Adjunctive Therapy and Mortality in Patients With Unstable Pulmonary Embolism

Percutaneous interventions for pulmonary embolism

Pulmonary embolism (PE) ranks as a leading cause of in-hospital mortality and the third most common cause of cardiovascular death. The spectrum of PE manifestations varies widely, making it difficult to determine the best treatment approach for specific patients. Conventional treatment options include anticoagulation, thrombolysis, or surgery, but emerging percutaneous interventional procedures are being investigated for their potential benefits in heterogeneous PE populations. These novel interventional techniques encompass catheter-directed thrombolysis, mechanical thrombectomy, and hybrid approaches combining different mechanisms. Furthermore, inferior vena cava filters are also available as an option for PE prevention. Such interventions may offer faster improvements in right ventricular function, as well as in pulmonary and systemic haemodynamics, in individual patients. Moreover, percutaneous treatment may be a valid alternative to traditional therapies in high bleeding risk patients and could potentially reduce the burden of mortality related to major bleeds, such as that of haemorrhagic strokes. Nevertheless, the safety and efficacy of these techniques compared to conservative therapies have not been conclusively established. This review offers a comprehensive evaluation of the current evidence for percutaneous interventions in PE and provides guidance for selecting appropriate patients and treatments. It serves as a valuable resource for future researchers and clinicians seeking to advance this field. Additionally, we explore future perspectives, proposing "percutaneous primary pulmonary intervention" as a potential paradigm shift in the field.

Inferior Vena Cava Filters and Complications: A Systematic Review

Inferior vena cava (IVC) filters have been used since the 1960s to treat patients with acute risk of pulmonary embolism (PE) to prevent migration of thrombus by trapping it within the filter. Traditional usage has been in patients with contraindication to anticoagulation that carry a significant mortality risk. In this systematic review, we sought to evaluate complications associated with placement of inferior vena cava filters based on published data from the past 20 years. A search was performed on October 6th, 2022, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic reviews, using three databases (ProQuest, PubMed and ScienceDirect) for articles published between the dates of February 1, 2002 and October 1, 2022. Results were filtered to include full-text, clinical studies, and randomized trials written in English pertaining to keywords "IVC filter AND complications", "Inferior Vena Cava Filter AND complications", "IVC filter AND thrombosis" and "Inferior Vena Cava Filter AND thrombosis". Articles identified by the three databases were pooled and further screened for relevance based on inclusion and exclusion criteria. Initial search results yielded 33,265 hits from all three databases combined. Screening criteria were applied, with 7721 results remaining. After further manual screening, including removal of duplicate hits, a total of 117 articles were selected for review. While there are no consensus guidelines for best practice, there is compelling evidence that IVC filters can provide significant protection against PE with minimal complications if the treatment window is appropriate. Increase in the variety of filter models has led to broader availability, but skepticism remains about their efficacy and safety, with ongoing controversy surrounding appropriate indications. Further research is needed to establish clear guidelines on appropriate indications for IVC placement and to determine time course of complications versus benefits for indwelling filters.

Risk Stratification in Patients with Acute Pulmonary Embolism: Current Evidence and Perspectives

Risk stratification is one of the cornerstones of the management of acute pulmonary embolism (PE) and determines the choice of both diagnostic and therapeutic strategies. The first step is the identification of patent circulatory failure, as it is associated with a high risk of immediate mortality and requires a rapid diagnosis and prompt reperfusion. The second step is the estimation of 30-day mortality based on clinical parameters (e.g., original and simplified version of the pulmonary embolism severity index): low-risk patients without right ventricular dysfunction are safely managed with ambulatory anticoagulation. The remaining group of hemodynamically stable patients, labeled intermediate-risk PE, requires hospital admission, even if most of them will heal without complications. In recent decades, efforts have been made to identify a subgroup of patients at an increased risk of adverse outcomes (intermediate-high-risk PE), who might benefit from a more aggressive approach, including reperfusion therapies and admission to a monitored unit. The cur-rent approach, combining markers of right ventricular dysfunction and myocardial injury, has an insufficient positive predictive value to guide primary thrombolysis. Sensitive markers of circulatory failure, such as plasma lactate, have shown interesting prognostic accuracy and may play a central role in the future. Furthermore, the improved security of reduced-dose thrombolysis may enlarge the indication of this treatment to selected intermediate–high-risk PE.

Short-term effects of fibrinolytic therapy on the hemodynamic parameters of patients with intermediate- and high-risk pulmonary embolism

Objective

We aimed to determine the effect of fibrinolytic therapy on hemodynamic parameters at 4 hours after treatment and bleeding complications in patients with intermediate- and high-risk pulmonary embolism.

Methods

This single-center, retrospective, cohort study included patients with intermediate- and high-risk pulmonary embolism treated with fibrinolytics. Their demographic and clinical characteristics, complications, and vital signs at the initiation of and 4 hours after fibrinolytic therapy were evaluated. The primary outcome was the change in the patients’ vital signs at 4 hours after fibrinolytic therapy, compared by the Mann-Whitney U-test.

Results

Seventy-nine patients were included in this study. The systolic and diastolic blood pressures of the high-risk group at 4 hours after fibrinolytic therapy were higher than those at the initiation of fibrinolytic therapy (80 mmHg vs. 99 mmHg, P = 0.029; 49 mmHg vs. 67 mmHg, P = 0.011, respectively). In the intermediate-risk group, the oxygen saturation increased (94% vs. 96%, P = 0.004) and pulse rate decreased (104 beats/min vs. 91 beats/min, P < 0.001).

Conclusion

Blood pressure at 4 hours after fibrinolytic therapy increased in patients with high-risk pulmonary embolism. Also, oxygen saturation and pulse rate improved in intermediate-risk patients.

Trends in Mortality of Acute Pulmonary Embolism

Despite substantial advances in the diagnosis and management, pulmonary embolism (PE) continues to be a significant cause of mortality. In this article, we provide a concise overview of the evolution of worldwide mortality trends related to PE. Despite the data being derived mainly from observational studies, there is a clear trend toward decreasing mortality over time from PE. Whether this truly represents a treatment effect or is more related to increased diagnosis of small PEs is not fully clear. Modern approaches to PE management such as the PE response teams have the potential to further reduce the mortality from PE.

Effects of Thrombolytic Therapy in Low-Risk Patients With Pulmonary Embolism

We performed this investigation to determine the effects on mortality of thrombolytic therapy in low-risk patients with pulmonary embolism (PE). This was a retrospective cohort study based on administrative data from the Nationwide Inpatient Sample, 2016 and 2017. Patients with a primary (first-listed) diagnosis of acute PE who were not in shock and not on a ventilator who did not have acute cor pulmonale were defined as low-risk. Patients were identified by International Classification of Diseases-10-Clinical Modification Codes. Mortality was assessed according to treatment with catheter-directed thrombolysis, intravenous thrombolytic therapy, or anticoagulants alone. Mortality with inferior vena cava (IVC) filters was also assessed. Mortality was lowest in low-risk patients treated with anticoagulants alone, 6,765 of 331,430 (2.0%). Mortality was somewhat higher with catheter-directed thrombolysis, 195 of 6915 (2.8%; p <0.0001), and highest with intravenous thrombolysis 510 of 5,200 (9.8%; p <0.0001). Matched patients showed similar results. IVC filters did not reduce mortality in patients treated with anticoagulants alone. Mortality was only 0.5% higher in patients treated with anticoagulants who had saddle PE than in patients with nonsaddle PE, 450 of 17,935 (2.5%) versus 6,315 of 313,495 (2.0%; p <0.0001). However, a larger proportion of low-risk patients with saddle PE received catheter-directed thrombolysis than patients who had nonsaddle PE, 2,330 of 21,760 (11%) versus 4,585 of 321,785 (1.4%; p <0.0001). Similarly, a larger proportion of patients with saddle PE received intravenous thrombolytic therapy than patients with nonsaddle PE, 1,495 of 21,760 (6.9%) versus 3,705 of 321,785 (1.2%; p <0.0001). In conclusion, low-risk patients with PE did not have lower mortality with catheter-directed thrombolysis or intravenous thrombolytic therapy than with anticoagulants alone, and IVC filters did not reduce mortality with anticoagulants alone.

Catheter-Directed Thrombolysis in Submassive Pulmonary Embolism and Acute Cor Pulmonale

Treatment of submassive (intermediate-risk) pulmonary embolism (PE), defined as hemodynamically stable with right ventricular (RV) dysfunction, showed lower in-hospital all-cause mortality with intravenous thrombolytic therapy than with anticoagulants, but at an increased risk of major bleeding. The present investigation was performed to test whether catheter-directed thrombolysis reduces mortality without increasing bleeding in submassive PE. This was a retrospective cohort study based on administrative data from the Nationwide Inpatient Sample. In 2016, 13,130 patients were hospitalized with PE and acute cor pulmonale, were stable, and treated with catheter-directed thrombolysis in 1,500 (11%) or anticoagulants alone in 11,630 (89%). Mortality was lower with catheter-directed thrombolysis than with anticoagulants in unmatched patients, 35 of 1,500 (2.3%) compared with 755 of 11,630 (6.5%; p <0.0001) and in matched patients, 30 of 1,260 (2.4%) compared with 440 of 6,910 (6.4%; p <0.0001). Time-dependent analysis showed catheter-directed thrombolysis reduced mortality if administered within the first 3 days. Patients with saddle PE treated with anticoagulants had lower mortality than non-saddle PE, 75 of 1,730 (4.3%) compared with 680 of 9,900 (6.9%; p < 0.0001) in unmatched patients and 45 of 1,305 (3.4%) compared with 395 of 5,605 (7.0%; p < 0.0001) in matched patients. Mortality was not lower with inferior vena cava filters either in those who received catheter-directed thrombolysis or those treated with anticoagulants. There were no fatal or nonfatal adverse events associated with catheter-directed thrombolysis. In conclusion, patients with submassive PE appear to have lower in-hospital all-cause mortality with catheter-directed thrombolysis administered within 3 days than with anticoagulants, and risks are low.