Does oral anticoagulation reduce stroke and mortality in patients with atrial fibrillation and 1 stroke risk factor (CHA2DS2-VASc score 1 in men, 2 in women)?
This editorial argues that patients with atrial fibrillation and a single additional stroke risk factor (CHA2DS2-VASc 1 in men, 2 in women) derive a net clinical benefit from oral anticoagulation for stroke prevention.
HomeCirculationVol. 133, No. 15Should Patients With Atrial Fibrillation and 1 Stroke Risk Factor (CHA2DS2-VASc Score 1 in Men, 2 in Women) Be Anticoagulated? Free AccessResearch ArticlePDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessResearch ArticlePDF/EPUBShould Patients With Atrial Fibrillation and 1 Stroke Risk Factor (CHA2DS2-VASc Score 1 in Men, 2 in Women) Be Anticoagulated?Yes: Even 1 Stroke Risk Factor Confers a Real Risk of Stroke Gregory Y.H. Lip, MD and Peter Brønnum Nielsen, PhD Gregory Y.H. LipGregory Y.H. Lip From University of Birmingham Institute of Cardiovascular Sciences, City Hospital, UK (G.Y.H.L.); and Aalborg Thrombosis Research Unit, Department of Clinical Medicine, Faculty of Health, Aalborg University, Denmark (G.Y.H.L., P.B.N.). and Peter Brønnum NielsenPeter Brønnum Nielsen From University of Birmingham Institute of Cardiovascular Sciences, City Hospital, UK (G.Y.H.L.); and Aalborg Thrombosis Research Unit, Department of Clinical Medicine, Faculty of Health, Aalborg University, Denmark (G.Y.H.L., P.B.N.). Originally published12 Apr 2016https://doi.org/10.1161/CIRCULATIONAHA.115.016713Circulation. 2016;133:1498–1503Although all clinical scores have modest predictive value for high-risk patients who sustain events, the CHA2DS2-VASc score is clearly superior in identifying low-risk patients with thromboembolism rates 70% should be the goal. We also are aware of common clinical features that influence TTR, and such common factors can be incorporated into the SAMe-TT2R2 score (sex female, age 0.9%/y.Nonetheless, the prescription of OAC is not equally distributed across patients with manifestation of different risk factors included in the CHA2DS2-VASc score. Paradoxically, important drivers of stroke such as increased age and diabetes mellitus have been shown to have a negative association with OAC prescription patterns.33Data from the EuroObservational Research Program-Atrial Fibrillation Pilot General Registry provided a firm answer on outcomes in relation to guideline adherence.34 In this study, guideline-adherent (ie, 2012 European Society of Cardiology updated guideline) OAC treatment was associated with significantly better outcomes in terms of bleeding, thromboembolic events, and all-cause death.What Should Be Our Clinical Approach to Stroke Prevention?To provide contemporary clinical guidance, a recent overview of stroke prevention in AF proposes an algorithm to address 2 questions35: "Will my patient benefit from OAC treatment?" And if the answer is yes, then "What sort of OAC treatment should I offer?"Step 1 is to identify low-risk patients (CHA2DS2-VASc score 0 in men and 1 in women). These patients do not need any antithrombotic therapy. Step 2 is to offer stroke prevention, which is OAC to those with ≥1 additional stroke risk factors (ie, CHA2DS2-VASc ≥1 in men and 2 in women). In Step 2, OAC is recommended for ≥1 stroke risk factors (excluding female sex as a lone risk factor), regardless of the absolute value of the CHA2DS2-VASc score (whether 2, 3, 8, or 9). Step 3 is then to decide on type of OAC, especially if a patient is previously anticoagulation naïve. By assessing the SAMe-TT2R2 score, the treating physician is provided with some guidance on whether a patient will (on probability) be able to obtain a sufficiently high TTR (>65%–70% of the time) when treated with a VKA.36–39 Of note, real-world studies show that good average individual TTR (ie, good-quality anticoagulation control, average TTR >70%) is associated with low stroke and bleeding risks.40,41This approach would avoid a trial of VKA (or warfarin stress test), which may put patients at risk of thromboembolism as a result of poor TTRs in the initial inception phase.42 Those patients with a SAMe-TT2R2 score >2 can be flagged for education and more regular review or follow-up to ensure good anticoagulation control or can be offered an NOAC (Figure 2).Download figureDownload PowerPointFigure 2. Algorithm for risk stratification and optimal selection of antithrombotic treatment. *CHA2DS2-VASc score of 1 in men or 2 in women. AF indicates atrial fibrillation; NOAC, non–vitamin K oral anticoagulation; OAC, oral anticoagulation; and VKA, vitamin K antagonist.The 3 individual steps suggested in this algorithm have been investigated independently with positive results but remain to be investigated in the full form (Figure 2). Although contemporary (European) guidelines recommend the use of NOACs in favor of VKA treatment, it is important to realize that choice of stroke prophylactic drugs is also affected by costs and reimbursement in different parts of the world, and VKA remains widely used.43 Hence, the suggested steps could aid prescribing physicians in recommending optimal treatment choices, acknowledging that the costs and effects of the drugs are different.ConclusionThe risk of stroke in AF is not homogeneous. Risk assessments should be carefully evaluated in each patient, assessing clinical manifestations (also beyond risk factors in scores) and patient values and preferences. Obviously, a 64-year-old female patient with AF and documented hypertension has the same risk of stroke the day she turn 65 as the day before. However, because actual stroke risks vary in an individual patient, researchers should be less obsessed while trying to identify the exact stroke risk.Indeed, stroke risk scores such as CHA2DS2-VASc are designed to be reductionist and simple to facilitate their broad practical use in everyday (and often busy) clinical settings. However, we should understand that a patient who gets 1 point for age of 74 years may be at higher absolute risk than a younger 65-year-old man who gets 1 point for mild, well-treated hypertension. This is not failure of any stroke risk prediction scheme, and it is not necessary for risk scores to identify the exact stroke risk. Rather, stroke risk prediction schemes should provide useful thresholds at which important dichotomous clinical decisions are made, for example, nonuse of antithrombotic therapy (in low-risk patients, ie, men with a CHA2DS2-VASc of 0 and women with a CHA2DS2-VASc of 1) versus anticoagulation for those with ≥1 additional stroke risk factor.Finally, evidence of benefit from OAC treatment exists for reducing stroke and mortality even in the presence of 1 additional stroke risk factor (ie, CHA2DS2-VASc score 1 in men or 2 in women)44; hence, this should trigger the prescribing physician to initiate a conversation with the AF patient about optimal stroke prevention. After all, OAC reduces strokes, thromboembolism, and death in AF, and OAC refers to NOAC or well-managed warfarin (with TTR >70%).We should be less obsessed with identifying the exact stroke risk, which is not possible because the clinical status of a patient with AF (along with associated risk) does not remain static, given the elderly age, multiple comorbidities, and frequent hospitalizations associated with AF. Thus, in most patients with AF with at least 1 additional risk factor for stroke, we should be considering OAC given the elevated risk of AF-related stroke that is more likely to be fatal and disabling compared with non-AF related strokes.DisclosuresDr Lip reports guideline membership/reviewing for various guidelines and position statements from European Society of Cardiology, European Heart Rhythm Association, The National Institute for Health and Care Excellence, etc; serving on steering committees for various phase II and III studies, Health Economics serving as an investigator in various clinical trials in cardiovascular disease, including those on antithrombotic therapies in AF, acute coronary syndrome, lipids, etc; serving as a consultant for Bayer/Janssen, Astellas, Merck, Sanofi, BMS/Pfizer, Biotronik, Medtronic, Portola, Boehringer Ingelheim, Microlife; and Daiichi-Sankyo; and serving as a speaker for Bayer, BMS/Pfizer, Medtronic, Boehringer Ingelheim, Microlife, Roche, and Daiichi-Sankyo. Dr Nielsen has been serving as a speaker for Boehringer Ingelheim.FootnotesThe opinions expressed in this article are not necessarily those of the editors or of the American Heart Association.This article is Part I of a 2-part article. Part II appears on p 1504.Correspondence to Gregory Y.H. Lip, MD, University of Birmingham Institute of Cardiovascular Sciences, City Hospital, Dudley Rd, Birmingham, B18 7QH UK. E-mail email protectedReferences1. Hart RG, Pearce LA, Aguilar MI. Meta-analysis: antithrombotic therapy to prevent stroke in patients who have nonvalvular atrial fibrillation.Ann Intern Med. 2007; 146:857–867.CrossrefMedlineGoogle Scholar2. Huisman MV, Rothman KJ, Paquette M, Teutsch C, Diener HC, Dubner SJ, Halperin JL, Ma C, Zint K, Elsaesser A, Bartels DB, Lip GY; GLORIA-AF Investigators. Antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation: the GLORIA-AF Registry, phase II.Am Med. Stroke Risk in Atrial Fibrillation Working of 12 risk stratification schemes to stroke in patients with nonvalvular atrial the predictive of a from area under the curve to reclassification and Med. Net reclassification for risk prediction a Singer K, A risk scheme to ischemic stroke and other thromboembolism in atrial fibrillation: the study stroke risk Heart Lip Nielsen The value of the European Society of Cardiology guidelines for stroke risk stratification in patients with atrial fibrillation categorized as low risk using the Anticoagulation and Risk Factors in Atrial Fibrillation Stroke a nationwide cohort Lip C, of risk stratification schemes for predicting stroke and thromboembolism in patients with atrial fibrillation: nationwide cohort of net reclassification to measure of Med. on of net reclassification to measure of by and Med. K, A for the net reclassification Net reclassification and a literature review and Intern Med. the net reclassification help and Intern Med. A on the evaluation of do not on integrated discrimination and net reclassification Med. on and statistics with Lip Factors quality of anticoagulation control among patients with atrial fibrillation on the SAMe-TT2R2 Lip the CHA2DS2-VASc score for stroke risk stratification in patients with atrial Lip Nielsen Atrial fibrillation patients categorized as for to the 2014 Cardiovascular Society algorithm are not Nielsen Lip the CHA2DS2-VASc score for stroke prevention in atrial fibrillation: a focus on vascular disease, and simple practical C, Lip The value of the CHA2DS2-VASc score for stroke risk stratification in patients with atrial fibrillation with a CHADS2 score a nationwide cohort Lip C, C, C, A, C, M, A, A, A, C, A, M, 2012 update of the guidelines for the management of atrial fibrillation: an update of the guidelines for the management of atrial fibrillation: with the of the European Heart Rhythm MD, 2014 guideline for the management of patients with atrial fibrillation: a report of the American College of Heart on and the Heart Rhythm risks and the clinical or Med. risks in possibilities and Singer of diagnosed atrial fibrillation in for management and stroke the and Risk Factors in Atrial Fibrillation (ATRIA) Friberg M, Lip Net clinical benefit of warfarin in patients with atrial fibrillation: a report from the Atrial Fibrillation Lip or no therapy in patients with nonvalvular AF with 0 or 1 stroke risk factor based on the CHA2DS2-VASc Friberg M, Benefit of anticoagulation in patients with atrial fibrillation and a CHA2DS2-VASc score of Singer The net clinical benefit of warfarin
Lip et al. (Mon,) studied this question.