Restenosis after femoropopliteal PTA and elective stent implantation: predictive value of monocyte counts

A Single-Center Study on the Outcomes of Target Limb Revascularization in Femoropopliteal Lesions Treated With Drug Coated Balloons and Bare Metal Stents

Purpose:

Multiple randomized controlled trials have shown that both drug coated balloons (DCBs) and bare metal stents (BMSs) significantly reduce restenosis in femoropopliteal lesions compared with plain balloon angioplasty. However, few studies have directly compared DCB and BMS treatments. Therefore, the goal of our study was to determine if the rate of target lesion revascularization (TLR) differs between DCB and BMS treatment at our center.

Materials and methods:

We performed a retrospective chart review of femoropopliteal interventions at a single center from 2009 to 2017. The intervention, patient and lesion characteristics, and TLR events were recorded. Exclusion criteria were loss of follow-up, death, bail-out stenting, and amputation within 60 days of treatment. Freedom from TLR was analyzed over a 3 year period with Kaplan-Meier survival curves. Cox hazard ratios were calculated to account for patient and lesion characteristics.

Results:

A total of 322 lesions (234 patients) treated with DCBs and 225 lesions (194 patients) treated with BMSs were included in this study. There were significant differences in baseline patient and lesion characteristics between groups—a greater proportion of women, patients with dyslipidemia, and lesions with popliteal involvement were treated with DCBs. There was no difference in the freedom from TLR between DCBs and BMSs. Accounting for patient and lesion characteristics, there was still no difference between DCBs and BMSs on the hazard of TLR. While our analysis did not detect a difference in the rate of TLR, there was a significant difference in the type of TLR. Compared with DCBs, a greater proportion of lesions initially treated with BMSs were retreated via surgical bypass rather than endovascular intervention, suggesting that lesions treated with DCBs may be more amenable to future endovascular intervention.

Conclusion:

Our retrospective analysis showed no difference in the rate of TLR between lesions treated with DCBs and BMSs. However, DCBs were more often used in complicated lesions involving popliteal arteries and may also allow for easier endovascular reintervention.

A Single-Center Experience of Paclitaxel in the Treatment of Femoropopliteal Disease-No Evidence for an Association With Mortality

PURPOSE

Paclitaxel-coated devices have been increasingly used in endovascular treatment of femoropopliteal disease as they limit recurrence of lesions and improve patient outcomes. However, a recent meta-analysis reported that these devices increase mortality risk at 2 years post-intervention but did not account for confounding variables. Therefore, our goal was to evaluate mortality after paclitaxel treatment of femoropopliteal disease using patient-level data.

METHODS

We performed a retrospective review of all patients who received endovascular treatment for femoropopliteal lesions at our center between December 2009 and July 2017. There were 388 patients in the paclitaxel group and 314 control patients.

RESULTS

Survival analysis with hazard ratios showed no difference between mortality in the paclitaxel and control groups. Age, renal insufficiency, and chronic limb-threatening ischemia were significant predictors of mortality. We also used logistic regression to evaluate mortality at 1, 2, and 5 years post-intervention and found no difference between the paclitaxel and control groups at any time point, while age, renal insufficiency, and chronic limb-threatening ischemia at the time of intervention were all associated with the risk of death. Finally, we tallied the causes of death in our cohort and found no difference in the distribution of causes between groups.

CONCLUSION

Our single-center, retrospective study provides no evidence of increased risk of death with paclitaxel treatment in femoropopliteal disease. Contrastingly, age, renal insufficiency, and chronic limb-threatening ischemia were the most important factors contributing to mortality and therefore should be included as potential confounders in future studies assessing mortality in femoropopliteal disease.

Increased intermediate CD14++CD16++ monocyte subset levels associate with restenosis after peripheral percutaneous transluminal angioplasty

BACKGROUND AND AIMS

We aimed at studying the association of three major human monocyte subsets after percutaneous transluminal angioplasty (PTA) in patients with femoropopliteal disease.

METHODS

We prospectively studied 67 sequential patients (40 male, 27 female; mean age 71 ± 11 years) treated with femoropopliteal angioplasty. Multi-color flow cytometry characterized monocyte subsets from venous blood for expression of CD14 and CD16 and intracellular myeloperoxidase (MPO) prior to, and 3, 6 and 12 months post PTA. Analyses tested associations between monocyte subsets and risk for restenosis.

RESULTS

16/67 patients (24%) developed restenosis within 12 months after PTA. Patients with hyperlipidemia had increased risk for restenosis (HR = 1.7, 95% CI 0.7-2.9, p = 0.001). Increased baseline monocytes associated with an increased risk of late restenosis (HR = 4.9, 95% CI: 1.3-18.6, p = 0.047). CD14⁺⁺CD16⁺⁺ 'intermediate' monocytes assessed at baseline, and after 3, 6, and 12 months significantly associated with the risk for subsequent restenosis: HR = 3.9 (95% CI: 2.4-6.5, p = 0.029), HR = 5.7 (95% CI = 0.7-44.7, p = 0.013), HR = 6.5 (95% CI: 2.5-16.9, p = 0.001) and HR = 1.5 (95% CI = 1.4-15.5 p = 0.001), respectively. Moreover, the probability for freedom of restenosis decreased with increased levels of intermediate subsets at 12 months after PTA. Additionally, intracellular MPO expression in CD14⁺⁺CD16⁺⁺ measured at 3, 6 and 12 months associated with an increased restenosis risk (HR = 1.5, 95% CI: 0.8-2.1, p = 0.214, HR = 1.9, 95% CI: 1.0-2.3 p = 0.051 and HR = 1.4, 95% CI: 1.0-1.8, p = 0.052).

CONCLUSIONS

Our results imply altered innate immunity after angioplasty. Elevated CD14⁺⁺CD16⁺⁺ intermediate monocyte frequencies and increased MPO expression may identify individuals at heightened risk for restenosis.

Association of total white cell count with mortality and major adverse events in patients with peripheral arterial disease: a systematic review

OBJECTIVES

Peripheral arterial disease (PAD) is principally caused by atherosclerosis, an established inflammatory disease. Total white cell count (TWCC) is a marker of inflammation and has been associated with outcomes for patients with inflammatory diseases. The aim of this systematic review was to assess the association of TWCC with mortality and major adverse events (MAEs) in PAD patients.

METHODS

Studies investigating the association of TWCC with outcome in patients with PAD were identified by a literature search using the Medline and Cochrane databases. To be eligible for inclusion, studies needed to investigate the association of TWCC with mortality or a composite endpoint that included mortality in patients with PAD. Studies were excluded when the primary focus was carotid artery disease, aortic aneurysmal disease, intracranial vascular disease, or rheumatoid arthritis and treatment with chemotherapy or transplantation of stem cells. Secondary searching of reference lists and relevant reviews was performed.

RESULTS

Ten studies including 8,490 patients with PAD met the inclusion criteria. All studies investigated more than 100 patients with four studies assessing more than 1,000 patients. Study quality varied with well-established risk factors of outcome such as age, smoking, diabetes, and the ankle brachial index being adjusted for inconsistently. The study populations were also disparate. Few studies reported relative risk and 95% confidence intervals for the association of TWCC with mortality or MAE. TWCC was positively and significantly associated with death alone in four of five studies investigating 3,387 patients. TWCC was positively and significantly associated with MAE in five of six studies investigating a total of 6,846 patients.

CONCLUSIONS

Current evidence suggests a positive association of TWCC with mortality and MAEs in patients with PAD. Further well-designed prospective studies are required with high-quality analysis and more complete reporting of outcomes.

CCN4 regulates vascular smooth muscle cell migration and proliferation

The migration and proliferation of vascular smooth muscle cells (VSMCs) are essential elements during the development of atherosclerosis and restenosis. An increasing number of studies have reported that extracellular matrix (ECM) proteins, including the CCN protein family, play a significant role in VSMC migration and proliferation. CCN4 is a member of the CCN protein family, which controls cell development and survival in multiple systems of the body. Here, we sought to determine whether CCN4 is involved in VSMC migration and proliferation. We examined the effect of CCN4 using rat cultured VSMCs. In cultured VSMCs, CCN4 stimulated the adhesion and migration of VSMCs in a dose-dependent manner, and this effect was blocked by an antibody for integrin α5β1. CCN4 expression was enhanced by the pro-inflammatory cytokine tumor necrosis factor α (TNF-α). Furthermore, knockdown of CCN4 by siRNA significantly inhibited the VSMC proliferation. CCN4 also could up-regulate the expression level of marker proteins of the VSMCs phenotype. Taken together, these results suggest that CCN4 is involved in the migration and proliferation of VSMCs. Inhibition of CCN4 may provide a promising strategy for the prevention of restenosis after vascular interventions.

Heme oxygenase-1 system and gastrointestinal inflammation: A short review

Heme oxygenase-1 (HO-1) system catalyzes heme to biologically active products: carbon monoxide, biliverdin/bilirubin and free iron. It is involved in maintaining cellular homeostasis and many physiological and pathophysiological processes. A growing body of evidence indicates that HO-1 activation may play an important protective role in acute and chronic inflammation of gastrointestinal tract. This review focuses on the current understanding of the physiological significance of HO-1 induction and its possible roles in the gastrointestinal inflammation studied to date. The ability to upregulate HO-1 by pharmacological means or using gene therapy may offer therapeutic strategies for gastrointestinal inflammation in the future.

Restenosis after lower extremity interventions: current status and future directions

The incidence of restenosis after percutaneous peripheral interventions (PPI) varies considerably depending upon the vascular bed but appears to be highest in the femoropopliteal and tibioperoneal arteries. The restenosis process in the periphery does not appear to stop at the 6-month mark, as seen with bare metal stents in the coronary arteries, but continues for a longer time, possibly years, after the intervention. This review evaluates the incidence of restenosis following lower extremity arterial interventions and potential drugs or devices that could alter this process, including nonpharmacological (stents, cryoplasty, Cutting Balloon angioplasty, atherectomy, brachytherapy, and photodynamic therapy) and pharmacological (systemic and direct drug delivery) approaches. A global strategy to achieve optimal outcome with PPI is offered: (1) obtain excellent acute angiographic results with less dissection and recoil, (2) protect the distal tibial vascular bed, and (3) reduce smooth muscle cell proliferation with pharmacological intervention.

(GT)N dinucleotide repeat polymorphism of haem oxygenase-1 promotor region is not associated with inflammatory bowel disease risk or disease course

Haem oxygenase-1 (HO-1) up-regulation was suggested to reduce mucosal tissue damage in inflammatory bowel disease (IBD) and an up-regulation of HO-1 expression in patients with Crohn's disease (CD) and ulcerative colitis (UC) was demonstrated. A HO-1 gene promoter microsatellite (GT)(n) dinucleotide repeat polymorphism was associated with regulation of HO-1 in response to inflammatory stimuli. We therefore hypothesized that IBD patients might segregate into phenotypes with high or low HO-1 inducibility. Ethylenediamine tetraacetic acid blood samples were obtained from 179 CD patients, 110 UC patients and 56 control patients without inflammation. Genomic DNA was purified and the 5'-flanking region of the HO-1 gene containing the (GT)(n) dinucleotide repeat was amplified. Polymerase chain reaction (PCR) products were purified and the length of the PCR fragments was analysed. The number of (GT)(n) repeats in the population studied ranged from 13 to 42. The distribution of the allele frequencies was comparable in patients and controls for both the short and the long alleles. The frequencies of short-, middle- and long-sized alleles were not changed among the groups studied. No correlation was found between IBD and microsatellite instability detected in five individals. Our data indicate that (GT)(n) dinucleotide repeats of the HO-1 promotor region have no significance for the pathophysiology and disease course of IBD.

Preventing restenosis after angioplasty: a multistage approach

Arterial reconstruction procedures, including balloon angioplasty, stenting and coronary artery bypass, are used to restore blood flow in atherosclerotic arteries. Restenosis of these arteries has remained a major limitation of the application of these procedures, especially in the case of balloon angioplasty. Post-angioplasty restenosis results from two major processes: neointimal formation and constrictive remodelling. Neointimal formation is initiated by arterial injury with a resultant loss of contractile phenotype in tunica media, leading to VSMC [vascular SM (smooth muscle) cell] migration from the tunica media to the intima. Migrated VSMCs contribute to the intimal thickening by the excessive synthesis of ECM (extracellular matrix) and proliferation. However, increased neointimal mass is not solely responsible for luminal narrowing. Inward constrictive remodelling is also considered as a major cause of delayed failure of angioplasty. At later stages after angioplasty, the increase in contractile forces leads to lumen narrowing. Recent studies show that SM contractile proteins are re-expressed in the neointima, concomitant with late lumen loss. Therefore one important question is whether the restoration of contractile phenotype, which can suppress VSMC migration, is favourable or detrimental. In this review, the importance of viewing restenosis as a multistage process is discussed. Different stages of restenosis occur in a sequential manner and are related to each other, but in each stage a different strategy should be taken into consideration to reduce restenosis. Defining the role of each process not only reshapes the current concept, but also helps us to target restenosis with more efficacy.

Critical limb ischemia: will atherectomy and laser-directed therapy be the answer?

The interventional treatment of peripheral atherosclerotic occlusive disease is increasingly becoming accepted as an appropriate initial form of therapy. Standard methods of treatment include balloon angioplasty and stent assisted angioplasty. Laser catheters and mechanical atherectomy catheters are newer tools, which can be utilized to assist in achieving and maintaining patency in these vessels. In this report, we review the efficacy, safety, and potential advantages of these ablative devices when used for the treatment of peripheral arterial occlusive disease.