Predictors of Occlusion after Carotid Stenting.

BACKGROUND: Carotid artery stent (CAS) occlusion is a rare complication not well studied. We used a national dataset to assess real world CAS experience to determine the rate of stent occlusion. The purpose of this study was to 1) Identify risk factors associated with CAS occlusion on long-term follow-up (LTFU) and 2) Determine the adjusted odds of death/transient ischemic attack (TIA)/stroke (cerebrovascular accident (CVA)) in patients with occlusion. METHODS: The national Vascular Quality Initiative CAS dataset (2016-2021) comprised the sample. The primary endpoint was occlusion on LTFU (9-21 months postoperatively as defined by the Vascular Quality Initiative LTFU dataset) with secondary endpoint examining a composite of death/TIA/CVA. Descriptive analyses used chi-square and Wilcoxon tests for categorical and continuous variables respectively. Adjustment variables were selected a priori based on clinical expertise and univariate analyses. Multivariable logistic regression was used to model the odds of occlusion and the odds of death/TIA/CVA. Generalized estimating equations accounted for center level variation. RESULTS: During the study period, 109 occlusions occurred in 12,143 cases (0.9%). On univariate analyses, symptomatic indication, prior stroke, prior neck radiation, lesion calcification (>50%), stenosis (>80%), distal embolic protection device (compared to flow reversal), balloon size, >1 stent and current smoking at time of LTFU were predictive for occlusion. Age ≥ 65, coronary artery disease (CAD), elective status, preoperative statin, preoperative and discharge P2Y12 inhibitor, use of any protection device intraoperatively and protamine were protective. On multivariable analyses, age ≥ 65, CAD, elective status and P2Y12 inhibitor on discharge were protective for occlusion, while patients with prior radiation and those taking P2Y12 inhibitor on LTFU were at increased odds. The adjusted odds of death/TIA/CVA in patients with occlusion on LTFU were 6.05; 95% confidence interval: 3.61-10.11, P < 0.0001. CONCLUSIONS: This study provides an in-depth analysis of predictors for CAS occlusion on LTFU. On univariate analyses, variables related to disease severity (urgency, degree of stenosis, nature of lesion) and intraoperative details (balloon diameter, >1 stent) were predictive for occlusion. These variables were not statistically significant after risk adjustment. On multivariable analyses, prior neck radiation was strongly predictive of occlusion. Elective status, patient age ≥ 65, CAD, and P2Y12 inhibitor upon discharge (but not on LTFU) were protective for occlusion. Additionally, patients who developed occlusion had high odds for death/TIA/CVA. These findings provide important data to guide clinical decision-making for carotid disease management, particularly identifying high-risk features for CAS occlusion. Closer postoperative follow-up and aggressive risk factor modification in these patients may be merited.

Outcomes of carotid artery stenting in patients with radiation arteritis compared with those with atherosclerotic disease.

OBJECTIVE: Head and neck malignancies are often treated with radiotherapy (RT). Nearly 80% of patients who have undergone RT will develop carotid radiation arteritis to some degree and 29% will develop stenosis >50%. Surgery in a radiated neck has higher rates of complications, and carotid artery stenting (CAS) has become the primary therapy. The outcomes for CAS in patients with radiation arteritis have not been rigorously evaluated. The objective of the present study was to evaluate the differences in perioperative outcomes, restenosis rates, the need for reintervention, and freedom from mortality between RT patients and patients with atherosclerotic disease who had undergone CAS. METHODS: The national Vascular Quality Initiative CAS dataset from 2016 to 2019 comprised the sample for analyses (n = 7343). The primary independent variable was previous head and/or neck RT. The primary endpoint was the interval to mortality. The secondary endpoints were the cumulative incidence of restenosis (>50% and >70% by duplex ultrasound) and reintervention. We also examined the following secondary perioperative endpoints: myocardial infarction, in-hospital mortality (death before discharge), neurologic events, ipsilateral stroke, and contralateral stroke. Kaplan-Meier and multivariable Cox proportional hazard models were used to assess for mortality, and cumulative incidence function estimates were used for the nonfatal endpoints. RESULTS: Of the 7218 patients, 1199 (17%) had undergone prior RT. We found a significant difference in the 3-year estimates of mortality for those with and without prior RT (9.4% and 7.5%, respectively; P = .03). Furthermore, on adjusted analysis, we observed a 58% increase in the risk of mortality for those with prior RT (adjusted hazard ratio, 1.58; 95% confidence interval, 1.13-2.21). We did not observe any differences in the risk of perioperative complications (myocardial infarction, in-hospital mortality, ipsilateral or contralateral stroke), restenosis (>50% or >70%), or reintervention for the prior RT group compared with those without RT. CONCLUSIONS: The CAS patients with RT had significantly greater mortality at all time points compared with those without RT, even after adjusting for other covariates. No significant difference was found in the incidence of perioperative complications, reintervention, or restenosis between the two groups. The present study is unique because of the large sample size and length of follow-up. The results suggest that for this high-risk group, CAS provides the same patency as it does for atherosclerotic carotid stenosis and avoids potentially morbid cranial nerve injury and wound healing complications.

The effect of rurality on the risk of primary amputation is amplified by race.

OBJECTIVE: Primary amputation (ie, without attempted revascularization) is a devastating complication of peripheral artery disease. Racial disparities in primary amputation have been described; however, rural disparities have not been well investigated. The purpose of this study was to examine the impact of rurality on risk of primary amputation and to explore the effect of race on this relationship. METHODS: The national Vascular Quality Initiative amputation data set was used for analyses (N = 6795). The outcome of interest was primary amputation. Independent variables were race/ethnicity (non-Latinx whites vs nonwhites) and rural residence. Multivariable logistic regression examined impact of rurality and race/ethnicity on primary amputation after adjustment for relevant covariates and included an interaction for race/ethnicity by rural status. RESULTS: Primary amputation occurred in 49% of patients overall (n = 3332), in 47% of rural vs 49% of urban patients (P = .322), and in 46% of whites vs 53% of nonwhites (P < .001). On multivariable analysis, nonwhites had a 21% higher odds of undergoing primary amputation overall (adjusted odds ratio [AOR], 1.21; 95% confidence interval [CI], 1.05-1.39). On subgroup analysis, rural nonwhites had two times higher odds of undergoing primary amputation than rural whites (AOR, 2.06; 95% CI, 1.53-2.78) and a 52% higher odds of undergoing primary amputation than urban nonwhites (AOR, 1.52; 95% CI, 1.19-1.94). In the urban setting, nonwhites had a 21% higher odds of undergoing primary amputation than urban whites (AOR, 1.21; 95% CI, 1.05-1.39). CONCLUSIONS: In these analyses, rurality was associated with greater odds for primary amputation in nonwhite patients but not in white patients. The effect of race on primary amputation was significant in both urban and rural settings; however, the effect was significantly stronger in rural settings. These findings suggest that race/ethnicity has a compounding effect on rural health disparities and that strategies to improve health of rural communities need to consider the particular needs of nonwhite residents to reduce disparities.

Geographic variation in amputation rates among patients with diabetes and/or peripheral arterial disease in the rural state of West Virginia identifies areas for improved care.

OBJECTIVE: Amputation is a devastating but preventable complication of diabetes and peripheral arterial disease (PAD). Multiple studies have focused on disparities in amputation rates based on race and socioeconomic status, but few focus on amputation trends in rural populations. The objective of this study was to identify the prevalence of major and minor amputation among patients admitted with diabetes and/or PAD in a rural, Appalachian state, and to identify geographic areas with higher than expected major and minor amputations using advanced spatial analysis while controlling for comorbidities and rurality. METHODS: Patient hospital admissions of West Virginia residents with diagnoses of diabetes and/or PAD and with or without an amputation procedure were identified from the West Virginia Health Care Authority State Inpatient Database from 2011 to 2016 using relevant International Classification of Diseases, 9th edition and 10the edition codes. Bayesian spatial hierarchical modeling was conducted to identify areas of high risk, while controlling for important confounders for amputation. RESULTS: Overall, there were 5557 amputations among 459,452 hospital admissions with diabetes and/or PAD from 2011 to 2016. The majority of the amputations were minor (61.7%; n = 3430), with a prevalence of 7.5 per 1000 and 40.4% (n = 2248) were major, with a prevalence of 4.9 per 1000. Geographic analysis found significant variation in risk for both major and minor amputation across the state, even after adjusting for the prevalence of risk factors. Analyses indicated an increased risk of amputation in the central and northeastern regions of West Virginia at the county level, although zip code-level patterns of amputation varied, with high-risk areas identified primarily in the northeastern and south central regions of the state. CONCLUSIONS: There is significant geographic variation in risk of amputation across West Virginia, even after adjusting for disease-related risk factors, suggesting priority areas for further investigation. The level of granularity obtained using advanced spatial analyses rather than traditional methods demonstrate the value of this approach, particularly when risk estimates are used to inform policy or public health intervention.

Community-engaged research in vascular surgery: An approach to decrease amputation disparities and effect population-level change.

Community-engaged research (CEnR) is a powerful tool to create sustainable and effective change in health outcomes. CEnR engages community members as equal partners, amplifying their voices and priorities by including them throughout the research process. Such engagement increases the relevance and meaning of research, improves the translation of research findings into sustainable health policy and practice, and ultimately enhances mutual trust among academic, clinical, and community partners for ongoing research partnership. There are a number of key principles that must be considered in the planning, design, and implementation of CEnR. These principles are focused on inclusive representation and participation, community empowerment, building community capacity, and protecting community self-determination. Although vascular surgeons may not be equipped to address these issues from the ground up by themselves, they should work with a team who can help them incorporate these elements into their CEnR project designs and proposals. This may be best accomplished by collaborating with researchers and community-based organizations who already have this expertise and have established social capital within the community. This article describes the theory and principles of CEnR, its relevance to vascular surgeons, researchers, and patients, and how using CEnR principles in vascular surgery practice, research, and outreach can benefit our patient population, with a specific focus on reducing disparities related to amputation.

Mixed methods research: A primer for the vascular surgeon.

Mixed methods research is an approach that intentionally integrates both quantitative and qualitative research methods to answer a research question. The hallmark of mixed methods research is a focus on designing studies that integrate both quantitative and qualitative data, yielding greater results than either method could yield on its own. There are a number of fundamental concepts that are essential to conducting mixed methods research. These include a methodological approach that employs one of the three core study designs, involvement of a multidisciplinary team that includes both methodological and subject matter experts, and meticulous planning to ensure that the data collected can ultimately be integrated to yield findings that answer the original research question to the investigators' (and funders') satisfaction. In this article, we will discuss mixed methods research designs, data sources typically used in mixed methods research, and common data analysis and integration strategies. We will also provide examples of mixed methods research projects that have been used in vascular surgery. The intent of this article was to provide an overview of the field of mixed methods research, enabling the reader to critically assess mixed methods research studies in the literature and consider how this methodology might benefit their own research endeavors.