Ultra-Low-Dose Systemic Tissue Plasminogen Activator in High-Risk Submassive Pulmonary Embolism

Prevalence and Risk Factors of Pulmonary Embolism in COPD Patients Complicated with Secondary Polycythemia

Purpose

This study aimed to establish the prevalence of pulmonary embolism (PE) in chronic obstructive pulmonary disease (COPD) patients with secondary polycythemia (SP) and explore the risk factors for PE in COPD patients with SP.

Patients and Methods

We analyzed the prevalence of PE among COPD patients with SP who were hospitalized at Qinghai Provincial People's Hospital between January 2015 and December 2020. From January 2021 to January 2024, we enrolled patients into three groups (COPD+SP+PE, COPD+SP, and control) and performed laboratory measurements, biomarkers, echocardiography, and pulmonary function tests. Patients in the COPD+SP group received clinical treatment, and biomarkers were measured again seven days after treatment.

Results

The prevalence of PE in patients with COPD SP was 5.21%. We found that COPD+SP+PE group had significantly higher levels of erythrocyte distribution width (RDW), platelet volume distribution width (PDW), mean platelet volume (MPV), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), monocyte to large platelet ratio (MLPR), 5-hydroxytryptamine (5-HT), activated protein C (APC), urokinase-type plasminogen activator (u-PA), thrombomodulin (TM), interleukin-38 (IL-38), tissue factor (TF), and fractalkine (FKN) in contrast to COPD+SP group. Biomarkers, such as FKN, β-thromboglobulin (β-TG), APC, u-PA, TM, TF, and IL-38, were risk factors for COPD patients with SP who are complicated by PE. Clinical treatment significantly reduced the levels of β-TG, IL-38, APC, endothelin-1 (ET-1), u-PA, FKN, TM, 5-HT, and neutrophil extracellular traps (NETs) in patients with COPD+SP.

Conclusion

PE incidence was significantly higher in patients with COPD and SP. In COPD patients with SP, routine joint detection of blood and cardiac markers, blood gas analysis, and pulmonary function tests can help to identify patients with PE. APC, u-PA, TF, FKN, TM, and IL-38 are risk factors for PE in patients with COPD and SP, and clinical treatment can effectively reduce this risk.

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.