CHA2DS2-VASc score use in sinus rhythm: Can it predict cardiovascular events?

The CHA2DS2-VASc score has been developed to stratify patients with atrial fibrillation with regard to risk of thromboembolism, and is a universally accepted guide to antithrombotic therapy in patients with atrial fibrillation.1 However, higher scores have also been recently associated with increased mortality in patients with atrial fibrillation2 and recent studies have investigated this association further in patients without atrial fibrillation. Such small studies in patients without atrial fibrillation determined that an increased CHA2DS2-VASc score was associated with increased risk of stroke and thromboembolism3 as well increased risk of developing new atrial fibrillation in patients with4 and without prior ischaemic stroke.5 In this issue of the journal Renda et al. present a large study of 22,179 middle-aged individuals with 18,367 in sinus rhythm.6 The main purpose of the study was to assess the prognostic yield of CHA2DS2-VASc score in the non-atrial fibrillation population for new onset atrial fibrillation, cardiovascular morbidity and mortality. The authors should be congratulated for a well-designed and executed study which provides the largest study to date assessing the role of CHA2DS2-VASc score as a risk factor for new atrial fibrillation. The participants were stratified according to their CHA2DS2-VASc score into five different groups (0, 1, 2, 3 and ≥4) and the risk of major adverse cardiovascular events was compared between the different groups. Over a 15-year follow up period in the participants with sinus rhythm; they identified 5% with an ischaemic stroke, 9% with coronary events, 7% cardiovascular mortality and 24% all cause mortality. A CHA2DS2-VASc ≥ 2 was associated with double the risk of all cause mortality, cardiovascular death and ischaemic stroke. Cumulative incidences, absolute and relative risks of major adverse events and mortality were greater with increasing CHA2DS2-VASc score in subjects with and, importantly, without atrial fibrillation. Moreover, the incidence of atrial fibrillation during the follow-up period was 14% and was more common with higher CHA2DS2VASc score. More importantly they found that CHA2DS2-VASc ≥ 2 was an independent predictor for new onset atrial fibrillation, with a hazard ratio of 2.2. Furthermore, a novel and clinically relevant finding was that the incidence of ischaemic stroke was similar in patients with a CHA2DS2-VASc ≥ 4 in sinus rhythm and patients with a CHA2DS2-VASc = 2 in atrial fibrillation. This is an important finding as it could further help sub-categorise patients with embolic stroke of undetermined source (ESUS) who could potentially benefit from anticoagulation. In conclusion, this large study confirms the predictive role of CHA2DS2-VASc score for new onset atrial fibrillation in a population based on a large prospective cohort over several years of follow-up and also identifies that cumulative incidence of atrial fibrillation is greater with increasing CHA2DS2-VASc strata. Whilst this is not surprising as most of the risk factors for atrial fibrillation7 are constituents of the CHA2DS2-VASc score, it is the first large study to support this. Finally, although recently published data showed that anticoagulating patients with ESUS and sinus rhythm was not superior to antiplatelet therapy in preventing stoke recurrence8 the current study by Renda et al.6 would support that in future such studies should be directed towards patients at higher risk of showing atrial fibrillation, and the CHA2DS2-VASc score could be such a discriminating variable. The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. The author(s) received no financial support for the research, authorship, and/or publication of this article.