Improving Stroke Risk Stratification Using the CHADS ₂ and CHA ₂ DS ₂ -VASc Risk Scores in Patients With Paroxysmal Atrial Fibrillation by Continuous Arrhythmia Burden Monitoring

Abstract

Background and Purpose-In patients with atrial fibrillation (AF), stroke risk stratification schema do not consider AF parameters. The aim of the study is to assess the impact of combining risk factors with continuous AF burden monitoring. Methods-In this retrospective study 568 patients implanted with a DDDR-P pacemaker (AT-500; Medtronic) and a history of AF were continuously monitored for 1 year. Results-During follow-up, 14 patients (2.5%) had a thromboembolic event. Patients were divided into 3 groups: AF burden Յ5 minutes per day (AF-free; nϭ223 Key Words: anticoagulation Ⅲ antithrombotics Ⅲ atrial fibrillation Ⅲ embolic stroke Ⅲ heart-brain relationships Ⅲ platelet inhibitors Ⅲ prevention Ⅲ prognosis T he burden of atrial fibrillation (AF) and the duration of arrhythmia episodes have never been included in risk stratification schemes because reliance on clinical symptoms and intermittent electrocardiographic assessments can underestimate AF burden. 1,2 Diagnostic features in implantable devices are sophisticated enough to provide reliable information on atrial arrhythmias, allowing data to generate hypotheses on stroke risk stratification. [1][2][3][4] The aim of the study is to test the hypothesis that continuous AF burden monitoring would enhance the sensitivity/specificity of stroke risk stratification schema based on clinical risk factors. MethodsPatients with a dual-chamber pacemaker (Medtronic AT-500) and a history of paroxysmal atrial tachyarrhythmias were included into this study. A day-by-day trend of AF burden (ϭtime spent in AF during each day) was available for each patient during 1-year follow-up with data on minutes/hour spent at high atrial rates. 2 Patients were divided into 3 groups: (1) maximum AF burden Յ5 minutes per day (AF-free); (2) maximum AF burden Ͼ5 minutes but Ͻ24 hours per day (AF-5 minutes); and (3) AF burden of Ն24 hours, the latter considering also the following days (AF-24 hours). Patients were also classified according to the CHADS 2 and the CHA 2 DS 2 -VASc 5 risk scores. A committee of 2 physicians, blinded to AF burden, evaluated the thromboembolic Sensitivity and specificity of each score in predicting TE events, either alone or in combination with AF, were assessed. The number of patients who would require long-term oral anticoagulation therapy (OAC) was calculated according to each combination. Uni-and multivariable logistic regressions were performed considering the CHADS 2 and the CHA 2 DS 2 -VASc scores as continuous variables, whereas AF burden was analyzed by class. For each regression model, the predicted probabilities were used to assess the discriminatory ability of each risk score by means of the C-statistic and its 95% CI. Statistical analysis was made by SPSS (SPSS Inc, Chicago, IL) software, Version 11.5. ResultsData from 568 patients (70Ϯ10 years) were analyzed. Patients were categorized into 3 AF groups: AF-free (nϭ223 [39%]), AF-5 minutes (nϭ179 [32%]), and AF-24 hours (nϭ166 [29%]). In groups AF-free, AF-5 minutes, and AF-24 hours, respectively, asp...

Detection and Predictors of Atrial Fibrillations in patients after pacemaker implantations.

“…These data add to current evidence that measuring daily AF burden may have important clinical relevance and support the search for specific thresholds of AF burden associated with a substantial increase in the risk of stroke [17,18] . Integration of AF presence/duration/ burden has the potential to contribute to improved clinical risk stratification, and its aid to clinical decision-making should be tested prospectively [19,20] . About 25-30% of patients presenting with strokes have AF that was not previously recognized [21] .…”

Unmet need and limitations of current anticoagulation therapy for stroke prevention in atrial fibrillation patients: a questionnaire based study

“…18 The accumulated evidence shows that CHA2DS2-VASc is better at identifying "truly low-risk" patients with AF and is as good as, and possibly better than, scores such as CHADS2 in identifying patients who develop stroke and thromboembolism. 19,20 It is positive sign that cardiologists are assessing proper score to give prophylaxis for SPAF.…”

Risk Stratification Using the CHA 2 DS 2 ‐VASc Score in Takotsubo Syndrome: Data From the Takotsubo Italian Network

“…The validity of CHA 2 DS 2 ‐VASc score on stroke‐risk stratification in patients with atrial fibrillation (AF) has been well documented 1, 2 and, although initially developed only for patients with AF, it has proved to be a helpful scoring system for evaluating the complexity of comorbidities in different clinical settings. The application of CHA 2 DS 2 ‐VASc score in patients without AF is relatively new and only a few non‐AF studies have explored this simple method of risk assessment 3, 4, 5…”