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.

An early experience on the effect of solid organ transplant status on hospitalized COVID-19 patients.

We compared the outcome of COVID-19 in immunosuppressed solid organ transplant (SOT) patients to a transplant naïve population. In total, 10 356 adult hospital admissions for COVID-19 from March 1, 2020 to April 27, 2020 were analyzed. Data were collected on demographics, baseline clinical conditions, medications, immunosuppression, and COVID-19 course. Primary outcome was combined death or mechanical ventilation. We assessed the association between primary outcome and prognostic variables using bivariate and multivariate regression models. We also compared the primary endpoint in SOT patients to an age, gender, and comorbidity-matched control group. Bivariate analysis found transplant status, age, gender, race/ethnicity, body mass index, diabetes, hypertension, cardiovascular disease, COPD, and GFR <60 mL/min/1.73 m2 to be significant predictors of combined death or mechanical ventilation. After multivariate logistic regression analysis, SOT status had a trend toward significance (odds ratio [OR] 1.29; 95% CI 0.99-1.69, p = .06). Compared to an age, gender, and comorbidity-matched control group, SOT patients had a higher combined risk of death or mechanical ventilation (OR 1.34; 95% CI 1.03-1.74, p = .027).

A hybrid approach for vascular control and repair of an expanding iatrogenic femoral artery pseudoaneurysm.

Surgical repair of iatrogenic femoral pseudoaneurysms in the setting of distorted anatomy, multiple prior interventions, and ongoing hemorrhage requires extensive proximal and distal dissection for control. Furthermore, profunda femoral and other arterial branch control may not always be feasible and can lead to considerable blood loss at the time of surgical exploration. We present a simple, safe, and effective hybrid approach for inflow, outflow, and branch control for treatment of a proximally located, actively expanding, iatrogenic common femoral artery pseudoaneurysm recalcitrant to multiple sessions of percutaneous thrombin injection.

Impact of the COVID-19 pandemic on interventional cardiology training in the United States.

OBJECTIVES: We sought to determine the effect of COVID-19 related reduction in elective cardiac procedures and acute coronary syndrome presentations on interventional cardiology (IC) training. BACKGROUND: The COVID-19 pandemic has significantly disrupted healthcare in the United States, including cardiovascular services. The impact of COVID-19 on IC fellow training in the United States has not been assessed. METHODS: The Society for Cardiovascular Angiography and Interventions (SCAI) surveyed IC fellows training in both accredited and advanced non-accredited programs, as well as their program directors (PD). RESULTS: Responses were received from 135 IC fellows and 152 PD. All respondents noted reductions in procedural volumes beginning in March 2020. At that time, only 43% of IC fellows had performed >250 PCI. If restrictions were lifted by May 15, 2020 78% of IC fellows believed they would perform >250 PCI, but fell to only 70% if restrictions persisted until the end of the academic year. 49% of IC fellows felt that their procedural competency was impaired by COVID-19, while 97% of PD believed that IC fellows would be procedurally competent at the end of their training. Most IC fellows (65%) noted increased stress at work and at home, and many felt that job searches and/or existing offers were adversely affected by the pandemic. CONCLUSION: The COVID-19 pandemic has substantially affected IC training in the United States, with many fellows at risk of not satisfying current program procedural requirements. These observations support a move to review current IC program requirements and develop mitigation strategies to supplement gaps in education related to reduced procedural volume.

COVID-19 in recent heart transplant recipients: Clinicopathologic features and early outcomes.

BACKGROUND: The impact of COVID-19 on heart transplant (HTx) recipients remains unclear, particularly in the early post-transplant period. METHODS: We share novel insights from our experience in five HTx patients with COVID-19 (three within 2 months post-transplant) from our institution at the epicenter of the pandemic. RESULTS: All five exhibited moderate (requiring hospitalization, n = 3) or severe (requiring ICU and/or mechanical ventilation, n = 2) illness. Both cases with severe illness were transplanted approximately 6 weeks before presentation and acquired COVID-19 through community spread. All five patients were on immunosuppressive therapy with mycophenolate mofetil (MMF) and tacrolimus, and three that were transplanted within the prior 2 months were additionally on prednisone. The two cases with severe illness had profound lymphopenia with markedly elevated C-reactive protein, procalcitonin, and ferritin. All had bilateral ground-glass opacities on chest imaging. MMF was discontinued in all five, and both severe cases received convalescent plasma. All three recent transplants underwent routine endomyocardial biopsies, revealing mild (n = 1) or no acute cellular rejection (n = 2), and no visible viral particles on electron microscopy. Within 30 days of admission, the two cases with severe illness remain hospitalized but have clinically improved, while the other three have been discharged. CONCLUSIONS: COVID-19 appears to negatively impact outcomes early after heart transplantation.

Outcomes of Bone Grafting of Bone Cysts After Total Ankle Arthroplasty.

BACKGROUND: The operative treatment of bone cysts after total ankle replacements (TAR) is not well described. Bone cysts may cause component migration, implant failure, and pain. Surgery is performed on cysts with the goals of reducing pain and preventing component failure. METHODS: We retrospectively evaluated a consecutive series of 726 primary TARs performed between January 1998 and May 2013 and identified those who had a subsequent bone cyst grafting procedure. We identified cyst location and method of treatment. Clinical outcomes including secondary procedures, infection rate, complications, and failure rate were recorded. Thirty-one patients were treated with a total of 33 operative procedures for bone cysts after TAR. Of these patients, 22 (71.0%) were males with an average age of 62.2 and median follow-up 65.9 months. RESULTS: Intraoperatively, 22 tibial cysts (71.0%), 20 talar cysts (64.5%), 5 fibular cysts (16.1%), and 13 multiple cysts (41.9%) were treated. Allograft was used in 25 procedures (75.8%), calcium phosphate in 4 (12.1%), cement in 3 (9.1%), and autograft in 1 (3.0%). These procedures were supplemented by calcaneus autograft, allograft mixed with mesenchymal stem cells, platelet-rich plasma, recombinant human bone morphogenic protein-2, and demineralized bone matrix. There were no infections or wound complications. Of the 27 subjects with a successful second surgery, the success rate for bone grafting of cysts was 90.9% (95% CI: 50.8, 98.7%) at 24 months and 60.6% (95% CI: 25.1%, 83.4%) at 48 months. One patient needed a repeat bone grafting. The 4 failures observed postprocedure resulted in 3 tibial and talar component revisions, and 1 tibiotalocalcaneal (TTC) fusion. CONCLUSIONS: Grafting bone cysts without revision of TAR was in general an effective and safe means for treating patients with peri-prosthetic bone cysts. Treatment with grafting and supplemental materials may improve implant survivorship and might improve the structural support surrounding the implant. Further exploration of the etiology of bone cysts may aid in the prevention and treatment of cystic formation in the TAR. LEVEL OF EVIDENCE: Level IV, case series.

New treatment options for acute edema attacks caused by hereditary angioedema.

PURPOSE: New treatment options for acute edema attacks caused by hereditary angioedema (HAE) are reviewed. SUMMARY: HAE is characterized by mutations in the C1 inhibitor gene leading to either a reduced expression of C1 inhibitor in the plasma or expression of a functionally impaired C1 inhibitor. HAE is classified into two major types based on the cause of the C1 inhibitor deficiency. Type I HAE is defined by a reduced expression of C1 inhibitor in the plasma, whereas type II HAE is characterized by the expression of a dysfunctional C1 inhibitor protein. Clinical data were reviewed for C1 inhibitor, ecallantide, and icatibant in the treatment of acute edema attacks caused by HAE. C1 inhibitor leads to a faster onset of edema relief and is effective in decreasing the duration of edema. Dosing strategies include fixed dosing and weight-based dosing. Optimal dosing strategies have not been established, but fixed dosing (500-1000 units) or 20 units/kg has been effective in clinical trials and reports. No comparative trials suggest that one strategy is superior to another; however, the approved labeling for acute treatment is based on weight. Ecallantide is also efficacious for treating acute episodes; however, the available evidence is limited to a single published trial. Icatibant has shown variable effects in two trials with placebo and active controls. CONCLUSION: In patients with HAE, most edema episodes only involve the skin and gastrointestinal tract, though airway obstruction caused by laryngeal angioedema is the most common cause of death. I.V. C1 inhibitor should be considered first-line treatment for acute edema attacks because of its fast onset of action and effectiveness, though it is not clear whether fixed or weight-based dosing is preferred. Ecallantide can be considered as a second-line treatment option.

Genotype-phenotype aspects of type 2 long QT syndrome.

OBJECTIVES: The purpose of this study was to investigate the effect of location, coding type, and topology of KCNH2(hERG) mutations on clinical phenotype in type 2 long QT syndrome (LQTS). BACKGROUND: Previous studies were limited by population size in their ability to examine phenotypic effect of location, type, and topology. METHODS: Study subjects included 858 type 2 LQTS patients with 162 different KCNH2 mutations in 213 proband-identified families. The Cox proportional-hazards survivorship model was used to evaluate independent contributions of clinical and genetic factors to the first cardiac events. RESULTS: For patients with missense mutations, the transmembrane pore (S5-loop-S6) and N-terminus regions were a significantly greater risk than the C-terminus region (hazard ratio [HR]: 2.87 and 1.86, respectively), but the transmembrane nonpore (S1-S4) region was not (HR: 1.19). Additionally, the transmembrane pore region was significantly riskier than the N-terminus or transmembrane nonpore regions (HR: 1.54 and 2.42, respectively). However, for nonmissense mutations, these other regions were no longer riskier than the C-terminus (HR: 1.13, 0.77, and 0.46, respectively). Likewise, subjects with nonmissense mutations were at significantly higher risk than were subjects with missense mutations in the C-terminus region (HR: 2.00), but that was not the case in other regions. This mutation location-type interaction was significant (p = 0.008). A significantly higher risk was found in subjects with mutations located in alpha-helical domains than in subjects with mutations in beta-sheet domains or other locations (HR: 1.74 and 1.33, respectively). Time-dependent beta-blocker use was associated with a significant 63% reduction in the risk of first cardiac events (p < 0.001). CONCLUSIONS: The KCNH2 missense mutations located in the transmembrane S5-loop-S6 region are associated with the greatest risk.

Light-activated RNA interference using double-stranded siRNA precursors modified using a remarkable regiospecificity of diazo-based photolabile groups.

Diazo-based precursors of photolabile groups have been used extensively for modifying nucleic acids, with the intention of toggling biological processes with light. These processes include transcription, translation and RNA interference. In these cases, the photolabile groups have been typically depicted as modifying the phosphate backbone of RNA and DNA. In this work we find that these diazo-based reagents in fact react very poorly with backbone phosphates. Instead, they show a remarkable specificity for terminal phosphates and very modest modification of the nucleobases. Furthermore, the photo deprotection of these terminal modifications is shown to be much more facile than nucleobase modified sites. In this study we have characterized this regiospecificity using RNA duplexes and model nucleotides, analyzed using LC/MS/MS. We have also applied this understanding of the regio-specificity to our technique of light activated RNA interference (LARI). We examined 27-mer double-stranded precursors of siRNA ('dsRNA'), and have modified them using the photo-cleavable di-methoxy nitro phenyl ethyl group (DMNPE) group. By incorporating terminal phosphates in the dsRNA, we are able to guide DMNPE to react at these terminal locations. These modified dsRNA duplexes show superior performance to our previously described DMNPE-modified siRNA, with the range of expression that can be toggled by light increasing by a factor of two.