Left ventricular systolic dysfunction, heart failure, and the risk of stroke and systemic embolism in patients with atrial fibrillation: insights from the ARISTOTLE trial

BACKGROUND

We examined the risk of stroke or systemic embolism (SSE) conferred by heart failure (HF) and left ventricular systolic dysfunction (LVSD) in the Apixaban for Reduction in Stroke and Other Thromboembolic Events in Atrial Fibrillation Trial (ARISTOTLE), as well as the effect of apixaban versus warfarin.

METHODS AND RESULTS

The risk of a number of outcomes, including the composite of SSE or death (to take account of competing risks) and composite of SSE, major bleeding, or death (net clinical benefit) were calculated in 3 patient groups: (1) no HF/no LVSD (n=8728), (2) HF/no LVSD (n=3207), and (3) LVSD with/without symptomatic HF (n=2736). The rate of both outcomes was highest in patients with LVSD (SSE or death 8.06; SSE, major bleeding, or death 10.46 per 100 patient-years), intermediate for HF but preserved LV systolic function (5.32; 7.24), and lowest in patients without HF or LVSD (1.54; 5.27); each comparison P<0.0001. Each outcome was less frequent in patients treated with apixaban: in all ARISTOTLE patients, the apixaban/warfarin hazard ratio for SSE or death was 0.89 (95% confidence interval, 0.81-0.98; P=0.02); for SSE, major bleed, or death it was 0.85 (0.78-0.92; P<0.001). There was no heterogeneity of treatment effect across the 3 groups.

CONCLUSIONS

Patients with LVSD (with/without HF) had a higher risk of SSE or death (but similar rate of SSE) compared with patients with HF but preserved LV systolic function; both had a greater risk than patients without either HF or LVSD. Apixaban reduced the risk of both outcomes more than warfarin in all 3 patient groups.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00412984.

Recommendations for thromboprophylaxis in the 2012 focused update of the ESC guidelines on atrial fibrillation: a commentary

The objective of this article is to provide a commentary on the recommendations for stroke prevention from the 2012 focused update of the European Society of Cardiology guidelines on the management of atrial fibrillation and the evidence (or lack of it) supporting these recommendations. These guidelines strongly advocate a major clinical practice shift towards initially focusing on the identification of 'truly low risk' patients who do not need any antithrombotic therapy. After this initial decision-making step, effective stroke prevention - that is, oral anticoagulation therapy (whether as well-controlled adjusted dose warfarin or with one of the novel oral anticoagulants) - could be offered to patients with atrial fibrillation with ≥ 1 stroke risk factors. The 2012 focused update guideline also provides additional guidance on advances in stroke and bleeding risk assessment that are evident since publication of the 2010 guideline, as well as recommendations on the use of the novel oral anticoagulants and the left atrial appendage occlusion devices that have been increasingly used in European clinical practice over the last 2 years.