Publications

IMPORTANCE: Inferior vena cava filters (IVCFs) are commonly used to prevent pulmonary embolism in selected clinical scenarios, despite limited evidence to support their use. Current recommendations from professional societies and the US Food and Drug Administration endorse timely IVCF retrieval when clinically feasible. Current IVCF treatment patterns and outcomes remain poorly described.

OBJECTIVES: To evaluate temporal trends and practice patterns in IVCF insertion and retrieval among older US patients and report the incidence of periprocedural and long-term safety events of indwelling and retrieved IVCFs.

DESIGN, SETTING, AND PARTICIPANTS: Prespecified, retrospective, observational cohort of Medicare Fee-for-Service (FFS) beneficiaries, leveraging 100% of samples of inpatient and outpatient claims data from January 1, 2013, to December 31, 2021.

EXPOSURE: First-time IVCF insertion while insured by Medicare FFS.

MAIN OUTCOMES AND MEASURES: The primary safety outcome was the composite of all-cause death, filter-related complications (eg, fracture, embolization), operating room visits following filter-related procedures, or new diagnosis of deep vein thrombosis (DVT). Events were considered periprocedural if they occurred within 30 days of IVCF insertion or retrieval and long-term if they occurred more than 30 days after.

RESULTS: Among 270 866 patients with IVCFs placed during the study period (mean age, 75.1 years; 52.8% female), 64.9% were inserted for first-time venous thromboembolism (VTE), 26.3% for recurrent VTE, and 8.8% for VTE prophylaxis. Of these patients, 63.3% had major bleeds or trauma within 30 days of IVCF insertion. The volume of insertions decreased from 44 680 per year in 2013 to 19 501 per year in 2021. The cumulative incidence of retrieval was 15.3% at a median of 1.2 years and 16.8% at maximum follow-up of 9.0 years. Older age, more comorbidities, and Black race were associated with a decreased likelihood of retrieval, whereas placement at a large teaching hospital was associated with an increased likelihood of retrieval. The incidence of caval thrombosis and DVT among patients with nonretrieved IVCFs was 2.2% (95% CI, 2.1%-2.3%) and 9.2% (95% CI, 9.0%-9.3%), respectively. The majority (93.5%) of retrieval attempts were successful, with low incidence of 30-day complications (mortality, 0.7% [95% CI, 0.6%-0.8%]; filter-related complications, 1.4% [95% CI, 1.2%-1.5%]).

CONCLUSIONS AND RELEVANCE: In this large, US real-world analysis, IVCF insertion declined, yet retrievals remained low. Strategies to increase timely retrieval are needed, as nonretrieved IVCFs may have long-term complications.

BACKGROUND: Left atrial appendage occlusion (LAAO) is increasingly used as an alternative to oral anticoagulation for stroke prevention in select patients with atrial fibrillation. Data on outcomes in racial and ethnic minority individuals are limited. This analysis assessed differences in the use and outcomes of LAAO by race and ethnicity in a large national registry.

METHODS AND RESULTS: This analysis acquired data on patients who underwent WATCHMAN FLX implantation from the retrospective NCDR (National Cardiovascular Data Registry) LAAO registry through September 2022. All patients with an attempted WATCHMAN FLX implantation and known race and ethnicity were included. Baseline characteristics and 1-year event rates were compared. A total of 97 185 patients were analyzed; 87 339 were White individuals (90%), 3750 Black individuals (3.9%), and 2866 Hispanic individuals (Hispanic/Latinx), 2.9%). Black and Hispanic patients were younger, with a higher incidence of prior stroke and significant bleeding compared with White patients. Black and Hispanic patients were treated with LAAO in smaller numbers relative to their proportion of the US population. Rates of procedural success were similar between groups. Though direct oral anticoagulants were prescribed in most patients across the groups, dual and single antiplatelet therapy were prescribed more often in Black patients. Black patients had significantly higher rates of 1-year death and bleeding compared with White and Hispanic patients.

CONCLUSIONS: Patients from racial and ethnic minority groups comprise a disproportionately small fraction of all patients who undergo LAAO. Black and Hispanic patients were younger but had significantly higher comorbidities compared with White patients. Procedural success was similar among the groups, but Black patients experienced higher rates of death and bleeding at 1 year.

BACKGROUND: There is substantial hospital-level variation in 30-day risk-standardized mortality rate (RSMR) and risk-standardized readmission rate (RSRR) after transcatheter aortic valve replacement (TAVR). However, the relationship between hospital RSMRs and RSRRs has not been well characterized.

METHODS: We analyzed data on 141,905 Medicare fee-for-service beneficiaries who underwent TAVR across 512 hospitals between October 1, 2015 and December 31, 2020. The primary and secondary outcomes of interest were 30-day all-cause mortality and 30-day all-cause readmissions, respectively. Hierarchical logistic regression models with random hospital-level intercepts were used to estimate RSMRs and RSRRs for each hospital. We used Pearson correlation coefficient (r) and restricted cubic spline regression to determine the relationship between RSMR and RSRR in the overall cohort and within subgroups based on hospital characteristics.

RESULTS: The median (IQR) hospital-level 30-day RSMR was 2.2% (2.1%-2.4%), ranging from 1.3% to 3.5%. Similarly, the median (IQR) hospital-level 30-day RSRR was 13.2% (12.7%-13.8%), ranging from 10.6% to 16.8%. In the overall cohort, there was weak correlation between 30-day RSMR and RSRR after TAVR (r=0.25, 95% CI 0.17-0.33, p<0.001). Subgroup analyses by hospital characteristics demonstrated weakest correlation between RSMR and RSRR for non-JCAHO accredited hospitals (r=0.07), hospitals in the Midwest (r=0.12) and West (r=0.14), and hospitals with low TAVR volume (r=0.15).

CONCLUSIONS: Risk-standardized mortality and readmission rates after TAVR are weakly correlated, suggesting that hospital practices and processes of care influencing mortality are likely different from those influencing readmissions after TAVR, thereby necessitating measurement of both outcomes and developing specific interventions to decrease mortality and readmissions.

Cardiovascular devices are essential for the treatment of cardiovascular diseases including cerebrovascular, coronary, valvular, congenital, peripheral vascular and arrhythmic diseases. The regulation and surveillance of vascular devices in real-world practice, however, presents challenges during each individual product's life cycle. Four examples illustrate recent challenges and questions regarding safety, appropriate use and efficacy arising from FDA approved devices used in real-world practice. We outline potential pathways wherein providers, regulators and payors could potentially provide high-quality cardiovascular care, identify safety signals, ensure equitable device access, and study potential issues with devices in real-world practice.

IMPORTANCE: Many medical journals, including JAMA, restrict the use of causal language to the reporting of randomized clinical trials. Although well-conducted randomized clinical trials remain the preferred approach for answering causal questions, methods for observational studies have advanced such that causal interpretations of the results of well-conducted observational studies may be possible when strong assumptions hold. Furthermore, observational studies may be the only practical source of information for answering some questions about the causal effects of medical or policy interventions, can support the study of interventions in populations and settings that reflect practice, and can help identify interventions for further experimental investigation. Identifying opportunities for the appropriate use of causal language when describing observational studies is important for communication in medical journals.

OBSERVATIONS: A structured approach to whether and how causal language may be used when describing observational studies would enhance the communication of research goals, support the assessment of assumptions and design and analytic choices, and allow for more clear and accurate interpretation of results. Building on the extensive literature on causal inference across diverse disciplines, we suggest a framework for observational studies that aim to provide evidence about the causal effects of interventions based on 6 core questions: what is the causal question; what quantity would, if known, answer the causal question; what is the study design; what causal assumptions are being made; how can the observed data be used to answer the causal question in principle and in practice; and is a causal interpretation of the analyses tenable?

CONCLUSIONS AND RELEVANCE: Adoption of the proposed framework to identify when causal interpretation is appropriate in observational studies promises to facilitate better communication between authors, reviewers, editors, and readers. Practical implementation will require cooperation between editors, authors, and reviewers to operationalize the framework and evaluate its effect on the reporting of empirical research.

The effectiveness of intravascular ultrasound (IVUS) with angiography compared with angiography guidance alone in treating aortic conditions, such as dissections, aneurysms, and blunt traumatic injuries, remains unclear. This systematic review and meta-analysis evaluates the current literature for IVUS use during thoracic endovascular aortic repair (TEVAR) and abdominal endovascular aortic repair (EVAR). A comprehensive search of MEDLINE, EMBASE, and Cochrane CENTRAL databases was conducted in March 2024 adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies comparing outcomes of TEVAR/EVAR with and without IVUS were identified. The outcomes of interest included contrast volume, fluoroscopy and procedural time, perioperative endoleak, and reinterventions and all-cause mortality during follow-up. Data with 95% confidence intervals (CIs) were extracted. Pooled analysis was performed using a random-effect model. Subgroup analysis was performed stratified by the condition being treated. Risk of bias was assessed using the Newcastle-Ottawa Scale for observational studies. A total of 4,219 patients (n = 2,655 IVUS and n = 1,564 non-IVUS) from 9 observational studies were included. The IVUS group exhibited a reduction in contrast agent volume (weighted mean difference -34.65 mL, 95% CI -54.73 to -14.57) and fluoroscopy time (weighted mean difference -6.13 minutes, 95% CI -11.10 to -1.15), with no difference in procedural time. The perioperative type I and III endoleak occurrences were similar (risk ratio 2.36, 95% CI 0.55 to 10.11; risk ratio 0.72, 95% CI 0.09 to 5.77, respectively). Reintervention and mortality during follow-up were comparable (hazard ratio 0.80, 95% CI 0.33 to 1.97; hazard ratio 0.75, 95% CI 0.47 to 1.18, respectively). All the included studies had small risks of bias. In conclusion, this meta-analysis provides evidence that IVUS enables the safe deployment of TEVAR/EVAR with reduced contrast agent and radiation exposure.