Efficacy and safety of low molecular weight heparin in patients with mechanical heart valves: systematic review and meta-analysis

Late dysfunction of a mechanical aortic valve after long-term low molecular weight heparin therapy: a case report

Background

To date, vitamin K anticoagulants are the only recommended long-term therapy for mechanical heart valves. Bleeding episodes, thromboembolic events, and international normalized ratio monitoring are difficult and prevalent complications for these patients. This report reflects the late mechanical aortic valve dysfunction after long-term low molecular weight heparin therapy.

Case summary

A 66-year-old male patient underwent mechanical aortic valve replacement in 2007. He was administered therapeutic doses of enoxaparin for nearly 12 years due to warfarin-related bleeding complications and labile international normalized ratios. However, he experienced multiple cardiovascular and cerebrovascular thromboembolic events, including an anterolateral ST-elevation myocardial infarction with left anterior descending artery thrombus, treated with thrombus aspiration and stenting. The patient was eventually admitted with symptoms and signs of acute heart failure, and echocardiography, fluoroscopy, and a cardiac computed tomography detected mechanical aortic valve prosthesis dysfunction, with an immobile leaflet and pannus. The patient demonstrated no improvement despite switching to unfractionated heparin, and he ultimately underwent redo aortic bioprosthetic valve surgery with a favourable outcome.

Discussion

Low molecular weight heparin is prescribed for patients with aortic mechanical valves who are intolerant to vitamin K antagonists or as bridging in certain situations. Anti-Xa factor monitoring should be considered for long-term prescriptions.

Management of anticoagulation in patients with infective endocarditis

Infective endocarditis (IE) carries a high risk of vascular complications (e.g., cerebral embolism, intracerebral hemorrhage, and renal infarction), which are correlated with increased early and late mortality. Although anticoagulation is the cornerstone for management of thromboembolic complications, it remains controversial and challenging in patients with IE. An appropriate anticoagulation strategy is crucial to improving outcomes and requires a good understanding of the indication, timing, and regimen of anticoagulation in the setting of IE. Observational studies have shown that anticoagulant treatment failed to reduce the risk of ischemic stroke in patents with IE, supporting that IE alone is not an indication for anticoagulation. In the absence of randomized controlled trials and high-quality meta-analyses, however, current guidelines on IE were based largely on observational data and expert opinion, providing few specific recommendations on anticoagulation. A multidisciplinary approach and patient engagement are required to determine the timing and regimen of anticoagulation in patients with IE, especially in specific situations (e.g., receiving warfarin anticoagulation at the time of IE diagnosis, cerebral embolism or ischemic stroke, intracerebral hemorrhage, or urgent surgery). Collectively, individualized strategies on anticoagulation management of IE should be based on clinical evaluation, available evidence, and patient engagement, and ultimately be developed by the multidisciplinary team.

DOACs in the Anticoagulation of Mechanical Valves: A Systematic Review and Future Perspectives

Valvular heart disease is a common disease often necessitating valve replacement. Mechanical heart valves (MHVs) are often used in younger patients because of their longer durability. Their main disadvantage is the need for lifelong anticoagulation. Warfarin is considered a standard treatment, but it is far from perfect. Direct oral anticoagulants (DOACs) are a new and more patient-friendly alternative to warfarin when anticoagulation is required, but have not yet been approved for the indication of mechanical valves.

EVIDENCE ACQUISITION

A literature search of Pubmed, Embase, Web of Science (Core Collection), and Cochrane Library (from inception to May 2023) was performed using a search string that was well defined and not modified during the study. An extensive overview of the search terms used in each database can be found in the Appendix. Only prospective clinical trials were included in this review. A total of 10 publications were included in this review.

RELEVANCE TO CLINICAL PRACTICE

This systematic review summarizes the different types of DOACs and their possible use in the anticoagulation of mechanical valves. We aim to propose future directions in anticoagulation research for mechanical valves.

CONCLUSIONS

DOAC use in MHVs has been halted due to the failure of both dabigatran and apixaban in two major clinical trials. However, rivaroxaban was successful in two small clinical trials. Ample research is still needed to explore new valve designs as well as new anticoagulation targets.

Perioperative Management of Patients Receiving Antithrombotic Therapy in Schemes and Algorithms

Currently, antithrombotic therapy is the basis of the pathogenetic treatment of many cardiovascular diseases, such as coronary heart disease, stroke, peripheral vascular disease, as well as mechanical heart valves, heart rhythm disturbances, venous thromboembolism. At the same time, chronic use of antiplatelet and/or anticoagulant drugs is a complicating factor in invasive and surgical procedures, as it increases the risk of bleeding. In this regard, a fundamentally important and complex question arises: how to minimize the risk of periprocedural bleeding without exposing the patient to an increased risk of ischemic and thromboembolic complications? Perioperative management of patients who take antithrombotic drugs for a long time is a complex problem that depends on many factors - the risk of surgery, anesthesia, cardiovascular risks, and the urgency of surgery. Each clinical situation should be assessed individually, collegially, with the participation of surgeons, anesthesiologists, and therapists. The introduction of a checklist into clinical practice for each planned surgical patient will allow us to calculate the individual risk of bleeding and thromboembolic complications, and provide an optimal preventive strategy for perioperative management of the patient. The algorithms and schemes presented in the article for the perioperative management of patients with non-cardiac interventions are aimed at standardizing the management of patients before non-cardiac surgical interventions, which will reduce hemorrhagic risks in the presence of the necessary antithrombotic therapy.

Bridging therapy according to new clinical guidelines: A review

In modern world it is really important to know how to manage patients taking anticoagulant or antiplatelet therapy. There is an increasing number of patients, who have gone through PCI or any other cardiac intervention and who also need another surgery which cannot be postponed till the end of dual antiplatelet therapy. The number of patients who take oral anticoagulant has also increased last years. Algorithms of perioperative bridging therapy and antiplatelet therapy discontinuation can help to decrease both ischemic and hemorrhagic complications. Multidisciplinary risk assessment remains a critical component of perioperative care.

Prosthetic Aortic Valve Thrombosis Complicated by Left Main Coronary Artery Bifurcation Embolism: Case Report and Review of Literature

Coronary embolism due to prosthetic valve thrombosis is a rare cause of acute coronary syndrome. We report the challenging case of a 66-year-old female patient with non-ST-elevation myocardial infarction caused by left main coronary artery bifurcation embolism in the setting of mechanical aortic valve thrombosis. The patient was treated with intravenous thrombolysis. Four hours later, she suffered an anterior ST-elevation myocardial infarction due to left anterior descending artery embolization. Repeat coronary angiogram showed complete disappearance of the LMCA embolus with only distal LAD occlusion. The patient was further treated medically with excellent outcome.

A meta-analysis of bridging anticoagulation between low molecular weight heparin and heparin

BACKGROUND

Patients with mechanical heart valves (MHV) have an increased risk of thromboembolic complications. Low molecular weight heparin (LMWH) and unfractionated heparin (UFH) are often recommended for bridging anticoagulation; however, it is not clear which strategy is more beneficial.

METHODS

The PubMed, EMBASE, and Cochrane databases were searched from January 1960 to March 2019. Randomized controlled trials and observational studies were analyzed. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of the studies. Stata 11.0 was used for the meta-analysis.

RESULTS

A total of 6 publications were included; 1366 events were selected, involving 852 events with LMWH and 514 events with UFH. The thromboembolism risk of the LMWH group was lower than that of the UFH group (risk ratio [RR] = 0.34, 95% confidence interval [CI] 0.12-0.95, P = .039). The incidence of major bleeding was lower in the LMWH group than in the UFH group, albeit without statistical significance (RR = 0.94, 95% CI 0.68-1.30, P = .728), as was mortality (RR = 0.52, 95% CI 0.16-1.66, P = .271). Subgroup analysis showed that LMWH cardiac surgery patients had a higher risk of major bleeding compared with UFH cardiac surgery patients (RR = 1.17, 95% CI 0.72-1.90, P = .526); but among non-cardiac surgery patients, the LMWH group had a lower risk of major bleeding than the UFH group (RR = 0.79, 95% CI 0.51-1.22, P = .284), although the difference was not statistically significant.

CONCLUSION

Our meta-analysis suggests that LMWH not only reduces the risk of thromboembolism in patients with MHV but also does not increase the risk of major bleeding. LMWH may provide safer and more effective bridging anticoagulation than UFH in patients with MHV. It is still necessary to conduct future randomized studies to verify this conclusion.

Ibrutinib increases the risk of hypertension and atrial fibrillation: Systematic review and meta-analysis

Introduction

Ibrutinib is an oral covalent inhibitor of Bruton's tyrosine kinase approved for the treatment of patients with chronic lymphocytic leukemia (CLL), mantle cell lymphoma and Waldenstrӧm’s macroglobulinemia. Ibrutinib has an increased risk of atrial fibrillation but the mechanism is unknown, and hypertension may play a role in the pathogenesis of this adverse drug reaction.

Methods

We aimed to review the risk of hypertension and atrial fibrillation as adverse events associated with ibrutinib through a systematic review with meta-analysis of randomized controlled trials (RCTs) retrieved in December 2018 on MEDLINE, EMBASE, CENTRAL and ClinicalTrials.gov. The data were pooled using random-effects meta-analyses using the risk ratio (RR) with the 95% confidence interval (95%CI). The confidence on the pooled estimates was ascertained through the grading of recommendations assessment, development, and evaluation (GRADE) approach.

Results

There were 8 eligible RCTs (2580 patients), all reporting safety data of interest. Ibrutinib was associated with a significant increase in the risk of hypertension with a RR of 2.82 (95%CI 1.52–5.23) with moderate quality evidence. Ibrutinib increased significantly the risk of atrial fibrillation with a RR of 4.69 (95%CI 2.17–7.64) with high quality evidence.

Conclusions

Ibrutinib was associated with significantly increased risks of both hypertension and atrial fibrillation.

Cardiac Harms of Sofosbuvir: Systematic Review and Meta-Analysis

INTRODUCTION

Sofosbuvir is a new direct-acting pyrimidine nucleotide analogue antiviral drug that has shown remarkable efficacy in the treatment of hepatitis C in clinical trials. However, observational anecdotal data have recently suggested an increased risk of serious bradycardia among patients treated with sofosbuvir and amiodarone.

OBJECTIVE

We aimed to estimate and characterize the cardiac safety of sofosbuvir by performing a systematic review of randomized controlled trials (RCTs).

METHODS

We conducted a systematic review of RCTs (PROSPERO 2016: CRD42016033109) comparing sofosbuvir and non-sofosbuvir regimens in patients with chronic hepatitis C by searching the MEDLINE, Embase, and Cochrane Library databases up to January 2017. Non-published data were obtained from the sofosbuvir marketing authorization holder. Random-effects meta-analysis was performed to derive pooled estimates of relative risks (RRs) and corresponding 95% confidence intervals (CIs).

RESULTS

Six trials, enrolling 2346 patients (1625 treated with sofosbuvir), were included. The overall risk of bias across studies was moderate. The risk of reported cardiac events (RR 0.87; 95% CI 0.41-1.85), arrhythmias (RR 0.93; 95% CI 0.34-2.51), bradycardia (RR 0.47; 95% CI 0.04-5.20), and tachycardia (RR 0.91; 95% CI 0.20-4.20) were not significantly different between sofosbuvir and non-sofosbuvir regimens. The risks of reported syncope, presyncope, loss of consciousness, or palpitations were similar among those receiving sofosbuvir regimens and controls.

CONCLUSIONS

The pooled data from RCTs did not show an increased risk of cardiac outcomes, including arrhythmias (and bradycardia), among sofosbuvir-treated patients, although the overall quality of the evidence supporting this conclusion was very low. Registration: PROSPERO 2016:CRD42016033109 at http://www.crd.york.ac.uk/PROSPERO/ .

The optimal anticoagulant therapy for mechanical heart valves in a gallbladder cancer patient with hepatic metastases: A case report

RATIONALE

Developing an optimal anticoagulant strategy poses a challenging task in patients with mechanical heart valves (MHVs) throughout their lifetime. We report an optimal anticoagulant therapy in a cancer patient with hepatic metastases after MHV replacement.

PATIENT CONCERNS

A 68-year-old female with MHVs suffered from gallbladder cancer with hepatic metastases. Her international normalized ratio (INR) fluctuated owing to the declined hepatic function.

DIAGNOSES

Gallbladder cancer and hepatic metastases, with a history of mechanic aortic valve replacement and mitral valve replacement.

INTERVENTIONS

Warfarin was discontinued and Vitamin K1 was immediately administrated via intravenous infusion. low-molecular-weight heparin (LMWH) was regarded as a preferable option, and nadroparin at the dosage of 4100IU daily was administered.

OUTCOMES

No adverse event occurred during the patient's hospitalization and two-week follow up after discharge.

LESSONS

LMWH may represent a reasonable alternative regarding the inhibition of thrombus and bleeding in MHVs carriers with cancer and hepatic metastases.

Mechanical Mitral Valve Thrombosis Secondary to Tinzaparin as an Anticoagulation Bridging Strategy

For patients with mechanical heart valves, oral vitamin K antagonists effectively reduce the risk of valve thrombosis. Bridging strategies that use intravenous unfractionated heparin or subcutaneous low molecular weight heparin (LMWH) are required when reversal of anticoagulation is needed for invasive procedures or bleeding complications. There is limited data comparing anticoagulation efficacy between subtypes of LMWH and dosing regimens in this context. This report describes the case of a 45-year-old man with acute mechanical mitral valve thrombosis and suggests that the use of once daily dosing of subcutaneous tinzaparin may be an inappropriate anticoagulation bridging strategy.

Early postoperative bridging anticoagulation after mechanical heart valve replacement: a systematic review and meta-analysis

OBJECTIVE

To perform a systematic review and meta-analysis of studies evaluating anticoagulation during the early postoperative period following mechanical heart valve implantation.

METHODS

Five literature databases were searched to assess the rates of bleeding and thromboembolic events among patients receiving oral anticoagulation (OAC), both with and without bridging anticoagulation therapy with unfractionated heparin (UFH) or subcutaneous low molecular weight heparin (LMWH). The studies' results were pooled via a mixed effects meta-analysis. Heterogeneity (I(2) ) and publication bias were both evaluated.

RESULTS

Twenty-three studies including 9534 patients were included. The bleeding rates were 1.8% (95% confidence interval CI 1.0-3.3) in the group receiving OAC, 2.2% (95% CI 0.9-5.3) in the OAC + UFH group, and 5.5% (95% CI 2.9-10.4) in the OAC + LMWH group (P = 0.042). The thromboembolic event rate was 2.1% (95% CI 1.5-2.9) in the group receiving OAC, as compared with 1.1% (95% CI 0.7-1.8) when the bridging therapy groups were combined as follows: OAC + UFH and OAC + LMWH (P = 0.035). Most of the analyses showed moderate heterogeneity and negative test results for publication bias.

CONCLUSIONS

Bridging therapy following cardiac valve surgery was associated with a lower thromboembolic event rate, although the difference was small, with considerable overlap of the CIs. Direct comparisons are missing. Bridging therapy with UFH appears to be safe; however, this observation has a risk of bias. Early bridging therapy with LMWH appears to be associated with consistently high bleeding rates across multiple analyses. On the basis of the quality of the included studies, more trials are necessary to establish the clinical relevance of bridging therapy and the safety of LMWH.