Oral vasodilators for primary Raynaud's phenomenon

Raynaud's Phenomenon: Reviewing the Pathophysiology and Management Strategies

Raynaud's phenomenon (RP) is a multifactorial vasospastic disorder characterized by a transient, recurrent, and reversible constriction of peripheral blood vessels. RP is documented to affect up to 5% of the general population, but variation in its prevalence is commonly recognized owing to many factors, including varied definitions, gender, genetics, hormones, and region. Furthermore, RP may be idiopathic or be a clinical manifestation of an underlying illness. Patients with RP classically describe a triphasic discoloration of the affected area, beginning with pallor, followed by cyanosis, and finally ending with erythema. This change in color spares the thumb and is often associated with pain. Each attack may persist from several minutes to hours. Moreover, the transient cessation of blood flow in RP is postulated to be mediated by neural and vascular mechanisms. Both structural and functional alterations observed in the blood vessels contribute to the vascular abnormalities documented in RP. However, functional impairment serves as a primary contributor to the pathophysiology of primary Raynaud's. Substances like endothelin-1, angiotensin, and angiopoietin-2 play a significant role in the vessel-mediated pathophysiology of RP. The role of nitric oxide in the development of this phenomenon is still complex. Neural abnormalities resulting in RP are recognized as either being concerned with central mechanisms or peripheral mechanisms. CNS involvement in RP may be suggested by the fact that emotional distress and low temperature serve as major triggers for an attack, but recent observations have highlighted the importance of locally produced factors in this regard as well. Impaired vasodilation, increased vasoconstriction, and several intravascular abnormalities have been documented as potential contributors to the development of this disorder. RP has also been observed to occur as a side effect of various drugs. Recent advances in understanding the mechanism of RP have yielded better pharmacological therapies. However, general lifestyle modifications along with other nonpharmacological interventions remain first-line in the management of these patients. Calcium channel blockers, alpha-1 adrenoreceptor antagonists, angiotensin-converting enzyme inhibitors, nitric oxide, prostaglandin analogs, and phosphodiesterase inhibitors are some of the common classes of drugs that have been found to be therapeutically significant in the management of RP. Additionally, anxiety management, measures to avoid colder temperatures, and smoking cessation, along with other simple modifications, have proven to be effective non-drug strategies in patients experiencing milder symptoms.

Vasodilators for primary Raynaud's phenomenon

BACKGROUND

Numerous agents have been suggested for the symptomatic treatment of primary Raynaud's phenomenon. Apart from calcium channel blockers, which are considered to be the drugs of choice, evidence of the effects of alternative pharmacological treatments is limited. This is an update of a review first published in 2008.

OBJECTIVES

To assess the effects of drugs with vasodilator effects on primary Raynaud's phenomenon as determined by frequency, severity, and duration of vasospastic attacks; quality of life; adverse events; and Raynauds Condition Score.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases, and the World Health Organization International Clinical Trials Registry Platform and the ClinicalTrials.gov trial register to November 16, 2020.

SELECTION CRITERIA

We included randomized controlled trials evaluating effects of oral, intravenous, and topical formulations of any drug with vasodilator effects on subjective symptoms, severity scores, and radiological outcomes in primary Raynaud's phenomenon. Treatment with calcium channel blockers was not assessed in this review, nor were these agents compared.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, assessed studies using the Cochrane "Risk of bias" tool, and extracted study data. Outcomes of interest included frequency, severity, and duration of attacks; quality of life (QoL); adverse events (AEs); and the Raynaud Condition Score (RCS). We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We identified seven new studies for this update. In total, we included 15 studies involving 635 participants. These studies compared different vasodilators to placebo. Individual studies used different methods and measures to report different outcomes. Angiotensin-converting enzyme (ACE) inhibitors Combining data from three studies revealed a possible small increase in the frequency of attacks per week after treatment (captopril or enalapril) compared to placebo (mean difference [MD] 0.79, 95% confidence interval [CI] 0.43 to 1.17; low-certainty evidence). There was no evidence of a difference between groups in severity of attacks (MD -0.17, 95% CI -4.66 to 4.31; 34 participants, 2 studies; low-certainty evidence); duration of attacks (MD 0.54, 95% CI -2.42 to 1.34; 14 participants, 1 study; low-certainty evidence); or AEs (risk ratio [RR] 1.35, 95% CI 0.67 to 2.73; 46 participants, 3 studies; low-certainty evidence). QoL and RCS were not reported. Alpha blockers Two studies used alpha blockers (buflomedil or moxisylyte). We were unable to combine data due to the way results were presented. Buflomedil probably reduced the frequency of attacks compared to placebo (MD -8.82, 95% CI -11.04 to -6.60; 31 participants, 1 study; moderate-certainty evidence) and may improve severity scores (MD -0.41, 95% CI -0.62 to -0.30; moderate-certainty evidence). With moxisylyte, investigators reported fewer attacks (P < 0.02), less severe symptoms (P < 0.01), and shorter duration of attacks, but the clinical relevance of these results is unclear. No evidence of a difference in AEs between buflomedil and placebo groups was noted (RR 1.41, 95% CI 0.27 to 7.28; 31 participants, 1 study; moderate-certainty evidence). More AEs were observed in participants in the moxisylyte group than in the placebo group. Prostaglandin/prostacyclin analogues One study compared beraprost versus placebo. There was no evidence of benefit for frequency (MD 2.00, 95% CI -0.35 to 4.35; 118 participants, low-certainty evidence) or severity (MD -0.06, 95% CI -0.34 to 0.22; 118 participants, low-certainty evidence) of attacks. Overall, more AEs were noted in the beraprost group (RR 1.59, 95% CI 1.05 to 2.42; 125 participants; low-certainty evidence). This study did not report on duration of attacks, QoL, or RCS. Thromboxane synthase inhibitors One study compared a thromboxane synthase inhibitor (dazoxiben) versus placebo. There was no evidence of benefit for frequency of attacks (MD 0.8, 95% CI -1.81 to 3.41; 6 participants; very low-certainty evidence). Adverse events were not reported in subgroup analyses of participants with primary Raynaud's phenomenon, and the study did not report on duration of attacks, severity of symptoms, QoL, or RCS. Selective serotonin reuptake inhibitors One study compared ketanserin with placebo. There may be a slight reduction in the number of attacks per week with ketanserin compared to placebo (MD -14.0, 95% CI -27.72 to -0.28; 41 participants; very low-certainty evidence) and reduced severity score (MD -133.00, 95% CI -162.40 to -103.60; 41 participants; very low-certainty evidence). There was no evidence that ketanserin reduced the duration of attacks (MD -4.00, 95% CI -14.82 to 6.82; 41 participants; very low-certainty evidence), or that AEs were increased in either group (RR 1.54, 95% CI 0.89 to 2.65; 41 participants; very low-certainty evidence). This study did not report on QoL or RCS. Nitrate/nitrate derivatives Four studies compared topical treatments of nitroglycerin or glyceryl trinitrate versus placebo, each reporting on limited outcomes. Meta-analysis demonstrated no evidence of effect on frequency of attacks per week (MD -1.57, 95% CI -4.31 to 1.17; 86 participants, 2 studies; very low-certainty evidence). We were unable to pool any data for the remaining outcomes. Phosphodiesterase inhibitors Three studies compared phosphodiesterase inhibitors (vardenafil, cilostazol or PF-00489791) to an equivalent placebo. Results showed no evidence of a difference in frequency of attacks (standardized MD [SMD] -0.05, 95% CI -6.71 to 6.61; 111 participants, 2 studies; low-certainty evidence), severity of attacks (MD -0.03, 95% CI -1.04 to 0.97; 111 participants, 2 studies; very low-certainty evidence), duration of attacks (MD -1.60, 95% CI -7.51 to 4.31; 73 participants, 1 study; low-certainty evidence), or RCS (SMD -0.8, 95% CI -1.74 to 0.13; 79 participants, 2 studies; low-certainty evidence). Study authors reported that 35% of participants on cilostazol complained of headaches, which were not reported in the placebo group. PF-00489791 caused 34 of 54 participants to experience AEs versus 43 of 102 participants receiving placebo (RR 1.49). Headache was most common, affecting 14 participants (PF-00489791) versus nine participants (placebo).

AUTHORS' CONCLUSIONS

The included studies investigated several different vasodilators (topical and oral) for treatment of primary Raynaud's phenomenon. Small sample sizes, limited data, and variability in outcome reporting yielded evidence of very low to moderate certainty. Evidence is insufficient to support the use of vasodilators and suggests that vasodilator use may even worsen disease.

A Randomized Controlled Trial of Acupressure for the Treatment of Raynaud's Phenomenon: The difficulty of conducting a trial in Raynaud's phenomenon

OBJECTIVE

To examine the effect of acupressure on Raynaud's phenomenon (RP) in a randomized controlled clinical trial (RCT) and to evaluate the difficulties of conducting a RP RCT.

METHODS

A pilot single center RCT of acupressure vs. targeted patient education was conducted for the treatment of RP. Patients with either primary (N = 15) or secondary (N = 8) RP were randomized in an 8-week study. The primary endpoints included a decrease in the frequency and duration of RP. Secondary endpoints included several serum biomarkers including endothelial dysfunction, Raynaud's attack symptoms, Raynaud's Condition Score, and patient and physician global assessments of RP. Primary data analysis was conducted using the last observation carried forward and t-tests or a Wilcoxon rank test was used to compare the two groups.

RESULTS

23 patients were randomized and 7 discontinued prematurely. 78% of patients were female, 96% were Caucasian, and the mean age was 49.8 (SD=16) years. No statistically significant differences were detected between the acupressure vs. education groups in primary and secondary outcomes (p> 0.05). Frequency of attacks decreased by 6.7 attacks (SD=8.8) in the acupressure group vs. 7.2 (SD=12.8) in the education group (p=0.96), and the duration of attacks decreased by 11.4 (SD=19.9) minutes in the acupressure group vs. an increase of 0.8 minutes (SD=11.2) in the education group (p=0.14). There were no adverse events noted in the RCT.

CONCLUSION

This pilot study does not support efficacy of acupressure for RP.

Evaluation of test characteristics for outcome measures used in Raynaud's phenomenon clinical trials

OBJECTIVE

Randomized controlled trials (RCTs) in Raynaud's phenomenon (RP) have shown conflicting efficacy data. Also, there is no consensus on the outcome measures that should be used. Our objectives were to assess the reliability of individual core set measures used in 3 RCTs, evaluate the placebo response for individual core set measures, and determine if a composite of individual core set measures will decrease the placebo response, which may improve our ability to see treatment effects in future trials.

METHODS

We analyzed core set measures from 249 patients in the placebo-treated groups from 3 RCTs. Core set measures analyzed included the Raynaud's Condition Score (RCS); patient and physician assessment of RP; pain, numbness, and tingling during an RP attack; average number of attacks/day; and duration of attacks. Intraclass correlation coefficients (ICCs) were calculated during the run-in period to the RCTs.

RESULTS

ICCs of ≥0.70 were observed for the RCS, attack symptoms, and average attacks/day. A high placebo response rate was observed for all individual core measures except the duration of attacks. For the RCS, the placebo response ranged from 56% with ≥10% improvement to 19.5% with ≥60% improvement. In contrast, placebo response rates of 10-20% were observed when several core set measures were combined to develop a composite score.

CONCLUSION

Outcome measures used in RCTs of RP are associated with marked variability. A combination of outcome measures is associated with low placebo responses. Future studies are needed to assess if a composite score will be able to differentiate placebo from an effective agent.

Oral vasodilators for primary Raynaud's phenomenon

BACKGROUND

Many different drugs have been suggested for the symptomatic treatment of primary Raynaud's phenomenon. Apart from calcium channel blockers, which are considered the drugs of choice, the evidence of the effects of alternative pharmacological treatments is limited. This is an update of a review first published in 2008.

OBJECTIVES

To assess the effects of various drugs with vasodilator actions on primary Raynaud's phenomenon.

SEARCH METHODS

For this update the Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched 14 May 2012), CENTRAL (Issue 4, 2012) and clinical trials databases. We contacted one pharmaceutical company and one trial author for additional information. In addition, the reference lists of relevant studies were searched for additional citations. There were no language restrictions.

SELECTION CRITERIA

Randomised controlled trials evaluating the effects of oral formulations of any drug with vasodilator effects on subjective symptoms in primary Raynaud's phenomenon. Treatment with, or comparison with, calcium channel blockers was not assessed in this review.

DATA COLLECTION AND ANALYSIS

Two members of the review team independently assessed the trials for inclusion and their quality and extracted the data. Data extraction included adverse events. We contacted trial authors for missing data.

MAIN RESULTS

Eight studies involving 290 participants were included. Two trials examined the effects of captopril, the rest were single trials on single drugs. All comparisons were with placebo. The methodological quality of most trials was poor.Enalapril was associated with a small increase in the frequency of attacks per week (difference in means 0.8; 95% CI 0.43 to 1.17). The difference between the intervention groups on a subjective improvement score was non-significant. There was a significant effect of buflomedil on the frequency of attacks per week (weighted mean difference (WMD) -8.8; 95% CI -17.55 to -0.09), but there was no evidence of effect on the severity score. The proportion with fewer attacks was significantly higher on moxisylyte than on placebo (relative risk (RR) 4.33; 95% CI 1.36 to 13.81). For captopril, beraprost, dazoxiben and ketanserin there was no evidence of an effect on the frequency, severity or duration of attacks. Beraprost and moxisylyte gave significantly more adverse effects than placebo.

AUTHORS' CONCLUSIONS

Poor methodological quality, small sample sizes and the limited data available resulted in low precision of the statistical results and limited value of the overall results .The overall results show that there is no evidence for an effect of vasodilator drugs on primary Raynaud's phenomenon.

Perniosis in a long-distance cyclist crossing Mongolia

We report a case of severe perniosis in a long-distance cyclist. This case demonstrates the importance of identifying those at risk of cold-related injuries who are about to embark on extensive travel in cold environments.

Primary Raynaud's phenomenon in an infant: a case report and review of literature

Raynaud's phenomenon (RP) is an extremely unusual finding in early infancy. In the present report we describe a one-month-old previously healthy male infant who presented with unilateral acrocyanosis. Although infantile acrocyanosis is known to be a benign and self-resolving condition, it is generally bilateral and symmetric. The unilateral nature of the acrocyanosis was an atypical finding in this infant. Consequently, he was closely monitored to evaluate the progression of his acrocyanosis. Based on his benign clinical course and failure to demonstrate other etiologies contributing to his acrocyanosis, he was diagnosed to have primary RP. Due to the rarity of RP in children, we review the progress in understanding the pathophysiology, epidemiology and management of RP and additionally discuss the differential diagnosis of unilateral and bilateral acrocyanosis in infants.

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.

Systemic sclerosis: bilateral improvement of Raynaud's phenomenon with unilateral digital sympathectomy

OBJECTIVES

To demonstrate that unilateral digital sympathectomy, in patients with Raynaud's phenomenon (RP) and systemic sclerosis (SSc), may result in bilateral resolution of RP and digital ulcerations.

METHODS

We report a case of SSc and RP that had bilateral benefits from unilateral digital sympathectomy. A computer-assisted Medline/PubMed search of the medical literature was performed for 1960 through June 2009 using the keywords sympathectomy, Raynaud's phenomenon, systemic sclerosis, CREST, and digital ulcers. These searches were also combined with text words unilateral, ipsilateral, bilateral, digital sympathectomy, selective sympathectomy, autonomic nervous system, hyperhidrosis, etiology, pathogenesis, hypothesis, and treatment. Only pertinent literature, primarily in the English language, was included.

RESULTS

The majority of patients with SSc have RP and many suffer from digital ulcerations. Medical and behavioral management may have limited benefit and surgical intervention can be considered in recalcitrant cases, although efficacy data are sparse. We describe a man with limited SSc who underwent unilateral digital sympathectomy but manifested bilateral benefit. To our knowledge, this is the first published report of contralateral response with this procedure. The patient ultimately demonstrated these digital benefits when stressed with extreme cold and hypoxia while mountaineering. Despite the onset of high-altitude sickness and cerebral edema, his fingers remained unaffected while other mountaineers sustained severe frostbite or died of hypothermia.

CONCLUSIONS

Selective unilateral sympathectomy in SSc, for RP with digital ulcerations, can result in bilateral benefits despite intense challenge with cold and hypoxia.