Current Controversies in Thrombolytic Use in Acute Pulmonary Embolism

Clinical outcomes of submassive pulmonary embolism thrombolysis-an Indian experience

BACKGROUND

Acute pulmonary thromboembolism is the most dangerous presentation of venous thromboembolic disease. The role of thrombolysis in massive pulmonary embolism has been studied extensively, but the same is not there for submassive pulmonary embolism. This study is aimed at evaluating the effects of thrombolysis in acute submassive pulmonary embolism. This was a prospective, case-control, observational study. Patients presenting with acute submassive pulmonary embolism were divided into thrombolysis group and control group depending on whether they received thrombolysis plus anticoagulation or anticoagulation only, respectively.

RESULTS

A total of 86 patients were included in the study. Forty-two patients were in the thrombolysis group, and 44 patients were in the control group. The mean ± SD age in the control and thrombolysis groups was 63.3 ± 14.7 and 56.4 ± 13.8 years, respectively. The two groups were well matched in sex distribution and associated comorbidities like COPD, active surgery, major trauma, and immobilization. On echocardiography, dilated RA/RV in pre-treatment vs. post-treatment was seen in 20 (45.5%) vs. 20 (45.5%) in the control group and 26 (61.9%) vs. 11 (26.2%) in the thrombolysis group. Similarly, RV systolic dysfunction in pre-treatment vs. post-treatment was seen in 24 (54.5%) vs. 21 (47.7%) in the control group and 22 (52.4%) vs. 8 (19.0%) in the thrombolysis group. Pulmonary artery pressure in pre-treatment vs. post-treatment was 64.4 ± 15.0 vs. 45.9 ± 9.9 mmHg in the control group and 68.3 ± 17.4 vs. 31.4 ± 6.9 mmHg in the thrombolysis group. In control vs. thrombolysis group, there were 5 vs. 1 death, 6 vs. 1 hemodynamic decompensation, and 6 vs. 1 patient needing mechanical ventilation.

CONCLUSION

Thrombolysis in submassive pulmonary embolism is associated with better right ventricular functions, lower pulmonary artery pressures, and comparable mortality rates.

Comparison of urokinase and reteplase thrombolytic treatment in patients with high-risk pulmonary embolism

Thrombolytic treatment is recommended for patients with high-risk pulmonary embolism. The present study compared thrombolytic therapy with urokinase and reteplase. A total of 37 patients presenting with acute high-risk pulmonary embolism at the Intensive Care Unit of Weinan Central Hospital of Shaanxi Province (Weinan, China) between June 2013 and January 2017 were retrospectively analyzed. According to their treatment, these subjects were assigned to the reteplase group (n=16) or the urokinase group (n=21). Systolic blood pressure (SBP), heart rate (HR) and respiratory rate (RR) were recorded prior to, and at 2, 4, 24 and 48 h after thrombolytic therapy. Complications, including bleeding, were closely monitored. Changes in blood gas analysis, troponin-T (TNT), pro-B-type natriuretic peptide (pro-BNP) and D-dimer (D-D) were observed. In the reteplase and urokinase group, 11 and 13 cases exhibited marked improvement, treatment was rated as effective in 4 and 6 cases, and 1 and 2 mortalities occurred, resulting in an overall effective rate of 93.8 and 90.5%, respectively (P>0.05). In the reteplase group, one patient was unsuccessfully resuscitated and died. In the urokinase group, one patient died of gastric hemorrhage after 22 h of thrombolysis, while another patient died of brain failure resuscitation. The treatment improved the SBP in each of the two groups (P<0.05), and this outcome was similar between these two groups (P>0.05). HR and RR were similar prior to and after thrombolytic therapy (P>0.05). In contrast to the urokinase group, TNT was significantly decreased after thrombolyis compared with the baseline in the reteplase group. Complications in the reteplase group were higher, but in contrast to the urokinase group, no life-threatening bleeding occurred. Although reteplase is as effective as urokinase in treating high-risk pulmonary embolism, reteplase may reduce myocardial damage.

Catheter-directed therapy as a treatment for submassive pulmonary embolism: A meta-analysis

AIMS

Catheter-directed therapy (CDT) is included in the guidelines for diagnosing and treating massive pulmonary embolism. However, few studies have evaluated the efficacy of CDT as a treatment for submassive pulmonary embolism (SPE). Therefore, we used evidence-based medicine to evaluate the effectiveness and safety of CDT in treating SPE.

METHODS

Search terms describing CDT in SPE and patients with intermediate pulmonary embolism were entered into the PubMed, Embase and Cochrane Library databases to identify relevant articles without language restrictions published between January 1990 and December 2016. A quality assessment and data extraction were performed by two investigators. The clinical efficacy of and major complications associated with treatment were analysed using a fixed effects model.

KEY FINDINGS

A total of 552 patients in 16 studies were included in this meta-analysis. The clinical success rate in CDT was approximately 100% (95% confidence interval (CI): 99%, 100%), the primary bleeding rate was 0.02% (95% CI: 0%, 0.05%), and mortality during hospitalization was approximately 0% (95% CI: 0%, 0.01%). The mean decrease in pulmonary artery systolic pressure after treatment was -14.9% (95% CI: -19.25%, -10.55%), and the mean post-treatment change in the ratio of the right to the left ventricle (RV/LV) was -0.35% (95% CI: -0.48%, -0.22%).

SIGNIFICANCE

CDT is effective and safe as a treatment for SPE and could be a first-line treatment for SPE under specific conditions.

Terapia fibrinolítica sistêmica no tromboembolismo pulmonar

O tromboembolismo pulmonar permanece como um grande desafio terapêutico para os médicos especialistas, pois, apesar de todo investimento e desenvolvimento em seu diagnóstico, profilaxia e tratamento, essa condição continua sendo a principal causa de morte evitável em ambiente hospitalar. Ainda restam muitas dúvidas em relação a qual perfil de paciente vai se beneficiar de fato da terapia fibrinolítica sistêmica, sem ficar exposto a um grande risco de sangramento. A estratificação de risco e a avaliação do prognóstico do evento, através de escores clínicos de insuficiência ventricular direita, marcadores de dilatação e disfunção do ventrículo direito e avaliação da massa trombótica, associados ou de forma isolada, são ferramentas que podem auxiliar na identificação do paciente que irá se beneficiar dessa terapia. Os únicos consensos em relação à terapia fibrinolítica no tratamento do tromboembolismo pulmonar são: não deve ser indicada de forma rotineira; nenhum dos escores ou marcadores, isoladamente, devem justificar seu uso; e os pacientes com instabilidade hemodinâmica são os mais beneficiados. Além disto, deve-se avaliar cada caso em relação ao risco de sangramento, especialmente no sistema nervoso central.

Efficacy and Safety of Thrombolytic Therapy in Acute Submassive Pulmonary Embolism: Follow-Up Study

BACKGROUND

Thrombolysis in acute submassive pulmonary embolism (PE) remains controversial. So we studied impact of thrombolytic therapy in acute submassive PE in terms of mortality, hemodynamic status, improvement in right ventricular function, and safety in terms of major and minor bleeding.

METHOD

A single-center, prospective, randomized study of 86 patients was conducted at LPS Institute of Cardiology, G.S.V.M. Medical College, Kanpur, India. Patients received thrombolysis (single bolus of tenecteplase) with unfractionated heparin (UFH, group I) or placebo with UFH (group II).

RESULT

Mean age of patients was 54.35 ± 12.8 years with male dominance (M:F = 70%:30%). Smoking was the most common risk factor seen in 29% of all patients, followed by recent history of immobilization (25%), history of surgery or major trauma within past 1 month (15%), dyslipidemia (10%) and diabetes mellitus (10%). Dyspnea was the most common symptom in 80% of all patients, followed by chest pain in 55% and syncope in 6%. Primary efficacy outcome occurred significantly better in group I vs. group II (4.5% vs. 20%; P = 0.04), and significant difference was also found in hemodynamic decompensation (4.5% vs. 20%; P = 0.04), the fall in mean pulmonary artery systolic pressure (PASP) (28.8% vs. 22.5%; P = 0.03), improvement in right ventricular (RV) function (70% vs. 40%; P = 0.001) and mean hospital stay (8.1 ± 2.5 vs. 11.1 ± 2.14 days; P = 0.001). There was no difference in mortality and major bleeding as safety outcome but increased minor bleeding occurred in group I patients (16% vs. 12%; P = 0.04).

CONCLUSION

Patients with acute submassive PE do not derive overall mortality benefit, recurrent PE and rehospitalization with thrombolytic therapy but had improved clinical outcome in form of decrease in hemodynamic decompensation, mean hospital stay, PASP and improvement of RV function with similar risk of major bleed but at cost of increased minor bleeding.