Herzig, Matthew

Introduction: The use of intravascular ultrasound (IVUS) to guide lower extremity deep venous stent placement is associated with improved identification of the degree of maximal vessel stenosis, vessel obstruction, and thrombus burden, compared to venography alone. As the US medical system moves towards value-based care, the financial impact of interventional tools requires close consideration. Currently, there are limited evaluations of the cost effectiveness of IVUS during venous procedures. Research Question: This study seeks to examine the cost-effectiveness of IVUS in lower extremity deep venous interventions. Methods: Medicare fee-for-service claims data from 2016 through 2021 for beneficiaries aged ≥ 65 years undergoing lower extremity venous interventions with stent placement, thrombolysis, and/or thrombectomy were analyzed. Cost ratios between IVUS-guided and non-IVUS-guided procedures were assessed using gamma regression, adjusting for demographic and clinical variables. Results: A total of 52,610 patients were included, with 42.6% undergoing IVUS-guided procedures. IVUS utilization varied by setting, with higher usage in hospital-based outpatient centers (75.3%) and ambulatory surgical centers/outpatient-based laboratories (ASC/OBL; 86.4%) compared to inpatient hospitalizations (10.4%). Among inpatient procedures, IVUS-guided venous intervention was associated with greater cost than non-IVUS procedures at 90 days, with an adjusted cost ratio of 1.04 (95% CI 1.01-1.07), yet was associated with an average 0.6-day shorter hospitalization (p < 0.001; Figure 1, Figure 2 ). There were marginal increased costs associated with use of IVUS in inpatient procedures persisting through one- and three-years follow-up, with adjusted cost ratios of 1.05 (95% CI 1.02-1.08) and 1.05 (95% CI 1.02-1.09), respectively. In contrast, IVUS use was associated with significant cost savings in outpatient settings, with adjusted cost ratios of 0.71 (95% CI 0.69-0.73) in hospital-based outpatient settings and 0.75 (95% CI 0.73-0.78) in ASC/OBL at 90 days. These cost savings persisted at one- and three-year follow-up. Conclusions: IVUS-guided venous intervention was associated with cost savings in outpatient and ASC/OBL settings, while maintaining near cost equivalence in inpatient settings. These findings suggest that in addition to the clinical benefit of IVUS for venous intervention, IVUS is a cost-effective strategy, particularly in the outpatient setting.

Background: Proteomic approaches allow measurement of thousands of proteins in a single specimen, which can accelerate biomarker discovery. However, applying these technologies to massive biobanks is not currently feasible because of the practical barriers and costs of implementing such assays at scale. To overcome these challenges, we used a “virtual proteomic” approach, linking genetically predicted protein levels to clinical diagnoses in >40 000 individuals. Methods: We used genome-wide association data from the Framingham Heart Study (n=759) to construct genetic predictors for 1129 plasma protein levels. We validated the genetic predictors for 268 proteins and used them to compute predicted protein levels in 41 288 genotyped individuals in the Electronic Medical Records and Genomics (eMERGE) cohort. We tested associations for each predicted protein with 1128 clinical phenotypes. Lead associations were validated with directly measured protein levels and either low-density lipoprotein cholesterol or subclinical atherosclerosis in the MDCS (Malmö Diet and Cancer Study; n=651). Results: In the virtual proteomic analysis in eMERGE, 55 proteins were associated with 89 distinct diagnoses at a false discovery rate q<0.1. Among these, 13 associations involved lipid (n=7) or atherosclerosis (n=6) phenotypes. We tested each association for validation in MDCS using directly measured protein levels. At Bonferroni-adjusted significance thresholds, levels of apolipoprotein E isoforms were associated with hyperlipidemia, and circulating C-type lectin domain family 1 member B and platelet-derived growth factor receptor-β predicted subclinical atherosclerosis. Odds ratios for carotid atherosclerosis were 1.31 (95% CI, 1.08–1.58; P =0.006) per 1-SD increment in C-type lectin domain family 1 member B and 0.79 (0.66–0.94; P =0.008) per 1-SD increment in platelet-derived growth factor receptor-β. Conclusions: We demonstrate a biomarker discovery paradigm to identify candidate biomarkers of cardiovascular and other diseases.