A systematic review and meta-analysis of the effects of topical nitrates in the treatment of primary and secondary Raynaud's phenomenon

Managing Symptoms of Systemic Sclerosis for the Allergist-Immunologist

PURPOSE OF REVIEW

Systemic sclerosis (SSc) is a chronic, multisystem, autoimmune disease characterized by fibrosis, vasculopathy and immune system dysregulation. We provide a comprehensive review of features of systemic sclerosis that can potentially present to the allergist.

RECENT FINDINGS

A thorough understanding of the management options is crucial for clinicians involved in the care of patients with SSc to optimize clinical outcomes. Management of systemic sclerosis has drastically changed in the last decade and continues to evolve. This review provides an overview of management strategies for the various symptoms including skin, upper and lower airway, gastrointestinal and vascular manifestations. Institution of treatment early in the disease, including referral to rheumatology or specialized scleroderma centers, can help to both prevent and manage disease complications, and improve patient quality-of-life. While the landscape of systemic sclerosis management has evolved, we continue to recognize that there is still a need for better biomarkers and targeted therapies.

Part II: The treatment of primary and secondary Raynaud's phenomenon

Raynaud phenomenon (RP) presents with either primary or secondary disease, and both have the potential to negatively impact patient quality of life. First-line management of RP should include lifestyle modifications in all patients. Some patients with primary RP and most with secondary RP require pharmacologic therapies, which may include calcium channel blockers, topical nitrates, phosphodiesterase 5 inhibitors, or endothelin antagonists. Additional approaches to treatment for those with signs of critical ischemia or those who fail pharmacologic therapy include botulinum toxin injection and digital sympathectomy. Herein, we describe in detail the treatment options for patients with RP as well as provide treatment algorithms for each RP subtype.

Cold Hands or Feet: Is It Raynaud's or Not?

Raynaud's phenomenon is an exaggerated response to cold stimuli that may be primary or secondary. The diagnosis relies on patient history and physical examination to distinguish RP from other vasomotor dysfunction (e.g. acrocyanosis, pernio, small fiber neuropathy with vasomotor symptoms, and complex regional pain syndrome). Achenbach syndrome, or spontaneous venous hemorrhage, may also be mistaken for RP but is a self-limiting phenomenon. Laboratory evaluation and vascular diagnostic testing may identify SRP causes. Regardless of etiology, treatment includes warming with trigger avoidance, and consideration of vasodilators (eg. calcium channel, alpha-1 blockers). SRP with digital ulceration may require PDE5i, endothelin-1 receptor blockers, and prostanoids. Refractory cases may require pneumatic arterial pumps, botulinum toxin administration, or surgical sympathectomy.

State-of-the-art evidence in the treatment of systemic sclerosis

Systemic sclerosis (SSc) is a rare autoimmune connective tissue disease with multi-organ involvement, fibrosis and vasculopathy. Treatment in SSc, including early diffuse cutaneous SSc (dcSSc) and the use of organ-specific therapies, has improved, as evident from randomized clinical trials. Treatments for early dcSSc include immunosuppressive agents such as mycophenolate mofetil, methotrexate, cyclophosphamide, rituximab and tocilizumab. Patients with rapidly progressive early dcSSc might be eligible for autologous haematopoietic stem cell transplantation, which can improve survival. Morbidity from interstitial lung disease and pulmonary arterial hypertension is improving with the use of proven therapies. Mycophenolate mofetil has surpassed cyclophosphamide as the initial treatment for SSc-interstitial lung disease. Nintedanib and possibly perfinidone can be considered in SSc pulmonary fibrosis. Pulmonary arterial hypertension is frequently treated with initial combination therapy (for example, with phosphodiesterase 5 inhibitors and endothelin receptor antagonists) and, if necessary, the addition of a prostacyclin analogue. Raynaud phenomenon and digital ulcers are treated with dihydropyridine calcium channel blockers (especially nifedipine), then phosphodiesterase 5 inhibitors or intravenous iloprost. Bosentan can reduce the development of new digital ulcers. Trial data for other manifestations are mostly lacking. Research is needed to develop targeted and highly effective treatments, best practices for organ-specific screening and early intervention, and sensitive outcome measurements.

Raynaud's Phenomenon with Focus on Systemic Sclerosis

Raynaud’s phenomenon is a painful vascular condition in which abnormal vasoconstriction of the digital arteries causes blanching of the skin. The treatment approach can vary depending on the underlying cause of disease. Raynaud’s phenomenon can present as a primary symptom, in which there is no evidence of underlying disease, or secondary to a range of medical conditions or therapies. Systemic sclerosis is one of the most frequent causes of secondary Raynaud’s phenomenon; its appearance may occur long before other signs and symptoms. Timely, accurate identification of secondary Raynaud’s phenomenon may accelerate a final diagnosis and positively alter prognosis. Capillaroscopy is fundamental in the diagnosis and differentiation of primary and secondary Raynaud’s phenomenon. It is helpful in the very early stages of systemic sclerosis, along with its role in disease monitoring. An extensive range of pharmacotherapies with various routes of administration are available for Raynaud’s phenomenon but a standardized therapeutic plan is still lacking. This review provides insight into recent advances in the understanding of Raynaud’s phenomenon pathophysiology, diagnostic methods, and treatment approaches.

Beneficial Extracardiac Effects of Cardiovascular Medications

Cardiovascular diseases are the most common cause of death worldwide, with cardiovascular medications being amongst the most common medications prescribed. These medications have diverse effects on the heart, vascular system, as well as other tissues and organ systems. The extra cardiovascular effects have been found to be of use in the treatment of non-cardiovascular diseases and pathologies. Minoxidil is used to manage systemic hypertension with its well-known side effect of hirsutism used to treat alopecia and baldness. Sildenafil was originally investigated as a treatment option for systemic hypertension; however, its side effect of penile erection led to it being widely used for erectile dysfunction. Alpha-1 blockers such as terazosin are indicated to treat systemic hypertension but are more commonly used for benign prostatic hyperplasia and post-traumatic stress disorder. Beta blockers are the mainstay treatment for congestive heart failure and systemic hypertension but have been found useful to help in patients with intention tremors as well as prophylaxis of migraines. Similarly, calcium channel blockers are indicated in medical expulsion therapy for ureteric calculi in addition to their cardiovascular indications. Thiazides are commonly used for treating systemic hypertension and as diuretics. Thiazides can cause hypocalciuria and hypercalcemia. This side effect has led to thiazides being used to treat idiopathic hypercalciuria and associated nephrolithiasis. Spironolactone is commonly utilized in treating heart failure and as a diuretic for edema. It's well described anti-androgen side effects have been used for acne vulgaris and hirsutism in polycystic ovarian syndrome. This review article discusses how the various extracardiovascular effects of commonly used cardiovascular medications are put to use in managing non-cardiovascular conditions.

Management of Endothelial Dysfunction in Systemic Sclerosis: Current and Developing Strategies

Systemic Sclerosis (SSc) is an autoimmune disease marked by dysregulation of the immune system, tissue fibrosis and dysfunction of the vasculature. Vascular damage, remodeling and inadequate endothelial repair are hallmarks of the disease. Since early stages of SSc, damage and apoptosis of endothelial cells (ECs) can lead to perivascular inflammation, oxidative stress and tissue hypoxia, resulting in multiple clinical manifestations. Raynaud's phenomenon, edematous puffy hands, digital ulcers, pulmonary artery hypertension, erectile dysfunction, scleroderma renal crisis and heart involvement severely affect quality of life and survival. Understanding pathogenic aspects and biomarkers that reflect endothelial damage in SSc is essential to guide therapeutic interventions. Treatment approaches described for SSc-associated vasculopathy include pharmacological options to improve blood flow and tissue perfusion and, more recently, cellular therapy to enhance endothelial repair, promote angiogenesis and heal injuries. This mini-review examines the current knowledge on cellular and molecular aspects of SSc vasculopathy, as well as established and developing therapeutic approaches for improving the vascular compartment.

Treatment of systemic sclerosis

Systemic sclerosis (SSc) is a rare connective tissue disease characterized by skin and visceral fibrosis, vascular hyperreactivity and obliterative vasculopathy. Some of its complications such as interstitial lung disease (ILD), pulmonary arterial hypertension (PAH) and heart involvement can be life-threatening and are associated with a high mortality and a poor prognosis. Many clinical trials were carried out in order to improve the survival and prognosis of SSc patients. The management of SSc is based on the frequent and regular assessment of the potential organ damage, and if present, the establishment of graduated pharmacological therapeutic strategies, associated with non-pharmacological procedures. Several randomized clinical trials have showed significant positive outcomes regarding some specific involvements. Many advances have been made, especially in the field of targeted therapies and personalized medicine, based on specific characteristics of the patient and the SSc.

Raynaud's phenomenon and digital ulcers: advances in evaluation and management

PURPOSE OF REVIEW

The aim of this review is to give an update on advances in evaluation and management of systemic sclerosis (SSc)-related Raynaud's phenomenon and digital ulceration, focusing on reports from the last 18 months. The increasing recognition of the huge impact of Raynaud's phenomenon and of digital ulceration on the everyday lives of patients with SSc has sparked enthusiasm internationally to develop better outcome measures and better treatments, and so a review is timely.

RECENT FINDINGS

There have been recent advances in the development of patient reported outcome instruments [e.g. the Hand Disability in Systemic Sclerosis-Digital Ulcers (HDISS-DU) instrument] and also in noninvasive imaging techniques, including thermography and laser Doppler methods. Improved outcome measures will facilitate future clinical trials, both early phase proof-of-concept and later phase trials. New insights have been gained into mechanisms of action and methods of administration of 'conventional' therapies, for example phosphodiesterase inhibitors and intravenous prostanoids. New treatment approaches are being investigated, including topical and procedural therapies.

SUMMARY

Clinicians can look forward to seeing these advances translating into clinical benefit over the next 5 years. To help ensure this, they should strive whenever possible to recruit patients with SSc-related digital vasculopathy into observational studies and clinical trials.

Raynaud Phenomenon and Other Vasospastic Disorders

Vasospastic disorders are prevalent in the general population and can affect individuals of any age. Primary (or idiopathic) vasospastic disorders often have a benign course; treatment focuses on the control of symptoms. Secondary vasospastic disorders occur owing to an underlying condition and have an increased risk of complications, including tissue loss and digital ulcerations; treatment should focus on the underlying condition. In this review, we discuss the pathophysiology, clinical presentation, diagnosis, and management of vasospastic disorders, including Raynaud syndrome, acrocyanosis, livedo reticularis, and pernio.

Updates in Systemic Sclerosis Treatment and Applicability to Pediatric Scleroderma

Juvenile-onset systemic sclerosis (jSSc) is a complex multisystem inflammatory-driven disease of fibrosis, requiring multifaceted treatment including pharmacologic therapy, supportive care, and lifestyle modification. Most regimens are adapted from adult SSc treatment given the rarity of the disease. Landmark trials over the past decade in adult SSc have led to 2 Food and Drug Administration-approved therapies for SSc-associated interstitial lung disease, and several ongoing trials of other biological agents are underway. Resetting the immune system with autologous stem cell transplant to halt this disease earlier in its course, especially in pediatric onset where disease burden can accumulate, is on the horizon.

Raynaud's phenomenon

Raynaud's phenomenon (RP) is a common vasospastic condition which affects ~5% of the general population. The majority of individuals have primary RP; however, Raynaud's can also occur secondary to a broad range of underlying medical conditions and drug therapies. RP is a cardinal feature in patients with systemic sclerosis and is often the earliest symptom of the disease. Unlike primary RP, patients with secondary RP can develop persistent digital ischaemia, including ulcers and gangrene. Patients require a comprehensive clinical assessment and investigation, in particular, the detection of autoantibodies and nailfold capillaroscopic abnormalities. Non-pharmacological management is indicated in all patients. There are a wide range of available drug therapies to treat RP, including when complicated by digital ulceration, and surgical intervention is sometimes required. Future research is needed to understand the complex pathogenesis of RP and to measure the impact and severity of RP to develop optimised approaches to management.

Raynaud's phenomenon and related vasospastic disorders

Raynaud's phenomenon, which is characterized by episodic digital pallor, cyanosis and rubor upon exposure to cold environment or to stress, is relatively common, although the prevalence depends on the climate. Still, it is under-diagnosed, under-treated, and often confused with other conditions. Primary Raynaud's phenomenon (i.e., Raynaud disease) must be distinguished from secondary Raynaud's phenomenon (i.e., Raynaud syndrome) as long-term morbidity and outcomes differ vastly between the two conditions. Additionally, the practitioner must differentiate between Raynaud's phenomenon and related vascular disorders, such as acrocyanosis, pernio, and livedo reticularis. In this article, we review differences between the conditions and suggest an approach to diagnosis and treatment strategy for these disorders.

An update on the pharmacotherapeutic options and treatment strategies for systemic sclerosis

INTRODUCTION

Systemic sclerosis (SSc) is a multi-dimensional connective tissue disease of unknown etiology. Given the immense clinical complexity of SSc, the treatment of this condition is not standardized and considerable heterogeneity exists in SSc management approaches. The purpose of this article is to highlight novel therapeutic strategies and new medications under development for the treatment of systemic sclerosis (SSc).

AREAS COVERED

Herein, the authors focus primarily on recently completed clinical trials and phase 3 and 4 clinical trials of therapeutic agents that show promise in SSc. This review is organized by the clinical complications that occur in SSc, for which novel treatment strategies are under study.

EXPERT OPINION

Combining therapies to address the individual manifestations of SSc is a cornerstone to the comprehensive management of this condition. Therapeutic strategies must take into account the organs involved, the level of disease activity in each area, and the disease stage. Controlling the complex biological network, progressive vasculopathy and fibrosis, as well as manifestations of end-organ dysfunction are all critical considerations when determining the best treatment approach for SSc.

Laser Doppler imaging evaluation of nitroglycerin patch application in systemic sclerosis patients

Recent studies suggest the use of topical nitroglycerin (NTG) application in systemic sclerosis (SSc)-associated Raynaud phenomenon (RP). With the current study, we aimed to characterize for the first time the microvascular response to a NTG patch (Trinipatch^® 5 mg/24 h) applied to the hand dorsum in patients with SSc using Laser Doppler imaging (LDI) at baseline and following a cold challenge. The study included 21 patients with SSc and 13 controls. Blood flow was evaluated by LDI at the level of the fingertips and metacarpus. Microvascular morphology was evaluated by nailfold capillaroscopy (NC). LDI revealed decreased fingertip baseline perfusion and a stronger vasoconstrictor response to a cold challenge in patients with SSc versus control. Metacarpal application of a NTG patch led to an increase in blood flow and hand temperature in patients with SSc. Furthermore, NTG administration led to a faster reperfusion after cold challenge. Correlation analyses revealed that the magnitude of the vasodilatory response was inversely related to baseline fingertip perfusion and hand temperature, but unrelated to the number of capillaries/mm assessed using NC. In conclusion, we provide evidence of a vasodilatory reaction following NTG patch application in patients with SSc using LDI and a protective effect against cold challenge. The magnitude of the response to NTG was related to functional, but not structural features. Our results support a further evaluation of the NTG patch as a possible therapeutic agent in SSc-associated RP.

Scleroderma of the Hand: Evaluation and Treatment

Scleroderma is derived from Latin meaning hard skin. It is an uncommon, noninflammatory connective tissue disorder characterized by increased fibrosis of the skin and in certain variants, multiple other organ systems. Scleroderma involves a spectrum of pathologic changes and anatomic involvement. It can be divided into localized and systemic scleroderma. Hand involvement is common and can include calcium deposits within the soft tissues, digital ischemia, and joint contracture. Nonsurgical management consists of lifestyle modifications, biofeedback, therapy for digital stiffness/contracture, and various pharmacologic medications. When nonsurgical measures are unsuccessful, certain surgical options may be indicated, each with their inherent advantages and pitfalls. Patients with scleroderma who are undergoing surgical intervention pose unique difficulties because of their poorly vascularized tissue and deficient soft-tissue envelopes, thus increasing their susceptibility to wound healing complications and infection. Some subgroups of patients are frequently systemically ill, and specific perioperative measures should be considered to reduce their surgical risk. The spectrum of hand manifestations seen in patients with scleroderma will be reviewed with the focus on evaluation and management.

Raynaud's phenomenon

Raynaud's phenomenon (RP) is common, affecting approximately 5% of the population, and is important to the rheumatologist because it is often the presenting symptom of connective tissue disease, especially of systemic sclerosis (SSc)-spectrum disorders. RP therefore provides a window of opportunity for early diagnosis. When RP is associated with SSc it is particularly challenging to treat. This review begins with a discussion of some of the recent advances in our understanding of the pathogenesis of RP: it is through increased understanding of the complex pathophysiology of RP that we are most likely to develop new therapies. The following questions are then addressed (with three clinical scenarios demonstrating key principles of assessment and management): 1. How can we predict underlying connective tissue disease in the patient presenting with Raynaud's? 2. How can we measure severity of Raynaud's? 3. What are the latest advances in treatment of connective tissue disease-related digital vasculopathy?

Raynaud's phenomenon

Raynaud's phenomenon can be either primary (idiopathic) or secondary to underlying disease including systemic sclerosis. Primary Raynaud's phenomenon is very common, affecting approximately 3%-5% of the general population. Although much rarer, systemic sclerosis-related Raynaud's phenomenon can be particularly severe, progressing to digital ulceration in approximately 50% of patients. Raynaud's phenomenon can have a major impact on quality of life. This review has a focus on the systemic sclerosis-related Raynaud's phenomenon (which is the most researched form of Raynaud's phenomenon and probably the most challenging to treat) and on recent advances. Epidemiology (including transition from 'isolated' to systemic sclerosis-related Raynaud's phenomenon), pathogenesis, diagnosis and assessment are discussed, followed by the treatment of both 'uncomplicated' and 'complicated' Raynaud's phenomena (i.e. Raynaud's phenomenon which has progressed to digital ulceration and/or critical ischaemia). Finally, some of the major challenges for the next 5-10 years are highlighted.

Management of Raynaud’s phenomenon in systemic sclerosis—a practical approach

Raynaud’s phenomenon is nearly universal in systemic sclerosis. Vasculopathy is part of systemic sclerosis. Raynaud’s phenomenon can cause of complications and impairment, especially when tissue ischemia and digital ulcers develop. There are many treatment options for Raynaud’s phenomenon in systemic sclerosis often with sparse data and few robust studies comparing the different treatment options. Recommendations from guidelines usually include calcium channel blockers as first-line pharmacological treatment. In the clinical setting, multiple variables such as financial factors, geography where access to medications varies, and patient factors, baseline hypotension, can influence the treatment for Raynaud’s phenomenon and digital ulcers. Prostacyclins and PDE-5 inhibitors are reserved for more severe Raynaud’s phenomenon or healing of digital ulcers. Prevention of digital ulcers may also include endothelin receptor blocker (bosentan) in some countries. Other treatments had less consensus. Algorithms developed by systemic sclerosis experts might be helpful in deciding which treatment to choose for each setting, using a step-wise strategy, which intends to complement guidelines. This review focuses on a practical approach to the treatment of Raynaud’s phenomenon and digital ulcers in systemic sclerosis, based on algorithms designed by systemic sclerosis experts using consensus, and we review the evidence that supports treatment from initial to second and third-line options.

The clinical effects of l-arginine and asymmetric dimethylarginine: implications for treatment in secondary Raynaud's phenomenon

Secondary Raynaud's phenomenon (RP) is often the sentinel clinical finding in systemic sclerosis and may precede systemic disease by several years. Altered nitric oxide metabolism plays a critical role in both fibrosis and severe secondary RP phenotypes in these patients. Increased flux through inducible nitric oxide synthase (iNOS) drives cutaneous fibrosis. Failure of flux through endothelial nitric oxide synthase (eNOS) contributes to increased vasoconstriction and decreased vasorelaxation. The underproduction of nitric oxide by eNOS is in part due to increased levels of asymmetric dimethylarginine (ADMA), an endogenous competitive inhibitor of nitric oxide synthase. The inhibitory effects of increased ADMA levels may be counteracted increasing serum l‐arginine, which is often an effective treatment strategy in these patients. As such, l‐arginine‐based therapies should be considered in managing secondary RP, particularly given their favourable safety and tolerability profile. While there is no established dosing regimen, studies of oral l‐arginine in secondary RP suggest that divided dosing may begin at 1–2 g/day and may be titrated up to 10 g/day. Conversely, primary RP is not associated with increased ADMA production which likely accounts for the failure of l‐arginine trials to show benefit in primary RP.

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.