Under-reporting of venous and arterial thrombotic events in randomized clinical trials: a meta-analysis

Aldosterone and cardiovascular diseases

Aldosterone's role in the kidney and its pathophysiologic actions in hypertension are well known. However, its role or that of its receptor [minieralocorticoid receptor (MR)] in other cardiovascular (CV) disease are less well described. To identify their potential roles in six CV conditions (heart failure, myocardial infarction, atrial fibrillation, stroke, atherosclerosis, and thrombosis), we assessed these associations in the following four areas: (i) mechanistic studies in rodents and humans; (ii) pre-clinical studies of MR antagonists; (iii) clinical trials of MR antagonists; and (iv) genetics. The data were acquired from an online search of the National Library of Medicine using the PubMed search engine from January 2011 through June 2021. There were 3702 publications identified with 200 publications meeting our inclusion and exclusion criteria. Data strongly supported an association between heart failure and dysregulated aldosterone/MR. This association is not surprising given aldosterone/MR's prominent role in regulating sodium/volume homeostasis. Atrial fibrillation and myocardial infarction are also associated with dysregulated aldosterone/MR, but less strongly. For the most part, the data were insufficient to determine whether there was a relationship between atherosclerosis, stroke, or thrombosis and aldosterone/MR dysregulation. This review clearly documented an expanding role for aldosterone/MR's dysregulation in CV diseases beyond hypertension. How expansive it might be is limited by the currently available data. It is anticipated that with an increased focus on aldosterone/MR's potential roles in these diseases, additional clinical and pre-clinical data will clarify these relationships, thereby, opening approaches to use modulators of aldosterone/MR's action to more precisely treat these CV conditions.

Assessing the Risk of Thromboembolism in Cancer Patients Receiving Immunotherapy

Malignancy has long been implicated with hypercoagulability, leading to an increased rate of both venous and arterial thromboembolism (VTE and ATE). Immunotherapy has established itself as a cornerstone of modern cancer therapy by promoting antitumor immune responses, though there have been some suggestions that immune-related adverse events could include increased rates of VTE and ATE. In this review, we examine the available evidence regarding the use of immune checkpoint inhibitors (ICIs) and thrombosis. First, we describe the potential mechanisms by which ICIs might lead to thrombophilia given the overlap between the immune system, coagulation cascade, and platelet adhesion and activation. In addition, while there is some preclinical data evaluating immunotherapy associated ATEs in animal models, there is a paucity of evidence exploring potential mechanism of VTEs in ICIs. Second, we review the incidence of ATE and VTE in patients receiving ICIs in the published literature. Finally, we discuss current limitations in understanding, areas of conflicting evidence, and approaches to further investigation.

Risk of venous and arterial thromboembolic events in women with advanced breast cancer treated with CDK 4/6 inhibitors: A systematic review and meta-analysis

BACKGROUND

Cyclin-dependent kinase inhibitors (CDKIs) may increase the risk of thrombotic events of endocrine therapy (ET) in women with hormone-sensitive, HER2-negative advanced breast cancer (BC). Aim of our systematic review is the estimate of the risk of venous and arterial thromboembolism in women with advanced BC treated with CDKIs in phase III randomized controlled trials (RCTs).

METHODS

Studies were identified by electronic search of MEDLINE, EMBASE and CENTRAL database until October 2021. Risk of bias was assessed according to Cochrane criteria. Differences in thrombotic outcomes among groups were expressed as pooled odds ratio (OR) and corresponding 95% confidence interval (CI), which were calculated using both a fixed-effects and a random-effects model. Statistical heterogeneity was evaluated using the I² statistic.

RESULTS

We included 7 phase III RCTs (4415 patients) for a total of 15 papers (7 were the first published paper and 8 the follow-up papers). Reporting of thrombotic events was at high risk of bias. Women with advanced BC treated with CDKIs and ET had a two to threefold increased risk of venous thromboembolic event (VTE) compared to ET plus placebo arm [OR 2.90 (95% CI 1.32, 6.37; I² = 0%) in the main papers and OR 2.20 (95% CI 0.93, 5.20; I² = 49%) in the follow-up papers]. Women with advanced BC treated with CDKIs and ET had a non-significant mild increased risk of arterial thromboembolic event compared to ET plus placebo arm [OR 1.22 (95% CI 0.47, 3.18 I² = 0%)].

CONCLUSIONS

CDKIs in combination with endocrine therapy are associated with a two to threefold higher risk of VTE in comparison to endocrine therapy alone in women with advanced breast cancer, while the risk of arterial events is still to be defined.

Safety of low-dose subcutaneous recombinant interleukin-2: systematic review and meta-analysis of randomized controlled trials

Standard-dose intravenous recombinant interleukin-2 (rIL-2) is indicated for the treatment of some subtypes of cancer; however, severe adverse events, including venous thromboembolism (VTE), may complicate its administration. Low-dose subcutaneous rIL-2 is being studied for the management of immune-mediated diseases, since it can modulate the immunological response by specifically targeting T regulatory (T_reg) cells; importantly, it is supposed to cause fewer or no complications. In this systematic review and meta-analysis of phase II-III randomized controlled trials (RCTs), we investigated the safety of low-dose (<6 Million International Unit [MIU]/day) and ultra-low-dose (≤1 MIU/day) rIL-2 for severe adverse events (grade III-V) with a focus on VTE. Data of 1,321 patients from 24 RCTs were analysed: 661 patients were randomized to the rIL-2 arm (on top of standard of care) and 660 patients to standard of care alone or placebo. Two studies reported higher rates of thrombocytopenia in the low-dose rIL-2 arm. Ultra-low-dose rIL-2 was reported to be well tolerated in 6 studies with a negligible rate of severe adverse events. Symptomatic VTE events were not reported in any of the study arms (absolute risk difference 0% [95%CI −0.1%; +0.1%]). Our results may facilitate the study and introduction in clinical practice of low-dose rIL-2 for potentially new indications.

Direct-acting antiviral drugs for chronic hepatitis C and risk of major vascular events: a systematic review

Direct-acting antiviral drugs (DAAs) were recently approved for treating hepatitis C virus-related chronic hepatitis. As advanced chronic liver disease may predispose patients to thrombotic events, it is still uncertain whether DAAs may influence the actual risk of major arterial and venous thrombotic events. We performed a systematic review to assess the incidence of major vascular events in patients receiving DAAs for HCV chronic hepatitis during phase-III randomized controlled trials (RCTs). Two reviewers identified studies through Pubmed database until October 2015. Reporting and incidence of any vascular events were compared with reporting and incidence of major bleeding, anemia (a prespecified safety outcome) and headache (a common non-prespecified safety outcome). 33 RCTs, encompassing 14,764 patients, were included. Only 13 (39%) and 4 (12%) RCTs provide data on any arterial or venous events, respectively. Occurrence of anemia and headache is reported in all studies. Crude unweighted rate of major arterial events is 0.16% (95% CI 0.10-0.24) of the total included population and 0.47% in those 13 RCTs reporting data. Crude unweighted rate of major venous events is 0.03% of the total included population (95% CI 0.01-0.08) and 0.22% in those four RCTs reporting data. Crude unweighted rate of major bleeding is 0.07% (95% CI 0.03-0.1). Incidence of thrombotic events in HCV patients receiving DAAs may be low, but an incorrect estimation cannot be excluded.

Hemostasis in Overt and Subclinical Hyperthyroidism

CONTEXT

There are contradictory results on the effect of hyperthyroidism on hemostasis. Inadequate population-based studies limited their clinical implications, mainly on the risk of venous thromboembolism (VTE). The present review focuses on hemostatic changes in overt and subclinical hyperthyroidism.

METHODS

A systematic literature search was conducted employing MEDLINE database. The following words were used for the search: Hyperthyroidism; thyrotoxicosis; Graves disease; goiter, nodular; hemostasis; blood coagulation factors; blood coagulation disorders; venous thromboembolism; bleeding; fibrinolysis. The articles that were related to hyperthyroidism and hemostasis are used in this manuscript.

RESULTS

Hyperthyroidism, either overt or subclinical, renders a hypercoagulable state, although there are several studies with contradictory findings in the literature. Hypercoagulability may be caused by an increase in the level of various coagulation factors such as factor (F) VIII, FX, FIX, von Willebrand F (vWF), and fibrinogen, while hypofibrinolysis by changes in coagulation parameters such as a decrease in plasmin and plasmin activator or an increase in α2-antiplasmin, plasminogen activator inhibitor-1 and thrombin activatable fibrinolysis inhibitor.

CONCLUSIONS

Although many reports are in favor of a hypercoagulable state in overt hyperthyroidism but this finding at the biochemical level and its clinical implication, on the occurrence of VTE, has yet to be confirmed.

Intravenous immune globulin and thromboembolic adverse events: A systematic review and meta-analysis of RCTs

Prior case reports and observational studies indicate that intravenous immune globulin (IVIg) products may cause thromboembolic events (TEEs), leading the FDA to require a boxed warning in 2013. The effect of IVIg treatment on the risk of serious TEEs (acute myocardial infarction, ischemic stroke, or venous thromboembolism) was assessed using adverse event data reported in randomized controlled trials (RCTs) of IVIg. RCTs of IVIg in adult patients from 1995 to 2015 were identified from Pubmed, Embase, ClinicalTrials.Gov, and two large prior reviews of IVIg's therapeutic applications. Trials at high risk of detection or reporting bias for serious adverse events were excluded. 31 RCTs with a total of 4,129 participants (2,318 IVIg-treated, 1,811 control) were eligible for quantitative synthesis. No evidence was found of increased TEE risk among IVIg-treated patients compared with control patients (odds ratio = 1.10, 95% CI: 0.44, 2.88; risk difference = 0.0%, 95% CI: -0.7%, 0.7%, I(2)  = 0%). No significant increase in risk was found when arterial and venous TEEs were analyzed as separate endpoints. Trial publications provided little specific information concerning the methods used to ascertain potential adverse events. Care should be taken in extrapolating the results to patients with higher baseline risks of TEE. Am. J. Hematol. 91:594-605, 2016. © 2016 Wiley Periodicals, Inc.

Effect of thromboprophylaxis with anticoagulant drugs on the incidence of arterial thrombotic events in medical inpatients: a systematic review

Pharmacological prophylaxis of venous thromboembolism (VTE) is recommended for medical inpatients. Since arterial thrombosis (AT) shares some risk factors with VTE, it would be reasonable to assess the efficacy of thromboprophylaxis by considering both VTE and AT as outcome events. We performed a systematic review and meta-analysis of phase III RCTs on thromboprophylaxis in medical inpatients, to evaluate the quality of reporting and the incidence of AT, and the effect of thromboprophylaxis with anticoagulants on AT incidence. Studies were identified by a combined search strategy until May 2015. Differences in outcomes among groups were expressed as pooled odds ratios (OR) and 95 % confidence intervals (CI). Statistical heterogeneity was assessed by I (2) statistic. Twenty phase III RCTs, encompassing 54,742 patients, were included; of these, 3 (15 %) reported on AT as a pre-defined secondary outcome and 8 (40 %) on at least one AT outcome. Raw-unweighed incidence of fatal MI in the three RCTs is 0.37 % in patients receiving unfractionated heparin or enoxaparin, and 0.38 % in controls (OR 0.97, 95 % CI 0.62-1.52; I (2) = 0 %). A non-statistically significant increase in AT is reported in patients on enoxaparin compared to control (OR 1.95, 95 % CI 0.89-4.27; I (2) = 13 %). AT is underreported in RCTs on VTE prophylaxis in medical inpatients. Published data suggest that incidence of fatal MI in these patients may be clinically relevant. Insufficient data are available to draw firm conclusions on the effects of thromboprophylaxis with anticoagulants on AT incidence in this setting.