Differences among clinical classification schemes for predicting stroke in atrial fibrillation: implications for therapy in daily practice.
BACKGROUND
Several clinical classification schemes (CCSs) for predicting stroke in nonvalvular atrial fibrillation (NVAF) have been developed to help identify patients eligible for anticoagulation.


OBJECTIVE
To estimate the agreement in predicting the risk of stroke among four widespread CCSs, and to determine their implications for thromboprophylaxis in clinical practice.


METHODS
The authors conducted a prospective, multicenter, observational study of adults with NVAF in 12 emergency departments (EDs) in July 2000 and February 2001. The proportions of patients classified as having high, moderate, and low risk of stroke among the following CCSs were compared: the Atrial Fibrillation Investigators (AFI), the Stroke Prevention in Atrial Fibrillation (SPAF), the CHADS(2) (an acronym for congestive heart failure, hypertension, age >75 years, diabetes mellitus, and prior stroke or transient ischemic attack), and the American College of Chest Physicians (ACCP).


RESULTS
One thousand two hundred twenty patients were included. The proportions of patients stratified as having high/moderate/low risk of stroke according to each CCS were: 70%/22%/8% (AFI), 38%/41%/21% (SPAF), 13%/45%/42% (CHADS(2)), and 86%/7%/7% (ACCP). The agreement was medium between AFI and ACCP (kappa = 0.52) and poor among the rest of them (AFI/SPAF, kappa = 0.01; AFI/CHADS(2), kappa = 0.02; SPAF/CHADS(2), kappa = 0.18; SPAF/ACCP, kappa = 0.11; CHADS(2)/ACCP, kappa = 0.03). The agreements in selecting patients as eligible for antiplatelet therapy or anticoagulation were: AFI/SPAF, kappa = 0.45; AFI/CHADS(2), kappa = 0.22; AFI/ACCP, kappa = 0.91; SPAF/CHADS(2), kappa = 0.47; SPAF/ACCP, kappa = 0.11; CHADS(2)/ACCP, kappa = 0.03.


CONCLUSIONS
In the ED population studied, these CCSs showed relevant differences in the risk of stroke stratification and, therefore, in the identification of patients with NVAF eligible for anticoagulation.
Laguna
Pedro
P
Arrhythmia Division, Spanish Society of Emergency Medicine (PL, AM, CDA, IM, PG), Madrid, Spain.
Martín
Alfonso
A
Del Arco
Carmen
C
Millán
Isabel
I
Gargantilla
Pedro
P
D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000150:complications*; D015331:Cohort Studies; D004635:Emergency Medicine / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D010818:Practice Patterns, Physicians'; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D020521:Stroke / Q000175:diagnosis* / Q000188:drug therapy / Q000209:etiology*; D015912:Thrombolytic Therapy
D000925:Anticoagulants