TABLE 2.

Stroke Risk Stratification Schemes in Patients With Atrial Fibrillation and Estimated Ischemic Stroke Rates on Validation Cohorts of Atrial Fibrillation Patients on Aspirin Alone

Schemes and Stroke Rates	Stroke Risk Category
	Low Risk	Moderate Risk	High Risk
CHADS2,59 1 point CHF, HTN, age >75, DM; 2 points prior ischemic stroke, TIA	Score 0	Score 1 or 2	>2
Stroke rate*62	0.8	2.7	5.3
Stroke rate†62	0.8	2.2–4.5	8.6–13.7
AFI46	Not moderate or high risk	Age >65 yr; not high risk	HTN, DM, prior cerebral ischemia
Stroke rate*62	0.9	1.7	3.5
Stroke rate†62	NR	NR	6.1
Framingham39, prior cerebral ischemia = 6 points; DM = 4; female = 6; age 0–10 points; BP <120 = 0; 120–139 = 1; 140–159 = 2; 160–179 = 3; >179 = 4	≤7	7–13	>13
Stroke rate*62	1.4	3.2	4.2
Stroke rate†62	NR	NR	7.9
SPAF60	Not moderate or high risk	HTN; no high risk features	Prior cerebral ischemia, women >75 yr; recent HF or LV dysfunction by echo, SBP >160
Stroke rate*62,63	1.1	2.7, 3.6	3.6
Stroke rate†62	NR	NR	6.5
ACCP61	Not moderate or high risk	Age 65–75, CAD, DM, Thyrotoxicosis	More than 1 moderate risk factor, prior cerebral ischemia, HTN, HF or LV dysfunction by echo, age >75
Stroke rate*62	0.5	1.0	3.0
Stroke rate†62	NR	NR	5.1

AFI indicates Atrial Fibrillation Investigators; SPAF, Stroke Prevention in Atrial Fibrillation; ACCP, American College of Chest Physicians; NR, not reported; CAD, coronary artery disease; HTN, hypertension; DM, diabetes mellitus; HF, heart failure; LV, left ventricle. All validation cohorts reported consist of atrial fibrillation (AF) patients using aspirin. For estimates from other validation cohorts comprised in part of AF patients not on any anti-thrombotic therapy (and hence at a higher risk) or patients on aspirin and fixed dose warfarin.^{39,59,64–66}

^*Primary ischemic stroke prevention.

^†Validation cohort includes patients with prior ischemic stroke or TIA.