Is thrombosis a contributor to heart failure pathophysiology? Possible mechanisms, therapeutic opportunities, and clinical investigation challenges

Anticoagulation Therapy and NOACs in Heart Failure

Current evidence indicates that heart failure (HF) confers a hyper-coagulable state that is associated with adverse events including stroke, systemic embolism, and mortality. This may be due to the elevated levels of pro-thrombotic and pro-inflammatory cytokines that are seen in patients with acute and chronic HF. Left ventricular wall motion abnormalities in patients with systolic dysfunction predispose to local thrombosis due to blood stasis as does atrial fibrillation (AF) which leads to blood stasis in regions of the atria. The high risk of thromboemboli in HF patients with AF has resulted in the use anticoagulation therapy to prevent the occurrence of catastrophic events. There is evidence, however, that the pro-inflammatory, pro-thrombotic state that exists in HF puts patients who are in sinus rhythm at risk. The novel oral anticoagulants (NOACs) have been shown in RCT to have at least equivalent efficacy in reducing stroke as warfarin while exposing patients to a lower risk of bleeding. The fact that the NOACs don't require routine monitoring to assure that patients remain within the therapeutic range and have relatively simple dosing requirements and a safer risk profile makes them attractive substitutes to warfarin in HF patients with atrial fibrillation and other conditions (e.g. deep venous thrombosis). Post hoc analyses from a subset of HF patients from the RCTs in AF patients have demonstrated similar findings as were reported in the entire populations that were included in the trials. As a result, NOACS are commonly used now in HF patients with AF. For HF patients with reduced ejection fraction in sinus rhythm, the use of warfarin in randomized clinical trials (RCT) to reduce stroke has been disappointing and associated with increase bleeding risk when compared to aspirin. The advantages of the NOACs over warfarin, however, raise the question of whether they might improve outcomes in HF patients who are in sinus rhythm. The currently ongoing COMMANDER-HF trial has been designed to address this issue. In this chapter we review evidence of existence of a prothombotic state in HF, the pharmacodynamics and clinical trials of the NOACs and the outcomes from NOAC substudies in the HF subgroup. We also discuss the rationale for using anticoagulation in HF independent of arrhythmia burden.

Rationale and design of a randomized, double-blind, event-driven, multicentre study comparing the efficacy and safety of oral rivaroxaban with placebo for reducing the risk of death, myocardial infarction or stroke in subjects with heart failure and significant coronary artery disease following an exacerbation of heart failure: the COMMANDER HF trial

AIMS

Thrombin is a critical element of crosstalk between pathways contributing to worsening of established heart failure (HF). The aim of this study is to explore the efficacy and safety of rivaroxaban 2.5 mg bid compared with placebo (with standard care) after an exacerbation of HF in patients with reduced ejection fraction (HF-rEF) and documented coronary artery disease.

METHODS

This is an international prospective, multicentre, randomized, double-blind, placebo-controlled, event-driven study of approximately 5000 patients for a targeted 984 events. Patients must have a recent symptomatic exacerbation of HF, increased plasma concentrations of natriuretic peptides (B-type natriuretic peptide ≥200 pg/mL or N-terminal pro-B-type natriuretic peptide ≥800 pg/mL), with left ventricular ejection fraction ≤40% and coronary artery disease. Patients requiring anticoagulation for atrial fibrillation or other conditions will be excluded. After an index event (overnight hospitalization, emergency department or observation unit admission, or unscheduled outpatient parenteral treatment for worsening HF), patients will be randomized 1:1 to rivaroxaban or placebo (with standard of care). The primary efficacy outcome event is a composite of all-cause mortality, myocardial infarction or stroke. The principal safety outcome events are the composite of fatal bleeding or bleeding into a critical space with potential permanent disability, bleeding events requiring hospitalization and major bleeding events according to International Society on Thrombosis and Haemostasis bleeding criteria.

CONCLUSION

COMMANDER HF is the first prospective study of a target-specific oral antithrombotic agent in HF. It will provide important information regarding rivaroxaban use following an HF event in an HF-rEF patient population with coronary artery disease.

Bivalirudin is associated with improved clinical and economic outcomes in heart failure patients undergoing percutaneous coronary intervention: Results from an observational database

BACKGROUND

Outcomes with bivalirudin compare favorably with heparin ± GPIIb/IIIa receptor inhibition (heparin ± GPI) during percutaneous coronary intervention (PCI). Patients with congestive heart failure (CHF) have increased risk for complications. The objective was to investigate clinical and economic outcomes for bivalirudin ± GPI vs. heparin ± GPI among PCI patients with CHF.

METHODS

Using the Premier Hospital Database, PCI patients with CHF were stratified by anticoagulant: bivalirudin, bivalirudin ± GPI, heparin and heparin ± GPI. The probability of receiving bivalirudin ± GPI was estimated using individual and hospital variables. Using propensity scores, each bivalirudin ± GPI patient was matched to a heparin ± GPI patient. The primary outcome was in-hospital death. Bleeding rates, transfusion, length of stay and in-hospital cost were ascertained.

RESULTS

Overall, 116,313 patients at 315 hospitals received bivalirudin (n = 45,559) bivalirudin + GPI (n = 8,115), heparin (n = 27,972) or heparin + GPI (n = 34,667). Patients had STEMI (21.2%), NSTEMI (29.1%), unstable angina (16.6%), stable angina (5.7%) or other ischemic heart disease (24.2%). Of these, 79.1% of bivalirudin patients matched, resulting in 84,948 analyzed patients. Compared with heparin ± GPI patients, bivalirudin ± GPI patients had fewer deaths (3.3% vs. 3.9%; p < 0.0001), less clinically apparent bleeding (10.2% vs. 11.4%; p < 0.0001), clinically apparent bleeding with transfusion (2.7% vs. 3.2%, p <0.0001), and transfusion (8.5% vs. 9.8%, p < 0.0001). Patients receiving bivalirudin had shorter length of stay (6.3 vs. 6.8 days; p < 0.0001) and lower in-hospital cost (mean $26,706 vs. $27,166 [median $19,414 vs. $19,798]; p < 0.0001). In conclusion, this is the largest retrospective analysis of PCI patients with CHF and demonstrates bivalirudin ± GPI compared with heparin ± GPI is associated with lower inpatient rates of death, bleeding, and cost.

Decompensated Heart Failure Is a Strong Independent Predictor of Functional Outcome After Ischemic Stroke

BACKGROUND

Up to 24% of stroke patients have chronic heart failure. The aim of this study was to determine the frequency and prognostic significance of decompensated heart failure (DHF) in acute stroke patients.

METHODS AND RESULTS

Five hundred sixty-six patients (median age 73 y, 48% men) admitted to the stroke unit within 24 hours after stroke were prospectively included. Diagnosis of DHF was made by a cardiologist during hospitalization. Function outcome was assessed 1 month after stroke onset with the use of a modified Rankin Scale. Unfavorable outcome was defined as scores 3-6. DHF was diagnosed in 17% of patients. Fifty-seven percent of patients with DHF had preserved ejection fraction. Patients with DHF were older and more often female and more frequently suffered from hypertension, diabetes mellitus, atrial fibrillation, and myocardial infarction. They also had more severe neurologic deficit and more often had hyperglycemia, leukocytosis, fever, pneumonia, and renal failure. After multivariate analysis, adjusting for age, stroke severity, atrial fibrillation, myocardial infarction, hyperglycemia, pneumonia, fever, leukocytosis, proteinuria, and reduced ejection fraction, DHF remained an independent predictor of worse outcome (odds ratio 2.34, 95% CI 1.12-4.89; P = .02).

CONCLUSIONS

DHF is a strong independent predictor of poor functional prognosis after ischemic stroke.

Evidence-based co-medication in heart failure: necessary or bystander?

This article refers to 'Impact of aspirin and statins on longterm survival in patients with acute myocardial infarction complicated by heart failure: an analysis in 1746 patients' by C. Lewinter et al., published in this issue on page 95-102.

Chronic exercise leads to antiaggregant, antioxidant and anti-inflammatory effects in heart failure patients

BACKGROUND

Heart failure (HF) patients are at an increased risk of thrombotic events. Here, we investigated the effects of exercise training on platelet function and factors involved in its modulation in HF.

DESIGN AND METHODS

Thirty HF patients were randomized to 6 months of supervised exercise training or to a control group that remained sedentary. Exercise training consisted of 30 min of moderate-intensity treadmill exercise, followed by resistance and stretching exercises, performed three times a week. Blood was collected before and after the intervention for platelet and plasma obtainment.

RESULTS

Peak VO2 increased after exercise training (18.0 ± 2.2 vs. 23.8 ± 0.5 mlO2/kg/min; p < 0.05). Exercise training reduced platelet aggregation induced by both collagen and ADP (approximately -6%; p < 0.05), as well as platelet nitric oxide synthase activity (0.318 ± 0.030 vs. 0.250 ± 0.016 pmol/10(8) cells; p < 0.05). No difference in the above-mentioned variables were observed in the control group. No significant difference was observed in intraplatelet cyclic guanosine monophosphate levels among groups. There was a significant increase in the activity of the antioxidant enzymes superoxide dismutase and catalase in plasma and platelets, resulting in a decrease in both lipid and protein oxidative damage. Systemic levels of the inflammatory markers C-reactive protein, fibrinogen, and tumour necrosis factor α were also reduced in HF after training.

CONCLUSIONS

Our results suggest that regular exercise training is a valuable adjunct to optimal medical management of HF, reducing platelet aggregation via antioxidant and anti-inflammatory effects, and, therefore, reducing the risk of future thrombotic events.