The impact of heart failure and left ventricular dysfunction in predicting stroke, thromboembolism, and mortality in atrial fibrillation patients: a systematic review.

PurposeAtrial 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.MethodsA literature search was performed to identify studies that examined stroke/ SE in relation to AF and HF. Overall, 405 articles satisfied the preinclusion criteria.FindingsIn 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.ImplicationsLV 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.