Clinician perspectives regarding CYP2C19 genotype testing in patients with critical limb ischemia: A Delphi approach.

OBJECTIVES: Antiplatelet therapy is an essential element in the management of patients with arterial vascular disease. In peripheral arterial disease (PAD), dual antiplatelet therapy (DAPT), primarily clopidogrel and aspirin, is routinely prescribed following intervention. There is sparse data regarding the need for DAPT, the appropriate duration, or the heterogeneity of treatment effects for antiplatelet regimens across patients, leading to potential uncertainty and heterogeneity around treatment practices. An example of heterogeneity of treatment effects is a patients' metabolizer status for the use of clopidogrel. The aim of the study was to (1) assess clinicians' knowledge of and attitudes toward managing patients with CYP2C19 mutations, (2) identify barriers to implementation of CYP2C19 testing and management policies, and (3) reach consensus for CYP2C19 testing and management strategies for patients with PAD who undergo peripheral vascular interventions (PVI). METHODS: A modified Delphi method was used to establish consensus amongst PAD interventionalists around CYP2C19 testing. All practicing Yale New Haven Hospital PAD interventionalists with backgrounds in interventional cardiology, vascular surgery, or interventional radiology were approached by email for participation. Round 1 included the collection of baseline demographic questions, knowledge questions, and three statements for consensus. Knowledge questions were rated on a 0-10 Likert scale with the following anchors: 0 ("Not at all"), 5 ("Neutral), and 10 ("Very Much"). Participants were asked to rate the importance of the three consensus statements on a 9-point Likert scale from 1 ("Strongly Disagree") to 10 ("Strongly Agree"). In Round 2, participants were shown the same consensus statements, the median response of the group from the previous round, and their previous answers. Participants were instructed to revise their rating using the results from the previous round. This process was repeated for Round 3. RESULTS: Of the 28 experts invited to participate, 13 agreed (46%). Participants were predominantly male (92.3%) and white (61.5%) with representation from interventional cardiology (46.2%) and vascular surgery (53.8%). Most participants reported more than 10+ years in practice (61.5%). PAD interventionalists felt they would benefit from more education regarding CYP2C19 mutations (median score 8.0, interquartile range 5.0-8.5). They indicated some familiarity with CYP2C19 mutations (7.0, 6.0-9.5) but did not feel strongly that CYP2C19 was important to their practice (6.0, 5.5-7.5). In each round, the median responses for the three consensus statements were 5, 6, and 9, respectively. With each successive round the interquartile range narrowed indicative of evolving consensus but did not reach the prespecified interquartile range for consensus of 1 for any of the statements. CONCLUSIONS: PAD interventionalists practicing at an academic health system recognize the heterogenous response of their patients to clopidogrel therapy but are unsure when to leverage genetic testing to improve outcomes for their patients. Our study identified gaps regarding PAD interventionalists' knowledge, perceived barriers, and attitudes toward CYP2C19 testing in PAD. This information highlights the need for randomized data on genetic testing for clopidogrel responsiveness in peripheral vascular disease following intervention to help guide antiplatelet management.

Structure Guided Discovery of Novel Pan Metallo-ß-Lactamase Inhibitors with Improved Gram-Negative Bacterial Cell Penetration.

The use of ß-lactam (BL) and ß-lactamase inhibitor combination to overcome BL antibiotic resistance has been validated through clinically approved drug products. However, unmet medical needs still exist for the treatment of infections caused by Gram-negative (GN) bacteria expressing metallo-ß-lactamases. Previously, we reported our effort to discover pan inhibitors of three main families in this class: IMP, VIM, and NDM. Herein, we describe our work to improve the GN coverage spectrum in combination with imipenem and relebactam. This was achieved through structure- and property-based optimization to tackle the GN cell penetration and efflux challenges. A significant discovery was made that inhibition of both VIM alleles, VIM-1 and VIM-2, is essential for broad GN coverage, especially against VIM-producing P. aeruginosa. In addition, pharmacokinetics and nonclinical safety profiles were investigated for select compounds. Key findings from this drug discovery campaign laid the foundation for further lead optimization toward identification of preclinical candidates.

Pharmacologic characterization of atogepant: A potent and selective calcitonin gene-related peptide receptor antagonist.

BACKGROUND: The trigeminal sensory neuropeptide calcitonin gene-related peptide (CGRP) is identified as an essential element in migraine pathogenesis. METHODS: In vitro and in vivo studies evaluated pharmacologic properties of the CGRP receptor antagonist atogepant. Radioligand binding using 125I-CGRP and cyclic adenosine monophosphate (cAMP) accumulation assays were conducted in human embryonic kidney 293 cells to assess affinity, functional potency and selectivity. Atogepant in vivo potency was assessed in the rat nitroglycerine model of facial allodynia and primate capsaicin-induced dermal vasodilation (CIDV) pharmacodynamic model. Cerebrospinal fluid/brain penetration and behavioral effects of chronic dosing and upon withdrawal were evaluated in rats. RESULTS: Atogepant exhibited high human CGRP receptor-binding affinity and potently inhibited human α-CGRP-stimulated cAMP responses. Atogepant exhibited significant affinity for the amylin1 receptor but lacked appreciable affinities for adrenomedullin, calcitonin and other known neurotransmitter receptor targets. Atogepant dose-dependently inhibited facial allodynia in the rat nitroglycerine model and produced significant CIDV inhibition in primates. Brain penetration and behavioral/physical signs during chronic dosing and abrupt withdrawal were minimal in rats. CONCLUSIONS: Atogepant is a competitive antagonist with high affinity, potency and selectivity for the human CGRP receptor. Atogepant demonstrated a potent, concentration-dependent exposure/efficacy relationship between atogepant plasma concentrations and inhibition of CGRP-dependent effects.

A generalized canine transfer function accurately reconstructs central aortic pressure waveforms to enable enhanced pulse wave analysis.

Routine preclinical blood pressure evaluation is an important risk assessment tool. Although proximal aortic pressure is most relevant for key target organs, abdominal aortic pressures are more commonly recorded. Pulse pressure amplification and waveform distortion in abdominal waveforms make it inappropriate for central hemodynamic analytical methods without the use of a mathematical transfer function. Clinical transfer functions have been developed to estimate ascending aortic waveforms from brachial or radial artery waveforms in humans, but no preclinical analogues exist. The aim of this study was to develop a canine-specific transfer function to reconstruct thoracic aortic pressure waveforms from abdominal aortic data to enable the application of central hemodynamic analytical methods. Simultaneous abdominal and thoracic blood pressures were recorded from seven conscious, male beagle dogs administered 3 well-characterized pharmacologic standards and animals were appointed to a training (n = 3) or validation (n = 4) group at baseline and during dosing. A generalized transfer function was developed from the training group data and evaluated for its ability to synthesize thoracic pressure waves in the training and validation groups. Select hemodynamic parameters were evaluated in measured and synthesized thoracic data. There was a high degree of correlation between measured and synthesized thoracic parameters (r2 = 0.74-0.99). There was no difference between indices computed from synthesized or actual thoracic waveforms at baseline or after administration of pharmacologic standards. This work demonstrates that a generalized preclinical transfer function can reproduce thoracic pressure waves across a range of hemodynamic responses thus enabling the application of central hemodynamic analytical methods.

Development and characterization of canine-specific computational models to predict pulsatile arterial hemodynamics and ventricular-arterial coupling.

Pulsatile hemodynamics analyses provide important information about the ventricular-arterial system which cannot be inferred by standard blood pressure measurements. Pulse wave analysis (PWA), wave separation analysis (WSA), and wave power analysis (WPA) characterize arterial hemodynamics with limited preclinical applications. Integrating these tools into preclinical testing may enhance understanding of disease or therapeutic effects on cardiovascular function. We used a canine rapid ventricular pacing (RVP) heart failure model to: (1) Characterize hemodynamics in response to RVP and (2) assess analyses from flow waveforms synthesized from pressure compared to those derived from measured flow. Female canines (n = 7) were instrumented with thoracic aortic pressure transducers, ventricular pacing leads, and an ascending aortic flow probe. Data were collected at baseline, 1 week, and 1 month after RVP onset. RVP progressively reduced stroke volume (SV), the PWA SV estimator, and WSA and WPA pulsatility and wave reflection indices. Indices derived from synthesized flow exhibited similar directional changes and high concordance with measured flow calculations. Our data demonstrate the value of analytical hemodynamic methods to gain deeper insight into cardiovascular function in preclinical models. These approaches can provide complementary value to standard endpoints in evaluating potential effects of pharmaceutical agents intended for human use.

Trends and impact of intravascular ultrasound and optical coherence tomography on percutaneous coronary intervention for myocardial infarction.

Background: Intravascular imaging with either intravascular ultrasound (IVUS) or optical coherence tomography (OCT) during percutaneous coronary intervention (PCI) is associated with improved outcomes, but these techniques have previously been underutilized in the real world. We aimed to examine the change in utilization of intravascular imaging-guided PCI over the past decade in the United States and assess the association between intravascular imaging and clinical outcomes following PCI for myocardial infarction (MI). Methods: We surveyed the National Inpatient Sample from 2008 to 2019 to calculate the number of PCIs for MI guided by IVUS or OCT. Temporal trends were analyzed using Cochran-Armitage trend test or simple linear regression for categorical or continuous outcomes, respectively. Multivariable logistic regression was used to compare outcomes following PCI with and without intravascular imaging. Results: A total of 2,881,746 PCIs were performed for MI. The number of IVUS-guided PCIs increased by 309.9 % from 6,180 in 2008 to 25,330 in 2019 (P-trend < 0.001). The percentage of IVUS use in PCIs increased from 3.4 % in 2008 to 8.7 % in 2019 (P-trend < 0.001). The number of OCT-guided PCIs increased 548.4 % from 246 in 2011 to 1,595 in 2019 (P-trend < 0.001). The percentage of OCT guidance in all PCIs increased from 0.0 % in 2008 to 0.6 % in 2019 (P-trend < 0.001). Intravascular imaging-guided PCI was associated with lower odds of in-hospital mortality (adjusted odds ratio 0.66, 95 % confidence interval 0.60-0.72, p < 0.001). Conclusions: Although the number of intravascular imaging-guided PCIs have been increasing, adoption of intravascular imaging remains poor despite an association with lower mortality.

Association of respiratory failure with inhibition of NaV1.6 in the phrenic nerve.

As part of a drug discovery effort to identify potent inhibitors of NaV1.7 for the treatment of pain, we observed that inhibitors produced unexpected cardiovascular and respiratory effects in vivo. Specifically, inhibitors administered to rodents produced changes in cardiovascular parameters and respiratory cessation. We sought to determine the mechanism of the in vivo adverse effects by studying the selectivity of the compounds on NaV1.5, NaV1.4, and NaV1.6 in in vitro and ex vivo assays. Inhibitors lacking sufficient NaV1.7 selectivity over NaV1.6 were associated with respiratory cessation after in vivo administration to rodents. Effects on respiratory rate in rats were consistent with effects in an ex vivo hemisected rat diaphragm model and in vitro NaV1.6 potency. Furthermore, direct blockade of the phrenic nerve signaling was observed at exposures known to cause respiratory cessation in rats. Collectively, these results support a significant role for NaV1.6 in phrenic nerve signaling and respiratory function.

Development of ProTx-II Analogues as Highly Selective Peptide Blockers of Nav1.7 for the Treatment of Pain.

Inhibitor cystine knot peptides, derived from venom, have evolved to block ion channel function but are often toxic when dosed at pharmacologically relevant levels in vivo. The article describes the design of analogues of ProTx-II that safely display systemic in vivo blocking of Nav1.7, resulting in a latency of response to thermal stimuli in rodents. The new designs achieve a better in vivo profile by improving ion channel selectivity and limiting the ability of the peptides to cause mast cell degranulation. The design rationale, structural modeling, in vitro profiles, and rat tail flick outcomes are disclosed and discussed.

Association of sleep apnea with outcomes in peripheral artery disease: Insights from the PORTRAIT study.

BACKGROUND: Sleep apnea is a predictor of adverse cardiovascular outcome in many cardiovascular diseases but whether it is associated with worse health status outcomes or mortality in peripheral artery disease (PAD) is unknown. METHODS: PORTRAIT is an international (US, Netherlands, Australia) prospective PAD registry that consecutively enrolled patients who presented with new-onset or recent exacerbations of PAD symptoms to any of 16 vascular specialty clinics. Health status was assessed upon presentation and at 12 months with the disease-specific Peripheral Artery Questionnaire (PAQ). Higher PAQ scores indicate better health status. A sequentially-adjusted hierarchical linear regression model examined the association between sleep apnea and 1-year PAQ symptoms, quality of life, and summary scores. Five-year survival curves by comorbid sleep apnea status for US patients were compared using the log-rank test. RESULTS: The mean age of the 1204 PORTRAIT participants was 67.6 ± 9.4 years with 37.5% women and 8.3% (n = 100) having sleep apnea. Patients with sleep apnea were more likely to be from the US, more sedentary, and to have diabetes, obesity, coronary disease, more depressive symptoms and a history of prior peripheral interventions. Paradoxically, they also had higher ankle-brachial indices, but lower PAQ Summary scores at presentation and 12 months (41.2 ± 22.0 vs. 49. 9± 21.6 and 58.6 ± 27.9 vs. 71.3 ± 24.9, respectively, p = <0.05). The association between sleep apnea and 1-year health status persisted after multivariable adjustment, but there were no differences in all-cause mortality over 5 years (28.0% vs. 23.4%, p = 0.76). CONCLUSION: In patients presenting with PAD, comorbid sleep apnea is independently associated with worse health status over time. Future studies should test whether better treatment of sleep apnea can improve the health status of patients with PAD. CLINICAL TRIAL REGISTRATION: NCT01419080.

Effect of osteopathic manipulative treatment on pulmonary function testing in children with asthma.

CONTEXT: Asthma is a leading cause of pediatric chronic illness, and poor disease control can lead to decreased quality of life and impaired academic performance. Although osteopathic manipulative treatment (OMT) has been shown to have positive effects on pulmonary function in adult patient populations, less is known about its impact in children. OBJECTIVES: To evaluate changes in pulmonary function testing (PFT) in pediatric patients on the same day they received OMT compared with PFT in those who received usual care. METHODS: We recruited patients between the ages of 7-18 years with a diagnosis of asthma who were receiving routine care at a primary care asthma clinic and had undergone baseline spirometry. Patients were excluded if they met any of the following criteria: clinical indication for pre- and postbronchodilator spirometry on the day of their visit, albuterol use in the last 8 hours, oral steroid use in the previous 2 weeks, or diagnosis of asthma exacerbation in the previous 4 weeks. Eligible patients were then randomized to either an OMT or a control group. Patients in the OMT group were treated with rib raising and suboccipital release in addition to standard asthma care, while control group patients received standard care only. A second PFT was performed for patients in both groups at the end of the visit. OMT was performed by multiple osteopathic pediatric residents specifically trained for this study. Change in spirometry results (forced vital capacity [FVC], forced expiration volume in 1 second [FEV1], FVC/FEV1, and forced expiratory flow 25-75%) were then compared. RESULTS: The study population included 58 patients: 31 (53.4%) were assigned to the OMT group and 27 (46.6%) were assigned to the standard of care group. Patients who received OMT had greater improvement in all spirometry values compared to the usual group; however, these changes were not statistically significant. CONCLUSIONS: The benefits of OMT on short term spirometry results in pediatric asthma patients remain unclear.

Safety and efficacy outcomes of the Pioneer Plus catheter in endovascular revascularization of lower extremity chronic total occlusions.

OBJECTIVE: Our aim was to evaluate the efficacy and safety outcomes of the Pioneer Plus catheter (Philips, San Diego, Calif) and report the in-hospital and 30-day outcomes of lower extremity chronic total occlusion (CTO) interventions assisted by the Pioneer Plus catheter. In addition, we explored the factors associated with procedural success. METHODS: We conducted a retrospective review of 135 consecutive procedures in 116 patients from July 2011 to September 2018 performed by eight operators with various levels of experience at a high-volume center where the Pioneer Plus catheter was used for lower extremity CTO. The patient demographics, preprocedural symptoms, preprocedural testing results, procedural setting, and angiography findings were abstracted. The outcomes were divided into device-related and procedure-related outcomes. Device-related efficacy outcome included procedural success. Device-related safety outcomes included device-related complications. Procedure-related outcomes included procedure-related complications, 30-day major adverse cardiovascular events, and 30-day major adverse limb events. We conducted univariate comparisons of the provider, patient, and procedural characteristics stratified by procedural success. RESULTS: Procedural success was observed in 118 procedures overall (87.4%), and success rates ≤95.8% were observed for operators with an experience level of >25 devices deployed. No device-related complications, such as pseudoaneurysm formation, vessel perforation, or arteriovenous fistula formation, were observed. The Pioneer Plus catheter was mostly often used for CTO in the superficial femoral and popliteal arteries. Overall, the procedure-related complications included access site hematoma (5.2%), major bleeding (0.7%), pseudoaneurysm formation (0.7%), distal embolization (1.5%), and acute arterial thrombosis (1.5%). The 30-day major adverse limb events included index limb unplanned amputation (0.7%), index limb reintervention (4.4%), and index limb acute limb ischemia (0.7%) and occurred in 5.9% of the procedures. The only factor associated with procedural success was operator experience (P < .0001). CONCLUSIONS: The results from the present study have shown that Pioneer Plus catheter use is safe and effective when used to cross lower extremity CTO. However, further investigation is needed to identify patient- and provider-level factors to optimize patient outcomes.

Systematic review and meta-analysis of outcomes of lower extremity peripheral arterial interventions in patients with and without chronic kidney disease or end-stage renal disease.

OBJECTIVE: Patients with chronic kidney disease (CKD) have a greater risk of peripheral arterial disease (PAD). Although individual studies have documented an association between CKD and/or end-stage renal disease (ESRD) and adverse outcomes in patients undergoing PAD interventions in an era of technological advances in peripheral revascularization, the magnitude of the effect size is unknown. Therefore, we performed a meta-analysis to compare the outcomes of PAD interventions for patients with CKD/ESRD with those patients with normal renal function, stratified by intervention type (endovascular vs surgical), reflecting contemporary practice. METHODS: Five databases were analyzed from January 2000 to June 2019 for studies that had compared the outcomes of lower extremity PAD interventions for patients with CKD/ESRD vs normal renal function. We included both endovascular and open interventions, with an indication of either claudication or critical limb ischemia. We analyzed the pooled odds ratios (ORs) across studies with 95% confidence intervals (CIs) using a random effects model. Funnel plot and exclusion sensitivity analyses were used for bias assessment. RESULTS: Seventeen observational studies with 13,140 patients were included. All included studies, except for two, had accounted for unmeasured confounding using either multivariable regression analysis or case-control matching. The maximum follow-up period was 114 months (range, 0.5-114 months). The incidence of target lesion revascularization (TLR) was greater in those with CKD/ESRD than in those with normal renal function (OR, 1.68; 95% CI, 1.25-2.27; P = .001). The incidence of major amputations (OR, 1.97; 95% CI, 1.37-2.83; P < .001) and long-term mortality (OR, 2.28; 95% CI, 1.45-3.58; P < .001) was greater in those with CKD/ESRD. The greater TLR rates with CKD/ESRD vs normal renal function were only seen with endovascular interventions, with no differences for surgical interventions. The differences in rates of major amputations and long-term mortality between the CKD/ESRD and normal renal function groups were statistically significant, regardless of the intervention type. CONCLUSIONS: Patients with CKD/ESRD who have undergone lower extremity PAD interventions had worse outcomes than those of patients with normal renal function. When stratifying our results by intervention (endovascular vs open surgery), greater rates of TLR for CKD/ESRD were only seen with endovascular and not with open surgical approaches. Major amputations and all-cause mortality were greater in the CKD/ESRD group, irrespective of the indication. Evidence-based strategies to manage this at-risk population who require PAD interventions are essential.

Safety and efficacy of paclitaxel drug-coated balloon in femoropopliteal in-stent restenosis.

INTRODUCTION: The femoropopliteal (FP) segment is a common site of involvement in peripheral arterial disease (PAD) and endovascular therapy has been shown to be safe and effective in the treatment of FP disease. Self-expanding nitinol stents are now frequently used for the treatment of FP disease but in-stent restenosis (ISR) remains a major issue that can lead to recurrence of symptoms requiring repeated revascularizations. Compared to plain old balloon angioplasty (POBA), drug-coated balloons (DCBs) have shown promising results with reduction of ISR rates and target lesion revascularization (TLR). AREAS COVERED: The aim of this review is to describe the mechanisms and classification of ISR and to summarize the available data on outcomes of all DCBs, especially in the treatment of FP ISR. EXPERT OPINION: Currently available data supports the use of DCBs as a first-line therapy in patients with FP ISR, with lower rates of TLR and higher patency rates at 1-year follow-up, when compared to POBA. Further randomized studies are essential to evaluate longer term safety and efficacy of DCBs.

Utility of Intravascular Ultrasound in Peripheral Vascular Interventions: Systematic Review and Meta-Analysis.

OBJECTIVES: We sought to compare outcomes between intravascular ultrasound- (IVUS) versus angiography (AO)-guided peripheral vascular interventions (PVIs). Introduction: Intravascular ultrasound facilitates plaque visualization and angioplasty during PVIs for peripheral arterial disease. It is unclear whether IVUS may improve the durability of PVIs and lead to improved clinical outcomes. METHODS: This is a study-level meta-analysis of observational studies. The primary end points of this study were rates of primary patency and reintervention. Secondary end points included rates of vascular complications, periprocedural adverse events, amputations, technical success, all-cause mortality, and myocardial infarction. RESULTS: Eight observational studies were included in this analysis with 93 551 patients. Mean follow-up was 24.2 ± 15 months. Intravascular ultrasound-guided PVIs had similar patency rates when compared with AO-guided PVIs (relative risk [RR]: 1.30, 95% confidence interval [CI]: 0.99-1.71, P = .062). There was no difference in rates of reintervention in IVUS-guided PVIs when compared to non-IVUS-guided PVIs (RR: 0.41, 95% CI: 0.15-1.13, P = .085). There is a lower risk of periprocedural adverse events (RR: 0.81, 95% CI: 0.70-0.94, P = .006) and vascular complications (RR: 0.81, 95% CI: 0.68-0.96, P = .013) in the IVUS group. All-cause mortality (RR: 0.76, 95% CI: 0.56-1.04, P = .084), amputation rates (RR 0.83, 95% CI: 0.32-2.15, P = .705), myocardial infarctions (RR: 1.19, 95% CI: 0.58-2.41, P = .637), and technical success (RR: 1.01, 95% CI: 0.86-1.19, P = .886) were similar between the groups. Conclusions: Intravascular ultrasound-guided PVIs had similar primary patency and reintervention when compared with AO-guided PVIs with significantly lower rates of periprocedural adverse events and vascular complications in the IVUS-guided group.

Characterization of Ubrogepant: A Potent and Selective Antagonist of the Human Calcitonin Gene‒Related Peptide Receptor.

A growing body of evidence has implicated the calcitonin gene-related peptide (CGRP) receptors in migraine pathophysiology. With the recent approval of monoclonal antibodies targeting CGRP or the CGRP receptor, the inhibition of CGRP-mediated signaling has emerged as a promising approach for preventive treatments of migraine in adults. However, there are no small-molecule anti-CGRP treatments available for treating migraine. The current studies aimed to characterize the pharmacologic properties of ubrogepant, an orally bioavailable, CGRP receptor antagonist for the acute treatment of migraine. In a series of ligand binding assays, ubrogepant exhibited a high binding affinity for native (K i=0.067 nM) and cloned human (K i=0.070 nM) and rhesus CGRP receptors (K i=0.079 nM), with relatively lower affinities for CGRP receptors from rat, mouse, rabbit and dog. In functional assays, ubrogepant potently blocked human α-CGRP stimulated cAMP response (IC50 of 0.08 nM) and exhibited highly selective antagonist activity for the CGRP receptor compared with other members of the human calcitonin receptor family. Furthermore, the in vivo CGRP receptor antagonist activity of ubrogepant was evaluated in a pharmacodynamic model of capsaicin-induced dermal vasodilation (CIDV) in rhesus monkeys and humans. Results demonstrated that ubrogepant produced concentration-dependent inhibition of CIDV with a mean EC50 of 3.2 and 2.6 nM in rhesus monkeys and humans, respectively. Brain penetration studies with ubrogepant in monkeys showed a CSF/plasma ratio of 0.03 and low CGRP receptor occupancy. In summary, ubrogepant is a competitive antagonist with high affinity, potency, and selectivity for the human CGRP receptor. SIGNIFICANCE STATEMENT: Ubrogepant is a potent, selective, orally delivered, small-molecule competitive antagonist of the human calcitonin generelated peptide receptor. In vivo studies using a pharmacodynamic model of capsaicin-induced dermal vasodilation (CIDV) in rhesus monkeys and humans demonstrated that ubrogepant produced concentration-dependent inhibition of CIDV, indicating a predictable pharmacokinetic-pharmacodynamic relationship.

Combining an in silico proarrhythmic risk assay with a tPKPD model to predict QTc interval prolongation in the anesthetized guinea pig assay.

Human-based in silico models are emerging as important tools to study the effects of integrating inward and outward ion channel currents to predict clinical proarrhythmic risk. The aims of this study were 2-fold: 1) Evaluate the capacity of an in silico model to predict QTc interval prolongation in the in vivo anesthetized cardiovascular guinea pig (CVGP) assay for new chemical entities (NCEs) and; 2) Determine if a translational pharmacokinetic/pharmacodynamic (tPKPD) model can improve the predictive capacity. In silico simulations for NCEs were performed using a population of human ventricular action potential (AP) models. PatchXpress® (PX) or high throughput screening (HTS) ion channel data from respectively n = 73 and n = 51 NCEs were used as inputs for the in silico population. These NCEs were also tested in the CVGP (n = 73). An M5 pruned decision tree-based regression tPKPD model was used to evaluate the concentration at which an NCE is liable to prolong the QTc interval in the CVGP. In silico results successfully predicted the QTc interval prolongation outcome observed in the CVGP with an accuracy/specificity of 85%/73% and 75%/77%, when using PX and HTS ion channel data, respectively. Considering the tPKPD predicted concentration resulting in QTc prolongation (EC5%) increased accuracy/specificity to 97%/95% using PX and 88%/97% when using HTS. Our results support that human-based in silico simulations in combination with tPKPD modeling can provide correlative results with a commonly used early in vivo safety assay, suggesting a path toward more rapid NCE assessment with reduced resources, cycle time, and animal use.

Drug-coated balloon versus plain old balloon angioplasty in femoropopliteal disease: An updated meta-analysis of randomized controlled trials.

BACKGROUND: Drug-coated balloon (DCB) angioplasty has emerged as a mainstay of therapy for the treatment of peripheral arterial disease (PAD) involving the superficial femoral and popliteal arteries. We performed a meta-analysis including all available randomized controlled trials (RCTs) to date which compare DCB to plain balloon angioplasty (POBA) in femoropopliteal disease (FPD). METHODS: Five databases were analyzed including EMBASE, PubMed, Cochrane, Scopus, and Web-of-Science from January 2000 to September 2018 for RCTs comparing DCB to POBA in patients with FPD. Heterogeneity was determined using Cochrane's Q-statistics. Random effects model was used. RESULTS: Twenty-two RCTs, including five trials of in-stent restenosis (ISR) intervention, with 3,217 patients were included in the analysis. Mean follow-up was approximately 21.6 ± 14.4 months. Overall, DCB use was associated with a 51% reduction in target vessel revascularization (TLR) when compared to POBA at follow-up (relative risk [RR]: 0.49, 95% confidence interval [CI]: 0.40-0.61, P < 0.0001). Rates of TLR were 45% lower in the DCB group when compared to POBA in patients with ISR (RR: 0.55, 95% CI: 0.37-0.81, P = 0.002). DCB was associated with lower rates of binary stenosis, late lumen loss and higher primary safety endpoints. Major amputation and mortality were not different between DCB and POBA. CONCLUSIONS: Use of DCBs is associated with improved vessel patency and a lower risk of TLR when compared to POBA in patients with FPD, especially in the setting of ISR. There was no difference in mortality between DCB and POBA in our meta-analysis. Extended follow-up of the available RCT data will be essential to analyze long-term device-related mortality.

Review of the Current Basic Science Strategies to Treat Critical Limb Ischemia.

Critical limb ischemia (CLI) is a highly morbid disease with many patients considered poor surgical candidates. The lack of treatment options for CLI has driven interest in developing molecular therapies within recent years. Through these translational medicine studies in CLI, much has been learned about the pathophysiology of the disease. Here, we present an overview of the macrovascular and microvascular changes that lead to the development of CLI, including impairment of angiogenesis, vasculogenesis, and arteriogenesis. We summarize the randomized clinical controlled trials that have used molecular therapies in CLI, and discuss the novel imaging modalities being developed to assess the efficacy of these therapies.

Review of the Latest Percutaneous Devices in Critical Limb Ischemia.

Critical limb ischemia (CLI) is a terminal stage of peripheral arterial disease that, in the absence of intervention, may lead to lower extremity amputation or death. Endovascular interventions have become a first-line approach to the management of CLI and have advanced considerably within the past decade. This review summarizes the types of percutaneous devices and the techniques that are available for the management of CLI and the data supporting their use. These include devices that establish and maintain vessel patency, including percutaneous transluminal angioplasty, drug-coated balloons, bare metal stents, drug-eluting stents, bioresorbable vascular scaffolds, and atherectomy; devices that provide protection from embolization; and, cell-based therapies. Additionally, ongoing trials with important implications for the field are discussed.