Thromboembolism in heart failure: who should be treated?

Fibrinolysis in Dogs with Intracavitary Effusion: A Review

Simple Summary

In blood vessels there is a balance between clot formation and its dissolution. Fibrinolysis normally allows the breakdown of blood clots during the healing of injured blood vessels. This process is mediated by the activation of a blood enzyme (plasmin) which breaks down a meshed protein (fibrin) which holds blood clots at the site of the vessel injury. In some diseases, the activation of plasmin becomes excessive, leading to bleeding tendencies (hyperfibrinolysis). Under normal conditions, abdominal and thoracic cavities are filled with a small amount of fluid deriving from the blood. The results of recent studies have shown that, in dogs, all types of pathologic intracavitary fluids have an increased fibrinolytic activity. This increased fibrinolytic activity is also present in their blood, in some cases reaching a hyperfibrinolytic state. Hyperfibrinolysis and bleeding tendencies have also been documented in cardiopathic dogs with ascites. The latter result is surprising considering that thrombotic events are commonly documented in humans and cats with some cardiac diseases.

Abstract

Physiologic fibrinolysis is a localized process in which stable fibrin strands are broken down by plasmin in response to thrombosis. Plasmin activation can also take place separately from the coagulation process, resulting in pathologic fibrinolysis. When plasmin activation exceeds the neutralizing capacity of plasmin inhibitors, severe bleeding can potentially take place. Although the processes which regulate coagulation and fibrinolysis in the blood are well known, it is less clear as to what extent the same processes take place in the body cavities and whether they influence systemic hemostasis. The results of the studies herein cited demonstrate that coagulation followed by fibrinogenolytic/fibrinolytic activity takes place in all kinds of canine ascitic and pleural fluids. Moreover, systemic clotting abnormalities suggesting primary fibrinolysis/primary hyperfibrinolysis (i.e., elevated plasma fibrin/fibrinogen degradation products [FDPs] and normal D-dimer concentrations with fibrinogen concentrations ≤ 100 mg/dL or above this cut-off, respectively) occur in dogs with intracavitary effusion. Enhanced fibrinolytic activity in dogs with intracavitary effusion can also be detected using rotational thromboelastometry (ROTEM), although the degree of agreement between ROTEM and FDPs, D-dimer and fibrinogen concentrations is poor. Finally, contrary to the thrombotic events commonly documented in some humans and cats with cardiac diseases, bleeding tendencies due to primary fibrinolysis/primary hyperfibrinolysis have been documented in dogs with cardiogenic ascites.

Regenerating a ventricular cavity during left ventricular assist device implantation

Ten months after an ineffective percutaneous coronary stent placement, a 53-year-old patient was rehospitalized with NYHA functional class IV congestive heart failure, ischemic heart disease and left ventricular aneurysm. Echocardiography revealed thrombus formation in the left ventricle with apical aneurysm. Even though left ventricular assist device (LVAD) implantation improves quality of patients' lives with an increase of its overall use, it becomes more complicated in the presence of ventricular thrombus. We decided to perform ventricular reconstruction with thrombus extraction concomitant to HeartMate 3™ LVAD implantation. The patient was recovered uneventfully, and discharged on postoperative day 14. This report shares the patient's case and the surgical procedure.

The neuropeptide galanin promotes an anti-thrombotic phenotype on endocardial endothelial cells from heart failure patients

Thromboembolic complications are a significant cause of mortality and re-hospitalization in heart failure (HF) patients. One source of thrombi is the ventricular endocardial surface that becomes increasingly pro-thrombotic as HF progresses. Anticoagulation comes with bleeding risks so identifying therapeutic agents for improving cardiac endothelial health are of critical clinical importance. Endocardial endothelial cells are closely apposed to cardiac sympathetic nerves. In HF, cardiac sympathetic nerves are dysregulated and promote disease progression. Whether endocardial endothelial health and function is impacted by sympathetic dysregulation in HF is unknown. Also unexplored is the impact of neuropeptides, such as galanin and neuropeptide Y (NPY), co-released from sympathetic nerve terminals, on endothelial health. In this study we examined the effect of sympathetic nerve-released neurotransmitters and neuropeptides on the procoagulant phenotype of cultured human endocardial endothelial cells from HF patients. As a functional readout of procoagulant state we examined thrombin-mediated von Willebrand factor (vWF) extrusion and multimer expression. We demonstrate that vWF extrusion and multimer expression is promoted by thrombin, that isoproterenol (a beta-adrenergic receptor agonist) augments this effect, whereas co-treatment with the beta-blockers propranolol and carvedilol blocks this effect. We also show that vWF extrusion and multimer expression is attenuated by treatment with the neuropeptide galanin, but not with NPY. Our results are consistent with a protective role of beta-blockers and galanin on endocardial endothelial health in heart failure. Improving endothelial health through galanin therapy is a future clinical application of this study.

Pharmacotherapy of Congestive Heart Failure in Elderly Patients

With longer life expectancy, as well as better survival rates after myocardial infarction, the population of elderly patients with congestive heart failure steadily increases. Large, randomized, placebo-controlled studies have shown significant beneficial effects for several classes of drugs (angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, β-blockers, aldosterone antagonists) in patients with congestive heart failure. In most of these studies, however, elderly patients were either excluded or represented only a minority of the study population. Therefore, the treatment benefit for the large population of patients aged 65 and older is still not very well documented. In this paper, we critically review the current literature with regard to outcome of heart failure therapy in this particular subpopulation.

Echocardiographic Detection of Left Ventricular Thrombus in Patients Undergoing Heartmate II Left Ventricular Assist Device Implantation

Purpose

Transthoracic (TTE) and transesophageal echocardiograms (TEE) are considered accurate in detecting the presence of left ventricular (LV) thrombus. A persistent LV thrombus poses risks of pump thrombosis and stroke in LVAD recipients. The relationship between pre-operative echocardiography and intraoperative findings at LVAD implantation has not previously been studied.

Methods

A retrospective review examined all patients undergoing LVAD placement or exchange from October 2011 to March 2014. Pre-Operative TTE and TEE data were validated with presence of LV thrombus during the direct inspection at the time of LVAD placement, and the findings were analyzed quantitatively.

Results

Between October 2011 and March 2014, 99 patients underwent a total of 107 LVAD implants. Pre-Operative TTE was available in 93 (86.9%) cases, while pre-operative TEE was available in 37 cases (34.6%). On pre-operative TTE, LV thrombus was correctly identified in only two cases, while on pre-operative TEE no cases of LV thrombus were identified correctly, and there were 2 false positive reports. Intraoperative inspection revealed presence of LV thrombus in 14 cases. The sensitivity of pre-operative TTE was 16.7% and the specificity 100% in detecting LVT, compared to 0% and 93.8%, respectively, for TEE.

Conclusions

Pre-Operative echocardiogram offers low accuracy for presence of LV thrombus. Overall, the sensitivity is too low to reliably exclude thrombus. This could have significant implications in planning off-pump LVAD exchange as thrombus could be missed. More data are necessary to determine whether this could have significant effects on thromboembolic complications and survival.

Evaluation of hemostatic and fibrinolytic markers in dogs with ascites attributable to right-sided congestive heart failure

OBJECTIVE

To determine whether dogs with ascites secondary to right-sided congestive heart failure (CHF) have bleeding disorders associated with hypofibrinogenemia and discordant plasma fibrin-fibrinogen degradation products (FDPs) and D-dimer assay results (ie, a circulating concentration of FDPs higher than the reference range and a circulating concentration of D-dimer within the reference range).

DESIGN

Retrospective case-control study.

ANIMALS

80 client-owned dogs.

PROCEDURES

Dogs with ascites secondary to right-sided CHF (group 1; n = 20), unhealthy dogs without cardiac disease (group 2; 40), and dogs with left-sided CHF (group 3; 20) were included in the study. Urine bile acids-to-creatinine concentration ratios were calculated as a marker of liver function. Differences among groups regarding coagulation profile analysis results and prevalence of discordant FDPs and D-dimer assay results were determined.

RESULTS

No significant differences were detected among the 3 groups regarding urine bile acids-to-creatinine concentration ratios. Plasma fibrinogen concentration was significantly lower for group 1 versus groups 2 or 3. Prevalence of discordant FDPs and D-dimer assay results was significantly higher for group 1 versus groups 2 or 3. Eighteen group 1 dogs had discordant FDPs and D-dimer assay results. Ten of these dogs had concurrent hypofibrinogenemia, 2 of which had clinical signs of bleeding. Only 10 dogs in groups 2 or 3 had discordant FDPs and D-dimer assay results; none of these dogs had hypofibrinogenemia or clinical signs of bleeding.

CONCLUSIONS AND CLINICAL RELEVANCE

Dogs with right-sided CHF and ascites may be at increased risk for primary hyperfibrinogenolysis (ie, hypofibrinogenemia and discordant FDPs and D-dimer assay results).

[Cardiomyopathies. I: classification of cardiomyopathies--dilated cardiomyopathy]

Cardiomyopathies are common causes of heart failure and sudden cardiac death. According to the WHO classification, "specific" cardiomyopathies are differentiated from "idiopathic" cardiomyopathies. Thus, this classification is primarily based on pathophysiological characteristics. The diagnostic spectrum in cardiomyopathies comprises the entire spectrum of non-invasive and invasive cardiological examination techniques. The exact verification of certain cardiomyopathies necessitates additionally investigations. For example, immunohistological and molecular biological investigations of endomyocardial biopsies may confirm inflammatory cardiomyopathy, which is often induced by viruses. Several studies have shown that specific immunomodulatory treatment options can halt the progressive course of the disease. Several gene mutations have been identified in genetic/familial dilated cardiomyopathy. First-degree relatives should be screened for early stages. Primary prevention of sudden cardiac death shows increasing superiority of the implantable defibrillator compared with pharmacological approaches (i.e. amiodarone).

Haemostatic and inflammatory biomarkers in advanced chronic heart failure: role of oral anticoagulants and successful heart transplantation

Advanced chronic heart failure (CHF) is associated with abnormal haemostasis and inflammation, but it is not known how these abnormalities are related, whether they are modified by oral anticoagulants (OAT), or if they persist after successful heart transplantation. We studied 25 patients with CHF (New York Heart Association class IV, 10 of whom underwent heart transplantation) and 25 age- and sex-matched healthy controls by measuring their plasma levels of prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin (TAT) complexes, tissue plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), D-dimer, factor VII (FVII), fibrinogen, von Willebrand factor (VWF), tumour necrosis factor (TNF), soluble TNF receptor II (sTNFRII), interleukin 6 (IL-6), soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), endothelial-selectin (E-selectin) and thrombomodulin. CHF patients had higher plasma levels of TAT, D-dimer, t-PA, fibrinogen, VWF, TNF, IL-6, sTNFRII, sVCAM-1 (P = 0.0001), sICAM-1 (P = 0.003) and thrombomodulin (P = 0.007) than controls. There were significant correlations (r = 0.414-0.595) between coagulation, fibrinolysis, endothelial dysfunction and inflammation parameters, which were lower in those patients treated with OATs. Heart transplantation led to reductions in fibrinogen (P = 0.001), VWF (P = 0.05), D-dimer (P = 0.05) and IL-6 levels (P = 0.05), but all the parameters remained significantly higher (P = 0.01-0.0001) than in the controls. Advanced CHF is associated with coagulation activation, endothelial dysfunction and increased proinflammatory cytokine levels. Most of these abnormalities parallel each other, tend to normalize in patients treated with OATs and, although reduced, persist in patients undergoing successful heart transplantation, despite the absence of clinical signs of CHF.