Comparison of long-term outcomes of 50 and 100 mg rt-PA in the management of acute pulmonary thromboembolism

Evaluation of serum YKL-40 level among clinical risk scores for early mortality in acute pulmonary thromboembolism

INTRODUCTION

Pulmonary embolism (PE) often occurs secondary to deep vein thrombosis and is an important cause of mortality and morbidity. This study aimed to evaluate the relationship between YKL-40 level and clinical risk score in patients with PE.

METHODS

The study included a total of 100 patients, 80 patients diagnosed with PE in the emergency department and 20 healthy controls. Patients with PE were divided into four groups: high-risk patients (n = 20), high-intermediate-risk patients (n = 20), low-intermediate-risk patients (n = 20), and low-risk patients (n = 20). Serum YKL-40 levels were measured by enzyme-linked immunosorbent assay. Pulmonary artery obstruction index (PAOI) was calculated from computed tomography angiography images.

RESULTS

PAOI increased in correlation with PE risk and differed significantly between all patient groups (p < 0.001). Troponin-I levels were significantly higher in the high-risk and high-intermediate-risk groups compared to the other groups (p < 0.001), but did not differ significantly between high-risk and high-intermediate-risk patients (p = 0.09). YKL-40 level was significantly higher in the high-risk PE group than the high-intermediate-risk group (p < 0.001). In receiving operator characteristic curve analysis assessing the discriminatory value of YKL-40 for high-risk PE patients, a cut-off value of 227.2 ng/mL had sensitivity of 85 % and specificity of 70 %.

DISCUSSION

YKL-40 may be an important biomarker in decisions regarding early thrombolytic treatment in patients with high-intermediate-risk PE. In addition, medical treatments targeting YKL-40 may also reduce thrombotic tendency in high-risk patient groups.

Investigation of the need for computed tomography pulmonary angiography in the decision to discontinue treatment for pulmonary thromboembolism

BACKGROUND

Acute pulmonary thromboembolism (PTE) is an important cause of morbidity and mortality that can reduce quality of life due to long-term complications during and after treatment discontinuation.

OBJECTIVES

The aim of this study was to evaluate patients for these complications before discontinuing treatment and determine the necessity of computed tomography pulmonary angiography (CTPA) imaging.

METHODS

This retrospective study included 116 patients over the age of 18 who received anticoagulant treatment for at least 3 months and presented for treatment discontinuation to the Atatürk University Research Hospital Chest Diseases Outpatient Clinic between January 2015 and September 2019.

RESULTS

CTPA performed at treatment discontinuation showed complete thrombus resolution with treatment in 73 patients (62.9%). High pulmonary artery obstruction index (PAOI) at diagnosis was statistically associated with findings of residual or chronic thrombus on CTPA at treatment discontinuation (p = 0.001). In the differentiation of patients with residual/chronic thrombus and those with thrombus resolution, D-dimer at a cut-off value of 474 µg/L had 60% sensitivity and 70% specificity. At a cut-off value of 35.5 mmHg, mean pulmonary artery pressure on echocardiography had sensitivity and specificity of 72% and 77%, respectively. At a cut-off of 23.75, PAOI had sensitivity and specificity of 93% and 69%, respectively.

CONCLUSION

In addition to physical examination findings, D-dimer and echocardiography were guiding parameters in the evaluation of treatment discontinuation and thrombus resolution in patients presenting to the outpatient clinic for discontinuation of treatment for acute PTE. PAOI at diagnosis may be another important guiding parameter in addition to these examinations.

Efficacy and Safety of Different Dosage of Recombinant Tissue-type Plasminogen Activator (rt-PA) in the Treatment of Acute Pulmonary Embolism: A Systematic Review and Meta-analysis

Reperfusion therapies are recommended for patients with hemodynamic instability or high-risk acute pulmonary embolism (PE). Lower doses of tissue plasminogen activator (rt-PA) could be considered to improve bleeding complications. The aim of this study was to evaluate the efficacy and safety of a reduced dose of rt-PA for the treatment of acute PE, compared with anticoagulation and standard dose. PubMed Central, Scopus, Web of Science and Embase were searched for all relevant randomized studies and prospective observational studies that compared reduced dose of rt-PA with anticoagulation alone or standard dose of rt-PA in patients with acute PE. The risk ratios (RR, with 95% CI) were calculated according to the value of I2. Outcomes were described as bleeding events, all-cause death, and recurrence of PE. Thirteen articles, including four observational studies (4223 patients) and nine RCTs (780 patients), were included. In comparing reduced dose of rt-PA with anticoagulant, a greater incidence of total bleeding events in low dose was showed (RR, 5.08 (95% CI, (1.39–18.6), I2 = 0.0%). In the standard dose rt-PA vs. reduced dose, there was a greater incidence of total bleeding events in the standard dose of rt-PA, RR 1.48 (95% CI, (1.00–2.19), I2 = 0.0%) was shown. There were no statistical differences in recurrent PE or all-cause mortality. It concluded that in the absence of the benefit of a standard dose of rt-PA in comparison with dose reduction, a reduced dose of rt-PA showed a lower rate of total bleeding events and similar efficacy regarding mortality and PE recurrence rate.

Accelerated treatment with rtPA for pulmonary embolism induced circulatory arrest

Patients with circulatory arrest due to pulmonary embolism (PE) should be treated with fibrinolytics. Current guidelines do not specify which regimen to apply, and it has been suggested that the regimen of 100 mg rtPA/2 h should be used, because this is recommended for hemodynamic instable PE in the ESC/ERS Guideline. This two hour regimen, however, is incompatible with key principles of cardiopulmonary resuscitation (CPR), such as employment of interventions that allow fast evaluation of effectiveness, and limitation of the total duration of CPR to avoid poor neurological outcomes. Additionally, the low flow-state during CPR has important consequences for the pharmacokinetic properties of rtPA. Arguably, the volume of distribution is lower, the metabolism reduced and the half life time longer. Therefore, these changes largely discard the rationale to use high dosages of rtPA over a prolonged period of time. More importantly, these changes highlight that the guideline recommendations, based on studies in patients without circulatory arrest, cannot be easily translated to the situation of circulatory arrest. An accelerated regimen of rtPA (0.6 mg/kg/15 min., max 50 mg) is mentioned by the 2019 ESC/ERS Guideline. However, empirical support or a rationale is not provided. Due to the rarity of the situation and ethical difficulties associated with randomizing unconscious patients, a randomized head-to-head comparison between the two regimens is unlikely to ever be performed. With this comprehensive overview of the pharmacokinetics of rtPA and current literature, a strong rationale is provided that the accelerated protocol is the regimen of choice for patients with PE-induced circulatory arrest.

Thrombolytic therapy for pulmonary embolism

BACKGROUND

Thrombolytic therapy is usually reserved for people with clinically serious or massive pulmonary embolism (PE). Evidence suggests that thrombolytic agents may dissolve blood clots more rapidly than heparin and may reduce the death rate associated with PE. However, there are still concerns about the possible risk of adverse effects of thrombolytic therapy, such as major or minor haemorrhage. This is the fourth update of the Cochrane review first published in 2006.

OBJECTIVES

To assess the effects of thrombolytic therapy for acute pulmonary embolism.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 17 August 2020. We undertook reference checking to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared thrombolytic therapy followed by heparin versus heparin alone, heparin plus placebo, or surgical intervention for people with acute PE (massive/submassive). We did not include trials comparing two different thrombolytic agents or different doses of the same thrombolytic drug.

DATA COLLECTION AND ANALYSIS

Two review authors (ZZ, QH) assessed the eligibility and risk of bias of trials and extracted data. We calculated effect estimates using the odds ratio (OR) with a 95% confidence interval (CI) or the mean difference (MD) with a 95% CI. The primary outcomes of interest were death, recurrence of PE and haemorrhagic events. We assessed the certainty of the evidence using GRADE criteria.

MAIN RESULTS

We identified three new studies for inclusion in this update. We included 21 trials in the review, with a total of 2401 participants. No studies compared thrombolytics versus surgical intervention. We were not able to include one study in the meta-analysis because it provided no extractable data. Most studies carried a high or unclear risk of bias related to randomisation and blinding. Meta-analysis showed that, compared to control (heparin alone or heparin plus placebo), thrombolytics plus heparin probably reduce both the odds of death (OR 0.58, 95% CI 0.38 to 0.88; 19 studies, 2319 participants; low-certainty evidence), and recurrence of PE (OR 0.54, 95% CI 0.32 to 0.91; 12 studies, 2050 participants; low-certainty evidence). Effects on mortality weakened when six studies at high risk of bias were excluded from analysis (OR 0.71, 95% CI 0.45 to 1.13; 13 studies, 2046 participants) and in the analysis of submassive PE participants (OR 0.61, 95% CI 0.37 to 1.02; 1993 participants). Effects on recurrence of PE also weakened after removing one study at high risk of bias for sensitivity analysis (OR 0.60, 95% CI 0.35 to 1.04; 11 studies, 1949 participants). We downgraded the certainty of evidence to low because of 'Risk of bias' concerns. Major haemorrhagic events were probably more common in the thrombolytics group than in the control group (OR 2.84, 95% CI 1.92 to 4.20; 15 studies, 2101 participants; moderate-certainty evidence), as were minor haemorrhagic events (OR 2.97, 95% CI 1.66 to 5.30; 13 studies,1757 participants; low-certainty evidence). We downgraded the certainty of the evidence to moderate or low because of 'Risk of bias' concerns and inconsistency. Haemorrhagic stroke may occur more often in the thrombolytics group than in the control group (OR 7.59, 95% CI 1.38 to 41.72; 2 studies, 1091 participants). Limited data indicated that thrombolytics may benefit haemodynamic outcomes, perfusion lung scanning, pulmonary angiogram assessment, echocardiograms, pulmonary hypertension, coagulation parameters, composite clinical outcomes, need for escalation and survival time to a greater extent than heparin alone. However, the heterogeneity of the studies and the small number of participants involved warrant caution when interpreting results. The length of hospital stay was shorter in the thrombolytics group than in the control group (mean difference (MD) -1.40 days, 95% CI -2.69 to -0.11; 5 studies, 368 participants). Haemodynamic decompensation may occur less in the thrombolytics group than in the control group (OR 0.36, 95% CI 0.20 to 0.66; 3 studies, 1157 participants). Quality of life was similar between the two treatment groups. None of the included studies provided data on post-thrombotic syndrome or on cost comparison.

AUTHORS' CONCLUSIONS

Low-certainty evidence suggests that thrombolytics may reduce death following acute pulmonary embolism compared with heparin (the effectiveness was mainly driven by one trial with massive PE). Thrombolytic therapy may be helpful in reducing the recurrence of pulmonary emboli but may cause more major and minor haemorrhagic events, including haemorrhagic stroke. More studies of high methodological quality are needed to assess safety and cost effectiveness of thrombolytic therapy for people with pulmonary embolism.

Incidence of Major Bleeding in Patients with Pulmonary Thromboembolism Treated with Fixed Dose Alteplase 100 mg

BACKGROUND

Acute pulmonary thromboembolism (PTE) is a critical cardiopulmonary condition associated with high mortality and morbidity. In massive PTE, recently referred to as high risk PTE, the routine protocol for thrombolysis with recombinant tissue plasminogen activator (alteplase) is 100 mg over 2 hours. However, there are concerns about bleeding in patients with low body weight (< 50 kg), elderly patients, and Asians.

METHOD

We performed a retrospective study in patients who were diagnosed with intermediate or high risk PTE, and who were treated with a fixed dose of alteplase (100 mg) in a single center at Chungbuk National University Hospital between July 2008 and April 2018.

RESULTS

A total of 42 patients were reviewed, 4 patients dropped out, and 38 patients were included in the analysis. There were 18 males (47.4%), and the average age of the patients was 70.68 years (± standard deviation 13.15). Major bleeding was seen in 10/38 patients (26.3%), and 30/38 patients (78.9%) were successfully discharged.

CONCLUSION

The major bleeding risk was higher in our study (26.3%) than in a previously published meta-analysis (9.24%). Therefore, we suggest reducing the dose of alteplase in patients who are elderly, Asian, or have cardiovascular disease. Further prospective studies of efficacy and bleeding rate after low dose alteplase should be considered.

Update on Thrombolytic Therapy in Acute Pulmonary Thromboembolism

Thrombolytic treatment accelerates the dissolution of thrombus in acute pulmonary thromboembolism (PTE) and is potentially a lifesaving treatment. High-risk PTE is the clearest indication for this therapy, and its use in intermediate-risk cases is still controversial. A PTE response team may enable a rapid and effective determination of risk and treatment in these controversial clinical cases. Approved thrombolytic agents for the PTE treatment are streptokinase, urokinase, and alteplase. Currently, the most widely used agent is alteplase. It has a short infusion time (2 h) and a rapid effect. Newer, unapproved agents for the PTE treatment are tenecteplase and reteplase. The active resolution of thrombus via thrombolytic agents improves rapidly pulmonary perfusion, hemodynamic defect, gas exchange, and right ventricular dysfunction. However, it is important to determine appropriate candidates carefully, to prevent hemorrhage, which is the most important side effect of these drugs. Catheter-directed thrombolysis seems to be an alternative in patients not eligible for systemic thrombolytic therapy.

Thrombolytic therapy for pulmonary embolism

BACKGROUND

Thrombolytic therapy is usually reserved for patients with clinically serious or massive pulmonary embolism (PE). Evidence suggests that thrombolytic agents may dissolve blood clots more rapidly than heparin and may reduce the death rate associated with PE. However, there are still concerns about the possible risk of adverse effects of thrombolytic therapy, such as major or minor haemorrhage. This is the third update of the Cochrane review first published in 2006.

OBJECTIVES

To assess the effects of thrombolytic therapy for acute pulmonary embolism.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 16 April 2018. We undertook reference checking to identify additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared thrombolytic therapy followed by heparin versus heparin alone, heparin plus placebo, or surgical intervention for patients with acute PE. We did not include trials comparing two different thrombolytic agents or different doses of the same thrombolytic drug.

DATA COLLECTION AND ANALYSIS

Two review authors (JY, QH) assessed the eligibility and quality of trials and extracted data. We calculated effect estimates using the odds ratio (OR) with 95% confidence interval (CI) or the mean difference (MD) with 95% CI. We assessed the quality of the evidence using GRADE criteria.

MAIN RESULTS

We identified no new studies for inclusion in this 2018 update. We included in the review 18 trials with a total of 2197 participants. We were not able to include one study in the meta-analysis because it provided no data that we could extract. Most of the studies carried a high risk of bias because of high or unclear risk related to randomisation and blinding. Meta-analysis showed that, compared with heparin alone, or heparin plus placebo, thrombolytics plus heparin can reduce the odds of death (OR 0.57, 95% CI 0.37 to 0.87, 2167 participants, P = 0.01, low-quality evidence) and recurrence of PE (OR 0.51, 95% CI 0.29 to 0.89, 1898 participants, P = 0.02, low-quality evidence). Effects on mortality weakened when we excluded from analysis four studies at high risk of bias (OR 0.66, 95% CI 0.42 to 1.06, 2054 participants, P = 0.08). The incidence of major and minor haemorrhagic events was higher in the thrombolytics group than in the control group (OR 2.90, 95% CI 1.95 to 4.31, 1897 participants, P < 0.001, low-quality evidence; OR 3.09, 95% CI 1.58 to 6.06, 1553 participants, P = 0.001, very low-quality evidence, respectively). We downgraded the quality of the evidence to low or very low because of design limitations, potential influence of pharmaceutical companies, and small sample sizes. Length of hospital stay (mean difference (MD) -0.89, 95% CI -3.13 to 1.34) and quality of life were similar between the two treatment groups. Limited information from a small number of trials indicated that thrombolytics may improve haemodynamic outcomes, perfusion lung scanning, pulmonary angiogram assessment, echocardiograms, pulmonary hypertension, coagulation parameters, clinical outcomes, and survival time to a greater extent than heparin alone. However, the heterogeneity of the studies and the small number of participants involved warrant caution when results are interpreted. Similarily, fewer participants from the thrombolytics group required escalation of treatment. None of the included studies reported on post-thrombotic syndrome or compared the costs of different treatments.

AUTHORS' CONCLUSIONS

Low-quality evidence suggests that thrombolytics reduce death following acute pulmonary embolism compared with heparin. The included studies used a variety of thrombolytic drugs. Thrombolytic therapy may be helpful in reducing the recurrence of pulmonary emboli but may cause major and minor haemorrhagic events and stroke. More high-quality, blinded randomised controlled trials assessing safety and cost-effectiveness of therapies for pulmonary embolism are required.