Safety and Efficacy of Reduced-Dose Versus Full-Dose Alteplase for Acute Pulmonary Embolism: A Multicenter Observational Comparative Effectiveness Study

OBJECTIVES

Systemic thrombolysis improves outcomes in patients with pulmonary embolism (PE) but is associated with the risk of hemorrhage. The data on efficacy and safety of reduced-dose alteplase are limited. The study objective was to compare the characteristics, outcomes, and complications of patients with PE treated with full- or reduced-dose alteplase regimens.

DESIGN

Multicenter retrospective observational study.

SETTING

Tertiary care hospital and 15 community and academic centers of a large healthcare system.

PATIENTS

Hospitalized patients with PE treated with systemic alteplase.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Pre- and post-alteplase hemodynamic and respiratory variables, patient outcomes, and complications were compared. Propensity score (PS) weighting was used to adjust for imbalances of baseline characteristics between reduced- and full-dose patients. Separate analyses were performed using the unweighted and weighted cohorts. Ninety-eight patients were treated with full-dose (100 mg) and 186 with reduced-dose (50 mg) regimens. Following alteplase, significant improvements in shock index, blood pressure, heart rate, respiratory rate, and supplemental oxygen requirements were observed in both groups. Hemorrhagic complications were lower with the reduced-dose compared with the full-dose regimen (13% vs. 24.5%, p = 0.014), and most were minor. Major extracranial hemorrhage occurred in 1.1% versus 6.1%, respectively ( p = 0.022). Complications were associated with supratherapeutic levels of heparin anticoagulation in 37.5% of cases and invasive procedures in 31.3% of cases. The differences in complications persisted after PS weighting (15.4% vs. 24.7%, p = 0.12 and 1.3% vs. 7.1%, p = 0.067), but did not reach statistical significance. There were no significant differences in mortality, discharge destination, ICU or hospital length of stay, or readmission after PS weighting.

CONCLUSIONS

In a retrospective, PS-weighted observational study, when compared with the full-dose, reduced-dose alteplase results in similar outcomes but fewer hemorrhagic complications. Avoidance of excessive levels of anticoagulation or invasive procedures should be considered to further reduce complications.

Retrospective Analysis of Direct-Acting Oral Anticoagulants (DOACs) Initiation Timing and Outcomes After Thrombolysis in High- and Intermediate-Risk Pulmonary Embolism

Direct-acting oral anticoagulants (DOACs) are prescribed in the treatment of venous thromboembolism, including pulmonary embolism (PE). Evidence is limited regarding the outcomes and optimal timing of DOACs in patients with intermediate- or high-risk PE treated with thrombolysis. We conducted a retrospective analysis of outcomes among patients with intermediate- and high-risk PE who received thrombolysis, by choice of long-term anticoagulant agent. Outcomes of interest included hospital length of stay (LOS), intensive care unit LOS, bleeding, stroke, readmission, and mortality. Descriptive statistics were used to examine characteristics and outcomes among patients, by anticoagulation group. Patients receiving a DOAC (n = 53) had shorter hospital LOS compared to those in warfarin (n = 39) and enoxaparin (n = 10) groups (mean LOS 3.6, 6.3 and 4.5 days, respectively; P < .0001). This single institution retrospective study suggests DOAC initiation <48 h from thrombolysis may result in shorter hospital LOS compared to DOAC initiation ≥48 h (P < .0001). Further larger studies with more robust research methodology are needed to address this important clinical question.

Serotonergic antidepressants and hospitalization for bleeding in patients supported with a continuous flow left ventricular assist device

BACKGROUND

Continuous flow left ventricular assist devices (CF -LVAD) improve survival in patients with advanced heart failure, but confer risk of bleeding complications. Serotonergic antidepressants (SA) are commonly used in heart failure patients receiving LVADs, but their inhibitory effect on platelet function may contribute to bleeding risk.

METHODS

We performed a retrospective analysis of LVAD patients at our institution from 2016 -2019 comparing patients treated with SA after LVAD to those without SA. Demographic and clinical variables related to bleeding were collected on discharge from index hospitalization for CF-LVAD implantation and on admission for any bleeding event. The primary endpoint was incidence of bleeding requiring hospitalization after discharge. Secondary endpoints included overall number of admissions for bleeding, time to first hospitalization for a bleeding event, and incidence rate of hospitalizations for bleeding per patient year.

RESULTS

100 patients met inclusion criteria for the study. A total of 5 patients without a history of SA use and 31 patients who were prescribed SA after CF -LVAD implant were readmitted for a bleeding event after initial implant hospitalization (15% vs 46%, p = 0.004). Bleeding rate per person year (0.3 vs 0.61, p = 0.01) were significantly less in patients without SA use. Age-adjusted multivariable analysis found SA use to be associated with a hospitalization for bleeding (HR 2.3, 95% CI 0.99 -5.4). The higher incidence of hospitalization for bleeding was driven by non-gastrointestinal anatomical sites (6% vs 28%, p = 0.02) with a HR 7.7 (95% CI 0.96 -62).

CONCLUSIONS

SA treatment after CF-LVAD implantation was associated with an increased risk for bleeding complications requiring hospitalization, particularly non-gastrointestinal bleeding.

COVID-19 and venous thromboembolism: Known and unknown for imaging decisions

As we continue to fight against the current coronavirus disease-2019 (COVID-19) pandemic, healthcare professionals across the globe are trying to answer questions surrounding how to best help patients with the up-to-date available science while awaiting the development of new therapies and mass vaccination. Since early in the pandemic, studies indicated a heightened risk of venous thromboembolism (VTE) in COVID-19 infected patients. There have been differing expert opinions about how to assess pretest probability of VTE in this patient population. This has been partly due to the high prevalence of respiratory failure in this patient population and the use of D-dimer as a prognostic test which is also frequently elevated in patients with COVID-19 in absence of VTE. Some experts have argued for an approach similar to usual care with testing if clinical suspicion is high enough. Some have argued for more routine screening at different points of care. Others have even suggested empiric therapeutic anti-coagulation in moderate to severely ill COVID-19 patients. In the following article, we review and summarize the most current literature in hopes of assisting clinicians in decision making and guidance for when to be concerned for VTE in COVID-19 patients. We also discuss research gaps and share pathways currently being used within our institution.