Assessment of digital perfusion as a surrogate outcome in Raynaud's phenomenon clinical trials.

OBJECTIVES: Measurement of digital perfusion, sometimes coupled with a cold challenge, has been widely used as an objective outcome in trials evaluating drug therapies in Raynaud's Phenomenon (RP), in addition to patient-reported outcomes or to establish the proof-of-concept in preliminary studies. However, whether digital perfusion is a valid surrogate for clinical outcomes in RP trials has never been explored. The principal aim of this study was to evaluate the potential surrogacy of digital perfusion, by combining individual-level and trial-level data. METHODS: We used individual data from a series of n-of-1 trials, and trial data from a network meta-analysis. We estimated individual-level surrogacy through coefficients of determination between digital perfusion and clinical outcomes (R2ind). We further calculated the coefficients of determination between treatment effect on the clinical outcomes and on digital perfusion, at the individual level (R2TEInd) and at the trial level (R2trial), using non-weighted linear regression, with their 95% CI calculated through bootstrapping. RESULTS: Results from 33 patients and 24 trials were included in the final analysis. At the individual level, there was no correlation between digital perfusion and clinical outcomes at rest and in response to various cooling tests (the highest R2ind was 0.03 [-0.07; 0.09]), and R2TEinf was also very low 0.07 [0; 0.29]. At the trial level, the highest value of R2trial was 0.1 [0; 0.477]. CONCLUSIONS: Digital perfusion, at rest or in response to a cold challenge, and whatever the method used, does not fulfill the criteria of a valid surrogate for existing patient-reported outcomes in RP trials.

Individualized Net Benefit estimation and meta-analysis using generalized pairwise comparisons in N-of-1 trials.

BACKGROUND: The Net Benefit (Δ) is a measure of the benefit-risk balance in clinical trials, based on generalized pairwise comparisons (GPC) using several prioritized outcomes and thresholds of clinical relevance. We extended Δ to N-of-1 trials, with a focus on patient-level and population-level Δ. METHODS: We developed a Δ estimator at the individual level as an extension of the stratum-specific Δ, and at the population-level as an extension of the stratified Δ. We performed a simulation study mimicking PROFIL, a series of 38 N-of-1 trials testing sildenafil in Raynaud's phenomenon, to assess the power for such an analysis with realistic data. We then reanalyzed PROFIL using GPC. This reanalysis was finally interpreted in the context of the main analysis of PROFIL which used Bayesian individual probabilities of efficacy. RESULTS: Simulations under the null showed good size of the test for both individual and population levels. The test lacked power when being simulated from the true PROFIL data, even when increasing the number of repetitions up to 140 days per patient. PROFIL individual-level estimated Δ were well correlated with the probabilities of efficacy from the Bayesian analysis while showing similarly wide confidence intervals. Population-level estimated Δ was not significantly different from zero, consistently with the previous Bayesian analysis. CONCLUSION: GPC can be used to estimate individual Δ which can then be aggregated in a meta-analytic way in N-of-1 trials. GPC ability to easily incorporate patient preferences allow for more personalized treatment evaluation, while needing much less computing time than Bayesian modeling.

Iontophoresis of treprostinil promotes wound healing in a murine model of scleroderma-related ulcers.

OBJECTIVE: Systemic sclerosis (SSc) is a rare, chronic disease characterized by fibrosis, vascular alterations and digital ulcerations. Few drugs have shown efficacy to enhance wound healing of existing SSc-related ulcers. Local delivery of treprostinil, a prostacyclin analogue, may improve wound healing. The present work aimed first at developing a mouse model of SSc-related ulcerations and second at assessing the effect of iontophoresis of treprostinil on wound healing. METHODS: We used two murine models of SSc: chemically induced with HOCl, and urokinase-type plasminogen activator receptor (uPAR)-deficient. Excisional wounding was performed on the dorsal midline with a biopsy punch. Animals were randomized into three groups: treated with electrostimulation alone, with treprostinil iontophoresis or untreated. We assessed wound healing over time, as well as skin microvascular reactivity, inflammation, microvessel density and collagen distribution, before wounding and after re-epithelialization. RESULTS: uPAR-/- mice, but not HOCl-treated mice, showed impaired wound healing and decreased microvascular reactivity compared with their controls. Treprostinil iontophoresis improved wound healing and microvascular density and decreased inflammation in uPAR-/- mice, while electro-stimulation did not. However, treprostinil had no effect on microvascular reactivity and collagen distribution. CONCLUSION: This study suggests that excisional wounds in uPAR-/- mice are a relevant model of SSc-related ulcers. In addition, treprostinil iontophoresis enhances wound healing in this model. Further work in now needed to show whether this effect translates in humans.

Reproducibility of high-resolution laser speckle contrast imaging to assess cutaneous microcirculation for wound healing monitoring in mice.

OBJECTIVE: Laser speckle contrast imaging (LSCI) combines an excellent spatial and temporal resolution, with excellent reproducibility in humans. Recently, high-resolution LSCI (LSCI-HR), coupled or not with oximetry, have been marketed. They are promising approaches to assess wound healing, especially in rodents. However, their reproducibility and performance against a reference technique remain unknown. METHODS: Healthy skin perfusion was evaluated at day 0 and repeated at day 2, using LSCI-HR, high-resolution LSCI with oximetry by reflectance spectrometry (LSCI-OX), compared with laser Doppler imaging (LDI) as a reference. In a second experiment, cutaneous perfusion was measured daily during 8 days after wounding at two different sites. The reproducibility of haemoglobin oxygenation with LSCI-OX was also assessed in the two experiments. Reproducibility was expressed as within-subject coefficients of variation (CV, in %). RESULTS: The inter-day reproducibility of healthy skin perfusion was better when assessed with LSCI-HR and LSCI-OX, compared to LDI (CVs between 12 and 17% and between 26 and 29%, respectively). Inter-site reproducibility of perfusion during wound healing was also better with LSCI-HR compared to LDI (CV = 12% and 23%, respectively). Finally, we observed a good, positive correlation between perfusion measured with LDI and LSCI-HR on the periulcer area (average r = 0.77 ± 0.24). CONCLUSION: Recently developed high-resolution LSCI devices provide good reproducibility to assess healthy and wounded skin perfusion in mice. However, the reproducibility of haemoglobin oxygenation is poor.

Identifying new drugs associated with pulmonary arterial hypertension: A WHO pharmacovigilance database disproportionality analysis.

Since the 1960s, several drugs have been linked to the onset or aggravation of pulmonary arterial hypertension (PAH): dasatinib, some amphetamine-like appetite suppressants (aminorex, fenfluramine, dexfenfluramine, benfluorex) and recreational drugs (methamphetamine). Moreover, in numerous cases, the implication of other drugs with PAH have been suggested, but the precise identification of iatrogenic aetiologies of PAH is challenging given the scarcity of this disease and the potential long latency period between drug intake and PAH onset. In this context, we used the World Health Organization's pharmacovigilance database, VigiBase, to generate new hypotheses about drug associated PAH. METHODS: We used VigiBase, the largest pharmacovigilance database worldwide to generate disproportionality signals through the Bayesian neural network method. All disproportionality signals were further independently reviewed by experts in pulmonary arterial hypertension, pharmacovigilance and vascular pharmacology and their plausibility ranked according to World Health Organization causality categories. RESULTS: We included 2184 idiopathic PAH cases, yielding a total of 93 disproportionality signals. Among them, 25 signals were considered very likely, 15 probable, 28 possible and 25 unlikely. Notably, we identified 4 new protein kinases inhibitors (lapatinib, lorlatinib, ponatinib and ruxolitinib), 1 angiogenesis inhibitor (bevacizumab), and several chemotherapeutics (etoposide, trastuzumab), antimetabolites (cytarabine, fludarabine, fluorouracil, gemcitabine) and immunosuppressants (leflunomide, thalidomide, ciclosporin). CONCLUSION: Such signals represent plausible adverse drug reactions considering the knowledge of iatrogenic PAH, the drugs' biological and pharmacological activity and the characteristics of the reported case. Although confirmatory studies need to be performed, the signals identified may help clinicians envisage an iatrogenic aetiology when faced with a patient who develops PAH.

Balloon catheter vs oxytocin alone for induction of labor in women with one previous cesarean section and an unfavorable cervix: a multicenter, retrospective study.

PURPOSE: To compare the rate of vaginal birth between double-balloon catheter and oxytocin alone for induction of labor in women with one previous cesarean section and an unfavorable cervix. MATERIALS AND METHODS: A retrospective and observational study was conducted from 2013 to 2017, at the Saint-Etienne University Hospital where women received induction with a double-balloon catheter for 12 h and at the Grenoble Alpes University Hospital where women received induction with a low-dose oxytocin infusion. Primary outcome was the rate of vaginal birth. RESULTS: Out of 1920 women eligible for attempting a vaginal birth after one previous cesarean section, 501 had a labor induction. Among women with an unfavorable cervix, 160 received a double-balloon catheter in Saint Etienne and 152 received oxytocin alone in Grenoble. The vaginal birth rate was higher in the double-balloon catheter group (61% versus 47% in the oxytocin group). An induction of labor with oxytocin alone reduced chances of vaginal birth (aOR 0.38 CI-95% [0.22-0.66]) compared to cervical ripening with double-balloon catheter. The perinatal morbidity was similar in the two groups. There was, however, 3.9% uterine rupture in the oxytocin group versus 0.6% in the double-balloon group (p = 0.11). CONCLUSION: For induction of labor in women with one previous cesarean section and with unfavorable cervix, cervical ripening with a double-balloon catheter increases the rate of vaginal birth without increased risk of uterine rupture.

Induction of erythroferrone in healthy humans by micro-dose recombinant erythropoietin or high-altitude exposure.

The erythropoietin (Epo)-erythroferrone (ERFE)-hepcidin axis coordinates erythropoiesis and iron homeostasis. While mouse studies have established that Epo-induced ERFE production represses hepcidin synthesis by inhibiting hepatic BMP/SMAD signaling, evidence for the role of ERFE in humans is limited. To investigate the role of ERFE as a physiological erythroid regulator in humans, we conducted two studies: first, 24 males received six injections of saline (placebo), recombinant Epo (rhEpo) 20 UI kg-1 (micro-dose) or 50 UI kg-1 (low-dose). Second, we quantified ERFE in 22 subjects exposed to high altitude (3800 m) for 15 hours. In the first study, total hemoglobin mass (Hbmass) increased after low- but not after micro-dose injections, when compared to placebo. Serum ERFE levels were enhanced by rhEpo, remaining higher than after placebo for 48 (micro-dose) or 72 hours (low-dose) post-injections. Conversely, hepcidin levels decreased when Epo and ERFE arose, before any changes in serum iron parameters occurred. In the second study, serum Epo and ERFE increased at high altitude. The present results demonstrate that in healthy humans ERFE responds to slightly increased Epo levels not associated with Hbmass expansion and down-regulates hepcidin in an apparently iron-independent way. Notably, ERFE flags micro-dose Epo, thus holding promise as novel anti-doping biomarker.

Optimization of voriconazole therapy for treatment of invasive aspergillosis: Pharmacogenomics and inflammatory status need to be evaluated.

AIMS: Cytochrome 2C19 genotype-directed dosing of voriconazole (VRC) reduces the incidence of insufficient VRC trough concentrations (Cmin ) but does not account for CYP3A polymorphisms, also involved in VRC metabolism. This prospective observational study aimed to evaluate the utility of a genetic score combining CYP2C19 and CYP3A genotypes to predict insufficient initial VRC Cmin (<1 mg/L). METHODS: The genetic score was determined in hematological patients treated with VRC. The higher the genetic score, the faster the metabolism of the patient. The impact of the genetic score was evaluated considering initial VRC Cmin and all VRC Cmin (n = 159) determined during longitudinal therapeutic drug monitoring. RESULTS: Forty-three patients were included, of whom 41 received VRC for curative indication. Thirty-six patients had a genetic score ≥2, of whom 11 had an initial insufficient VRC Cmin . A genetic score ≥2 had a positive predictive value of 0.31 for having an initial insufficient VRC Cmin and initial VRC Cmin was not associated with the genetic score. The lack of association between the genetic score and VRC Cmin may be related to the inflammatory status of the patients (C-reactive protein [CRP] levels: median [Q1-Q3]: 43.0 [11.0-110.0] mg/L), as multivariate analysis performed on all VRC Cmin identified CRP as an independent determinant of the VRC Cmin adjusted for dose (P < .0001). CONCLUSION: The combined genetic score did not predict low VRC exposure in patients with inflammation, which is frequent in patients with invasive fungal infections. Strategies for the individualization of VRC dose should integrate the inflammatory status of patients in addition to pharmacogenetic variants.

Artificial sweeteners impair endothelial vascular reactivity: Preliminary results in rodents.

BACKGROUND AND AIMS: Prospective epidemiological studies highlighted recently the link between artificial sweeteners (AS) consumption and the risk of developing cardiometabolic diseases. However, underlying mechanisms remain unknown. Thus, the aim of this preliminary study was to characterize, in a healthy rat population, the effect of chronic AS consumption on body composition and vascular function, an early marker for cardiovascular disease. METHODS AND RESULTS: Healthy Wistar rats followed a 10-week standard diet including the consumption of water sweetened or not with a sucralose/acesulfame potassium solution at different concentrations: for moderate consumption at 1 and 2 mg.kg-1.day-1, respectively or high intake at 15 and 15 mg.kg-1.day-1 for both molecules (acceptable daily intake). Body fat composition has been evaluated and ex vivo aortic vasomotor function has been investigated with a pharmacological approach. CONCLUSION: Both groups of AS-treated rats showed a significant increase in subcutaneous and perirenal adipose tissue mass storage, without changes in total body mass. However, rats that have consumed AS at Acceptable Daily Intake (ADI) concentration revealed a significant vascular endothelial dysfunction compared to other groups. These results are interesting because they will help to better explain the observed increase in cardiometabolic risk.

Treatment by Posaconazole Tablets, Compared to Posaconazole Suspension, Does Not Reduce Variability of Posaconazole Trough Concentrations.

The delayed-release tablet formulation of posaconazole (POS-tab) results in higher plasma POS trough concentrations (Cmin) than the oral suspension (POS-susp), which raises the question of the utility of therapeutic drug monitoring (TDM). We aimed to compare the variability of the POS Cmin for the two formulations and identify determinants of the POS-tab Cmin and its variability. Demographic, biological, and clinical data from 77 allogeneic hematopoietic stem cell transplant patients (874 Cmin) treated with POS-tab (n = 41), POS-susp (n = 29), or both (n = 7) from January 2015 to December 2016 were collected retrospectively. Interpatient and within-subject coefficients of variation (CVs) of the Cmin adjusted to dose (D) were calculated for each formulation. Between-group comparisons were performed using a linear mixed effects model. The POS Cmin was higher for the tablet than for the suspension (median [25th-75th percentile]: 1.8 [1.2-2.4] mg/liter versus 1.2 [0.7-1.6] mg/liter, P < 0.0001). Interpatient CVs for the tablet and suspension were 60.8 versus 63.5% (P = 0.7), whereas within-subject CVs were 39.7 and 44.9%, respectively (P = 0.3). Univariate analysis showed that age and treatment by POS-tab were significantly and positively associated with the POS Cmin, whereas diarrhea was associated with a diminished POS Cmin Multivariate analysis identified treatment with POS-tab and diarrhea as independent factors of the POS Cmin, with a trend toward a lower impact of diarrhea during treatment with POS-tab (P = 0.07). Despite increased POS exposure with the tablet formulation, the variability of the POS Cmin was not significantly lower than that of the suspension. This suggests that TDM may still be useful to optimize tablet POS therapy.

Pulmonary arterial hypertension associated with protein kinase inhibitors: a pharmacovigilance-pharmacodynamic study.

The pathophysiology of pulmonary arterial hypertension (PAH) induced by protein kinase inhibitors (PKIs) remains unclear. To gain knowledge into this rare and severe pathology we performed a study combining a pharmacovigilance approach and the pharmacodynamic properties of PKIs.A disproportionality analysis on the World Health Organization pharmacovigilance database VigiBase using the reporting odds ratio (ROR) and 95% confidence interval was first performed. Then, we identified the most relevant cellular targets of interest through a systematic literature review and correlated the pharmacovigilance signals with the affinity for the different PKIs. We further performed a hierarchical cluster analysis to assess patterns of binding affinity.A positive disproportionality signal was found for dasatinib, bosutinib, ponatinib, ruxolitinib and nilotinib. Five non-receptor protein kinases significantly correlate with disproportionality signals: c-Src (r=0.79, p=0.00027), c-Yes (r=0.82, p=0.00015), Lck (r=0.81, p=0.00046) and Lyn (r=0.80, p=0.00036), all belonging to the Src protein kinase family, and TEC (r=0.85, p=0.00006). Kinases of the bone morphogenetic protein signalling pathway also seem to play a role in the pathophysiology of PKI-induced PAH. Interestingly, the dasatinib affinity profile seems to be different from that of other PKIs in the cluster analysis.The study highlights the potential role of the Src protein kinase family and TEC in PAH induced by PKIs. This approach combining pharmacovigilance and pharmacodynamics data allowed us to generate some hypotheses about the pathophysiology of the disease; however, the results have to be confirmed by further studies.

Short-term Efficiency and Tolerance of Ketoprofen and Methylprednisolone in Acute Sciatica: A Randomized Trial.

OBJECTIVE: Although anti-inflammatory drugs are commonly used in acute discogenic sciatica, data regarding their efficacy are scarce and controversial. We compared the efficacy and safety of intravenous ketoprofen and methylprednisolone with placebo in sciatica. DESIGN: Multicenter, double-blinded randomized controlled trial. SUBJECTS: Patients with confirmed discogenic acute sciatica, without neurologic deficit, were randomized into three arms. METHODS: Besides standard-of-care analgesic therapy, they received intravenous injections of methylprednisolone (60 mg/d) or ketoprofen (200 mg/d) or placebo for five days. The primary outcome was leg pain over five days. Secondary outcomes were clinical responses at days 3 and 5, lumbar pain, Straight Leg Raise Test and lumbar flexion index, analgesic consumption, realization of lumbar spine injections, and surgery during the study period. RESULTS: Fifty-four patients were randomized, and 50 completed the study. In patients admitted to the hospital for pain control with acute lumbar radicular pain due to intervertebral disc herniation and receiving an oral analgesic protocol including paracetamol, nefopam, tramadol, and morphine, there was no additional analgesic effect seen between groups. There was no significant difference in leg pain between the three groups over the study period. In the methylprednisolone group, however, we observed a higher rate of clinically relevant responses at day 3. No difference was observed on other secondary efficacy outcomes and safety. CONCLUSION: No significant difference in leg pain was observed between groups. However, there was a higher proportion of patients relieved with intravenous methylprednisolone at day 3, compared with ketoprofen or placebo.

Safety Profile of Sclerosing Agents: An Analysis From the World Health Organization Pharmacovigilance Database VigiBase.

BACKGROUND: Several sclerosing agents are used to treat chronic venous diseases. Although they do not seem to differ in terms of efficacy, their safety profiles might differ. OBJECTIVE: To compare the safety profile of sclerosing agents through an analysis of the World Health Organization pharmacovigilance database. METHODS: The authors performed a disproportionality analysis using the proportional reporting ratio (PRR) method to compare pharmacovigilance signals between each sclerosing agent among 6 adverse event syndromes of interest: hypersensitivity reactions, arterial thromboembolic disorders, venous thromboembolic disorders, cardiac arrhythmias, visual/neurological disturbances, and skin ulcerations. The cutoff for signal detection was defined by a logPRR lower boundary 95% confidence interval (CI) ≥0 and number of cases n ≥3. RESULTS: Of 1,227 Individual Case Safety Reports (ICSRs) identified, after removal of ICSRs with unselected indications, the authors selected 472 reports for the analysis. The authors found that polidocanol is associated with more reporting of venous embolic/thrombotic events (logPRR = 1.38 [95% CI 1.27-1.49]), ethanolamine with the higher pharmacovigilance disproportionality signal of cardiac arrhythmias (logPRR = 0.80 [95% CI 0.51-1.09]), and STS with more reporting of allergic reactions (logPRR = 1.79 [95% CI 1.59-1.98]). CONCLUSION: The safety profile of sclerosing agents significantly differs and should guide benefit-risk ratio assessment of such agents.

On-Demand Sildenafil as a Treatment for Raynaud Phenomenon: A Series of n-of-1 Trials.

Background: Treatment of Raynaud phenomenon (RP) with phosphodiesterase-5 inhibitors has shown moderate efficacy. Adverse effects decrease the risk-benefit profile of these drugs, and patients may not be willing to receive long-term treatment. On-demand single doses before or during exposure to cold may be a good alternative. Objective: To assess the efficacy and safety of on-demand sildenafil in RP. Design: Series of randomized, double-blind, n-of-1 trials. (ClinicalTrials.gov: NCT02050360). Setting: Outpatients at a French university hospital. Participants: Patients with primary or secondary RP. Intervention: Each trial consisted of a multiple crossover study in a single patient. Repeated blocks of 3 periods of on-demand treatment were evaluated: 1 week of placebo, 1 week of sildenafil at 40 mg per dose, and 1 week of sildenafil at 80 mg per dose, with a maximum of 2 doses daily. Measurements: Raynaud Condition Score (RCS) and frequency and daily duration of attacks. Skin blood flow in response to cooling also was assessed with laser speckle contrast imaging. Mixed-effects models were used and parameters were estimated in a Bayesian framework to determine individual and aggregated efficacy. Results: 38 patients completed 2 to 5 treatment blocks. On the basis of aggregated data, the probability that sildenafil at 40 mg or 80 mg was more effective than placebo was greater than 90% for all outcomes (except for RCS with sildenafil, 80 mg). However, the aggregated effect size was not clinically relevant. Yet, substantial heterogeneity in sildenafil's efficacy was observed among participants, with clinically relevant efficacy in some patients. Limitation: The response to sildenafil was substantially heterogeneous among patients. Conclusion: Despite a high probability that sildenafil is superior to placebo, substantial heterogeneity was observed in patient response and aggregated results did not show that on-demand sildenafil has clinically relevant efficacy. In this context, the use of n-of-1 trials may be an original and relevant approach in RP. Primary Funding Source: GIRCI (Groupement Interrégional de Recherche Clinique et d'Innovation) Auvergne Rhône-Alpes (academic funding) and Pfizer.

SGLT-2 inhibitors and the risk of lower-limb amputation: Is this a class effect?

Inhibitors of the sodium-glucose co-transporter-2 (SGLT-2) are a novel class of glucose-lowering agents that show promising results. However, the use of canagliflozin has been associated with an increased risk of lower-limb amputation. Whether this risk concerns other SGLT-2 inhibitors is unclear, and our objective was to address this issue. We performed a disproportionality analysis using the WHO global database of individual case safety reports (VigiBase). Among the 8 293 886 reports available between January 2013 and December 2017, we identified 79 reports of lower-limb amputation that were associated with SGLT-2 inhibitors. Among all blood glucose lowering drugs, the proportional reporting ratio (PRR) was increased only for SGLT-2 inhibitors (5.55 [4.23, 7.29]). While we observed an expected signal for canagliflozin (7.09 [5.25, 9.57]), the PRR was also high for empagliflozin (4.96 [2.89, 8.50]) and, for toe amputations only, for dapagliflozin (2.62 [1.33, 5.14]). In conclusion, our results reveal a positive disproportionality signal for canagliflozin, and also for empagliflozin, and, for toe amputations only, for dapagliflozin. However, our analysis relies on a limited number of cases and is exposed to the biases inherent to pharmacovigilance studies. Further prospective data are therefore needed to better characterize the risk of amputations with different SGLT-2 inhibitors.

Reproducibility of flow mediated skin fluorescence to assess microvascular function.

OBJECTIVE: Recent technical developments enable skin fluorescence to be quantified in vivo in humans. The present study aimed at determining whether flow mediated skin fluorescence was reproducible, sensitive to changes within an individual, and if it could differ between patients with coronary artery disease and healthy volunteers. METHODS: First, forearm flow mediated skin fluorescence recorded during and after brachial artery occlusion was assessed following successive forearm occlusion periods (1, 2, 3 and 5min) and expressed as ischemic and hyperemic responses (as % of baseline). Secondly, 3min flow mediated skin fluorescence was assessed before and after 10min local cooling to 15°C. In a third protocol, the inter-day reproducibility of ischemic and hyperemic responses to 3min occlusion was tested at an interval of 7days, and compared between healthy controls and patients with coronary artery disease (CAD). RESULTS: In the first protocol, we observed a time dependent increase in the ischemic and hyperemic responses to occlusion. Next, we observed a lower hyperemic response after local cooling (9.8±4.2 versus 17.8±2.5% respectively, P<0.001), while in contrast, the ischemic response was higher and exhibited greater variability (23±15 versus 11.8±6.4%; P=0.028). In the third protocol, the inter-day reproducibility of flow mediated skin fluorescence for a 3min occlusion period was excellent. The ischemic response was significantly lower in CAD patients than in healthy controls (6.7±4.8% vs 14.7±6.8% respectively, P<0.001). Similarly, the hyperemic response was significantly decreased in the CAD group compared to healthy controls (11.6±3.6% vs 19.5±5.4% respectively, P<0.001). CONCLUSION: We show that quantifying the ischemic and hyperemic flow mediated skin fluorescence is feasible, reproducible, sensitive to acute changes in skin blood flow, and distinguishes patients populations. However, more data are needed to evaluate the correlation with other methods or specific biochemical endothelial markers.

Assessing cutaneous microvascular function with iontophoresis: Avoiding non-specific vasodilation.

AIM: Iontophoresis of vasoactive agents is commonly used to assess cutaneous microvascular reactivity. However, it is known that iontophoresis can be limited by confounding non-specific vasodilatory effects. Despite this, there is still no standardization of protocols or data expression. Therefore, this study evaluated commonly used protocols of iontophoresis by assessing each for evidence of non-specific vasodilatory effects and examined the reproducibility of those protocols that are free of non-specific responses. METHODS: Twelve healthy participants were administered doses of acetylcholine (ACh) 1-2% and sodium nitroprusside (SNP) 1%, diluted in sodium chloride 0.9% or deionized water, and insulin 100U/mL in a sterile diluent using iontophoresis coupled with laser speckle contrast imaging (LSCI). Increases in blood flux at a control electrode, containing the diluent only, indicated a non-specific response. Reproducibility of iontophoresis protocols that were free of non-specific vasodilatory effects were subsequently compared to that of post-occlusive reactive hyperemia (PORH), used as a standard, in 20 healthy participants. RESULTS: Iontophoresis of ACh or SNP in sodium choloride (0.02mA for 200 and 400s, respectively) and ACh in deionized water (0.1mA for 30s) mediated the least non-specific vasodilatory effects. Microvascular responses to insulin were mediated mainly by non-specific effects. Compared to PORH, the intraday and interday reproducibility for iontophoresis of ACh and SNP (0.02mA for 200 and 400s, respectively) with LSCI was weaker, but still deemed good to excellent when data was expressed, in perfusion units or cutaneous vascular conductance, as the absolute peak blood flux response to the vascular reactivity test or as the change in blood flux between peak and baseline values. CONCLUSION: This study provides updated recommendations for assessing cutaneous microvascular function with iontophoresis.

Hierarchical evaluation of electrical stimulation protocols for chronic wound healing: An effect size meta-analysis.

Electrical stimulation (ES) has been tested for decades to improve chronic wound healing. However, uncertainty remains on the magnitude of the efficacy and on the best applicable protocol. We conducted an effect size meta-analysis to assess the overall efficacy of ES on wound healing, to compare the efficacy of the different modalities of electrical stimulation, and to determine whether efficacy differs depending on the wound etiology, size, and age of the chronic wound. Twenty-nine randomized clinical trials with 1,510 patients and 1,753 ulcers were selected. Overall efficacy of ES on would healing was a 0.72 SMD (95% CI: 0.48, 1) corresponding to a moderate to large effect size. We found that unidirectional high voltage pulsed current (HVPC) with the active electrode over the wound was the best evidence-based protocol to improve wound healing with a 0.8 SMD (95% CI: 0.38, 1.21), while evaluation of the efficacy of direct current was limited by the small number of studies. ES was more effective on pressure ulcers compared to venous and diabetic ulcers, and efficacy trended to be inversely associated with the wound size and duration. This study confirms the overall efficacy of ES to enhance healing of chronic wounds and highlights the superiority of HVPC over other type of currents, which is more effective on pressure ulcers, and inversely associated with the wound size and duration. This will enable to standardize future ES practices.