Anticoagulation for heart failure in sinus rhythm

Anticoagulation versus placebo for heart failure in sinus rhythm

BACKGROUND

People with chronic heart failure (HF) are at risk of thromboembolic events, including stroke, pulmonary embolism, and peripheral arterial embolism; coronary ischaemic events also contribute to the progression of HF. The use of long-term oral anticoagulation is established in certain populations, including people with HF and atrial fibrillation (AF), but there is wide variation in the indications and use of oral anticoagulation in the broader HF population.

OBJECTIVES

To determine whether long-term oral anticoagulation reduces total deaths and stroke in people with heart failure in sinus rhythm.

SEARCH METHODS

We updated the searches in CENTRAL, MEDLINE, and Embase in March 2020. We screened reference lists of papers and abstracts from national and international cardiovascular meetings to identify unpublished studies. We contacted relevant authors to obtain further data. We did not apply any language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCT) comparing oral anticoagulants with placebo or no treatment in adults with HF, with treatment duration of at least one month. We made inclusion decisions in duplicate, and resolved any disagreements between review authors by discussion, or a third party.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, and assessed the risks and benefits of antithrombotic therapy by calculating odds ratio (OR), accompanied by the 95% confidence intervals (CI).

MAIN RESULTS

We identified three RCTs (5498 participants). One RCT compared warfarin, aspirin, and no antithrombotic therapy, the second compared warfarin with placebo in participants with idiopathic dilated cardiomyopathy, and the third compared rivaroxaban with placebo in participants with HF and coronary artery disease. We pooled data from the studies that compared warfarin with a placebo or no treatment. We are uncertain if there is an effect on all-cause death (OR 0.66, 95% CI 0.36 to 1.18; 2 studies, 324 participants; low-certainty evidence); warfarin may increase the risk of major bleeding events (OR 5.98, 95% CI 1.71 to 20.93, NNTH 17). 2 studies, 324 participants; low-certainty evidence). None of the studies reported stroke as an individual outcome. Rivaroxaban makes little to no difference to all-cause death compared with placebo (OR 0.99, 95% CI 0.87 to 1.13; 1 study, 5022 participants; high-certainty evidence). Rivaroxaban probably reduces the risk of stroke compared to placebo (OR 0.67, 95% CI 0.47 to 0.95; NNTB 101; 1 study, 5022 participants; moderate-certainty evidence), and probably increases the risk of major bleeding events (OR 1.65, 95% CI 1.17 to 2.33; NNTH 79; 1 study, 5008 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Based on the three RCTs, there is no evidence that oral anticoagulant therapy modifies mortality in people with HF in sinus rhythm. The evidence is uncertain if warfarin has any effect on all-cause death compared to placebo or no treatment, but it may increase the risk of major bleeding events. There is no evidence of a difference in the effect of rivaroxaban on all-cause death compared to placebo. It probably reduces the risk of stroke, but probably increases the risk of major bleedings. The available evidence does not support the routine use of anticoagulation in people with HF who remain in sinus rhythm.

Stroke and mortality in patients with incident heart failure: the Diet, Cancer and Health (DCH) cohort study

OBJECTIVE

The objective was to test the hypothesis that the risk of stroke, death and the composite of 'stroke and death' would be increased among patients with incident heart failure (HF). While HF increases the risk of mortality, stroke and thromboembolism in general, the 'extreme high-risk' nature of incident HF is perhaps under-recognised in everyday clinical practice.

DESIGN

Prospective cohort study.

SETTING

Large Danish prospective epidemiological cohort.

PARTICIPANTS

Subjects in the Diet, Cancer and Health study.

OUTCOME MEASURES

Stroke, death and the composite of 'stroke and death' among patients with incident cases of HF, without concomitant atrial fibrillation.

RESULTS

From the original cohort, 1239 patients with incident HF were identified. Incidence rates show a higher incidence in the initial period following the diagnosis of HF, with a markedly higher rate of death and stroke (ischaemic or haemorrhagic) in the initial 30 days following the diagnosis of incident HF. While lower than the risk at 0-30 days, the higher risk did not return to normal at 6+ months after the diagnosis of incident HF. This risk increase was apparent for the end points of stroke (ischaemic or haemorrhagic or both) whether or not a vitamin K antagonist (VKA) was used. With VKA use, there was a lower adjusted HR for death and the composite of 'death or stroke' compared to non-VKA use at the three time intervals following diagnosis of HF, whether 0-30 days, 30 days to 6 months and 6+ months. On multivariate analysis, previous stroke/transient ischaemic attack/thromboembolism was a predictor of higher risk of stroke, death and the composite of 'stroke and death', while VKA treatment was a highly significant predictor of a lower risk for death (adjusted HR 0.46, 95% CI 0.28 to 0.74, p<0.001) and the combined end point of death or stroke (adjusted HR 0.64, 95% CI 0.43 to 0.96, p=0.003).

CONCLUSIONS

Based on relative hazards, incident HF is clearly a major risk factor for stroke, death and the composite of 'stroke and death', especially in the initial 30 days following initial diagnosis. The use of VKA therapy was associated with a lower risk of these end points. These findings would have major implications for the approach to management of patients presenting with incident HF, given the high risk of this population for death and stroke, which may be ameliorated by VKA therapy.