Publications

INTRODUCTION: National guidelines recommend forearm arteriovenous fistulas (AVFs) over upper arm AVFs as the initial permanent vascular access for hemodialysis if consistent with the end-stage kidney disease (ESKD) Life-Plan, but comparative outcomes are underexplored. Our objective was to assess longitudinal outcomes of forearm versus upper arm AVFs in patients with advanced kidney disease.

METHODS: Using multicenter data from three prospective studies (Hemodialysis Fistula Maturation [HFM] Study; PATENCY-1; and PATENCY-2), we conducted a cohort study of 1,516 patients who underwent upper extremity AVF creation (2014-2019). Demographic factors, comorbidities, procedural details, and 3 years of longitudinal follow-up were captured. Outcomes included primary, primary-assisted, and secondary patency at 3 years, successful AVF use, and access-related hand ischemia (ARHI) interventions. Forearm versus upper arm AVF outcomes were compared using Cox regression and logistic regression models. Subgroup analyses included outcomes stratified by site volume using model interaction terms.

RESULTS: The study population included 1,059 forearm AVFs and 457 upper arm AVFs; mean (SD) age was 56.2 (13.4) years and 25.2% were female. The overall primary, primary-assisted, and secondary patency at 3 years was 26.2% (95% CI 23.6% to 29.1%), 57.6% (54.6% to 60.9%), and 66.5% (63.6% to 69.5%), respectively, with no significant differences between forearm and upper arm AVFs. Successful AVF use at 12 months was also similar between forearm (66.1%) and upper arm AVFs (70.0%) (OR 1.02, 95% CI [0.71-1.48], p=0.91). Forearm AVFs had lower risk of ARHI interventions (HR 0.36, 95% CI [0.18-0.71], p=0.003) compared to upper arm AVFs. Subgroup analyses showed that compared to upper arm AVFs, patients who received forearm AVFs at low volume sites (≤30 access creations per year) were at higher risk for loss of primary-assisted (HR 2.03, 95% CI [1.21-3.41], p<0.001) and secondary patency (HR 2.53, 95% CI [1.33-4.83], p <0.001). Patients receiving forearm AVFs at low volume sites also had lower AVF use at 12 months (OR 0.52, 95% CI [0.21-1.31], p value of interaction =0.03).

CONCLUSIONS: Although forearm AVFs demonstrate similar long-term patency and usability to upper arm AVFs, they are associated with lower rates of ARHI. However, outcomes for forearm AVFs appear to have associations with institutional volume-significantly poorer results are seen at low-volume centers. System-level efforts are needed to improve outcomes for forearm AVFs, which serve as a critical lifeline for ESKD patients.

OBJECTIVE: Socioeconomic disparities are known to contribute to adverse outcomes after surgery; however, the role of individual wealth and neighborhood environment on both follow-up and outcomes following EVAR are not well understood.

METHODS: We included all fee-for-service Medicare beneficiaries ≥66 years who underwent infrarenal EVAR with a bifurcated endograft for intact AAA from 2011-2019. Patients were divided into cohorts using dual enrollment in Medicare/Medicaid (vs. Medicare only) as a measure of individual wealth and residence in a distressed community (vs. non-distressed community) as a measure of regional wealth (as defined by the Distressed Community Index, DCI). The primary outcome was the composite of late aneurysm rupture, aortic reintervention, conversion to open repair, or all-cause mortality at 9 years. The cumulative incidence of the primary composite outcome was determined using Kaplan Meier methods and compared across groups using log-rank tests.

RESULTS: Of 111,381 patients who underwent EVAR, 9,991 (9.0%) were dual-enrolled in Medicare/Medicaid, and 22,902 (21%) lived in distressed communities. A higher incidence of the primary outcome was observed in dual-enrolled vs. Medicare-only patients (83% vs 72%, hazard ratio (HR) 1.42[95% Confidence interval (CI) 1.38, 1.47] p<.01) and in those living in distressed vs. non-distressed communities (75% vs 72%, HR 1.09[1.06,1.11] p<.01). After adjustment for comorbidities and other disparity measures, the association between dual enrollment or DCI and the primary outcome was attenuated but remained significant (aHR 1.19 [95%CI 1.15, 1.23], aHR 1.03 [95%CI 1.00,1.05], respectively). When mortality was removed from the primary outcome, the relationships between dual enrollment or DCI and the composite outcome were no longer significant after adjustment (aHR 1.02, [0.93, 1.13], aHR 0.95, [0.89, 1.05]). Among EVAR-specific secondary outcomes, rates of 9-year all-cause mortality and late rupture were higher in dual-enrolled vs. Medicare-only patients, and mortality rates were higher in distressed vs. non-distressed patients. In addition, both dual-enrolled and residents of distressed communities had lower rates of EVAR-related office visits and AAA-related imaging in follow-up and higher rates of emergency department visits.

CONCLUSION: Among Medicare beneficiaries who underwent EVAR for AAA, socioeconomically disadvantaged beneficiaries had a higher incidence of the primary composite outcome, driven primarily by higher all-cause mortality. This study highlights the need for interventions targeted at improving access to appropriate disease surveillance and management of comorbidities for patients who are most vulnerable.

BACKGROUND: The Best Endovascular vs Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI) trial reported the superiority of surgical bypass compared with endovascular intervention for the treatment of chronic limb-threatening ischemia (CLTI) in patients deemed suitable for either; however, the generalizability of these findings to the broader CLTI population is in question. Herein, we analyzed perioperative (30-day) outcomes from the National Surgical Quality Improvement Project (NSQIP) for CLTI interventions.

METHODS: The NSQIP-Vascular targeted database was queried from 2014 to 2019, contemporaneous with BEST-CLI, for patients undergoing CLTI intervention. Surgical bypass groups included saphenous vein (OPEN-GSV) or alternative conduit (OPEN-Other) and were compared to the endovascular (intervention group) (ENDO). Inverse Probability weighting with regression adjustment assessed 30-day outcomes including perioperative death (POD), major amputation, major adverse limb events (MALE, major reintervention and/or amputation), composite MALE or POD, and major adverse cardiovascular events (MACE, myocardial infarction, or stroke). Results were provided as risk ratio (RR).

RESULTS: Of the total cohort, 6780 (34.1%) were in the OPEN-GSV group, 4201 (21.1%) in OPEN-Other, and 8887 (44.7%) in ENDO. Compared to OPEN-GSV, ENDO exhibited a higher risk for major amputation (RR, 1.38; P = .002), higher risk of MALE (RR, 1.23; P = .004), lower risk of MACE (RR, 0.48; P < .001), and similar risk for all other outcomes. Compared to OPEN-Other, ENDO exhibited a lower risk of MACE (RR, 0.49; P < .001) and POD (RR, 0.76; P = .040) and was similar for all other outcomes.

CONCLUSIONS: These data demonstrate a higher rate of early amputation and MALE among those who underwent ENDO vs OPEN-GSV. Conversely, early limb events were similar between ENDO and OPEN-Other. Both OPEN-GSV and OPEN-Other were associated with a higher risk of 30-day MACE. OPEN-Other was associated with a higher risk of MACE. These data highlight the importance of patient selection to optimize overall patient outcomes in CLTI.

BACKGROUND: Symptomatic peripheral artery disease (PAD) is prevalent and guideline-recommended therapies include optimal medical therapy (OMT), supervised exercise therapy (SET), and revascularization (stenting). The Claudication: Exercise Versus Endoluminal Revascularization (CLEVER) trial examined longitudinal patient-reported outcomes to assess response to OMT, SET, and stenting. The predictors of symptomatic improvement have not been fully assessed.

METHODS: This is a secondary analysis of the CLEVER trial, which randomized patients with claudication to OMT alone, OMT plus SET, or OMT plus stenting. The primary outcome was a change in the Peripheral Artery Questionnaire (PAQ) summary score by 10 points or more from baseline to 6 and 18 months. Multivariate logistic regression was used to identify predictors of response.

RESULTS: Of the 103 participants (66 men, median age 63 years), 65 (63%) had a response to therapy at 6 months. Of 98 participants who completed the 18-month PAQ, 52 (53%) had a symptomatic response. On binary logistic regression, when compared to OMT, SET (6 months: odds ratio [OR] 4.25, 95% CI: 1.33-13.58; 18 months: OR 3.92, 95% CI: 1.04-14.70) and ST (6 months: OR 5.19, 95% CI: 1.58-17.03; 18 months: OR 11.50, 95% CI: 2.89-45.72) were associated with an increase in PAQ at 6 and 18 months.

CONCLUSION: Among randomized patients in the CLEVER trial, treatment with either SET or stenting was predictive of clinically meaningful change in the PAQ summary score from baseline to 6 and 18 months. These interventions, with a prioritization of SET, should be more widely available to patients with PAD. This study adds to the findings of the CLEVER trial by denoting that SET and stenting are beneficial in patients with PAD, independent of comorbidities.

Endovascular renal denervation (RDN) is a catheter-based, procedural therapy for the treatment of hypertension that was approved by the US Food and Drug Administration (FDA) in November 2023. Early studies suggest that endovascular RDN reduces blood pressure (BP) in patients with hypertension. However, BP response to RDN is highly variable, optimal patient selection remains uncertain, and the procedure's high cost remains a significant challenge. The purpose of this review is to comprehensively examine the literature regarding the mechanism by which endovascular RDN reduces BP and the safety and effectiveness of RDN, and to discuss key considerations for selecting appropriate patients for endovascular RDN. Relevant studies in the field were identified from PubMed using search terms including 'renal denervation' and 'renal denervation for hypertension.' In conclusion, clinical trials have demonstrated a statistically significant BP-lowering effect of endovascular RDN, which based on multiple trials with long-term follow-up, appears to persist over several years with low complication rates. More research is needed to understand which patients benefit most from endovascular RDN and to evaluate the long-term outcomes, including the impact of endovascular RDN on cardiovascular events.

Although transcatheter aortic valve replacement (TAVR) devices can impair coronary access, there are limited real-world data comparing outcomes of percutaneous coronary intervention (PCI) in post-TAVR vs. non-TAVR patients. In this study, we compare procedural characteristics and outcomes between patients with vs. without a history of TAVR who undergo PCI. We used claims data for the Medicare population to evaluate the incidence of PCI after TAVR between 2011-2017. Then, using the CathPCI Registry, we compared PCI outcomes between patients with a history of TAVR vs. propensity score-matched non-TAVR patients. Of the 52,780 Medicare patients who underwent TAVR between 2011-2017, the incidence of acute myocardial infarction (AMI) was 10.2% and of PCI was 5.1% at 5 years. At five years, the incidence of stroke was 5.0% and of death was 64.0%. In the CathPCI Registry, procedural success for PCI was similar between 1,309 post-TAVR patients vs. 5,236 propensity-score matched patients without prior TAVR. However, post-TAVR patients required greater fluoroscopic time (21.9 vs 17.7 mins, p<0.001) and had higher rates of post-procedural stroke (0.8% vs 0.4%, p=0.02) and bleeding (5.1% vs 2.9%, p<0.001). Post-TAVR patients were more likely to have repeat PCI in the 3 years post-PCI (HR: 1.36, 95% C.I: 1.09, 1.70) and had higher rates of stroke (HR: 1.65, C.I.: 1.07-2.56, p=0.023) and death (HR: 1.23, C.I.: 1.11-1.38, p<0.001) compared to non-TAVR patients. In conclusion, in the CathPCI Registry, patients with a history of TAVR appeared to have similar procedural success but longer fluoroscopic times, more frequent post-procedural bleeding and stroke, and a higher likelihood of a repeat PCI compared with matched patients without a history of TAVR.

Pulmonary embolism (PE) is a life-threatening condition characterised by occlusion of the pulmonary vasculature, with a global incidence of approximately 1 in 1,000 patients. While pharmacological therapy remains the cornerstone of PE management, selected patients may benefit from catheter-directed treatments due to their potential for rapid symptom relief and swift haemodynamic stabilisation. Catheter-directed thrombolysis and catheter-directed mechanical thrombectomy are current treatment options, though their availability is still limited. This review provides a practical outlook on catheter-directed therapies for PE, outlining optimal procedural planning, device selection, technical execution, evaluation of results, and management of complications.

BACKGROUND: Use of a nitinol extravascular support implanted during AVF (arteriovenous fistula) creation has been gaining traction due to its potential to improve functional success and reduce interventions; however, comparative effectiveness data with traditional unsupported AVFs are lacking. The objective of this study was to compare outcomes of AVFs created with a vascular support device versus traditional unsupported AVFs in patients with advanced kidney disease.

METHODS: This was a comparative effectiveness retrospective observational cohort study conducted using data from the prospective, multi-center, single-arm VasQ US Pivotal trial (extravascular support AVF group) matched with an unsupported AVF control group developed using Medicare claims data from the same surgeons that participated in the trial. Eligible control participants were Medicare fee-for-service beneficiaries who underwent AVF creation (2017-2019). Endpoints included 6-month primary patency (primary endpoint), intervention rate, and functional success. Propensity score methods using inverse probability treatment weighting were used to examine the association between supported device use and outcomes.

RESULTS: A total of 782 unsupported AVF patients were compared to the 144 supported AVF patients from the Pivotal study. Compared with unsupported AVFs, primary patency at 180 days was superior for supported AVFs (66% vs 36% for control; OR, 3.27; 95% CI, 2.15-5.17; p < 0.0001). Intervention rate for supported AVFs (0.97 per patient-year; 95% CI, 0.71-1.28) was nearly half of unsupported AVFs (1.91 per patient-year; 1.58-2.07; p < 0.0001). Functional success for supported AVF patients was significantly greater than unsupported AVFs at 90 days (43.4% vs 26.7%, respectively; p = 0.005) and 180 days (72.5% vs 53.7%, respectively; p = 0.004).

CONCLUSIONS: AVFs created with extravascular support maintained higher primary patency, improved functional success, and had less reinterventions than unsupported AVFs. More patients may begin using their AVF for dialysis sooner with a lower risk of requiring a maturation procedure if created with extravascular support.