Genetic basis of ethnic disparities in VTE risk

Racial and ethnic disparities in eligibility for postpartum venous thromboembolism prophylaxis in the United States

BACKGROUND

Postpartum venous thromboembolism (VTE) incidence differs by race and ethnicity in the United States. However, it is unclear whether the eligibility criteria for postpartum VTE prophylaxis mirror this disparity.

OBJECTIVE

To characterize the prevalence of risk factors and eligibility for postpartum VTE prophylaxis, among US Birthing people, stratified by race and ethnicity.

METHODS

We analyzed the National Inpatient Sample from October 2015 to December 2019, using diagnosis and procedure codes to identify postpartum individuals and their VTE risk factors. We compared proportion of delivery hospitalizations meeting eligibility for thromboprophylaxis stratified by race or ethnicity, according to American College of Gynecology and Obstetrics, American College of Chest Physicians, Royal College of Obstetricians and Gynecologists (RCOG), and American Society for Hematology guidelines.

RESULTS

Among a national estimate of 14 967 861 delivery hospitalizations in the United States, the proportion of individuals eligible for thromboprophylaxis using the RCOG, American College of Chest Physicians, American College of Gynecology and Obstetrics, and American Society for Hematology guidelines were 32.9%, 8.0%, 0.2%, and 0.2%, respectively. Using the RCOG criteria, non-Hispanic Black individuals had the highest proportion of thromboprophylaxis eligibility (39.7%), whereas it was lowest among Hispanic individuals (30.8%). Racial disparities in thromboprophylaxis eligibility were driven by differences in clinical risk factors (38.8% non-Hispanic Black population vs 30.5% Hispanic population) and cesarean section rates (35.9% vs 32.2%), rather than history of VTE (0.3% vs 0.1%), inherited thrombophilia (0.2% vs 0.2%), or sickle cell disease (0.4% vs <0.1%).

CONCLUSION

Non-Hispanic Black individuals were most likely to qualify for postpartum thromboprophylaxis, attributable to clinical risk factors rather than inherited risk factors. An urgent need exists to better understand ethno-racial disparities in thromboprophylaxis use and to equitably address modifiable risk factors for postpartum VTE.

Construction and optimization of a polygenic risk model for venous thromboembolism in the Chinese population

BACKGROUND

Venous thromboembolism (VTE) has both environmental and genetic risk factors. It is regulated by polygenes and multisites. The polygenic risk score (PRS) has been widely used because any single genetic biomarker failed to accurately predict the genetic risk of VTE. However, no polygenic risk model has been proposed for VTE in the Chinese population. Thus, we aimed to construct a PRS model for the first episode of VTE in the Chinese population.

METHODS

First, single nucleotide polymorphisms (SNPs) associated with VTE in genome-wide association studies, meta-analyses, and candidate gene studies were screened as variables for the PRS. The logarithm of the odds ratio was used to weight the variables. Second, a training set with simulated data from 1000 cases of VTE and 1000 controls was created with different genotypes and frequencies. Finally, we calculated the area under the receiver operating characteristic curve (AUC) to evaluate the discriminatory ability of the PRS model.

RESULTS

We screened 53 SNPs potentially associated with the first episode of VTE in the Chinese population. The AUC of the PRS-53 model (containing 53 SNPs) was 0.748 (95% confidence interval, 0.727-0.770) in the training set. From the largest weight to the smallest weight, SNPs were incrementally added to the model to calculate the AUC for model optimization. The AUC of the PRS-10 model (containing 10 SNPs) was 0.718 (95% confidence interval, 0.696-0.740), with no statistically significant difference from the AUC for the PRS-53 model.

CONCLUSIONS

The PRS-10 and PRS-53 models showed similar predictive abilities and satisfactory discriminatory power and can be used to predict the genetic risk of the first episode of VTE in the Chinese population. The simplified PRS-10 model is more efficient in clinical practice.

Population-Based Disparities in Inferior Vena Cava Filter Procedures Among Medicare Enrollees With Acute Venous Thromboembolism

PURPOSE

Venous thromboembolism (VTE) imposes a significant clinical and financial burden on patients and society. Inferior vena cava filters (IVCFs) are considered for patients with absolute contraindications or failures of anticoagulation. However, studies examining the population-based disparities of IVCF placement and retrieval are limited. The association between patient and clinical characteristics in the likelihood of and time to IVCF placement and retrievals in a nationally representative cohort was examined.

METHODS

Medicare patients aged ≥65 years with index VTE claims between 2015 and 2018 were followed through 2019 to identify IVCF placements and retrievals. Rates were compared using survival analysis methods.

RESULTS

Of the 516,978 patients with VTE diagnoses, 5,864 (1.1%) had IVCFs placed, and 1,884 (32.1%) of those underwent retrieval procedures. Placement and retrieval rates varied significantly by demographics, comorbidity burden, and geographic region. From Cox regression, older age (hazard ratio [HR], 1.26; P < .0001), higher baseline comorbidity (Elixhauser) score (HR, 1.07; P < .0001), and outpatient (vs inpatient) site of VTE service (HR, 2.11; P < .0001) were associated with increased frequency of IVCF placement. The rate of retrieval was significantly lower for men (HR, 0.83; P = .0393), patients with higher comorbidity scores (HR, 0.95; P = .0037), and those with outpatient (vs inpatient) VTE sites of service (HR, 0.77; P = .0173). Neither facility- nor county-level characteristics were significantly associated with placements or retrievals.

CONCLUSIONS

This large cohort of Medicare beneficiaries with newly diagnosed VTE demonstrated inequities in IVCF placement and retrieval.

The Application of Whole-Exome Sequencing in Patients With FUO

Background

Fever of unknown origin (FUO) is still a challenge for clinicians. Next-generation sequencing technologies, such as whole exome sequencing (WES), can be used to identify genetic defects in patients and assist in diagnosis. In this study, we investigated the application of WES in individuals with FUO.

Methods

We performed whole-exome sequencing on 15 FUO patients. Clinical information was extracted from the hospital information system.

Results

In 7/15 samples, we found positive results, including potentially causative mutations across eight different genes: CFTR, CD209, IRF2BP2, ADGRV 1, TYK2, MEFV, THBD and GATA2.

Conclusions

Our results show that whole-exome sequencing can promote the genetic diagnosis and treatment of patients with FUO.

Using electronic health record system triggers to target delivery of a patient-centered intervention to improve venous thromboembolism prevention for hospitalized patients: Is there a differential effect by race?

Background

Racial disparities are common in healthcare. Venous thromboembolism (VTE) is a leading cause of preventable harm, and disparities observed in prevention practices. We examined the impact of a patient-centered VTE education bundle on the non-administration of preventive prophylaxis by race.

Methods

A post-hoc, subset analysis (stratified by race) of a larger nonrandomized trial. Pre-post comparisons analysis were conducted on 16 inpatient units; study periods were October 2014 through March 2015 (baseline) and April through December 2015 (post-intervention). Patients on 4 intervention units received the patient-centered, nurse educator-led intervention if the electronic health record alerted a non-administered dose of VTE prophylaxis. Patients on 12 control units received no intervention. We compared the conditional odds of non-administered doses of VTE prophylaxis when patient refusal was a reason for non-administration, stratified by race.

Results

Of 272 patient interventions, 123 (45.2%) were white, 126 (46.3%) were black, and 23 (8.5%) were other races. A significant reduction was observed in the odds of non-administration of prophylaxis on intervention units compared to control units among patients who were black (OR 0.61; 95% CI, 0.46–0.81, p<0.001), white (OR 0.57; 95% CI, 0.44–0.75, p<0.001), and other races (OR 0.50; 95% CI, 0.29–0.88, p = 0.015).

Conclusion

Our finding suggests that the patient education materials, developed collaboratively with a diverse group of patients, improved patient’s understanding and the importance of VTE prevention through prophylaxis. Quality improvement interventions should examine any differential effects by patient characteristics to ensure disparities are addressed and all patients experience the same benefits.

Assessing the Rate of Antipsychotic Use in Ambulatory Care Patients With a Venous Thromboembolism

Background: Evidence regarding the use of antipsychotics and associated venous thromboembolism (VTE) risk is inconclusive. Studies finding a relationship lack in-depth analysis; thus, the VTE risk among those treated with antipsychotic remains largely unknown. Objectives: The primary objective of this investigation was to compare the incidence of antipsychotic use in patients who developed a VTE versus those who did not. Methods: Data were collected via retrospective chart review from an ambulatory care clinic between January 2012 and August 2017. All active clinic patients within the study period were included unless they met the following criteria: age <18 years, pregnancy within the study period, and/or current or historical malignancy. The odds ratio (OR) of developing a VTE was determined using multivariate regression analysis controlling for age, gender, obesity, and smoking. Secondary end points were reviewed for participants who were exposed to an antipsychotic and subsequently developed a VTE within the study period. Results: A total of 7079 patients were included in the analysis, of whom 314 developed a VTE. Of these, 45 were exposed to an antipsychotic prior to VTE development. Nearly 25% of patients receiving an antipsychotic did not have a primary psychiatric diagnosis. Results suggest that antipsychotic use was significantly associated with increased risk of VTE development (OR = 1.481 [95% CI = 1.067 to 2.055]). Conclusion and Relevance: The results of this study suggest an association between antipsychotic use and VTE development. This association should be considered when prescribing antipsychotics and treating patients who develop a VTE after antipsychotic exposure.