Racial and gender disparities in the management of acute pulmonary embolism

OBJECTIVE

The aim of this study was to assess race and sex disparities in use and outcomes of various interventions in patient with acute pulmonary embolism (PE).

METHODS

We included 129,445 patients with acute PE from the NIS from January 2016 to December 2019. Rates of inferior vena cava (IVC) filter placement, catheter-directed thrombolysis (CDT), CDT with ultrasound, systemic thrombolysis, surgical embolectomy, percutaneous thrombectomy, extracorporeal membrane oxygenation, and mechanical ventilation were compared between race and sex subgroups, along with length of hospital stay, major bleeding events, mortality, and other adverse events. Multivariate linear regression analysis was used to adjust for variables that were significantly different between race and sex, including demographic factors, comorbidities, socioeconomic factors, and hospital characteristics.

RESULTS

Compared with White male patients, all subgroups had significantly higher odds of in-hospital mortality highest in Hispanic male patients (odds ratio [OR], 1.34; 95% confidence interval [CI], 1.090-1.640; P < .01). All subgroups also had a higher odds of major bleeding events and increased length of stay. All subgroups also had lower odds of receiving CDT, lowest in Black female patients (OR, 0.740; 95% CI, 0.660-0.820; P < .001) and Hispanic female patients (0.780; 95% CI, 0.650-0.940; P < .001) compared with White male patients. There was no significant difference in the use of systemic thrombolysis among subgroups.

CONCLUSIONS

Black and Hispanic patients and female patients are less likely to undergo CDT compared with White male patients, in addition to having higher odds of mortality, major bleeding, and increased length of stay after management of PE. Further efforts are needed to mitigate disparate outcomes of PE management at not only an institutional, but at a national, level to promote health care equality.

Impact of reperfusion therapies on clot resolution and long-term outcomes in patients with pulmonary embolism

OBJECTIVE

Major progress in reperfusion strategies has substantially improved the short-term outcomes of patients with pulmonary embolism (PE), however, up to 50% of patients report persistent dyspnea after acute PE.

METHODS

A retrospective study of the PE response team registry and included patients with repeat imaging at 3 to 12 months. The primary outcome was to determine the incidence of residual pulmonary vascular obstruction following acute PE. Secondary outcomes included the development of PE recurrence, right ventricular (RV) dysfunction, chronic thromboembolic pulmonary hypertension, readmission, and mortality at 12 months.

RESULTS

A total of 382 patients were included, and 107 patients received reperfusion therapies followed by anticoagulation. Patients who received reperfusion therapies including systemic thrombolysis, catheter-directed thrombolysis, and mechanical thrombectomy presented with a higher vascular obstructive index (47% vs 28%; P < .001) and signs of right heart strain on echocardiogram (81% vs 43%; P < .001) at the time of diagnosis. A higher absolute reduction in vascular obstructive index (45% vs 26%; 95% confidence interval, 14.0-25.6; P < .001), greater improvement in RV function (82% vs 65%; P = .021), and lower 12-month mortality rate (2% vs 7%; P = .038) and readmission rate (33% vs 46%; P = .031) were observed in the reperfusion group. No statistically significant differences were found between groups in the development of chronic thromboembolic pulmonary hypertension (8% vs 5%; P = .488) and PE recurrence (8% vs 6%; P = .646).

CONCLUSIONS

We observed a favorable survival and greater improvement in clot resolution and RV function in patients treated with reperfusion therapies.

Developmental or Procedural Vena Cava Interruption and Venous Thromboembolism: A Review

The inferior vena cava (IVC) and superior vena cava are the main conduits of the systemic venous circulation into the right atrium. Developmental or procedural interruptions of vena cava might predispose to stasis and deep vein thrombosis (DVT) distal to the anomaly and may impact the subsequent rate of pulmonary embolism (PE). This study aimed to review the various etiologies of developmental or procedural vena cava interruption and their impact on venous thromboembolism. A systematic search was performed in PubMed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines per each clinical question. For management questions with no high-quality evidence and no mutual agreements between authors, Delphi methods were used. IVC agenesis is the most common form of congenital vena cava interruption, is associated with an increased risk of DVT, and should be suspected in young patients with unexpected extensive bilateral DVT. Surgical techniques for vena cava interruption (ligation, clipping, and plication) to prevent PE have been largely abandoned due to short-term procedural risks and long-term complications, although survivors of prior procedures are occasionally encountered. Vena cava filters are now the most commonly used method of procedural interruption, frequently placed in the infrarenal IVC. The most agreed-upon indication for vena cava filters is for patients with acute venous thromboembolism and coexisting contraindications to anticoagulation. Familiarity with different forms of vena cava interruption and their local and systemic adverse effects is important to minimize complications and thrombotic events.

Racial and ethnic disparities in inferior vena cava filter placement for deep vein thrombosis in the United States

OBJECTIVE

We sought to determine whether racial and ethnic disparities existed in inferior vena cava (IVC) filter (IVCF) placement rates among Black and Latino patients for the treatment of acute proximal lower extremity (LE) deep vein thrombosis (DVT) in the United States from 2016 to 2019.

METHODS

We performed a retrospective review of National Inpatient Sample data to identify adult patients with a primary discharge diagnosis of acute proximal LE DVT from January 2016 to December 2019, including self-reported patient race and ethnicity. IVCF placement rates were identified using International Classification of Diseases, 10th revision, codes. Weighted multivariable logistic regression was used to compare IVCF use by race and ethnicity. The regression model was adjusted for patient demographics (ie, sex, primary payer, quartile classification of household income), hospital information (ie, region, location, teaching status, bed size), weekend admission, and clinical characteristics (ie, modified Charlson comorbidity index, hypertension, atrial fibrillation, diabetes mellitus type 2, congestive heart failure, dyslipidemia, coronary artery disease, smoking, obesity, alcohol abuse, chronic kidney disease, pulmonary embolism, malignancy, contraindications to anticoagulation, including other major bleeding).

RESULTS

Of 134,499 acute proximal LE DVT patients, 18,909 (14.1%) received an IVCF. Of the patients who received an IVCF, 12,733 were White (67.3%), 3563 were Black (18.8%), and 1679 were Latino (8.9%). IVCF placement decreased for all patient groups between 2016 and 2019. After adjusting for the U.S. population distribution, the IVCF placement rates were 11 to 12/100,000 persons for Black patients, 7 to 8/100,000 persons for White patients, and 4 to 5/100,000 persons for Latino patients. The difference in IVCF placement rates was statistically significant between patient groups (Black patients vs White patients, P < .05; Black patients vs Latino patients, P < .05; Latino patients vs White patients, P < .05).

CONCLUSIONS

This nationwide study showed that Black patients have higher IVCF placement rates compared with White and Latino patients. Given the known long-term complications and uncertain benefits of IVCFs, coupled with the 2010 U.S. Food and Drug Administration safety warning regarding adverse patient events for these devices, proactive measures should be taken to address this disparity among the Black patient population to promote health equity. Future work should assess whether clinician bias might be perpetuating this disparity.

Association of vena cava filters and catheter-directed thrombolysis for deep vein thrombosis with hospital readmissions

BACKGROUND

Acute deep vein thrombosis (DVT) affects >350,000 patients each year in the United States. Contemporary rehospitalization rates and predictors of acute DVT have not been well-characterized. We aimed to evaluate the all-cause 30-day readmission rate and its association with catheter-directed thrombolysis and vena cava filters in patients with proximal and caval DVT.

METHODS

Patients with an index hospitalization for acute proximal lower extremity DVT were evaluated for unplanned readmission rates at 30 days using the Nationwide Readmission Database from 2016 to 2017. We used Cox proportional hazard model to determine the predictors of 30-day readmissions and their association with inferior vena cava (IVC) filter and CDT use.

RESULTS

We identified 58,306 adult patients with an index hospitalization for acute proximal DVT. The unplanned 30-day rehospitalization rate was 14.7% (95% confidence interval [CI], 14.5-15.0%). There were 4995 patients (10.0%) who underwent CDT and 6085 (12.2%) who underwent IVC filter placement. In multivariable analysis, only CDT was associated with a lower hazard for rehospitalization (hazard ratio [HR], 0.77; 95% CI, 0.71-0.84; P < .001), whereas IVC filter placement (HR, 1.26; 95% CI, 1.19-1.34; P < .001), Charlson Comorbidity Index of >3 (HR, 1.47; 95% CI, 1.38-1.56; P < .001), malignancy (HR, 1.45; 95% CI, 1.34-1.57; P < .001), and length of stay >5 days (HR, 1.39; 95% CI, 1.33-1.46; P < .001), and acute kidney injury (HR, 1.18; 95% CI, 1.11-1.25; P < .001) were associated with higher readmission rates.

CONCLUSIONS

The 30-day unplanned rehospitalization rate continues to be high in patients with acute proximal DVT. CDT was associated with lower rehospitalization rates, whereas IVC filter placement was associated with increased rehospitalization rates.

Advanced Treatment of Hemodynamically Unstable Acute Pulmonary Embolism and Clinical Follow-up

High-risk acute pulmonary embolism (PE), defined as acute PE associated with hemodynamic instability, remains a significant contributor to cardiovascular morbidity and mortality in the United States and worldwide. Historically, anticoagulant therapy in addition to systemic thrombolysis has been the mainstays of medical therapy for the majority of patients with high-risk PE. In efforts to reduce the morbidity and mortality, a wide array of interventional and surgical therapies has been developed and employed in the management of these patients. However, the most recent guidelines for the management of PE have reserved the use of these advanced therapies in scenarios where thrombolytic therapy plus anticoagulation are unsuccessful. This is due largely to the lack of prospective, randomized studies in this population. Stemming from this, the approach to treatment of these patients varies widely depending on institutional experience and resources. Furthermore, morbidity and mortality remain unacceptably high in this population, with estimated 30-day mortality of at least 30%. As such, development of a standardized approach to treatment of these patients is paramount to improving outcomes. Early and accurate risk stratification in conjunction with a multidisciplinary team approach in the form of a PE response team is crucial. With the advent of novel therapies for the treatment of acute PE, in addition to the growing availability of and familiarity with mechanical circulatory support systems, such a standardized approach may now be within reach.

Incidence and Predictors of Acute Limb Ischemia in Patients With Acute Myocardial Infarction-Insight from National Readmission Database

Acute limb ischemia (ALI) has been a rare complication of acute myocardial infarction (AMI), however, with the increasing use of mechanical circulatory devices it is seen more frequently. The incidence and predictors of ALI in patients with AMI in contemporary clinical practice are unknown. A retrospective review of patients with index hospitalization for AMI in the Nationwide Readmission Database from 2016 to 2019 was done. We evaluated the annual incidence of ALI and its impact on outcomes. We used multivariate logistic regression analysis to determine predictors of ALI. In 1,283,586 patients with AMI, 3,971 patients (0.31%) had ALI and 365 (0.03%) had limb amputation. The 3 major predictors of ALI were peripheral artery disease (odds ratio [OR] 11.91, 95% confidence interval [CI]: 10.78 to 13.51), intravascular microaxial left ventricular assist device (OR 4.39, 95% CI 3.86 to 5.00), and veno-arterial extracorporeal membrane oxygenation (OR 4.37, 95% CI 3.19 to 6.01). Intra-aortic balloon pump had a substantially lower predictive ability (OR 1.81, 95% CI 1.63 to 2.0, p <0.0001) than other forms of mechanical circulatory support. The mortality rate in patients with ALI was significantly higher than those without ALI (19.49% vs 4.85%, p <0.0001). Patients who developed ALI had higher rates of amputation (1.59% vs 0.02%, p <0.0001). This observational nationwide study showed that ALI is an important complication in patients with AMI and is more frequently seen in patients who have peripheral artery disease, and require a left ventricular assist device or venoarterial extracorporeal membrane oxygenation. This complication was also associated with significantly higher in-hospital mortality.

Prevalence and outcomes of heparin-induced thrombocytopenia in hospitalized patients with venous thromboembolic disease: Insight from national inpatient sample

OBJECTIVE

The mainstay of therapy for patients with venous thromboembolic disease (VTE) is anticoagulation. In the inpatient setting, majority of these patients are treated with heparin or low molecular weight heparin. The prevalence and outcomes of heparin-induced thrombocytopenia (HIT) in hospitalized patients with venous thromboembolic disease (VTE) is unknown.

METHODS

This nationwide study identified patients with VTE from the National Inpatient Sample database between January 2009 and December 2013. Among these patients, we compared in-hospital outcomes of patients with and without HIT using a propensity score-matching algorithm. The primary outcome was in-hospital mortality. Secondary outcomes included rates of blood transfusions, intracranial hemorrhage, gastrointestinal bleed, length of hospital stay, and total hospital charges.

RESULTS

Among 791,932 hospitalized patients with VTE, 4948 patients (0.6%) were noted to have HIT (mean age, 62.9 ±16.2 years; 50.1% female). Propensity-matched comparison showed higher rates of in-hospital mortality (11.01% vs 8.97%; P < .001) and blood transfusions (27.20% vs 20.23%; P < .001) in patients with HIT compared with those without HIT. No significant differences were noted in intracranial hemorrhage rates (0.71% vs 0.51%; P > .05), gastrointestinal bleed (2.00% vs 2.22%; P > .05), length of hospital stay (median, 6.0 days; interquartile range [IQR], 3.0-11.0 vs median, 6.0 days; IQR, 3.0-10.0 days; P > .05), and total hospital charges (median, $36,325; IQR, $17,798-$80,907 vs median, $34,808; IQR, $17,654-$75,624; P > .05).

CONCLUSIONS

This nationwide observational study showed that 0.6% of hospitalized patients with VTE in the United States have HIT. The presence of HIT was associated with higher in-hospital mortality and blood transfusion rates compared with those without HIT.

Pulmonary artery diameter correlates with echocardiographic parameters of right ventricular dysfunction in patients with acute pulmonary embolism

Introduction

Right ventricular dysfunction (RVD) is a key component in the process of risk stratification in patients with acute pulmonary embolism (PE). Echocardiography remains the gold standard for RVD assessment, however, measures of RVD may be seen on CTPA imaging, including increased pulmonary artery diameter (PAD). The aim of our study was to evaluate the association between PAD and echocardiographic parameters of RVD in patients with acute PE.

Methods

Retrospective analysis of patients diagnosed with acute PE was conducted at large academic center with an established pulmonary embolism response team (PERT). Patients with available clinical, imaging, and echocardiographic data were included. PAD was compared to echocardiographic markers of RVD. Statistical analysis was performed using the Student's t test, Chi-square test, or one-way analysis of variance (ANOVA); P < 0.05 was considered statistically significant.

Results

270 patients with acute PE were identified. Patients with a PAD >30 mm measured on CTPA had higher rates of RV dilation (73.1% vs 48.7%, P < 0.005), RV systolic dysfunction (65.4% vs 43.7%, P < 0.005), and RVSP >30 mmHg (90.2% vs 68%, P = 0.004), but not TAPSE ≤1.6 cm (39.1% vs 26.1%, P = 0.086). A weak increasing linear relationship between PAD and RVSP was noted (r = 0.379, P = 0.001).

Conclusions

Increased PAD in patients with acute PE was significantly associated with echocardiographic markers of RVD. Increased PAD on CTPA in acute PE can serve as a rapid prognostic tool and assist with PE risk stratification at the time of diagnosis, allowing rapid mobilization of a PERT team and appropriate resource utilization.

Derivation and Validation of Spontaneous Coronary Artery Dissection Prediction Score in Patients With Myocardial Infarction

Spontaneous coronary artery dissection (SCAD) is an important cause of acute myocardial infarction (AMI); however, the prevalence of SCAD and its predictors in AMI are unknown. We sought to derive and validate a simple score that can help predict SCAD in patients with AMI. We analyzed the Nationwide Readmissions Database and created a risk score for SCAD in patients with an index hospitalization for AMI. We used a multivariate logistic regression analysis to determine the independent predictors of SCAD, and each was assigned points proportional to its regression coefficient. Among 1,155,164 patients with AMI, 8,630 (0.75%) had SCAD. Based on the derivation cohort, the independent predictors of SCAD were fibromuscular dysplasia (odds ratio [OR] 67.0, 95% confidence interval [CI] 42.0 to 107.9, p <0.01), Marfan or Ehlers-Danlos syndrome (OR 4.7, 95% CI 1.7 to 12.5, p <0.01), polycystic ovarian syndrome (OR 5.4, 95% CI 3.0 to 9.8, p <0.01), female gender (OR 1.99, 95% CI 1.9 to 2.1, p <0.01), and aortic aneurysm (OR 1.41, 95% CI 1.1 to 1.7, p <0.01). The SCAD risk score included fibromuscular dysplasia (5 points), Marfan or Ehlers-Danlos syndrome (2 points), polycystic ovarian syndrome (2 points), female gender (1 point), and aortic aneurysm (1 point). The C-statistics of the score were 0.58 (derivation cohort) and 0.61 (validation cohort). In conclusion, the SCAD score is an easy bedside clinical tool that can help clinicians identify patients with AMI who are at risk for SCAD.

Refined Balloon Pulmonary Angioplasty in Chronic Thromboembolic Pulmonary Hypertension: Initial Results of U.S. Regional Program

Objectives

We sought to evaluate the efficacy and safety of refined balloon pulmonary angioplasty (BPA) in the treatment of patients with chronic thromboembolic pulmonary hypertension (CTEPH).

Background

BPA is rapidly evolving therapeutic option for patients with nonsurgical CTEPH. There are few US studies that have reported on the outcomes of this novel therapeutic option.

Methods

This is a retrospective study of CTEPH patients that underwent BPA at Temple University Hospital. The primary efficacy endpoint was the change in pulmonary vascular resistance (PVR) after BPA as compared to baseline and the primary safety endpoint was the rate of hemoptysis within 24 hours. Secondary endpoints included death, WHO functional class, and 6-minute walk distance (6MWD). We used logistic regression to evaluate factors associated with a hemodynamic and functional response.

Results

A total of 211 BPA sessions were performed on 77 patients (average 2.7 ± 1.7 sessions/patient). After BPA the mean PVR improved by 26% (P<0.001) while the mean 6MWD improved by 71.7 meters (P <0.001) and WHO functional class improved by one functional class (P <0.001). Ten sessions (4.7%) were complicated by hemoptysis. The independent factors associated with a improved functional and hemodynamic response included the pre-procedural use of riociguat, reduce baseline PA compliance and > 3 BPA sessions per patient.

Conclusion

This single center study from the US showed that BPA with refined techniques in patients with CTEPH was safe and was associated with significant improvements in pulmonary hemodynamics and functional capacity.

Incidence and predictors of acute limb ischemia in acute myocardial infarction complicated by cardiogenic shock

OBJECTIVE

To describe the incidence and predictors of acute limb ischemia (ALI) in patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS).

METHODS

Patients with index hospitalizations for AMI complicated by cardiogenic shock from 2016 to 2019 in the US National Readmission Database were identified. We evaluated the incidence of ALI and its associated mortality, length of stay, and cost of hospitalization. We used multivariable logistic regression to determine independent predictors of ALI in this population.

RESULTS

A total of 84,615 patients had AMI complicated by cardiogenic shock and 1302 (1.54%) developed ALI. The rates of ALI increased from 1.29% in 2016 to 1.66% in 2019 (P ≤ .002). The use of microaxial mechanical circulatory support increased from 2.25% in 2016 to 13.36% in 2019 (P = .0001). The major predictors of ALI included peripheral arterial disease (odds ratio [OR], 7.34; 95% confidence interval [CI], 6.12-8.81), venoarterial extracorporeal membrane oxygenation (OR, 4.40; 95% CI, 3.19-6.07), and microaxial mechanical circulatory support (OR, 3.12; 95% CI, 2.74-3.55). ALI in patients with cardiogenic shock was associated higher mortality (39.20% vs 33.53%; P ≤ .0001).

CONCLUSIONS

This nationwide observational study shows that ALI is an important complication of AMI with cardiogenic shock. This complication is associated with higher mortality. In addition to peripheral artery disease, the use of mechanical circulatory devices was associated with significantly higher rates of ALI.

Clinical outcomes and factors associated with pulmonary infarction following acute pulmonary embolism: a retrospective observational study at a US academic centre

OBJECTIVE

Pulmonary infarction is a common clinical and radiographic finding in acute pulmonary embolism (PE), yet the clinical relevance and prognostic significance of pulmonary infarction remain unclear. The study aims to investigate the clinical features, radiographic characteristics, impact of reperfusion therapy and outcomes of patients with pulmonary infarction.

DESIGN, SETTING AND PARTICIPANTS

A retrospective cohort study of 496 adult patients (≥18 years of age) diagnosed with PE who were evaluated by the PE response team at a tertiary academic referral centre in the USA. We collected baseline characteristics, laboratory, radiographic and outcome data. Statistical analysis was performed by Student's t-test, Mann-Whitney U test, Fischer's exact or χ² test where appropriate. Multivariate logistic regression was used to evaluate potential risk factors for pulmonary infarction.

RESULTS

We identified 143 (29%) cases of pulmonary infarction in 496 patients with PE. Patients with infarction were significantly younger (52±15.9 vs 61±16.6 years, p<0.001) and with fewer comorbidities. Most infarctions occurred in the lower lobes (60%) and involved a single lobe (64%). The presence of right ventricular (RV) strain on CT imaging was significantly more common in patients with infarction (21% vs 14%, p=0.031). There was no significant difference in advanced reperfusion therapy, in-hospital mortality, length of stay and readmissions between groups. In multivariate analysis, age and evidence of RV strain on CT and haemoptysis increased the risk of infarction.

CONCLUSIONS

Radiographic evidence of pulmonary infarction was demonstrated in nearly one-third of patients with acute PE. There was no difference in the rate of reperfusion therapies and the presence of infarction did not correlate with poorer outcomes.

Pharmacomechanical Catheter-Directed Thrombolysis With the Bashir Endovascular Catheter for Acute Pulmonary Embolism: The RESCUE Study

BACKGROUND

Catheter-directed thrombolysis (CDT) has been associated with rapid recovery of right ventricular (RV) function. The Bashir catheter was developed for enhanced thrombolysis in large vessels such as the pulmonary arteries (PAs) with lower doses of tissue plasminogen activator (tPA).

OBJECTIVES

The aim of this study was to evaluate the efficacy and safety of tPA infused using a pharmacomechanical (PM) CDT device called the Bashir endovascular catheter in patients with intermediate-risk acute pulmonary embolism (PE).

METHODS

Patients with symptoms of acute PE with computed tomographic evidence of RV dilatation were enrolled. The Bashir catheter was used to deliver 7 mg tPA into each PA over 5 hours. The primary efficacy endpoint was the core laboratory-assessed change in computed tomographic angiography-derived RV/left ventricular (LV) diameter ratio at 48 hours, and the primary safety endpoint was serious adverse events (SAEs) including major bleeding at 72 hours.

RESULTS

At 18 U.S. sites, 109 patients were enrolled. The median device placement time was 15 minutes. At 48 hours after PM-CDT, the RV/LV diameter ratio decreased by 0.56 (33.3%; P < 0.0001). PA obstruction as measured by the refined modified Miller index was reduced by 35.9% (P < 0.0001). One patient (0.92%) had 2 SAEs: a retroperitoneal bleed (procedure related) and iliac vein thrombosis (device related). Two other procedure-related SAEs were epistaxis and non-access site hematoma with anemia.

CONCLUSIONS

PM-CDT with the Bashir endovascular catheter is associated with a significant reduction in RV/LV diameter ratio and a very low rate of adverse events or major bleeding in patients with intermediate-risk acute PE. The notable finding was a significant reduction in PA obstruction with low-dose tPA. (Recombinant tPA by Endovascular Administration for the Treatment of Submassive PE Using CDT for the Reduction of Thrombus Burden [RESCUE]; NCT04248868).

Impact of pulmonary embolism response teams on acute pulmonary embolism: a systematic review and meta-analysis

BACKGROUND

The impact of pulmonary embolism response teams (PERTs) on treatment choice and outcomes of patients with acute pulmonary embolism (PE) is still uncertain.

OBJECTIVE

To determine the effect of PERTs in the management and outcomes of patients with PE.

METHODS

PubMed, Embase, Web of Science, CINAHL, WorldWideScience and MedRxiv were searched for original articles reporting PERT patient outcomes from 2009. Data were analysed using a random effects model.

RESULTS

16 studies comprising 3827 PERT patients and 3967 controls met inclusion criteria. The PERT group had more patients with intermediate and high-risk PE (66.2%) compared to the control group (48.5%). Meta-analysis demonstrated an increased risk of catheter-directed interventions, systemic thrombolysis and surgical embolectomy (odds ratio (OR) 2.10, 95% confidence interval (CI) 1.74-2.53; p<0.01), similar bleeding complications (OR 1.10, 95% CI 0.88-1.37) and decreased utilisation of inferior vena cava (IVC) filters (OR 0.71, 95% CI 0.58-0.88; p<0.01) in the PERT group. Furthermore, there was a nonsignificant trend towards decreased mortality (OR 0.87, 95% CI 0.71-1.07; p=0.19) with PERTs.

CONCLUSIONS

The PERT group showed an increased use of advanced therapies and a decreased utilisation of IVC filters. This was not associated with increased bleeding. Despite comprising more severe PE patients, there was a trend towards lower mortality in the PERT group.

Changes in Lung Perfusion in Patients Treated with Percutaneous Mechanical Thrombectomy for Intermediate-Risk Pulmonary Embolism

BACKGROUND

Current pulmonary embolism treatment options rely heavily on anatomical clot location. However, anatomical location does not necessarily determine adverse outcomes; rather, clinical severity is secondary to the degree of perfusion impairment. Dual-energy computed tomography pulmonary angiogram (DE-CTPA) can map perfusion at the time of pulmonary embolism diagnosis. Single-photon emission computed tomography ventilation-perfusion scans allow for perfusion tracking similar to DE-CTPA.

METHODS

We present 3 patients with intermediate-risk pulmonary embolism treated with mechanical thrombectomy using the Inari FlowTriever System (Inari Medical, Irvine, Calif). Lung perfusion scoring was applied to pre-procedure and post-procedure imaging. We graded perfusion of each lobe in 3 planes. If the entire lobe was perfused, a score of 3 was assigned. If lung perfusion is normal, total perfusion score is 15. All patients had pre-procedure and follow-up transthoracic echocardiograms.

RESULTS

All 3 patients were diagnosed with pulmonary embolism via DE-CTPA that showed right ventricle strain and had deep venous thrombosis. Following mechanical thrombectomy, patients immediately experienced improvement in perfusion score; scores continued to improve at follow-up. All patients also had improvement in right ventricle size or function on follow-up echocardiogram.

DISCUSSION

Intermediate-risk pulmonary embolism often has large initial clot burden that predicts residual pulmonary vascular obstruction. Residual pulmonary vascular obstruction is associated with increased risk of death, recurrent thrombus, and chronic thromboembolic pulmonary hypertension. Clot removal via thrombectomy may decrease the prevalence of residual pulmonary vascular obstruction by improving lung perfusion. We found that mechanical thrombectomy increased lung perfusion immediately and at follow-up assessments.

Does the ISCHEMIA Trial Apply to My Patients?

PURPOSE OF REVIEW

The ISCHEMIA trial demonstrated no difference in myocardial infarction or death in patients with stable coronary disease and moderate or large ischemia territory treated either with invasive revascularization or optimal medical therapy. Whether the findings of the randomized control trial relates to real-world outcomes is uncertain.

RECENT FINDINGS

Contemporary guideline-directed medical therapy has had a significant impact on the prognosis of coronary artery disease. Various observational data appear to indicate limited generalizability of the ISCHEMIA trial in different populations. Further studies are warranted to evaluate the optimal modality of therapy in patients with stable coronary disease and moderate or severe ischemia. The applicability of ISCHEMIA and ISCHEMIA-CKD trials still requires further validation.

Association of annual volume and in-hospital outcomes of catheter-directed thrombolysis for pulmonary embolism

OBJECTIVE

We sought to evaluate the association between the institutional volume of catheter-directed thrombolysis (CDT) for pulmonary embolism and in-hospital mortality.

BACKGROUND

CDT is an increasingly utilized therapy in patients with intermediate/high-risk PE. However, data on the relationship between hospital volume and clinical outcomes remain limited.

METHODS

Patients who underwent CDT between October 1, 2015, and March 31, 2021, were identified in the Vizient Clinical Database. The primary outcome was in-hospital mortality. Secondary outcome were major complications, length of stay, and cost. Hospitals were dichotomized into <8 and ≥ 8 cases/year following restricted cubic spline analysis.

RESULTS

A total of 6741 CDT procedures at 171 hospitals were included with a median annual hospital volume of 4.1 cases (IQR = 1.9-8.3). A total of 44 hospitals (25.7%) were classified as high-volume ( ≥ 8 cases/year) and performed 60.9% of all CDT cases. CDT at high-volume centers was associated with lower in-hospital mortality (6.0% vs. 11.3%; p < 0.0001). Stroke and bleeding rates were similar, but pulmonary complications were more frequent at low-volume centers. CDT at high volume centers was associated with a significantly shorter length of stay and lower cost. The association between high CDT volume and in-hospital mortality persisted after adjustment for demographics (odds ratio [OR] = 0.49, [0.41-0.58]), demographics and risk factors (OR = 0.52 [0.44-0.62]), and demographics, risk factors, and troponin elevation (OR = 0.51 [0.40-0.66]).

CONCLUSION

In a large contemporary cohort of patients undergoing CDT in the United States, low annual institutional volume of CDT was associated with higher in-hospital mortality.

May-Thurner Anatomy in Patients With Chronic Thromboembolic Pulmonary Hypertension: An Important Clinical Association

OBJECTIVES

The aim of this study was to investigate the incidence of May-Thurner anatomy (MTA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH) and identify its predictors.

BACKGROUND

MTA is an anatomical variant characterized by compression of left common iliac vein by the overlying right iliac artery. Over time, this leads to venous intimal scarring, blood flow stasis, and the development of deep vein thrombosis (DVT). DVT is a known risk factor for the development of CTEPH. The prevalence of this anatomical variation in patients with CTEPH is unknown.

METHODS

A retrospective chart review was conducted in patients referred to Temple University Hospital's cardiac catheterization laboratory for the evaluation of CTEPH between January 2016 and June 2020. Among these patients, those who underwent invasive venography were evaluated for the presence of angiographic MTA. Multivariate regression was used to identify factors associated with presence of MTA.

RESULTS

A total of 193 patients with CTEPH were referred for pulmonary angiography, of whom 148 patients underwent invasive venography. MTA was identified in 44 patients (29.7%). Factors associated with the presence of MTA were lower extremity DVT (odds ratio: 3.5; 95% confidence interval: 1.58-7.8; P = 0.002), and left lower extremity post-thrombotic syndrome (odds ratio: 2.0; 95% confidence interval: 0.98-4.1; P = 0.05). Patients with MTA were more likely to undergo pulmonary thromboendarterectomy than patients without MTA (79.5% vs 58.7%; P = 0.015).

CONCLUSIONS

MTA is very common in patients with CTEPH. History of lower extremity DVT and or left lower extremity post-thrombotic syndrome was associated with the presence of MTA.

First-in-human experience of the Bashir Endovascular Catheter in the treatment of iliocaval deep vein thrombosis

Deep vein thrombosis (DVT) is a common disorder affecting approximately 900,000 new patients in the United States each year. Although the mainstay of treatment of DVT patients is therapeutic anticoagulation, some patients remain significantly symptomatic and therefore require more advanced interventions such as catheter-directed thrombolysis (CDT). We describe a case series of 13 patients with acute symptomatic inferior vena cava (IVC) and iliofemoral DVT that were treated with CDT using the Bashir Endovascular Catheter (BEC). We report the first-in-human use of BEC, which is a novel pharmacomechanical thrombolysis device. All the treated patients had complete and rapid resolution of their symptoms with excellent venous outflow. Despite initial promising results, larger studies using this catheter design will be needed to assess the role of BEC-directed therapy on rates of post-thrombotic syndrome and bleeding complications.

Superior Vena Cava Syndrome

Superior vena cava (SVC) syndrome comprises a constellation of clinical signs and symptoms caused by obstruction of blood flow through the SVC. The management of patients with life-threatening SVC syndrome is evolving from radiation therapy to endovascular therapy as the first-line treatment. There is a paucity of data and societal guidelines with regard to the management of SVC syndrome. This paper aims to update the practicing interventionalists with the contemporary and the evolving therapeutic approach to SVC syndrome. In addition, the review will focus on endovascular techniques, including catheter-directed thrombolysis, angioplasty, and stenting, and their associated complications.

Endovascular therapy for superior vena cava syndrome: A systematic review and meta-analysis

BACKGROUND

Superior vena cava (SVC) syndrome is caused by the obstruction of the SVC and can result in significant morbidity and mortality. In contemporary practice, endovascular therapy (ET) has become the standard of care for a majority of these patients. This study is a systematic review and meta-analysis of the available literature to assess technical success, restenosis, and recurrence of SVC syndrome following endovascular intervention.

METHODS

For this meta-analysis, we conducted a systematic literature review of PubMed, Cochrane Library, and Embase databases from inception to April 14, 2021 for studies on ET for SVC syndrome. Studies included full-length journal articles on the use of ET among adults with SVC syndrome. Case reports or case series with fewer than 20 patients were excluded. We evaluated the endpoints of technical success rate, restenosis rate, and recurrence rates in SVC syndrome patients after endovascular stenting. The results of this study were calculated using random-effects models.

FINDINGS

We identified 6,012 reports, of which 39 studies met our inclusion criteria and were included for analysis. A total of 2200 patients received ET for SVC syndrome. The weighted technical success rate was 98.8% (95% CI 98.2-99.3) with low heterogeneity (I²=17.4%, p = 0.185), restenosis rate was 10.5% (95% CI 8.4-12.6) with moderate heterogeneity (I²=53.5%, p<0.001), and recurrence rate was 10.8% (95% CI 8.1-13.5) with high heterogeneity (I²=75.8%, p<0.001). Total complication rate was 8.6% (95% CI 7.3%-9.9%) with a mean complication rate of 7.5% (95% CI 4.7%-10.3%).

INTERPRETATION

Our systematic review revealed high technical success, low restenosis, and low recurrence rates following ET. Collectively, these results support the paradigm of ET as an effective and safe treatment for patients with SVC syndrome.

FUNDING

None.

Contemporary Catheter-Based Treatment Options for Management of Acute Pulmonary Embolism

Introduction

Acute pulmonary embolism (PE) remains an important cause of cardiovascular mortality and morbidity in the USA and worldwide. Catheter-based therapies are emerging as a new armamentarium for improving outcomes in these patients.

Purpose of review

The purpose of this review is to familiarize the clinicians with (1) various types of catheter-based modalities available for patients with acute PE, (2) advantages, disadvantages, and appropriate patient selection for the use of these devices, and (3) evidence base and the relevance of such therapies in the COVID-19 pandemic.

Recent findings

There are four main types of catheter-based therapies in acute PE: (1) standard catheter-directed thrombolysis (CDT), (2) ultrasound-assisted CDT, (3) pharmacomechanical CDT, and (4) mechanical thrombectomy without thrombolysis. Ultrasound-assisted thrombolysis is the most widely studied modality in this group; however, evidence base for other catheter-based technologies is rapidly emerging.

Summary

Current use of catheter-based therapies is most suitable for patients with intermediate and high-risk acute PE. The adoption of a multidisciplinary approach like the pulmonary embolism response team (PERT) is desirable for appropriate patient selection and possibly/potentially improving patient outcomes. We discuss the current status of these therapies.

Three-dimensional microscale hanging drop arrays with geometric control for drug screening and live tissue imaging

Existing three-dimensional (3D) culture techniques are limited by trade-offs between throughput, capacity for high-resolution imaging in living state, and geometric control. Here, we introduce a modular microscale hanging drop culture where simple design elements allow high replicates for drug screening, direct on-chip real-time or high-resolution confocal microscopy, and geometric control in 3D. Thousands of spheroids can be formed on our microchip in a single step and without any selective pressure from specific matrices. Microchip cultures from human LN229 glioblastoma and patient-derived mouse xenograft cells retained genomic alterations of originating tumors based on mate pair sequencing. We measured response to drugs over time with real-time microscopy on-chip. Last, by engineering droplets to form predetermined geometric shapes, we were able to manipulate the geometry of cultured cell masses. These outcomes can enable broad applications in advancing personalized medicine for cancer and drug discovery, tissue engineering, and stem cell research.

Safety and efficacy of catheter directed thrombolysis (CDT) in elderly with pulmonary embolism (PE)

Introduction

Acute pulmonary embolism (PE) remains a common cause for morbidity and mortality in patients over 65 years. Given the increased risk of bleeding in the elderly population with the use of systemic thrombolysis, catheter-directed therapy (CDT) is being increasingly used for the treatment of submassive PE. Nevertheless, the safety of CDT in the elderly population is not well studied. We, therefore, aimed to evaluate the safety of CDT in our elderly patients.

Methods

We conducted a retrospective observational study of consecutive patients aged >65 years with a diagnosis of PE from our Pulmonary Embolism Response Team database. We compared the treatment outcomes of CDT versus anticoagulation (AC) in elderly. Propensity score matching was used to construct two matched cohorts for final outcomes analysis.

Results

Of 346 patients with acute PE, 138 were >65 years, and of these, 18 were treated with CDT. Unmatched comparison between CDT and AC cohorts demonstrated similar in-hospital mortality (11.1% vs 5.6%, p=0.37) and length of stay (LOS) (3.81 vs 5.02 days, p=0.5395), respectively. The results from the propensity-matched cohort mirrored results of the unmatched cohort with no significant difference between CDT and AC in-hospital mortality (11.8% vs 5.9%, p=0.545) or median LOS (3.76 vs 4.21 days, p=0.77), respectively.

Conclusion

In this observational study using propensity score-matched analysis, we found that patients >65 years who were treated with CDT for management of acute PE had similar mortality and LOS compared with those treated with AC. Further studies are required to confirm these findings.

First-in-Human Study to Assess the Safety and Feasibility of the Bashir Endovascular Catheter for the Treatment of Acute Intermediate-Risk Pulmonary Embolism

BACKGROUND

The Bashir Endovascular Catheter (BEC) is a novel pharmaco-mechanical device designed to enhance thrombolysis by increasing the exposure of thrombus to endogenous and exogenous thrombolytics. The aim of this prospective, multicenter, single-arm study was to evaluate the feasibility and initial safety of the BEC in patients with acute intermediate-risk pulmonary embolism (PE).

METHODS

Patients with symptomatic PE and right ventricular to left ventricular diameter ratio ≥0.9 as documented by computer tomography angiography were eligible for enrollment. The primary safety end points were device related death or adverse events, and major bleeding within 72 hours after BEC directed therapy.

RESULTS

Nine patients were enrolled across 4 US sites. The total dose of r-tPA (recombinant tissue-type plasminogen activator) was 14 mgs in bilateral PE and 12 mgs in unilateral PE over 8 hours delivered via the expanded BEC. At 30-day follow-up, there were no deaths or device-related adverse events. At 48 hours post-BEC therapy, the right ventricular to left ventricular diameter ratio decreased from 1.52±0.26 to 0.97±0.06 (P=0.0009 [95% CI, 0.33-0.82]; 37.0% reduction). Thrombus burden as measured by the Modified Miller Index decreased from 25.4±5.3 to 16.0±4.0 (P=0.0005; [95% CI, 5.5-13.4]; 37.1% reduction).

CONCLUSIONS

In this early feasibility study of the BEC for intermediate-risk PE, there were no deaths or device-related adverse events and a significant reduction in right ventricular to left ventricular diameter ratio and thrombus burden. Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT03927508.

Incidence of venous thromboembolism in coronavirus disease 2019: An experience from a single large academic center

Background

Infection with the novel severe acute respiratory syndrome coronavirus 2 has been associated with a hypercoagulable state. Emerging data from China and Europe have consistently shown an increased incidence of venous thromboembolism (VTE). We aimed to identify the VTE incidence and early predictors of VTE at our high-volume tertiary care center.

Methods

We performed a retrospective cohort study of 147 patients who had been admitted to Temple University Hospital with coronavirus disease 2019 (COVID-19) from April 1, 2020 to April 27, 2020. We first identified the VTE (pulmonary embolism [PE] and deep vein thrombosis [DVT]) incidence in our cohort. The VTE and no-VTE groups were compared by univariable analysis for demographics, comorbidities, laboratory data, and treatment outcomes. Subsequently, multivariable logistic regression analysis was performed to identify the early predictors of VTE.

Results

The 147 patients (20.9% of all admissions) admitted to a designated COVID-19 unit at Temple University Hospital with a high clinical suspicion of acute VTE had undergone testing for VTE using computed tomography pulmonary angiography and/or extremity venous duplex ultrasonography. The overall incidence of VTE was 17% (25 of 147). Of the 25 patients, 16 had had acute PE, 14 had had acute DVT, and 5 had had both PE and DVT. The need for invasive mechanical ventilation (adjusted odds ratio, 3.19; 95% confidence interval, 1.07-9.55) and the admission D-dimer level ≥1500 ng/mL (adjusted odds ratio, 3.55; 95% confidence interval, 1.29-9.78) were independent markers associated with VTE. The all-cause mortality in the VTE group was greater than that in the non-VTE group (48% vs 22%; P = .007).

Conclusions

Our study represents one of the earliest reported from the United States on the incidence rate of VTE in patients with COVID-19. Patients with a high clinical suspicion and the identified risk factors (invasive mechanical ventilation, admission D-dimer level ≥1500 ng/mL) should be considered for early VTE testing. We did not screen all patients admitted for VTE; therefore, the true incidence of VTE could have been underestimated. Our findings require confirmation in future prospective studies.

Predictors of intracranial hemorrhage in patients treated with catheter-directed thrombolysis for deep vein thrombosis

BACKGROUND

Although acute intracranial hemorrhage (ICH) is a rare complication of catheter-directed thrombolysis (CDT), it remains a major concern associated with the use of CDT. The incidence and clinical predictors of developing ICH in the setting of CDT are not known.

METHODS

The National Inpatient Sample database was used to identify all patients with proximal lower extremity or caval deep vein thrombosis (DVT) from January 2005 to December 2013 in the United States. Multivariate logistic regression was performed to identify the clinical predictors of ICH between patients with DVT who had received anticoagulation therapy alone and those who had been treated with CDT plus anticoagulation therapy.

RESULTS

Of 138,049 patients with proximal lower extremity or caval DVT, 7119 (5.2%) had received anticoagulation therapy and CDT. Of the patients treated with anticoagulation alone, ICH had occurred in 0.2% compared with 0.7% for those treated with CDT (P < .01). The independent predictors of ICH in the CDT cohort were a history of stroke (odds ratio [OR], 19.4; 95% confidence interval [CI], 8.8-42.8; P < .01), chronic kidney disease (OR, 2.2; 95% CI, 1.1-4.7; P = .03), age >74 years (OR, 2.2; 95% CI, 1.2-4.3; P = .02), male sex (OR, 1.8; 95% CI, 1.01-3.3; P = .048). Of those patients treated with anticoagulation alone, the risk factors for the development of ICH were a history of stroke, hospital teaching status, and age >74 years.

CONCLUSIONS

The results from the present nationwide observational study showed that of patients with DVT treated with CDT, the independent predictors for developing ICH were a history of stroke, chronic kidney disease, male sex, and age >74 years.

Catheter-Directed Thrombolysis of Iliocaval Thrombosis in Patients With COVID-19 Infection

We present the characteristics and outcomes of the first 2 cases of catheter-directed thrombolysis performed in patients presenting with coronavirus disease-2019 (COVID-19)-related iliocaval thrombosis. (Level of Difficulty: Beginner.).

Contemporary nationwide trends and in-hospital outcomes of adjunctive stenting in patients undergoing catheter-directed thrombolysis for proximal deep venous thrombosis

OBJECTIVE

Outflow venous stenting as an adjunct to catheter-directed thrombolysis (CDT) is performed to prevent recurrent thrombosis and to reduce the risk of post-thrombotic syndrome. Historical data show that stenting improves outcomes of surgical thrombectomy in patients with iliofemoral deep venous thrombosis (DVT), and recent observational data suggest that stenting improves long-term outcomes of CDT. However, the impact of stenting during CDT on acute safety outcomes is unknown. We sought to investigate the contemporary trends, safety outcomes, and resource utilization of adjunctive stent placement in patients undergoing CDT.

METHODS

Patients with proximal lower extremity and caval DVT were identified within the National Inpatient Sample from January 2005 to December 2013. From this data set, we stratified our patients into three groups: patients who received CDT alone, patients who received CDT plus angioplasty, and patients who received CDT plus angioplasty with stenting. We used an inverse probability treatment weighting algorithm to create three weighted cohorts. Cochran-Armitage test was used to evaluate the trends of stent placement among patients treated with CDT. The primary outcome was a composite end point of all-cause mortality, gastrointestinal bleed, or intracranial hemorrhage.

RESULTS

A total of 138,049 patients were discharged with a principal diagnosis of proximal and caval DVT; 7097 of these patients received CDT (5.1%). From this group, 2854 (40.2%) were treated with CDT alone, 2311 (32.6%) received adjunctive angioplasty alone, and 1932 (27.2%) received adjunctive angioplasty and stent. Adjunctive stenting had a significantly lower rate of primary composite outcome compared with CDT alone (2.7% vs 3.8%; P = .04). Stent placement was associated with a similar length of stay compared with angioplasty and CDT alone groups (6.8 vs 6.9 vs 7.1 days, respectively; P = .94) and higher in-hospital charges ($115,164.01 ± $76,985.31 vs $98,089.82 ± $72,921.94 vs $80,441.63 ± $74,024.98; P < .001).

CONCLUSIONS

This nationwide study suggests that one in four patients undergoing CDT is treated with adjunctive stent placement in the United States. This observational study showed that adjunctive stenting does not adversely affect the acute safety outcomes of CDT; however, it was associated with increased hospital charges.

Emergence of functional neuromuscular junctions in an engineered, multicellular spinal cord-muscle bioactuator

Three-dimensional (3D) biomimetic systems hold great promise for the study of biological systems in vitro as well as for the development and testing of pharmaceuticals. Here, we test the hypothesis that an intact segment of lumbar rat spinal cord will form functional neuromuscular junctions (NMJs) with engineered, 3D muscle tissue, mimicking the partial development of the peripheral nervous system (PNS). Muscle tissues are grown on a 3D-printed polyethylene glycol (PEG) skeleton where deflection of the backbone due to muscle contraction causes the displacement of the pillar-like "feet." We show that spinal cord explants extend a robust and complex arbor of motor neurons and glia in vitro. We then engineered a "spinobot" by innervating the muscle tissue with an intact segment of lumbar spinal cord that houses the hindlimb locomotor central pattern generator (CPG). Within 7 days of the spinal cord being introduced to the muscle tissue, functional neuromuscular junctions (NMJs) are formed, resulting in the development of an early PNS in vitro. The newly innervated muscles exhibit spontaneous contractions as measured by the displacement of pillars on the PEG skeleton. Upon chemical excitation, the spinal cord-muscle system initiated muscular twitches with a consistent frequency pattern. These sequences of contraction/relaxation suggest the action of a spinal CPG. Chemical inhibition with a blocker of neuronal glutamate receptors effectively blocked contractions. Overall, these data demonstrate that a rat spinal cord is capable of forming functional neuromuscular junctions ex vivo with an engineered muscle tissue at an ontogenetically similar timescale.

Rapid Isothermal Amplification and Portable Detection System for SARS-CoV-2

The COVID-19 pandemic provides an urgent example where a gap exists between availability of state-of-the-art diagnostics and current needs. As assay details and primer sequences become widely known, many laboratories could perform diagnostic tests using methods such as RT-PCR or isothermal RT-LAMP amplification. A key advantage of RT-LAMP based approaches compared to RT-PCR is that RT-LAMP is known to be robust in detecting targets from unprocessed samples. In addition, RT-LAMP assays are performed at a constant temperature enabling speed, simplicity, and point-of-use testing. Here, we provide the details of an RT-LAMP isothermal assay for the detection of SARS-CoV-2 virus with performance comparable to currently approved tests using RT-PCR. We characterize the assay by introducing swabs in virus spiked synthetic nasal fluids, moving the swab to viral transport medium (VTM), and using a volume of that VTM for performing the amplification without an RNA extraction kit. The assay has a Limit-of-Detection (LOD) of 50 RNA copies/μL in the VTM solution within 20 minutes, and LOD of 5000 RNA copies/μL in the nasal solution. Additionally, we show the utility of this assay for real-time point-of-use testing by demonstrating detection of SARS-CoV-2 virus in less than 40 minutes using an additively manufactured cartridge and a smartphone-based reader. Finally, we explore the speed and cost advantages by comparing the required resources and workflows with RT-PCR. This work could accelerate the development and availability of SARS-CoV-2 diagnostics by proving alternatives to conventional laboratory benchtop tests.