Frequent supraventricular extrasystoles (SVEs) are associated with the subsequent first-time appearance of atrial fibrillation (AF) and ischemic stroke. The aim of this study was to investigate the combined role of SVEs and an AF-related risk score for ischemic stroke, the CHADS2 score, on the occurrence of new AF in patients in sinus rhythm. The Shinken Database 2004-2010 lists 3,263 patients who underwent 24-hour Holter monitoring. A total of 2,589 patients were analyzed, after excluding 674 patients previously diagnosed with AF. Frequent SVEs were defined as ≥102 beats/day (the top quartile) and the presence of a clinical background for a CHADS2 score ≥2 points as a high CHADS2 score. During the mean follow-up period of 571.4 ± 606.4 days, new AF occurred in 38 patients (9.4 per 1,000 patient-years). The incidence of new AF was 2.7 and 37.7 per 1,000 patient-years for patients with nonfrequent SVEs (<102 beats/day) and low CHADS2 scores and those with frequent SVEs and high CHADS2 scores, respectively. Multivariate Cox regression analysis showed that the hazard ratio for frequent SVEs and a high CHADS2 score compared with nonfrequent SVEs and a low CHADS2 score was 9.49 (95% confidence interval 3.20 to 28.15, p <0.001), even after adjustment for gender, age, medications, and echocardiographic parameters. In conclusion, frequent SVEs and a high CHADS2 score independently and synergistically predict the first-time appearance of AF in patients in sinus rhythm, indicating an approximately 10-fold higher risk. Patients meeting these criteria should have more aggressive early intervention for preventing AF.
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