Decision aids for patients with carotid stenosis

BACKGROUND

Shared decision-making tools have been underused by clinicians in real-world practice. Changes to the National Coverage Determination by Medicare for carotid stenting greatly expand the coverage for patients, but simultaneously require a shared decision-making interaction that involves the use of a validated tool. Accordingly, our objective was to evaluate the currently available decision aids for carotid stenosis.

METHODS

We conducted a review of the literature for published work on decision aids for the treatment of carotid disease.

RESULTS

Four publications met inclusion criteria. We found the format of the decision aid impacted patient comprehension and decision making, although patient characteristics also played a role in the therapeutic decisions made. Notably, none of the available decision aids included the widely adopted transcarotid artery revascularization as an option.

CONCLUSIONS

Further work is needed in the development of a widespread validated decision aid instrument for patients with carotid stenosis.

Readmission After Lower Extremity Bypass Following Discharge to a Rehabilitation or Nursing Facility

INTRODUCTION

Hospital readmission after lower extremity arterial bypass (LEB) is common. Patients are often discharged to a facility after LEB as a bridge to home. Our objective was to define the association between discharge to a facility and readmission after LEB.

METHODS

We used the Vascular Quality Initiative to study patients who underwent LEB from 2017 to 2022. The primary exposure was discharge location. The primary outcome was 30-d hospital readmission.

RESULTS

We included 6076 patients across 147 centers. The overall 30-d readmission rate was 18%. Readmission occurred among 15% of patients discharged home, 22% of patients discharged to a rehabilitation facility, and 25% of patients discharged to a nursing home. After controlling for patient and procedural factors, there was no significant association between discharge location and 30-d readmission (rehabilitation versus home odds ratio: 1.06, 95% confidence interval: 0.87-1.29; nursing facility versus home odds ratio: 1.21, 95% confidence interval: 0.99-1.47). Female sex, end-stage renal disease, diabetes, heart failure, pulmonary disease, smoking, preoperative functional impairment, tibial bypass target, critical limb threatening or acute ischemia, and postoperative complications including surgical site infection, change in renal function and graft thrombosis were associated with an increased likelihood of readmission.

CONCLUSIONS

Patients discharged home after LEB experienced a similar likelihood of readmission as those discharged to a facility. While discharge to a facility may aid in care transitions, it did not appear to lead to reduced 30-d readmissions. The recommended discharge location should be predicated on patient care needs and not as a perceived mechanism to reduce readmissions.

The financial implications of cardiac stress testing prior to abdominal aortic aneurysm repair

BACKGROUND

The utilization and cost-effectiveness of stress testing before abdominal aortic aneurysm (AAA) repair remains insufficiently studied. We examined the variation and financial implications of stress testing, and their association with major adverse cardiovascular events (MACE).

METHODS

We studied patients who underwent elective endovascular (EVAR) or open AAA repair (OAR) at Vascular Quality Initiative centers from 2015 to 2019. We grouped centers into quintiles of preoperative stress testing frequency. We calculated the risk of postoperative MACE, a composite of in-hospital myocardial infarction, heart failure, or death, for each center-quintile. We obtained charges for stress tests locally and applied these to the cohort to estimate charges per 1000 patients.

RESULTS

We studied 32,459 patients (EVAR: 27,978; OAR: 4481; 283 centers). Stress test utilization varied across quintiles from 13.0% to 68.6% (median: 36.8%) before EVAR and 15.9% to 85.0% (median: 59.4%) before OAR. The risk of MACE was 1.4% after EVAR and 10.2% after OAR. There was a trend towards more common MACE after EVAR among centers with higher utilization of stress testing: 0.9% among centers in the lowest quintile, versus 1.7% in the highest quintile (p-trend = 0.068). There was no association between MACE and stress testing frequency for OAR (p-trend = 0.223). The estimated financial charges for stress testing before EVAR ranged from $125,806 per 1000 patients at 1^st-quintile centers, to $665,975 at 5^th-quintile centers. Charges before OAR ranged from $153,861 at 1^st-quintile centers, to $825,473 at 5^th-quintile centers.

CONCLUSION

Stress test use before AAA repair is highly variable and associated with substantial cost, with an unclear association with postoperative MACE. This highlights the need for improved stress testing paradigms prior to surgery.

A Case of Endofibrosis Presenting with Embolic Symptoms in a 43-Year-Old Cyclist

BACKGROUND

Endofibrosis is a rare clinical entity that usually manifests as claudication in cyclists and other endurance athletes. We report a case of a 43-year-old cyclist presenting with pain and cyanosis of his toes due to an embolism to his left anterior tibial artery. The source of the embolus was found to be an ulcerated, endofibrotic plaque in his left common femoral artery.

METHODS

We performed an extensive literature search using the PubMed database and identified 60 results on endofibrosis. Eight articles described thrombosis relating to endofibrosis. None of the articles described an embolic phenomenon relating to endofibrosis. The following search terms were used: endofibrosis, embolic, emboli, embolism, "distal occlusion," cyanosis, thrombosis, and thrombus.

RESULTS

The patient is a 43-year-old male cyclist who presented with pain and cyanosis of his second and third toes on his left foot for 1 week. The affected toes had a dark-purple discoloration involving the tissue overlying the distal phalanges. Computed tomography angiography showed an abrupt occlusion of the left anterior tibial artery in the mid-calf with a non-calcified plaque in the left common femoral artery. There were no other signs of arterial disease. He underwent left common femoral endofibrosectomy with patch angioplasty that revealed an ulcerated endofibrotic plaque with mural thrombus.

CONCLUSIONS

This case demonstrates an unusual presentation of a rare clinical entity. While there have been previous reports of thrombosis associated with endofibrosis, to our knowledge this is the first reported case of endofibrosis presenting with embolic symptoms.

The Prevalence and Regional Variation of Major Depressive Disorder Among Patients With Peripheral Arterial Disease in the Medicare Population

Background:

Current evidence suggests an association between coronary artery disease and major depressive disorder (MDD). Data to support a similar association between peripheral arterial disease (PAD) and MDD are more limited. This study examines the prevalence and regional variation of both PAD and MDD in a large contemporary patient sample.

Methods:

All Medicare claims, part A and B, from January 2009 until December 2011 were queried using diagnosis codes specific for a previously validated clinical algorithm for PAD and major depression. Codes for PAD included those specific to cerebrovascular disease, abdominal aortic aneurysm, and peripheral vascular disease. Peripheral arterial disease prevalence, major depression prevalence, and coprevalence rates were determined, respectively. Regional variation of both conditions was determined using zip code data to identify potential endemic areas of disease intensity for both diagnoses.

Results:

Over the study interval, the percentage of Medicare beneficiaries with a diagnosis of PAD remained relatively constant (3.0%-3.7%, n = 0.85-1.06 million in part A and 17.4%-17.5%, n = 4.82-4.93 million in part B), and MDD showed a similar trend (1.6%-2.7%, n = 0.46-0.79 million in part A and 6.1%-6.7%, n = 1.69-1.90 million in part B). The observed rate of MDD in those with an established diagnosis of PAD was 5-fold higher than those without PAD in part A claims (1.8-fold in part B claims). Moreover, there was a significant linear geographic correlation among patients with PAD and MDD ( r = .54, P ≤ .01).

Conclusions:

This study documents a correlation between PAD and MDD and may, therefore, identify an at-risk population susceptible to inferior clinical outcomes. Significant regional variation exists in the prevalence of PAD and MDD, though there appear to be specific endemic regions notable for both disorders. Accordingly, health-care resource allocation toward endemic regions may help improve population health among this at-risk cohort.

Human liver dendritic cells promote T cell hyporesponsiveness

The liver is believed to promote tolerance, which may be beneficial due to its constant exposure to foreign Ags from the portal circulation. Although dendritic cells (DCs) are critical mediators of immune responses, little is known about human liver DCs. We compared freshly purified liver DCs from surgical specimens with autologous blood DCs. Liver and blood DCs were equally immature, but had distinct subset compositions. BDCA-1(+) DCs represented the most prevalent liver DC subset, whereas the majority of peripheral blood DCs were CD16(+). Upon TLR4 ligation, blood DCs secreted multiple proinflammatory cytokines, whereas liver DCs produced substantial amounts of IL-10. Liver DCs induced less proliferation of allogeneic T cells both in a primary MLR and after restimulation. Similarly, Ag-specific CD4(+) T cells were less responsive to restimulation when initially stimulated by autologous liver DCs rather than blood DCs. In addition, liver DCs generated more suppressive CD4(+)CD25(+)FoxP3(+) T regulatory cells and IL-4-producing Th2 cells via an IL-10-dependent mechanism. Our findings are critical to understanding hepatic immunity and demonstrate that human liver DCs promote immunologic hyporesponsiveness that may contribute to hepatic tolerance.

CD11c identifies a subset of murine liver natural killer cells that responds to adenoviral hepatitis

The liver contains a unique repertoire of immune cells and a particular abundance of NK cells. We have found that CD11c defines a distinct subset of NK cells (NK1.1(+)CD3(-)) in the murine liver whose function was currently unknown. In naïve animals, CD11c(+) liver NK cells displayed an activated phenotype and possessed enhanced effector functions when compared with CD11c(-) liver NK cells. During the innate response to adenovirus infection, CD11c(+) NK cells were the more common IFN-gamma-producing NK cells in the liver, demonstrated enhanced lytic capability, and gained a modest degree of APC function. The mechanism of IFN-gamma production in vivo depended on TLR9 ligation as well as IL-12 and -18. Taken together, our findings demonstrate that CD11c(+) NK cells are a unique subset of NK cells in the murine liver that contribute to the defense against adenoviral hepatitis.

Circulating HLA-DR(+) natural killer cells have potent lytic ability and weak antigen-presenting cell function

Whether a freshly isolated immune cell can be equipped with both natural killing and antigen-presenting cell (APC) function has recently become controversial in mice. We sought to probe the existence of a candidate human cell with these properties by searching for cells in healthy subjects that co-express APC surface molecules and NK cell receptors. We have found that CD3(-)CD14(-)CD19(-) mononuclear cells of human blood, spleen, liver, and lymph nodes contain two distinct populations of cells that co-express HLA-DR (DR) and CD56. Circulating CD56(+) cells expressing high levels of DR were phenotypically and functionally similar to conventional CD56(-)dendritic cells (DC). Furthermore, we demonstrate here that a separate cohort of CD56(+) cells that express low levels of DR are NK cells that possess dual function as potent killers endowed with weak APC function.

Dendritic cells are required for effective cross-presentation in the murine liver

The liver harbors a diversity of cell types that have been reported to stimulate T cells. Although most hepatic dendritic cells are immature, a small population of CD11c(high) conventional dendritic cells (cDCs) exists that expresses high levels of costimulatory molecules. We sought to determine the relative contribution of cDCs to cross-presentation by the liver. In vitro, liver nonparenchymal cells (NPCs) depleted of cDCs induced only minimal proliferation and activation of antigen-specific CD8(+) T cells when loaded with soluble protein antigen. Using a transgenic mouse with the CD11c promoter driving expression of the human diphtheria toxin receptor, we found that selective depletion of cDCs in vivo reduced the number and activation of antigen-specific CD8(+) T cells in the liver after intravenous administration of soluble protein antigen. Adoptive transfer of DCs, but not CD40 stimulation, restored the hepatic T-cell response.

CONCLUSION

Our findings indicate that the ability of the liver to effectively cross-present soluble protein to antigen-specific CD8(+) T cells depends primarily on cDCs. Despite costimulation, other resident liver antigen-presenting cells cannot compensate for the absence of cDCs.