Direct oral anticoagulants vs. vitamin K antagonists for left ventricular thrombus: a systematic review and meta-analysis

Trial sequential analysis of efficacy and safety of direct oral anticoagulants and vitamin K antagonists against left ventricular thrombus

Meta-analysis may increase the risk of random errors. Trial sequential analysis (TSA) has been developed to adjust for these random errors. We conducted TSA on the efficacy and safety of direct oral anticoagulants (DOACs) and vitamin K antagonists (VKAs) in left ventricular thrombus (LVT) patients in order to estimate how many additional patients should be required to draw definite conclusions. PubMed, Scopus, and Cochrane Library databases were searched for articles directly comparing DOACs and VKAs for LVT in LV thrombus resolution, stroke, any thromboembolism, major bleeding, any bleeding, and all-cause death. TSA was conducted with a cumulative Z-curve, monitoring boundaries, and required sample size. A simulated trial was run and TSA estimated the sample sizes of trials needed to draw definite conclusions. Of 4749 articles, 25 studies were used for the analysis. TSA revealed the current sample size already demonstrated superiority of DOACs in LV thrombus resolution and stroke, and futility in any thromboembolism and all-cause death. Two other outcomes did not achieve the required sample size. The sample size of new trials needed to demonstrate the superiority of DOACs over VKAs was estimated 400 for any bleeding. Corresponding trials needed to demonstrate no significant differences could be estimated for major bleeding and any bleeding (n = 200 and n = 2000, respectively). Current results show that the sample size required to draw definite conclusions was not reached for two outcomes, and there was a risk of random error. Further randomized controlled trials with sample sizes estimated by TSA will work effectively to obtain valid conclusions.

Left ventricular thrombus in a patient with recurrent ischemic stroke events-The role of echocardiography

Key Clinical Message

Cardiac ultrasound is recommended in investigating ischemic stroke events. There is increasing evidence that direct oral anticoagulants can be safely used instead of vitamin K antagonists in the setting of left ventricular thrombus.

Abstract

Cardioembolic stroke is responsible for an increasing number of ischemic strokes. Compared to other causes of stroke, cardioembolic strokes affect a larger brain area. Left ventricular (LV) thrombi account for up to 10% of cardioembolic strokes. It is essential to identify patients at high risk of LV thrombus formation, such as patients with a history of myocardial infarction, patients with reduced ejection fraction, or patients with cardiomyopathies. We present a patient with an ischemic stroke, and the cardiac ultrasound revealed a reduced ejection fraction and the presence of LV thrombus at the apex. The patient had no prior history of cardiovascular diseases. Even in a resource-limited setting, cardiac ultrasound is recommended to investigate stroke or transient ischemic attack events, especially in patients with a prior history of myocardial infarction. Although patients with LV thrombus should be treated with oral anticoagulants for at least 3 months, the role of direct oral anticoagulants and the optimal period of anticoagulation in this setting needs further investigation.

Anticoagulation for Left Ventricle Thrombus-Case Series and Literature Review for Use of Direct Oral Anticoagulants

Left ventricular thrombus is a known complication following acute myocardial infarction that can lead to systemic thromboembolism. To obviate the risk of thromboembolism, the patient needs anticoagulation in addition to dual antiplatelet therapy. However, combining antiplatelets with anticoagulants substantially increases the bleeding risk. Traditionally, vitamin K antagonists (VKAs) have been the sheet anchor for anticoagulation in this scenario. The use of direct oral anticoagulants has significantly attenuated the bleeding risk associated with anticoagulation for atrial fibrillation and venous thromboembolism. Furthermore, in patients with atrial fibrillation undergoing percutaneous coronary intervention, the use of direct oral anticoagulants (DOACs) in conjunction with antiplatelets has been found to be noninferior in reducing ischemic events while significantly attenuating the bleeding compared with VKA. After initial case reports, multiple observational and nonrandomized studies have now safely and effectively utilized direct oral anticoagulants for anticoagulation in left ventricular thrombus. Here, we report a series of two cases presenting with left ventricular thrombus following acute myocardial infarction. In this case series, we try to address the issues concerning the choice and duration of anticoagulation in the case of postinfarct left ventricular thrombus. Pending the results of large randomized control trials, the judicious use of direct oral anticoagulant is warranted when taking into consideration the ischemic and bleeding profile in an individualized approach.

Left Ventricular Thrombosis: Current Perspective and Use of Direct Oral Anticoagulants

Left ventricular thrombus (LVT) is a serious risk factor for systemic embolism development. Despite the evident danger of this condition, current guidelines describe management of patients with this potentially fatal complication very briefly. LVT can complicate myocardial infarction where its incidence is around 10%, as well as various forms of cardiomyopathies and novel coronavirus infection. According to clinical guidelines vitamin K antagonists (VKAs) should be used as treatment of choice for thrombus resolution. However, experts point out that this therapy lacks necessary evidential base and bears certain difficulties because of pharmacokinetic and pharmacodynamical properties of VKAs. These drawbacks are absent in direct oral anticoagulants (DOACs), the possibility of using which in LVT is being actively studied. As for now, published results of 3 randomised clinical trials have demonstrated similar safety and efficacy profiles of DOACs and VKAs. Similarly, the majority of retrospective cohort studies did not observe significant differences between two groups, where some of them have shown superiority of DOACs especially in terms of earlier thrombus resolution. Nevertheless, some studies have found DOACs ineffective and even potentially unsafe regarding systemic embolism. Existing data does not allow to form an unambiguous conclusion about the equivalence of DOACs and VKAs for LVT resolution. Large randomised clinical trials are needed to determine efficacy and safety of such treatment in these patients.

Left ventricular thrombus in ischaemic heart disease: diagnosis, treatment, and gaps of knowledge

Although the management of ischaemic heart disease has markedly improved over the last decades, left ventricular thrombus remains a serious finding in patients with myocardial infarction. Routine diagnostic detection of left ventricular thrombus relies mainly on echocardiography; however, cardiac magnetic resonance has emerged as a method with higher diagnostic accuracy, while cardiac computed tomography angiography represents a valuable alternative modality. To reduce the left ventricular thrombus-associated morbidity and mortality, optimal selection of anticoagulation is warranted after balancing the risk of bleeding. In this review, we will discuss contemporary diagnostic modalities to detect left ventricular thrombus in ischaemic heart disease and summarize evidence on risk stratification and therapy. In addition, we propose a novel diagnosis, follow-up imaging, and treatment algorithm. Further, we identify knowledge gaps at different levels to address emerging research questions and to refine the design of future studies aiming to improve the management of patients in this clinical setting.

Different Oral Antithrombotic Therapy for the Treatment of Ventricular Thrombus: An Observational Study from 2010 to 2019

METHODS

This retrospective observational study was conducted from 2010 to 2019 in National Center of Cardiovascular Diseases of China. We included patients with VT confirmed by imaging. The primary outcome was the rate of thrombus resolution. Hazard ratio (HR) was calculated with or without adjustment for covariates using Cox proportional hazards regression models.

RESULTS

463 patients were included. 43.0% received VKAs, 16.6% received NOACs, and 40.4% received APT. Over a median of 468 days' follow-up, NOACs group was more likely to have the thrombus resolved within 12 months' follow-up than VKAs (HR 2.28, 95% CI 1.57 to 3.31) or APT (HR 2.92, 95% CI 1.97 to 4.33). After adjustment for baseline variables, the significance remained in the comparison of NOACs versus VKAs (HR 2.13, 95% CI 1.41 to 3.22) as well as NOACs versus APT (HR 2.55, 95% CI 1.53 to 4.27). No significant differences were identified in bleeding rate, thromboembolism rate, or all-cause death in 12 months' follow-up.

CONCLUSION

Our findings showed that patients who were male, diagnosed with MI with or without ventricular aneurysm, or diagnosed with coronary artery diseases medical history had a risk of thrombus unresolved. Patients with NOACs had a higher resolution and a similar safety profile comparing VKAs or APT, which persisted after adjusting for other factors. Large randomized controlled trials are required urgently. This trial is registered with NCT05006677.

Therapeutic efficacy of direct oral anticoagulants and vitamin K antagonists for left ventricular thrombus: Systematic review and meta-analysis

BACKGROUND

Although several meta-analyses have compared efficacies of vitamin K antagonists (VKAs) and direct oral anticoagulants (DOACs) for treatment of left ventricular thrombus (LVT), those meta-analyses included no single-arm studies.

METHODS AND RESULTS

PubMed, Scopus, and the Cochrane Library databases were searched for articles investigating thrombus resolution, stroke, any thromboembolism, major bleeding, any bleeding, or all-cause death in LVT treated with VKAs or DOACs, and single-class meta-analyses were also included (PROSPERO database, CRD42021230849). Event rates were pooled using a random effects model. Meta-regression analysis was performed to explore factors that may influence outcomes. 2,612 patients from 23 articles were included (VKAs: 2,004, DOACs: 608). There were no significant differences between VKAs and DOACs in the frequency of thrombus resolution (VKAs: 0.75 [95% confidence interval; 0.67 to 0.81], DOACs: 0.75 [0.67 to 0.82]), stroke (VKAs: 0.06 [0.04 to 0.10], DOACs: 0.02 [0.01 to 0.01]), any thromboembolism (VKAs: 0.08 [0.05 to 0.13], DOACs: 0.03 [0.01 to 0.10]), major bleeding (VKAs: 0.06 [0.04 to 0.09], DOACs: 0.03 [0.01 to 0.06]), any bleeding (VKAs: 0.08 [0.05 to 0.12], DOACs: 0.08 [0.06 to 0.10]), and all-cause death (VKAs: 0.07 [0.04 to 0.13], DOACs: 0.09 [0.05 to 0.16]). Meta-regression analysis revealed that increased duration of follow-up was associated with lower-rates of stroke (estimate: -0.040, p = 0.0495) with VKAs, but not with DOACs. There was significant publication bias for thrombus resolution, stroke, any thromboembolism, any bleeding, and all-cause death.

CONCLUSIONS

Efficacy and adverse outcomes of therapy with DOACs and VKAs do not differ. Randomized controlled trials are needed to determine the optimal anticoagulant strategy.

Meta-analysis comparing direct oral anticoagulants versus vitamin K antagonists in patients with left ventricular thrombus

Current American College of Cardiology/American Heart Association guidelines for stroke or ST-elevation myocardial infarction recommend the use of oral vitamin K antagonists (VKAs) as a first-line anticoagulant. Although several studies have compared the use of direct oral anticoagulants (DOACs) to VKAs for left ventricular thrombus (LVT) anticoagulation therapy, they are small scale and have produced conflicting results. Thus, this meta-analysis was performed to aggregate these studies to better compare the efficacy and safety of DOACs with VKAs in patients with LVT. Cochrane Library, Google Scholar, MEDLINE, and Web of Science database searches through January 10, 2021 were performed. Eight studies evaluating stroke or systemic embolism (SSE), six studies for LVT resolution, and five studies for bleeding were included. There were no statistically significant differences in SSE (OR 0.89; 95% CI 0.46, 1.71; p = 0.73; I² = 45%) and LVT resolution (OR 1.13; 95% CI 0.75, 1.71; p = 0.56; I² = 1%) between DOAC and VKA (reference group) therapy. DOAC use was significantly associated with lower bleeding event rates compared to VKA use (OR 0.61; 95% CI 0.40, 0.93; p = 0.02; I² = 0%). DOACs may be feasible alternative anticoagulants to vitamin K antagonists for LV thrombus treatment. Randomized controlled trials directly comparing DOACs with VKAs are needed.