1. Atrial Fibrillation and Cryptogenic Stroke: Is There a Link?
Rhea C. Pimentel, MD
Associate Professor of Medicine
Fellowship Program Director, Clinical Cardiac Electrophysiology Program

2. Disclosures Speakers Bureau: Medtronic
Speakers Bureau: St. Jude Medical
Speakers Bureau: Janssen Pharmaceuticals
Speakers Bureau: Boston Scientific

3. Talk Outline Epidemiology of atrial fibrillation and stroke
Management of thromboembolic risk
Outpatient monitoring considerations
Stroke risk based on atrial fibrillation burden

4. Epidemiology of Atrial Fibrillation and Stroke

5. Epidemiology of Atrial Fibrillation in the US: Rising Prevalence of the Disease
As of 2010, 2.66 million Americans are estimated to have AF1
Lifetime risk for developing AF is high2
1 in 4 for men and women aged 40 years
Prevalence increases rapidly with age3
3.8% for persons 60 years old
9% for persons 80 years old
AF prevalence is predicted to increase by 2.5 fold by 2050
Predicted Prevalence of AF1 1 2 3 4 5 6 7
1990
1995
2000
2005
2010
2015
2020
2025
2030
2035
2040
2045
2050
Year
Adults with AF (millions)
15.9 16
15.2
14.3
2.08
2.44
2.26
2.66
2.94
3.33
3.80
4.34
4.78
5.16
5.42
5.61 14
13.1
11.7
10.2
12.1
8.9
11.7
11.1
7.7
10.3
6.7
9.4
5.9
8.4
5.1
7.5
6.8
5.6
6.1
5.1
2000
Epidemiology of Atrial Fibrillation in the US: Rising Prevalence of the Disease
As of 2010, 2.66 million Americans are estimated to have atrial fibrillation (AF)1
Lifetime risk for developing AF is high: 1 in every 4 men and 1 in every 4 women aged 40 years will develop AF in their lifetime; thus, both men and women have the same lifetime risk2
The prevalence of AF is increasing, as shown in the graph3
Furthermore, prevalence increases rapidly with age:
3.8% of persons aged 60 years have AF, whereas 9% of persons aged 80 years have the disease4
In other words, AF affects 1 in 25 adults aged >60 years, and 1 in 10 adults aged >80 years4
The rising prevalence may be due to several reasons, including
The aging population4
An increase of predisposing factors for AF (hypertension and diabetes)5
Improved methods of detection
An increasing rate of cardiac surgical procedures
Improved survival with concomitant cardiovascular conditions (myocardial infarction and congestive heart failure)
References
Lloyd-Jones DM, Adams RJ, Brown TM, et al. Heart disease and stroke statistics—2010 update. A report from the American Heart Association. Circulation. 2010;121:e1-e170.
Lloyd-Jones DM, Wang TJ, Leip EP, et al. Lifetime risk for development of atrial fibrillation: the Framingham Heart Study. Circulation. 2004;110:
Miyasaka Y, Barnes ME, Gersh BJ, et al. Secular trends in incidence of atrial fibrillation in Olmsted County, Minnesota, 1980 to 2000, and implications on the projections for future prevalence. Circulation. 2006;114:
Go AS, Hylek EM, Phillips KA, et al. Prevalence of diagnosed atrial fibrillation in adults. National implications for rhythm management and stroke prevention: the AnTicoagulation and Risk Factors in Atrial Fibrillation (ATRIA) study. JAMA. 2001;285:
Naccarelli GV, Varker H, Lin J, Schulman KL. Increasing prevalence of atrial fibrillation and flutter in the United States. Am J Cardiol. 2009;104:
Year
AF affects 1 in 25 adults aged >60 years and 1 in 10 adults >80 years3
Lloyd-Jones DM et al. Circulation. 2010;121:e1-e170.
2. Lloyd-Jones DM et al. Circulation. 2004;110:
3. Go AS et al. JAMA. 2001;285:
Go AS. et al. JAMA 2001;285:

6. Independent Risk Factors for Atrial Fibrillation
Independent Risk Factors for Atrial Fibrillation* Framingham Heart Study
Men† (N=2090)
Women‡ (N=2641)
P0.0001
P0.05
P0.01
Independent Risk Factors for Atrial Fibrillation Framingham Heart Study
95% CI
Men
Women
*2-Year pooled logistic regression; †AF was diagnosed in 226 men in 16,529 follow-up person-examinations; ‡AF was diagnosed in 244 women in 23,763 follow-up person-examinations; §Valvular heart disease was a significantly more potent risk factor for the development of atrial fibrillation in women than in men.
DM = diabetes mellitus; HTN = hypertension; MI = myocardial infarction; CHF = congestive heart failure.
Benjamin EJ et al. JAMA. 1994;271:

7. Economic Impact and Public Health Burden of Hospitalizations in Those With Atrial Fibrillation
Significant public health burden; total AF-attributable costs estimated at 6.65 billion1-5
Annual cost per patient ~$47005
Associated with more hospitalizations than any other arrhythmia6
Approximately one third for cardiac rhythm disturbances1
Increased hospitalizations impact quality of life and health care costs2,7
Economic Impact and Public Health Burden of Hospitalizations in Those With Atrial Fibrillation
Atrial fibrillation (AF) represents a significant public health burden.1,2 It is the most common arrhythmia in clinical practice and accounts for approximately one-third of hospitalizations for cardiac rhythm disturbances2
Furthermore, hospitalizations for AF have increased substantially (2- to 3-fold).4 The Cost of Care in Atrial Fibrillation (COCAF) study was a prospective survey designed to evaluate the cost of care for patients with AF (N=671) who were treated by cardiologists in an outpatient setting. The costs of care were analyzed from the health care payer and societal perspectives. Compared with patients with paroxysmal AF, those with persistent or permanent AF were hospitalized much more frequently (P<0.05). Additionally, hospitalizations and pharmacotherapy accounted for the majority of costs (52% and 23%, respectively)3
In conclusion, the adverse trend toward hospitalization among an aging population combined with the prevalence of heart failure sets the stage for an enormous burden on the health care system4
References
Fuster V, Ryden LE, Cannon DS, et al. ACC/AHA/ESC 2006 Guidelines 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 European Society of Cardiology Committee for Practice Guidelines (writing committee to revise the 2001 guidelines for the management of patients with atrial fibrillation): developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society. Circulation. 2006;114:e257-e354.
LeHuezey J-Y, Paziaud D, Piot O, et al. Cost of care distribution in atrial fibrillation patients: the COCAF study. Am Heart J. 2004;147:
Singh SN, Tang XC, Singh BN, et al. Quality of life and exercise performance in patients in sinus rhythm versus persistent atrial fibrillation. J Am Coll Cardiol. 2006;48:
Wattigney WA, Mensah GA, Croft JB. Increasing trends in hospitalization for atrial fibrillation in the United States, 1985 through 1999: implications for primary prevention. Circulation. 2003;108:
1. Fuster V et al. Circulation. 2006;114:e257-e Le Heuzey J-Y et al. Am Heart J. 2004;147: Coyne KS et al. Value Health. 2006;9: Kim MH et al. Adv Ther. 2009;26: Reynolds MR et al. J Cardiovasc Electrophysiol. 2007;18: Singh SN et al. J Am Coll Cardiol. 2006;48: Wattigney WA et al. Circulation. 2003;108:

8. Distribution of $6.65 Billion (US) in Annual Atrial Fibrillation Treatment Costs for 2005
$235 million
(4%)
Drugs
Outpatient
Indirect inpatient
$1.53 billion
(23%)
$1.95 billion
(29%)
$2.93 billion
(44%)
Distribution of $6.65 Billion (US) in Annual Atrial Fibrillation Treatment Costs for 2005
Reference
Coyne KS, Paramore C, Grandy S, Mercader M, Reynolds M, Zimetbaum P. Assessing the direct costs of treating nonvalvular atrial fibrillation in the United States. Value Health. 2006;9:
Direct Inpatient
Adapted from Coyne KS et al. Value Health. 2006;9:

9. Atrial Fibrillation Adversely Affects Quality of Life*‡ †
SF-36 Score
Atrial Fibrillation Adversely Affects Quality of Life
This slide summarizes the results of a study comparing quality of life (QOL) in patients with intermittent AF and coronary artery disease patients referred to tertiary care and healthy controls (lower scores = poorer QOL)
Subjective health-related QOL in patients with AF is as impaired as in patients with significant cardiac disease and much worse than in healthy patients
Reference
Dorian P, Jung W, Newman D, et al. The impairment of health-related quality of life in patients with intermittent atrial fibrillation: implications for the assessment of investigational therapy. J Am Coll Cardiol. 2000;36:
SF-36 = 36-question Short-Form health survey.
*Across all scales, both the disease specific and generic QoL was significantly worse in the AF patients compared with the controls (P<0.05 compared with AF patients); †Values represent raw mean scores ± SD; ‡P<0.001 compared with AF patients.
Dorian P et al. J Am Coll Cardiol. 2000;36:

10. Atrial Fibrillation Is Associated With Increased Mortality
Cumulative Mortality by Age and Sex * * * * * *
Atrial Fibrillation Is Associated With Increased Mortality
Data show new-onset AF to be significantly and directly linked to increased rates of mortality1
In patients with CHF, new-onset AF increases the risk of mortality by 1.6-fold in men and by 2.7-fold in women2
In patients with MI, new-onset AF nearly doubles the risk of in-hospital and long-term mortality3
Cumulative mortality or rates of death over 3 years or more is presented in the graph, and we can see that mortality is increased in patients with AF in all age groups, regardless of sex1
References
Wolf RA, Mitchell JB, Baker CS, Kannel WB, D’Agostino RB. Impact of atrial fibrillation on mortality, stroke, and medical costs. Arch Intern Med. 1998;158:
Wang TJ, Larson MG, Levy D, et al. Temporal relations of atrial fibrillation and congestive heart failure and their joint influence on mortality. The Framingham Study. Circulation. 2003;107:
Pizzetti F, Turazza FM, Franziosi MG, et al. Incidence and prognostic significance of atrial fibrillation in acute myocardial infarction: the GISSI-3 data. Heart. 2001;86:
*P<0.05.
75-84
85-89
65-74
Age, y
Wolf PA et al. Arch Intern Med. 1998;158:

11. Strokes in Atrial Fibrillation (AF)
795,000 strokes occur annually in the US (from all causes)1
~185,000 strokes occur in people who have already had a previous stroke1
Patients with AF have a 5-fold higher risk of stroke
Over 87% of strokes are thromboembolic
Lloyd-Jones D et al. Circulation. 2010;121:e46-e215.

12. Strokes in Atrial Fibrillation (AF)
Stroke is the number one cause of long-term disability and the third leading cause of death in patients with AF
Annual stroke risk is equal for paroxysmal and permanent AF
Greater than 90% of thrombus accumulation originates in the Left Atrial Appendage (LAA)

13. Atrial Fibrillation and Cryptogenic Stroke Why AF Matters
After standard neurologic evaluation, 36% of stroke survivors are classified as cryptogenic
AF and Atrial Flutter (AFL) are intermittent in 30% of stroke patients2
AF detection in cryptogenic stroke changes patient treatment
Only indication for stroke patients to receive anticoagulation
Prevent future strokes by treatment of underlying cause
Interrupt natural history progression of atrial fibrillation
2Jabaudon D et al. Stroke. 2004;35:
3Tayal AH et al. Neurology. 2008;71:

14. Clinical Presentation of Atrial Fibrillation
AF presents with a wide range of symptoms1
May also be asymptomatic
Impact of asymptomatic AF2
Potential for underlying electrical and structural damage to atrial myocardium
While AF symptoms alone may not always be severe, untreated disease can result in significant morbidity and mortality3
LIGHT- HEADEDNESS
PALPITATIONS
DYSPNEA
SYNCOPE
CHEST PAIN
FATIGUE
Clinical Presentation of Atrial Fibrillation
Most patients with AF present with symptoms that include palpitations, chest pain, dyspnea, fatigue, and lightheadedness1
However, symptoms do not always correlate with AF, and some patients have asymptomatic episodes.1 At least one-third of patients report no symptoms of the disease and have no noticeable impairment of quality of life2
Note that even asymptomatic AF can have devastating consequences. The disease can cause electrical and structural damage to the atrial myocardium that can predispose individuals to clinical consequences, such as stroke2-4
References
Fuster V, Ryden LE, Cannon DS, et al. ACC/AHA/ESC 2006 Guidelines 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 European Society of Cardiology Committee for Practice Guidelines (writing committee to revise the 2001 guidelines for the management of patients with atrial fibrillation): developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society. Circulation. 2006;114:e257-e354.
Page RL, Tilsch TW, Connolly SJ, et al. Asymptomatic or “silent” atrial fibrillation: frequency in untreated patients and patients receiving azimilide. Circulation. 2003;107:
Stewart S, Hart CL, Hole DJ, McMurray JJV. A population-based study of long-term risks associated with atrial fibrillation: 20-year follow-up of the Renfrew/Paisley study. Am J Med. 2002;113:
Leonardi M, Bissett J. Prevention of atrial fibrillation. Curr Opin Cardiol. 2005;20:
THROMBO- EMBOLISM
DEATH
1. Fuster V et al. Circulation. 2006;114:e257-e Page RL et al. Circulation. 2003;107:
3. Stewart S et al. Am J Med. 2002;113:

15. Occurrence of Asymptomatic AF and Reliability of Symptoms
Strickberger1
Methods:
Multicenter trial following 48 patients for 12 months to correlate pacemaker-detected atrial tachyarrhythmia (AT) events with symptoms
Results/Conclusions:
“Almost 95% of documented AT episodes were asymptomatic, and symptoms attributed to atrial fibrillation were associated with AT only approximately 15% of the time.”
“No significant differences in the specific symptoms that correlated with or without a documented atrial tachyarrhythmia were observed.”
1 Strickberger SA, et al. Heart Rhythm. 2005;2:

16. Management of Thromboembolic Risk

17. Copyright © The American College of Cardiology.
From: 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
J Am Coll Cardiol. 2014;64(21):e1-e76. doi: /j.jacc
Summary of Recommendations for Risk-Based Antithrombotic Therapy
Copyright © The American College of Cardiology.
All rights reserved.

18. The CHADS2 Scoring System
A points based system for predicting risk of stroke in AF, based on key risk factors1,2
Prior stroke or TIA 2 points
Age >75y 1 point
Hypertension 1 point
Diabetes mellitus 1 point
Heart failure 1 point
Irrespective of clinical subtype of atrial fibrillation, appropriate anti thrombotic treatment is mandatory, based on risk factors for stroke and thromboembolism1
The CHADS2 score integrates elements from several stroke risk classification schemes and is based on a point system for risk2
The greater the number of points, the greater the risk and the greater the need for anti-thrombotic therapy
AF patients with zero points are recommended to take aspirin, patients with one point require anti-platelet or anti-coagulant therapy and patients with 2 or more points are recommended to receive an oral vitamin K antagonist, such as warfarin
Reference:
1 ACC/AHA/ESC 2006 guidelines J Am Coll Cardiol 2006;48:
2 Gage BF et al. JAMA 2001;285:2864–70.
TIA = transient ischemic attack
1. ACC/AHA/ESC 2006 guidelines J Am Coll Cardiol 2006;48:
2. Gage BF et al. JAMA 2001;285:2864–70. 18 18

19. CHA2DS2-VASc C H A2 D S2 V A Sc 9 Maximum Score Risk factor score 1 2
Congestive heart failure/LV dysfunction 1 H
Hypertension A2
Age ≥75y 2 D
Diabetes mellitus S2
Stroke/TIA/TE V
Vascular disease (prior myocardial infarction, peripheral artery disease, or aortic plaque) A
Age 65-74y Sc
Sex category (ie female gender)
Maximum Score 9
CHA2DS2-VASｃスコアは、2010年にLipよって提唱された、新しい脳卒中リスク評価です。年齢に重きを置き、新たに動脈疾患やSex categoryを加えた8項目、最高9点のリスク評価です。
従来のCHADS2スコアの0－1の部分がより細分化されたとの見方もできます。
今回は、この最も新しい脳卒中リスク評価におけるサブグル―プ解析が発表されました。
maximum score is 9 since age may contrubute 0, 1, or 2 points
Lip GY, et al., Chest 137, , 2010 19

20. Comparison of Stroke Risk
Friberg L: Eur Heart J 2012;33:

24. HAS-BLED score
Hypertension, Abnormal Liver or Renal Fxn, Stroke, Bleeding, Labile INR, Elderly, Drugs or Alcohol
Chest Nov;138(5):

26. 26 Oral anticoagulants vs aspirin for stroke prevention in AF
Content Points:
Previous meta-analyses of trials comparing the effects of oral anticoagulant and antiplatelet therapies on stroke used summary data from published trial reports. To more fully assess the differences between these therapies on stroke, van Walraven et al conducted a meta-analysis using pooled, individual patient data.1
The trials compared warfarin or 4-hydroxycoumadin versus aspirin. Compared with aspirin, oral anticoagulant therapy reduced the risk of all strokes by 45%, ischemic strokes by 52%, and cardiovascular events by 29% (P < for all comparisons). There was a greater incidence of major bleeding in oral anticoagulant groups (hazard ratio 1.71; P = 0.02), although overall mortality did not differ between patient groups.
The investigators concluded that oral anticoagulant therapy is more effective than oral antiplatelet therapy (aspirin) in decreasing the risk of stroke and cardiovascular events in patients with AF.
These clinical findings are consistent with current understanding of the vascular biology of AF-related stroke, which assigns a less important role to platelet activation relative to activation of the coagulation system.
1van Walraven C, Hart RG, Singer DE, Laupacis A, Connolly S, Petersen P, et al. Oral anticoagulants vs aspirin in nonvalvular atrial fibrillation: An individual patient meta-analysis. JAMA. 2002;288: 26

27. ACTIVE-W study
Patients with atrial fibrillation were randomized to standard therapy with oral anticoagulation (warfarin) or clopidogrel plus aspirin and followed for approximately two years
When halted in September 2005, ACTIVE-W had enrolled its target of 6600 patients.
Data safety and monitoring board stopped the trial after a clear increase in efficacy was seen in the warfarin arm of the trial.
Connolly S. American Heart Association Scientific Sessions 2005; Nov 13-16, 2005; Dallas, TX.

28. Vascular Events and Major Bleeding: ACTIVE-W
End point
Clopidogrel+ASA
Warfarin
Relative risk p
Vascular events (%/year)
5.64
3.63
1.45
0.0002
Major bleeding (%/year)
2.4
2.2
1.06
0.67
Connolly S. American Heart Association Scientific Sessions 2005; Nov 13-16, 2005; Dallas, TX.

29. Outpatient Monitoring Considerations

30. Cardiac Monitoring for Diagnosing AF
Recognition of AF may be difficult due to its often ‘silent’ nature
-- 1/3 of patients not aware of so-called ‘asymptomatic AF
Much earlier detection of the arrhythmia might allow
Timely introduction of therapies to treat AF (rate/rhythm control)
Interruption of the natural progression of AF
-- Assists in the decision to initiate or discontinue anticoagulation therapy
Ability to document onset mechanism of AF to aide in treatment
Camm AJ et al. Eur Heart J. 2010;31:
Jabaudon D et al. Stroke. 2004;35:

31. Cardiac Diagnostics Landscape
14-30 Day Mobile Cardiac Telemetry Monitor
Insertable Cardiac Monitor
24-Hour Holter
Event Recorder
2.5 Million
1.5 Million
250,000
25,000
Source: Frost & Sullivan report: North American Cardiac Monitoring and Diagnostic Services Markets

32. -FDA approved for up to 14 days of continuous monitoring
Long term monitor
Up to 14 days of monitoring
Way for patient to report symptoms during this time
No access to EKG’s during the monitoring period
-FDA approved for up to 14 days of continuous monitoring
-Patients may “mark” symptoms during this time
-No access to rhythm
strips during
monitoring period
Z100A | Feb. 2013

33. AliveCor Fully secure, HIPAA-compliant online access
FDA approved December 2012
Sold to US licensed medical providers as a prescription to record, transmit and store single channel EKG
Not covered by insurance
Currently only works with iPhones

34. As Cardiac Monitoring Evolves, Diagnostic Yield Improves
88%
Relative diagnostic yield
CardioNet MCOT
(Mobile Cardiac Outpatient Telemetry)
ECG symptom correlation
45% – 88%
Syncope
6% – 25%
Palpitations
39% – 68%
36%
Invasive Implantable Loop Recorder
AF Auto-trigger Monitor
15%
Event Monitor:
Looping Memory
Event Monitor: Non-looping
5% – 13%
Key Points
The technology available for arrhythmia monitoring has evolved since the Holter monitor was first developed in the late 1940s.
In subsequent slides we’ll take a closer look at the features, advantages, and drawbacks of the various methods shown here. As we’ll see, the diagnostic yield of these methods has increased substantially over time.
Mobile cardiac outpatient telemetry, or MCOT, is the latest milestone on the road to better arrhythmia diagnosis and management.
References:
Assar MD et al. Am J Cardiol. 2003;92:
Fechter P. Schweiz Med Wochenschr. 1991;121:
Fogel RI et al. Am J Cardiol. 1997;79:207-8.
Gibson TC et al. Am J Cardiol. 1984;53:
Kinlay S et al. Ann Intern Med. 1996;124:16-20.
Krahn AD et al. Circulation. 2001;104:46-51.
Krahn AD et al. PACE. 2004;27:
Linzer M et al. Am J Cardiol. 1990;66:214-9.
Reiffel JA et al. Am J Cardiol. 2005;95:
Rothman SA et al. J Cardiovasc Electrophysiol. 2007;18:241-7.
Zeldis SM et al. Chest. 1980;78:
Zimetbaum P et al. Am J Cardiol. 1997;79:371-2.
Holter Monitor
Assar MD et al. Am J Cardiol. 2003; Fechter P. Schweiz Med Wochenschr. 1991; Fogel RI et al. Am J Cardiol. 1997; Gibson TC et al. Am J Cardiol. 1984; Kinlay S et al. Ann Intern Med. 1996; Krahn AD et al. Circulation. 2001; Krahn AD et al. PACE. 2004; Linzer M et al. Am J Cardiol. 1990; Reiffel JA et al. Am J Cardiol. 2005; Rothman SA et al J Cardiovasc Electrophysiol. 2007; Zeldis SM et al. Chest. 1980; Zimetbaum P et al. Am J Cardiol

35. Stroke Risk Based on Atrial Fibrillation Burden

36. From: 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
J Am Coll Cardiol. 2014;64(21):e1-e76. doi: /j.jacc
Summary of Recommendations for Electrical and Pharmacological Cardioversion of AF and Atrial Flutter

39. Annualized TE Rate (95% Confidence Interval)
How Much AF For a Stroke: 5.5 Hrs?
Relationship Between Atrial Arrhythmia Burden and Stroke Risk (TRENDS Study)
Methods:
AT/AF Burden Subset
Annualized TE Rate (95% Confidence Interval)
Zero AT/AF burden
1.1 [0.8, 1.6] %
Low AT/AF burden (< 5.5 hours)
1.1 [0.4, 2.8] %
High AT/AF burden (≥ 5.5 hours)
2.4 [1.2, 4.5] %
Prospective, observational study analyzing 2,486 patients with ≥ 1 stroke risk receiving pacemakers or defibrillators that monitor atrial tachycardia (AT)/AF burden
Annualized TE rates were determined according to AT/AF burden subsets: zero, low (< 5.5 hours [median duration of subsets with nonzero burden]), and high (≥ 5.5 hours)
Results/Conclusions:
/AF burden ≥ 5.5 hours on any of 30 prior days appeared to double TE risk
4 Glotzer T, et al. Circ Arrhythm Electrophysiol. 2009;2:

40. TRENDS Study Subgroup Analysis Newly Detected AF (“NDAF”) in Patients with Thromboembolic Events
163 patients with previous ischemic stroke/TIA, no known AF, were continuous monitored via pacemaker or ICD
NDAF > 5 minute duration were found in 28% patients.
73% of patients had newly detected AT/AF on <10% of follow-up days
Time from Device Implant (months)
3 mo.
6 mo.
9 mo.
12 mo.
Freedom from AT/AF
0.5
0.6
0.7
0.8
0.9
1.0
Number at Risk:
163
127
111
106 67
89% of NDAF patients identified beyond 1 day
78% of NDAF patients identified beyond 7 days
60% of NDAF patients identified beyond 30 days
Ziegler P. et al. Stroke. 2010;41

41. How Much AF for a Stroke: 6 min? Assert Study
Results:
2580 pts with mean CHADS2 score of 2.29 followed prospectively for 2.5 yrs
10.1% pts with >1 Subclinical AF episode (>190 bpm for >6 min) within first 3 months
Associated with increased risk of Clinical AF (HR 5.56 [ ]; p<0.001)
Associated with increased risk of Ischemic Stroke or Systemic Embolism (HR 2.49 [ ]; p=0.007)
Cumulative Hazard
A lot of patients, followed for a long time (2.5 years)
Even a little bit of AF matters – risk of stroke was 2.5 times higher
More time in AF means more risk of stroke – 17 hours with almost 5 times greater stroke risk
Healey, JS et al. Subclinical Atrial Fibrillation and the Risk of Stroke. N Engl J Med 2012;366:

42. Among patients with AT/AF episodes >17
Among patients with AT/AF episodes >17.72 hours, annual rate of stroke or systemic embolism was 4.89 (95% CI, 1.96 to 10.07)

43. Conclusions
Atrial fibrillation (AF) is a common disorder with significant morbidity, mortality, economic and social considerations
Appropriate therapy for AF is dependent on a patient’s risk factors for thromboembolism
Long term cardiac monitoring can help diagnose AF and guide appropriate treatment
Prior observational studies have demonstrated a link between AF burden and stroke risk

44. Thank You