• heart failure
• stroke

Approximately 2%–3% of patients with heart failure (HF) will sustain a stroke; an outcome considered by many to be worse than death.1 Not only are these events twofold to threefold more common in patients with HF, over half of the strokes are life-threatening or severely disabling2 and compared with the general population are associated with longer hospital stays and higher rates of mortality.3 Although atrial fibrillation (AF) and HF are linked and frequently coexist, HF has been increasingly recognised as an independent predictor of ischaemic stroke after adjusting for the presence of AF.4 There is biological plausibility with multiple lines of evidence linking HF to a prothrombotic state characterised by perturbations in all components of Virchow’s triad. Despite this translational understanding, considerably less is known about the stroke risk profile of patients with HF in sinus rhythm when compared with the detailed phenotyping of stroke risk of patients with both AF and HF.

Chou et al in their Heart paper provide important, additional insight into the burden of stroke and myocardial infarction (MI) that arise in the context of HF without AF.5 The authors studied administrative data from a random sampling of 1 000 000 beneficiaries covered under the Taiwan National Health Insurance Database (99% of the population ~23 million people). International Classification of Disease, Ninth Revision (ICD-9) codes were used to identify a cohort with newly diagnosed systolic HF and to exclude those with a prior history of stroke or MI. Those with diagnosis codes for AF or flutter at baseline or during follow-up were also excluded leaving a HF cohort of 12 179 individuals. A comparator non-HF cohort was propensity matched 1:1 by age, sex, monthly income, urbanisation and selected comorbidities. Over a collective follow-up period of approximately 150 000 person years, there were 1766 ischaemic strokes, 387 …