Evidence-Based Therapies for Pharmacologic Prevention and Treatment of Acute Deep Vein Thrombosis and Pulmonary Embolism

Safety and efficacy of clot-dissolving therapies for submassive pulmonary embolism: A network meta-analysis of randomized controlled trials

BACKGROUND

Acute pulmonary embolism (PE) is a serious condition that needs quick and effective treatment. Anticoagulation therapy is the usual care for most PE patients but may not work well for higher-risk ones. Thrombolysis breaks the clot and improves blood flow. It can be given systemically or locally. Ultrasound-assisted catheter-directed thrombolysis (USAT) is a new technique that boosts clot-busting drugs. This network meta-analysis compares death, bleeding, and benefits of four treatments in acute submassive PE.

METHODS

We comprehensively searched relevant databases up to July 2023 for RCTs. The outcomes encompassed all-cause mortality, major and minor bleeding, PE recurrence, and hospital stay duration. Bayesian network meta-analysis computed odds ratios (OR) and 95 % CI estimates.

RESULTS

In this network meta-analysis of 23 RCTs involving 2521 PE patients, we found that SCDT had the most favorable performance for mortality, as it had the lowest odds ratio (OR) among the four interventions (OR 5.41e-42; 95 % CI, 5.68e-97, 1.37e-07). USAT had the worst performance for major bleeding, as it had the highest OR among the four interventions (OR 4.73e+04; 95 % CI, 1.65, 9.16e+13). SCDT also had the best performance for minor bleeding, as it had the lowest OR among the four interventions (OR 5.68e-11; 95 % CI, 4.97e-25, 0.386).

CONCLUSION

Our meta-analysis suggests that SCDT is the most effective treatment intervention in improving the risks of All-cause mortality and bleeding. Thrombolytic therapy helps in improving endpoints including the risk of PE recurrence and the duration of hospital stay.

The incidence of deep vein thrombosis after anterior cruciate ligament reconstruction: An analysis using routine ultrasonography of 260 patients

BACKGROUND

Recent studies regarding deep vein thrombosis (DVT) after anterior cruciate ligament (ACL) reconstruction investigated only symptomatic complications. The purpose of this study was to assess the true incidence of DVT after ACL reconstruction, regardless of symptom manifestation.

MATERIALS AND METHODS

Medical records of 260 patients who underwent isolated ACL reconstruction between January 2014 and December 2019 were retrospectively reviewed. Regardless of symptom manifestation, DVT was examined for all patients at 1 week postoperatively using ultrasonography. Demographics, injury mechanism (high energy direct injury and low energy indirect injury), soft tissue injury, preoperative anterior laxity, tourniquet time, and surgical technique (transtibial, anteromedial portal, and outside-in techniques) were investigated. Soft tissue injury was evaluated on magnetic resonance imaging (MRI) scans, based on the Tscherne classification. Risk factors for proximal DVT were identified using logistic regression analyses.

RESULTS

A total of 21 (8.1%) patients showed DVT. 5 (1.9%) patients had thrombosis at the popliteal vein; however, none of them exhibited symptoms. The other 16 patients had thrombosis at the distal veins: 1 patient at the anterior tibial vein, 5 patients at the posterior tibial vein, 3 patients at the peroneal vein, 6 patients at the soleal vein, and 1 patient at the muscular branch vein. The risk factors for proximal DVT included high energy direct injury (p = 0.013, odds ratio = 10.62) and grade 2 soft tissue injury (p = 0.039, odds ratio = 6.78).

CONCLUSIONS

The true incidence of DVT, including symptomatic and asymptomatic complications, were 8.1% after ACL reconstruction. This rate is higher than the previously known incidence which has been investigated only for symptomatic patients. Injury mechanism and soft tissue injury should be assessed when considering thromboprophylaxis.

Pharmacological interventions for preventing venous thromboembolism in people undergoing bariatric surgery

BACKGROUND

Venous thromboembolism (VTE), which comprises deep vein thrombosis (DVT) and pulmonary embolism (PE), is the leading cause of preventable death in hospitalised people and the third most common cause of mortality in surgical patients. People undergoing bariatric surgery have the additional risk factor of being overweight. Although VTE prophylaxis in surgical patients is well established, the best way to prevent VTE in those undergoing bariatric surgery is less clear.

OBJECTIVES

To evaluate the benefits and harms of pharmacological interventions (alone or in combination) on venous thromboembolism and other health outcomes in people undergoing bariatric surgery compared to the same pharmacological intervention administered at a different dose or frequency, the same pharmacological intervention or started at a different time point, another pharmacological intervention, no intervention or placebo.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 1 November 2021.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs in males and females of any age undergoing bariatric surgery comparing pharmacological interventions for VTE (alone or in combination) with the same pharmacological intervention administered at a different dose or frequency, the same pharmacological intervention started at a different time point, a different pharmacological intervention, no treatment or placebo.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. VTE and 2. major bleeding. Our secondary outcomes were 1. all-cause mortality, 2. VTE-related mortality, 3. PE, 4. DVT, 5. adverse effects and 6. quality of life. We used GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We included seven RCTs with 1045 participants. Data for meta-analysis were available from all participants. Four RCTs (597 participants) compared higher-dose heparin to standard-dose heparin: one of these studies (139 participants) used unfractionated heparin (UFH) and the other three (458 participants) used low-molecular-weight heparin (LMWH). One study compared heparin versus pentasaccharide (198 participants), and one study compared starting heparin before versus after bariatric surgery (100 participants). One study (150 participants) compared combined mechanical and pharmacological (enoxaparin) prophylaxis versus mechanical prophylaxis alone. The duration of the interventions ranged from seven to 15 days, and follow-up ranged from 10 to 180 days. Higher-dose heparin versus standard-dose heparin Compared to standard-dose heparin, higher-dose heparin may result in little or no difference in the risk of VTE (RR 0.55, 95% CI 0.05 to 5.99; 4 studies, 597 participants) or major bleeding (RR 1.19, 95% CI 0.48 to 2.96; I2 = 8%; 4 studies, 597 participants; low-certainty) in people undergoing bariatric surgery. The evidence on all-cause mortality, VTE-related mortality, PE, DVT and adverse events (thrombocytopenia) is uncertain (effect not estimable or very low-certainty evidence). Heparin versus pentasaccharide Heparin compared to a pentasaccharide after bariatric surgery may result in little or no difference in the risk of VTE (RR 0.83, 95% CI 0.19 to 3.61; 1 study, 175 participants) or DVT (RR 0.83, 95% CI 0.19 to 3.61; 1 study, 175 participants). The evidence on major bleeding, PE and mortality is uncertain (effect not estimable or very low-certainty evidence). Heparin started before versus after the surgical procedure Starting prophylaxis with heparin 12 hours before surgery versus after surgery may result in little or no difference in the risk of VTE (RR 0.11, 95% CI 0.01 to 2.01; 1 study, 100 participants) or DVT (RR 0.11, 95% CI 0.01 to 2.01; 1 study, 100 participants). The evidence on major bleeding, all-cause mortality and VTE-related mortality is uncertain (effect not estimable or very low-certainty evidence). We were unable to assess the effect of this intervention on PE or adverse effects, as the study did not measure these outcomes. Combined mechanical and pharmacological prophylaxis versus mechanical prophylaxis alone Combining mechanical and pharmacological prophylaxis (started 12 hours before surgery) may reduce VTE events in people undergoing bariatric surgery compared to mechanical prophylaxis alone (RR 0.05, 95% CI 0.00 to 0.89; number needed to treat for an additional beneficial outcome (NNTB) = 9; 1 study, 150 participants; low-certainty). We were unable to assess the effect of this intervention on major bleeding or morality (effect not estimable), or on PE or adverse events (not measured). No studies measured quality of life.

AUTHORS' CONCLUSIONS

Higher-dose heparin may make little or no difference to venous thromboembolism or major bleeding in people undergoing bariatric surgery when compared to standard-dose heparin. Heparin may make little or no difference to venous thromboembolism in people undergoing bariatric surgery when compared to pentasaccharide. There are inadequate data to draw conclusions about the effects of heparin compared to pentasaccharide on major bleeding. Starting prophylaxis with heparin 12 hours before bariatric surgery may make little or no difference to venous thromboembolism in people undergoing bariatric surgery when compared to starting heparin after bariatric surgery. There are inadequate data to draw conclusions about the effects of heparin started before versus after surgery on major bleeding. Combining mechanical and pharmacological prophylaxis (started 12 hours before surgery) may reduce VTE events in people undergoing bariatric surgery when compared to mechanical prophylaxis alone. No data are available relating to major bleeding. The certainty of the evidence is limited by small sample sizes, few or no events, and risk of bias concerns. Future trials must be sufficiently large to enable analysis of relevant clinical outcomes, and should standardise the time of treatment and follow-up. They should also address the effect of direct oral anticoagulants and antiplatelets, preferably grouping them according to the type of intervention.

The net benefit of thrombolysis in the management of intermediate risk pulmonary embolism: Systematic review and meta-analysis

Background

Benefit of thrombolytic therapy in patients with massive pulmonary embolism (PE) is evident. However, evidence supporting benefit in clinical outcomes of this approach in intermediate risk PE is lacking.

Objective

To determine the impact of thrombolysis on overall survival in intermediate risk PE patients.

Methods

We searched in MEDLINE (OVID), EMBASE, LILACS, and the Cochrane Central Register of Controlled Trials (CENTRAL) from present day. We also searched in other databases and unpublished literature. We included clinical trials without language restrictions. The risk of bias was evaluated with the Cochrane Collaboration's tool. The primary outcome was overall survival. Secondary outcomes were adverse events, including major bleeding, and all-cause mortality. The measure of the effect was the risk ratio with a 95% confidence interval (CI).

Results

We included 11 studies in the qualitative and quantitative analysis, with a total of 1855 patients. Risk of bias was variable among the study items. There were no results reported about overall survival in any of the studies. The risk ratio (RR) for all-cause mortality was 0.68 95% CI (0.40 to 1.16). The RR of overall bleeding, major bleeding and stroke were 2.72 95% CI (1.58 to 4.69), 2.17 95% CI (1.03 to 4.55), and 2.22 95% CI (0.17 to 28.73), respectively. Additionally, the RR for recurrent PE was 0.56 95% CI (0.23 to 1.37).

Conclusions

In patients with intermediate risk PE, the risk of bleeding is higher when thrombolysis is used. There was no significant difference between thrombolysis and anticoagulation in recurrence of PE, stroke, and all-cause mortality.

Clinical efficacy of low dose recombinant tissue-type plasminogen activator for the treatment of acute intermediate-risk pulmonary embolism

OBJECTIVES

To investigate the efficacy and safety of initial thrombolysis by recombinant tissue-type plasminogen activator (rt-PA) in compared with anticoagulant therapy in patients with acute intermediate-risk pulmonary embolism (PE).  Methods: Sixty-six patients with acute intermediate-risk PE were randomly assigned to receive rt-PA or LMWH between June 2014 and June 2017 in our department. We obtained information regarding the difference in the right ventricle/left ventricle (RV/LV) ratio, pulmonary artery systolic pressure (PASP), clinical symptoms improvement, PE-related mortality, hemodynamic decompensation, recurrent PE, and major and minor bleeding.  Results: In the rt-PA group, the mean PASP was reduced from 52.0±12.2 at baseline to 34.8±9.4 (p less than 0.001) and the mean RV/LV ratio was reduced from 1.26±0.22 at baseline to 0.96±0.18 (p less than 0.001) at 24 hours. In the LMWH group, the mean PASP was 53.4±12.8 at baseline and 48.5±11.9 at 24 hours (p=0.11), and the mean RV/LV ratio was 1.22±0.19 at baseline and 1.17±0.21 at 24 hours (p=0.31). In comparison with the LMWH group, there was a significant reduction in PASP and an improvement in the symptom severity in the rt-PA group. At 90 days, there was no difference in mortality, recurrent venous thromboembolism and major bleeding as a safety outcome, but increased minor bleeding and decreased hemodynamic decompensation occurred in the rt-PA group. Conclusions: In patients with acute intermediate-risk PE, low dose thrombolytic therapy is considered safe and effective, it can be recommended as an alternative option in clinical treatment.

Semiautomatic intermittent pneumatic compression device applied to deep vein thrombosis in major orthopedic surgery

Objective

To investigate the effect of additional semiautomatic intermittent pneumatic compression device (IPCD) in the prevention of deep vein thrombosis (DVT) of lower extremity in these patients undergoing major orthopedic surgery, when compared with the conventional graduated compression stockings alone.

Methods

The data of 112 patients undergoing major orthopedic surgery were retrospectively analyzed. 51 patients who ever received IPCD and graduated compression stockings during major orthopedic surgery were taken as the experimental group, and 61 patients who only received the conventional graduated compression stockings during surgery were taken as the observation group. The Doppler sonography was utilized to detect the presence of DVT and pulmonary embolism pre- and postoperatively. Besides, the mean and peak velocity of blood flow in femoral vein were recorded before and after surgery. And then, the comparisons between the two groups were made, respectively.

Results

When compared with the conventional graduated compression stockings alone, the intraoperative application of IPCD and stockings contributed the significant reduction of DVT (3.92%, 2/51 versus 9.84%, 6/61, X² = 5.632, P = 0.034). In terms of the mean and peak velocity of blood flow in femoral vein, the postoperative difference was higher in the observation group than those in the control group (149.56 ± 26.35 versus 130.15 ± 22.56 mm/s, P < 0.05). With respect to perioperative blood loss, the difference between the two groups was statistically significant (800.5 ± 320.7 versus 950.1 ± 305.9 ml, P = 0.031).

Conclusions

Intraoperative application of IPCD could promote blood circulation of lower limbs, and significantly decrease the incidence of potentially fatal DVT in patients undergoing major orthopedic surgery, when compared with the conventional graduated compression stockings.