CHA2DS2–VASc score explained

CHA2DS2–VASc score
Purpose:risk of stroke (for non-rheumatic atrial fibrillation)

The CHADS2 score and its updated version, the CHA2DS2-VASc score, are clinical prediction rules for estimating the risk of stroke in people with non-rheumatic atrial fibrillation (AF), a common and serious heart arrhythmia associated with thromboembolic stroke. Such a score is used to determine whether or not treatment is required with anticoagulation therapy or antiplatelet therapy,[1] since AF can cause stasis of blood in the upper heart chambers, leading to the formation of a mural thrombus that can dislodge into the blood flow, reach the brain, cut off supply to the brain, and cause a stroke.

A high score corresponds to a greater risk of stroke, while a low score corresponds to a lower risk of stroke. The CHADS2 score is simple and has been validated by many studies.[2] In clinical use, the CHADS2 score (pronounced "chads two") has been superseded by the CHA2DS2-VASc score ("chads vasc"[3]), which gives a better stratification of low-risk patients.

Use

The CHA2DS2-VASc score is a widely used medical tool used to guide physicians on blood thinning treatment to prevent stroke in people with non-valvular atrial fibrillation (AF).[4] [5]

CHADS2

The CHADS2 score does not include some common stroke risk factors, and its various pros/cons have been carefully discussed.[6] Adding together the points that correspond to the conditions that are present results in the CHADS2 score, that is used to estimate stroke risk.

CHADS2[7]
ConditionPoints
 C  Congestive heart failure1
 H Hypertension: blood pressure consistently above 140/90 mmHg (or treated hypertension on medication)1
 A Age ≥75 years1
 D Diabetes mellitus1
 S22
Annual stroke risk (%)
CHADS2 ScoreRisk95% CI
01.9 1.2 - 3.0
12.8 2.0 - 3.8
24.0 3.1 - 5.1
35.9 4.6 - 7.3
48.5 6.3 - 11.1
512.5 8.2 - 17.5
618.210.5 - 27.4

CHA2DS2-VASc

To complement the CHADS2 score, by the inclusion of additional 'stroke risk modifier' risk factors, the CHA2DS2-VASc-score has been proposed.[8]

In clinical use, the CHADS2 score has been superseded by the CHA2DS2-VASc score, which gives a better stratification of low-risk patients. The CHADS2 score has been outperformed by the CHA2DS2-VASc in multiple patient groups including patients with AF who are receiving outpatient elective electrical cardioversion.[9]

CHA2DS2-VASc
ConditionPoints
 C  Congestive heart failure (or Left ventricular systolic dysfunction)1
 H Hypertension: blood pressure consistently above 140/90 mmHg (or treated hypertension on medication)1
 A2 Age ≥75 years2
 D Diabetes Mellitus1
 S22
 V Vascular disease (e.g. peripheral artery disease, myocardial infarction, aortic plaque)1
 A Age 65 - 74 years1
 Sc Sex category (i.e. female sex)1
Thus, the CHA2DS2-VASc score is a refinement of CHADS2[10] score and extends the latter by including additional common stroke risk factors, that is, age 65–74, female gender and vascular disease.[11] In the CHA2DS2-VASc score, 'age 75 and above' also has extra weight, with 2 points.

The maximum CHADS2 score is 6, whilst the maximum CHA2DS2-VASc score is 9 (not 10, as might be expected from simply adding up the columns; the maximum score for age is 2 points).

Annual stroke risk (%)
CHA2DS2-VASc scoreFriberg 2012[12] Lip 201095% CI
0 0.2 0.0 0.0 - 0.0
1 0.6 0.6 0.0 - 3.4
2 2.2 1.6 0.3 - 4.7
3 3.2 3.9 1.7 - 7.6
4 4.8 1.9 0.5 - 4.9
5 7.2 3.2 0.7 - 9.0
6 9.7 3.60.4 - 12.3
711.2 8.01.0 - 26.0
810.811.10.3 - 48.3
912.2100 2.5 - 100

Major guidelines have used the above fixed annual stroke risk as a guideline of starting anticoagulant treatment; where the ischemic stroke risk of more than 1% to 2% should be an indication to start an anticoagulant therapy. However, actual risk of getting stroke varies according to sampling method and geographical regions, as well as use of appropriate study analysis methodology.[13] A meta-analysis of various studies in 2015 shown that annual stroke risk is less than 1% in 13 of the 17 studies for CHA2DS2-VASc score of 1, 6 out of 15 studies reported risk of 1 to 2% and 5 out of 15 studies reported risk of more than 2% for CHA2DS2-VASc score of 2.[14] Nevertheless, stroke rates vary by study setting (hospital vs community), population (trial vs general), ethnicity, etc. Some studies included in the metaanalysis include females with score 1 by virtue of gender (who are low risk), into the aggregate rates; others included do not account for followup anticoagulation use (thus lowering rates) and were analysed by excluding all patients ever started on anticoagulants ('conditioning on the future' error).[15]

The CHA2DS2-VASc Score has shown increasing popularity over time while the CHADS2 has shown decreasing popularity,[16] which could "partly be related to introduction of guidelines recommending the use of the CHA2DS2-VASc score for stroke risk stratification". The predictive abilities of risk scores for ischemic stroke in patients with kidney function impairment is questionable: a large head-to-head external validation study demonstrated poor discrimination and calibration in patients with reduced kidney function.[17]

Treatment recommendations

The CHA2DS2-VASc score has been used in the 2012 and subsequent European Society of Cardiology guidelines for the management of atrial fibrillation.[18] [19] [20] The 2014 American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society guidelines also recommend use of the CHA2DS2-VASc score.[21]

The European Society of Cardiology (ESC),[22] and National Institute for Health and Care Excellence (NICE)[23] guidelines recommend that if the patient has a CHA2DS2-VASc score of 2 and above, oral anticoagulation therapy (OAC) with a vitamin K antagonist (VKA, e.g. warfarin with target INR of 2-3) or one of the direct oral anticoagulant drugs (DOACs, e.g. dabigatran, rivaroxaban, edoxaban, or apixaban) is recommended.

If the patient is 'low risk' using the CHA2DS2-VASc score (that is, 0 in males or 1 in females), no anticoagulant therapy is recommended.

In males with 1 stroke risk factor (that is, a CHA2DS2-VASc score=1), antithrombotic therapy with OAC may be considered, and people's values and preferences should be considered.[24] Even a single stroke risk factor confers excess risk of stroke and mortality, with a positive net clinical benefit for stroke prevention with oral anticoagulation, when compared to no treatment or aspirin.[25] As mentioned above, thromboembolic event rates differ according to various guideline treatment thresholds and methodological approaches.[26]

Anticoagulation

Treatment recommendations based on the CHA2DS2-VASc score are shown in the following table:

ScoreRisk Anticoagulation TherapyConsiderations[27]
0 (male) or 1 (female)LowNo anticoagulant therapy No anticoagulant therapy
1 (male)ModerateOral anticoagulant should be consideredOral anticoagulant, with well controlled vitamin K antagonist (VKA, e.g. warfarin with time in therapeutic range >70%), or a direct oral anticoagulant (DOAC, e.g. dabigatran, rivaroxaban, edoxaban or apixaban)
2 or greaterHigh Oral anticoagulant is recommendedOral anticoagulant, with well controlled vitamin K antagonist (VKA, e.g. warfarin with time in therapeutic range >70%), or a direct oral anticoagulant (DOAC, e.g. dabigatran, rivaroxaban, edoxaban or apixaban)
Based on the ESC guidelines on AF, oral anticoagulation is recommended or preferred for people with one or more stroke risk factors (i.e. a CHA2DS2-VASc score of ≥1 in males, or ≥2 in females).[28] [29] This is consistent with a recent decision analysis model showing how the 'tipping point' on the decision to anticoagulate has changed with the availability of the 'safer' DOAC drugs, where the threshold for offering stroke prevention (i.e. oral anticoagulation) is a stroke rate of approximately 1%/year.[30]

Those patients recommended for stroke prevention treatment via oral anticoagulation, choice of drug (i.e. between a vitamin K antagonist and direct oral anticoagulant (DOAC)) can be evaluated using the SAMe-TT2R2 score to help decision-making on the most appropriate oral anticoagulant.[31] [32]

Bleeding risk

See main article: HAS-BLED. Stroke risk assessment should always include an assessment of bleeding risk. This can be done using validated bleeding risk scores, such as the HEMORR2HAGES or HAS-BLED scores.[33] The HAS-BLED score is recommended in guidelines, to identify the high risk patient for regular review and followup and to address the reversible risk factors for bleeding (e.g. uncontrolled hypertension, labile INRS, excess alcohol use or concomitant aspirin/NSAID use).[27] If the patient is taking warfarin, then knowledge of INR control is needed to assess the 'labile INR' criterion in HAS-BLED; otherwise for a non-warfarin patient, this criterion scores zero. A high HAS-BLED score is not a reason to withhold anticoagulation. Also, when compared to HAS-BLED, other bleeding risk scores that did not consider 'labile INR' would significantly underperform in predicting bleeding on warfarin, and would often inappropriately categorise many patients who sustained bleeds as 'low risk'.[34]

History

The CHA2DS2-VASc score expanded from the CHADS2 score, first published in 2001.[35]

External links

Notes and References

  1. Selecting patients with atrial fibrillation for anticoagulation: stroke risk stratification in patients taking aspirin . Circulation . 2004 . 110 . 16 . 2287 - 92 . Gage BF, van Walraven C, Pearce L . 15477396 . 10.1161/01.CIR.0000145172.55640.93 . etal. free .
  2. Gage BF, Waterman AD, Shannon W, Boechler M, Rich MW, Radford MJ . Validation of clinical classification schemes for predicting stroke: results from the National Registry of Atrial Fibrillation . JAMA . 285 . 22 . 2864–70 . 2001 . 11401607 . 10.1001/jama.285.22.2864. free .
  3. http://www.stopafib.org/newsitem.cfm/NEWSID/369/Professor%20Gregory%20Y.H.%20Lip/CHA2DS2-VASc%20for%20atrial%20fibrillation%20stroke%20prevention Professor Gregory Lip Discusses CHA2DS2-VASc Tool for Predicting Stroke Risk in Atrial Fibrillation
  4. Siddiqi . Tariq Jamal . Usman . Muhammad Shariq . Shahid . Izza . Ahmed . Jawad . Khan . Safi U. . Ya'qoub . Lina . Rihal . Charanjit S. . Alkhouli . Mohamad . Utility of the CHA2DS2-VASc score for predicting ischaemic stroke in patients with or without atrial fibrillation: a systematic review and meta-analysis . European Journal of Preventive Cardiology . 9 March 2021 . 29 . 4 . 625–631 . 10.1093/eurjpc/zwab018 . 33693717 . 2047-4881. free .
  5. Book: Kiser . Kathryn . Oral Anticoagulation Therapy: Cases and Clinical Correlation . 2017 . Springer . 9783319546438 . 20 . en.
  6. Karthikeyan G, Eikelboom JW. The CHADS2 score for stroke risk stratification in atrial fibrillation--friend or foe? Thromb. Haemost. 2010 Jul 5;104(1):45-8.
  7. Web site: Risk of Stroke with AF . 2007-09-14 . VA Palo Alto Medical Center and at Stanford University: the Sportsmedicine Program and the Cardiomyopathy Clinic . 2019-02-22 . https://web.archive.org/web/20190222174929/http://www.cardiology.org/tools/risk_of_stroke_AF.html . dead .
  8. Lip GY, Nieuwlaat R, Pisters R, Lane DA, Crijns HJ . Feb 2010 . Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the euro heart survey on atrial fibrillation . Chest . 137 . 2. 263–72 . 10.1378/chest.09-1584 . 19762550.
  9. Yarmohammadi H, Varr BC, Puwanant S, Lieber E, Williams SJ, Klostermann T, Jasper SE, Whitman C, Klein AL . Role of CHADS2 score in evaluation of thromboembolic risk and mortality in patients with atrial fibrillation undergoing direct current cardioversion (from the ACUTE Trial Substudy). . Am J Cardiol . 2012 . 110 . 2. 222–26. 10.1016/j.amjcard.2012.03.017. 22503581.
  10. Sandhu. R. K.. Bakal. J. A.. Ezekowitz. J. A.. McAlister. F. A.. Risk stratification schemes, anticoagulation use and outcomes: the risk-treatment paradox in patients with newly diagnosed non-valvular atrial fibrillation. Heart. 10 November 2011. 97. 24. 2046–50. 10.1136/heartjnl-2011-300901. free. 22076011. 12 February 2017.
  11. Web site: UCSF Cardiology Atrial Fibrillation Medical Management. cardiology.ucsf.edu. 12 February 2017. https://web.archive.org/web/20160729005615/https://cardiology.ucsf.edu/care/clinical/electro/fib-management.html. 29 July 2016. dead.
  12. Friberg . Leif . Rosenqvist . Mårten . Lip . Gregory YH . Evaluation of risk stratification schemes for ischaemic stroke and bleeding in 182 678 patients with atrial fibrillation: the Swedish Atrial Fibrillation cohort study . 13 January 2012 . Table 2 . European Heart Journal . 33 . 12 . 8 October 2020 . 10.1093/eurheartj/ehr488. 22246443 . free .
  13. Nielsen. Peter B. Stroke and thromboembolic event rates in atrial fibrillation according to different guideline treatment thresholds: A nationwide cohort study.. Scientific Reports. 2016. 6. 27410. 10.1038/srep27410. 27265586. 4893655. 2016NatSR...627410N.
  14. Gene R. Quinn. Olivia. N Severdija. Yuchiao. Chang. Daniel. E Singer. Wide Variation in Reported Rates of Stroke Across Cohorts of Patients with Atrial Fibrillation. Circulation. 31 October 2016. 135. 3. 208–19. 10.1161/CIRCULATIONAHA.116.024057. 27799272. 207608289. free.
  15. Nielsen. P. Lip. G. 2017 . Adding Rigor to Stroke Rate Investigations in Patients With Atrial Fibrillation.. Circulation. 135. 3. 220–223. 10.1161/CIRCULATIONAHA.116.025944. 28093493. 37525194. free.
  16. Lip . GY . Habboushe . J . Altman . C . Time trends in use of the CHADS2 and CHA2DS2-VASc scores, and the geographical and specialty uptake of these scores from a popular online clinical decision tool and medical reference . International Journal of Clinical Practice . 73 . 2 . 2019 . e13280 . 10.1111/ijcp.13280 . 30281876 . 52916514 .
  17. de Jong. Ype. Fu. Edouard L. van Diepen. Merel. Trevisan. Marco. Szummer. Karolina. Dekker. Friedo W. Carrero. Juan J. Gurbey. Ocak. Validation of risk scores for ischaemic stroke in atrial fibrillation across the spectrum of kidney function. European Heart Journal. 2021. 42. 15. 1476–1485. 10.1093/eurheartj/ehab059. 33769473. 8046502.
  18. Camm AJ, Lip GY, De Caterina R, Savelieva I, Atar D, Hohnloser SH, Hindricks G, Kirchhof P . Oct 2012 . 2012 focused update of the ESC Guidelines for the management of atrial fibrillation: an update of the 2010 ESC Guidelines for the management of atrial fibrillation--developed with the special contribution of the European Heart Rhythm Association . Europace . 14 . 10. 1385–413 . 10.1093/europace/eus305 . 22923145 . free .
  19. Camm . A. J. . Kirchhof . P. . Lip . G. Y. H. . Schotten . U. . Savelieva . I. . Ernst . S. . Van Gelder . I. C. . Al-Attar . N. . Hindricks . G. . 29 . Oct 2010 . Guidelines for the management of atrial fibrillation: the Task Force for the Management of Atrial Fibrillation of the European Society of Cardiology (ESC) . Eur Heart J . 31 . 19 . 2369–429 . 10.1093/eurheartj/ehq278 . 20802247 . Prendergast . B. . Heidbuchel . H. . Alfieri . O. . Angelini . A. . Atar . D. . Colonna . P. . De Caterina . R. . De Sutter . J. . Goette . A. . Gorenek . B. . Heldal . M. . Hohloser . S. H. . Kolh . P. . Le Heuzey . J.-Y. . Ponikowski . P. . Rutten . F. H. . Vahanian . A. . Auricchio . A. . Bax . J. . Ceconi . C. . Dean . V.. free .
  20. Kirchhof. Paulus. Benussi. Stefano. Kotecha. Dipak. Ahlsson. Anders. Atar. Dan. Casadei. Barbara. Castella. Manuel. Diener. Hans-Christoph. Heidbuchel. Hein. Hendriks. Jeroen. Hindricks. Gerhard. 7 October 2016. 2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS. European Heart Journal. 37. 38. 2893–2962. 10.1093/eurheartj/ehw210. 27567408. 12 February 2017. free. Panagiotis. Sanjay. Clare J.. Taylor. Juan Luis. Tamargo. Piotr. Suwalski. Sharma. Isabelle C.. Irina. Savelieva. Frank. Ruschitzka. Raphael. Rosenhek. Piotr. Van Gelder. Voors. John. Ulrich. Manolis. Antonis S.. Oldgren. Jonas. Popescu. Bogdan Alexandru. Schotten. Van Putte. Adriaan A.. Bart. Katja. Zeppenfeld. Jose Luis. Zamorano. Stephan. Windecker. Ponikowski. McMurray. Agewall. Scipione. Deftereos. Raffaele. De Caterina. Antonio. Coca. Filip. Casselman. Carerj. Dobrev. Werner. Budts. Gonzalo. Baron Esquivias. John. Camm. Stefan. Spiridon. Dobromir. Athanasios. Maxine. Manolis. Gregory Y. H.. Lip. Philippe. Kolh. Stefan H.. Hohnloser. Guenoun. Ferro. Bulent. Gorenek. Donna. Fitzsimons. Gerasimos. Filippatos. Vardas. José M..
  21. January CT, Wann LS, Alpert JS, Calkins H, Cigarroa JE, Cleveland JC Jr, Conti JB, Ellinor PT, Ezekowitz MD, Field ME, Murray KT, Sacco RL, Stevenson WG, Tchou PJ, Tracy CM, Yancy CW . Dec 2014 . 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society . 24685669 . J Am Coll Cardiol . 64 . 21. e1–76 . 10.1016/j.jacc.2014.03.022. free .
  22. Hindricks. Gerhard. Potpara. Tatjana. Dagres. Nikolaos. Arbelo. Elena. Bax. Jeroen J.. Blomström-Lundqvist. Carina. Boriani. Giuseppe. Castella. Manuel. Dan. Gheorghe-Andrei. Dilaveris. Polychronis E.. Fauchier. Laurent. 2020-08-29. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association of Cardio-Thoracic Surgery (EACTS). European Heart Journal. 42. 5. 373–498. 10.1093/eurheartj/ehaa612. 1522-9645. 32860505. free. 11379/546100. free.
  23. Web site: Atrial fibrillation: management Guidance and guidelines NICE. www.nice.org.uk. 12 February 2017. June 2014.
  24. Joundi. RA. Cipriano. LE. Sposato. LA. Saposnik. G. Stroke Outcomes Research Working. Group. Ischemic Stroke Risk in Patients With Atrial Fibrillation and CHA2DS2-VASc Score of 1: Systematic Review and Meta-Analysis.. Stroke: A Journal of Cerebral Circulation. May 2016. 47. 5. 1364–7. 27026630. 10.1161/strokeaha.115.012609. 3692570. free.
  25. Fauchier . L . Clementy . N . Bisson . A . Ivanes . F . Angoulvant . D . Babuty . D . Should Atrial Fibrillation Patients With Only 1 Nongender-Related CHA2DS2-VASc Risk Factor Be Anticoagulated? . Stroke . 2016 . 10.1161/STROKEAHA.116.013253 . 27231269 . 47 . 7 . 1831–6. 3666736 . free .
  26. Nielsen P . Larsen TB . Skjøth F. et al . 2016 . Stroke and thromboembolic event rates in atrial fibrillation according to different guideline treatment thresholds: A nationwide cohort study . Sci Rep . 6 . 27410 . 10.1038/srep27410 . 27265586 . 4893655 . 2016NatSR...627410N .
  27. Web site: (UK) . National Clinical Guideline Centre . Atrial Fibrillation . National Institute for Health and Care Excellence (UK) . 2023-10-31 . 25340239 . 2024-07-02.
  28. Lip GY, Lane DA . 2015 . Stroke prevention in atrial fibrillation: a systematic review . JAMA . 313 . 19. 1950–62 . 10.1001/jama.2015.4369 . 25988464.
  29. Sulzgruber . Patrick . Doehner . Wolfram . Niessner . Alexander . Valvular atrial fibrillation and a CHA2DS2-VASc score of 1-a statement of the ESC working group on cardiovascular pharmacotherapy and ESC council on stroke . European Heart Journal . 1 February 2021 . 42 . 5 . 541–543 . 10.1093/eurheartj/ehaa1081 . 33496325 . 1522-9645. free .
  30. Eckman MH, Singer DE, Rosand J, Greenberg SM . Jan 2011 . Moving the tipping point: the decision to anticoagulate patients with atrial fibrillation . Circ Cardiovasc Qual Outcomes . 4 . 1. 14–21 . 10.1161/circoutcomes.110.958108. 21139092 . 3058150.
  31. Apostolakis S, Sullivan RM, Olshansky B, Lip GY . Nov 2013 . Factors affecting quality of anticoagulation control among patients with atrial fibrillation on warfarin: the SAMe-TT₂R₂ score . 10.1378/chest.13-0054 . 23669885 . Chest . 144 . 5. 1555–63 .
  32. Proietti. Marco. Lip. Gregory Y.H.. Simple decision-making between a vitamin K antagonist and a non-vitamin K antagonist oral anticoagulant: using the SAMe-TT2R2 score. European Heart Journal - Cardiovascular Pharmacotherapy. July 2015. 1. 3. 150–152. 10.1093/ehjcvp/pvv012. free. 27533987. 2434/747445. free.
  33. Stroke Prevention in Patients With Atrial Fibrillation: A Systematic Review Update . Sanders . Gillian D. . Lowenstern . Angela . 2018-10-30 . Agency for Healthcare Resarch and Quality (AHRQ) . 10.23970/ahrqepccer214 . Borre . Ethan . Chatterjee . Ranee . Goode . Adam . Sharan . Lauren . LaPointe . Nancy M. Allen . Raitz . Giselle . Shah . Bimal.
  34. Proietti . Marco . Senoo . Keitaro . Lane . Deirdre A. . Lip . Gregory Y. H. . Apr 2016 . Major Bleeding in Patients with Non-Valvular Atrial Fibrillation: Impact of Time in Therapeutic Range on Contemporary Bleeding Risk Scores . Sci. Rep. . 6 . 24376 . 10.1038/srep24376 . 4828703 . 27067661. 2016NatSR...624376P .
  35. Web site: Ajam . Tarek . CHADS2 Score for Stroke Risk Assessment in Atrial Fibrillation: CHADS2 and CHA2DS2-VASc Score for Stroke Risk Assessment in Atrial Fibrillation . emedicine.medscape.com . 11 April 2021 . https://web.archive.org/web/20210125062332/https://emedicine.medscape.com/article/2172597-overview . 25 January 2021 . 27 February 2020.