title: The impact of heart failure and left ventricular dysfunction in predicting stroke, thromboembolism, and mortality in atrial fibrillation patients: a systematic review.
abstract: OBJECTIVE
  Atrial fibrillation (AF) is commonly associated with structural heart disease. Although heart failure (HF) has been proposed as a risk factor for stroke, the coexistence of the 2 diseases increases disproportionally the risk of thromboembolic events. Our objective was to conduct a systematic review to assess the effect of HF on the end points of stroke, systemic embolism (SE), or mortality in patients with AF.
  
  
  METHODS
  A literature search was performed to identify studies that examined stroke/ SE in relation to AF and HF. Overall, 405 articles satisfied the preinclusion criteria.
  
  
  RESULTS
  In studies in which HF was based on a clinical diagnosis, HF independently increased stroke/SE in 5 of 13 studies, conferring 1.6- to 3.1-fold increase in risk. When HF was defined as impaired left ventricular (LV) function on echocardiography, the additive risk was evident in 4 of 6 studies, with 1.7- to 2.6-fold increase in the risk of stroke/SE. The data about HF with preserved ejection fraction were less robust, although a recent presentation with acute decompensated HF increased the risk of stroke/SE, irrespective of ejection fraction.
  
  
  CONCLUSIONS
  LV systolic impairment as identified by echocardiography is an independent risk factor for stroke/SE, although the magnitude by which it increases the risk of stroke cannot be precisely quantified. Whether a clinical diagnosis of HF is a significant risk factor remains inconclusive, although when the diagnosis is certain (recent decompensation requiring hospitalization), it does seem to be a significant risk factor irrespective of LV systolic function.
authors.affiliation: University of Birmingham Centre for Cardiovascular Sciences, City Hospital, Birmingham, United Kingdom.
authors.forename: Megha
authors.initials: M
authors.lastname: Agarwal
authors.affiliation: University of Birmingham Centre for Cardiovascular Sciences, City Hospital, Birmingham, United Kingdom.
authors.forename: Stavros
authors.initials: S
authors.lastname: Apostolakis
authors.affiliation: University of Birmingham Centre for Cardiovascular Sciences, City Hospital, Birmingham, United Kingdom.
authors.forename: Deirdre A
authors.initials: DA
authors.lastname: Lane
authors.affiliation: University of Birmingham Centre for Cardiovascular Sciences, City Hospital, Birmingham, United Kingdom. Electronic address: g.y.h.lip@bham.ac.uk.
authors.forename: Gregory Y H
authors.initials: GY
authors.lastname: Lip
mesh_terms: D001281:Atrial Fibrillation / Q000150:complications* / Q000401:mortality*; D004452:Echocardiography; D006333:Heart Failure / Q000150:complications* / Q000000981:diagnostic imaging; D006801:Humans; D012307:Risk Factors; D020521:Stroke / Q000453:epidemiology / Q000209:etiology*; D013318:Stroke Volume; D013923:Thromboembolism / Q000453:epidemiology / Q000209:etiology*; D018487:Ventricular Dysfunction, Left / Q000150:complications* / Q000000981:diagnostic imaging
keywords: atrial fibrillation; cardiac failure; risk factors; stroke; thromboembolism