint was skin thickening as measured by the modified Rodnan skin score (mRSS). Further assessments included 20 MHz ultrasound, examination of digital ulcers (DUs) and evaluation of hand function by examining patients' fist closure. Furthermore, patients with SSc used the UK SSc Functional Score (UKFS), the modified scleroderma HAQ (SHAQ) and its visual analogue scale (VAS) to rate their disability related to specific organ systems.

RESULTS

The mean change from baseline mRSS (the primary endpoint) was 6.4 at Week 24 of bosentan treatment, which was statistically significant (P < 0.001). Patients with both diffuse and limited SSc exhibited a statistically significant mean difference in the mRSS. Moreover, there was a significant healing of DUs noted between baseline and at Week 24 of bosentan treatment (P < 0.001); however, the 20 MHz ultrasound and the fist closure evaluation revealed no significant differences. There were also no statistically significant changes between baseline and Week 24 in the UKFS, the modified SHAQ and its VAS.

CONCLUSION

In addition to the well-known effect of bosentan in prevention of DUs, the results of this study demonstrate that bosentan may also be effective at reducing skin fibrosis in patients with SSc.

Advances in the treatment of Raynaud's phenomenon

Raynaud's phenomenon is a common condition characterized by vasospasm of the digital arteries and resulting cyanosis and redness. It often does not require pharmacologic management, but in some cases symptoms are severe and pharmacologic management is necessary. Calcium channel blockers are often used first-line, but in some patients are ineffective. Patients with severe symptoms or intolerance to available therapies have prompted exploration of alternative therapies, including endothelin antagonists, phosphodiesterase-5 inhibitors, antioxidants, newer vasodilators, statins, and botulinum toxin. These newer therapies provide the focus for this review.