Cost-utility analysis of early versus delayed endovascular intervention in critical limb-threatening ischemia patients with rest pain

How multidisciplinary clinics may mitigate socioeconomic barriers to care for chronic limb-threatening ischemia

OBJECTIVE

Although multidisciplinary clinics improve outcomes in chronic limb-threatening ischemia (CLTI), their role in addressing socioeconomic disparities is unknown. Our institution treats patients with CLTI at both traditional general vascular clinics and a multidisciplinary Limb Preservation Program (LPP). The LPP is in a minority community, providing expedited care at a single facility by a consistent team. We compared outcomes within the LPP with our institution's traditional clinics and explored patients' perspectives on barriers to care to evaluate if the LPP might address them.

METHODS

All patients undergoing index revascularization for CLTI from 2014 to 2023 at our institution were stratified by clinic type (LPP or traditional). We collected clinical and socioeconomic variables, including Area Deprivation Index (ADI). Patient characteristics were compared using χ2, Student t, or Mood median tests. Outcomes were compared using log-rank and multivariable Cox analysis. We also conducted semi-structured interviews to understand patient-perceived barriers.

RESULTS

From 2014 to 2023, 983 limbs from 871 patients were revascularized; 19.5% of limbs were treated within the LPP. Compared with traditional clinic patients, more LPP patients were non-White (43.75% vs 27.43%; P < .0001), diabetic (82.29% vs 61.19%; P < .0001), dialysis-dependent (29.17% vs 13.40%; P < .0001), had ADI in the most deprived decile (29.38% vs 19.54%; P = .0061), resided closer to clinic (median 6.73 vs 28.84 miles; P = .0120), and had worse Wound, Ischemia, and foot Infection (WIfI) stage (P < .001). There were no differences in freedom from death, major adverse limb event (MALE), or patency loss. Within the most deprived subgroup (ADI >90), traditional clinic patients had earlier patency loss (P = .0108) compared with LPP patients. Multivariable analysis of the entire cohort demonstrated that increasing age, heart failure, dialysis, chronic obstructive pulmonary disease, and increasing WIfI stage were independently associated with earlier death, and male sex was associated with earlier MALE. Ten traditional clinic patients were interviewed via convenience sampling. Emerging themes included difficulty understanding their disease, high visit frequency, transportation barriers, distrust of the health care system, and patient-physician racial discordance.

CONCLUSIONS

LPP patients had worse comorbidities and socioeconomic deprivation yet had similar outcomes to healthier, less deprived non-LPP patients. The multidisciplinary clinic's structure addresses several patient-perceived barriers. Its proximity to disadvantaged patients and ability to conduct multiple appointments at a single visit may address transportation and visit frequency barriers, and the consistent team may facilitate patient education and improve trust. Including these elements in a multidisciplinary clinic and locating it in an area of need may mitigate some negative impacts of socioeconomic deprivation on CLTI outcomes.

Loss of c-Kit in Endothelial Cells Protects against Hindlimb Ischemia

BACKGROUND

Critical limb ischemia (CLI) is the end stage of peripheral artery disease (PAD), and around 30% of CLI patients are ineligible for current treatments. The angiogenic benefits of c-Kit have been reported in the ischemia scenario; however, the present study demonstrates the effects of specific endothelial c-Kit signaling in arteriogenesis during hindlimb ischemia.

METHODS

We created conditional knockout mouse models that decrease c-Kit (c-Kit VE-Cadherin CreERT2-c-Kit) or its ligand (SCF VE-Cadherin CreERT2-SCF) specifically in endothelial cells (ECs) after tamoxifen treatment. These mice and a control group (wild-type VE-Cadherin CreERT2-WT) were subjected to hindlimb ischemia or aortic crush to evaluate perfusion/arteriogenesis and endothelial barrier permeability, respectively.

RESULTS

Our data confirmed the lower gene expression of c-Kit and SCF in the ECs of c-Kit and SCF mice, respectively. In addition, we confirmed the lower percentage of ECs positive for c-Kit in c-Kit mice. Further, we found that c-Kit and SCF mice had better limb perfusion and arteriogenesis compared to WT mice. We also demonstrated that c-Kit and SCF mice had a preserved endothelial barrier after aortic crush compared to WT.

CONCLUSIONS

Our data demonstrate the deleterious effects of endothelial SCF/c-Kit signaling on arteriogenesis and endothelial barrier integrity.

The natural history of chronic limb-threatening ischemia after technical failure of endovascular intervention

OBJECTIVES

The treatment for chronic limb-threatening ischemia (CLTI) has changed dramatically in the last few decades with a shift toward an endovascular-first approach and aggressive revascularization to achieve limb salvage. As the size of the CLTI population and intervention rates increase, patients will continue to experience technical failure (TF). Here, we describe the natural history of patients after TF of endovascular intervention for CLTI.

METHODS

We conducted a retrospective cohort study of patients with CLTI who attempted endovascular intervention or bypass at our multidisciplinary limb salvage center from 2013 to 2019. Patient characteristics were collected according to the Society for Vascular Surgery's reporting standards. Primary outcomes included survival, limb salvage, wound healing, and revascularization patency. Product-limit Kaplan-Meier estimated survival functions for these outcomes, and between-group comparisons were made using Mantel-Cox log-rank nonparametric tests.

RESULTS

We identified 242 limbs from 220 unique patients who underwent primary bypass (n = 30) or attempted endovascular intervention (n = 212) at our limb salvage center. Endovascular intervention was a TF in 31 (14.6%) limbs. After TF, 13 limbs underwent secondary bypass and 18 limbs were managed medically. Patients who experienced TF tended to be older (P < .001), male (P = .003), current tobacco users (P = .014), have longer lesions (P = .001), and have chronic total occlusions of target arteries (P < .001) as compared with those who experienced technical success. Furthermore, the TF group had worse limb salvage (P = .047) and slower wound healing (P = .028), but their survival was not different. Survival, limb salvage, and wound healing were not different in patients who received secondary bypass or medical management after TF. The secondary bypass group was older (P = .012) and had a lower prevalence of tibial disease (P = .049) than the primary bypass group and trended toward decreased survival, limb salvage, and wound healing (P = .059, P = .083, and P = .051, respectively).

CONCLUSIONS

Increased age, male sex, current tobacco use, longer arterial lesions, and occluded target arteries are associated with TF of endovascular intervention. Limb salvage and wound healing are relatively poor after TF of endovascular intervention, but survival appears comparable with patients who experience technical success. Secondary bypass may not always rescue patients after TF, though our sample size limits statistical power. Interestingly, patients who received a secondary bypass after TF trended toward decreased survival, limb salvage, and wound healing compared with primary bypass.

Increased Medicaid eligibility of Affordable Care Act: Evidence of improved outcomes for patients with peripheral artery disease

Peripheral artery disease (PAD) is a debilitating disease that disproportionately affects people of low socioeconomic status and racial minority individuals. These groups also tend to have lower rates of revascularization and worse outcomes, including higher rates of major amputation. In 2010, the Affordable Care Act (ACA) was signed into law, providing better opportunities for health care access to millions of uninsured Americans, although the implementation of different components started at a later date. Political issues led to uneven adaptation by states of the different ACA components. In states that adopted Medicaid expansion under the ACA, similar to that under the Massachusetts Health Care Reform Law of 2006, patients of low socioeconomic status and racial minority patients gained better access to health care. This review article will examine the disparities that exist in peripheral artery disease outcomes, as well as the effects of the ACA and Medicaid expansion on revascularization, limb salvage, and major amputation rates.