Background The CHA 2 DS 2-VASc schema has recently been introduced to complement the CHADS2 score and improve the identification of atrial fibrillation （AF） patients at ＇truly low risk＇ for thromboembolism.We test...Background The CHA 2 DS 2-VASc schema has recently been introduced to complement the CHADS2 score and improve the identification of atrial fibrillation （AF） patients at ＇truly low risk＇ for thromboembolism.We tested the predictive ability of the CHA 2 DS 2-VASc,CHADS2 and van Walraven risk stratification schemes in a cohort of ＇lone＇ AF patients with a 12-year follow-up.Methods and Results We conducted a registry-based,observational cohort study of 345 patients initially diagnosed with ＇lone＇ AF between 1992 and 2007.At baseline,all patients had the CHADS2 and van Walraven scores of 0,and 262 （75.9%） had a CHA 2 DS 2VASc score=0.During follow-up （or within a year prior to stroke）,228 （66.1%）,234 （67.8%） and 150 patients （43.5%） retained the CHADS2,van Walraven and CHA 2 DS 2VASc scores of 0,respectively.The overall rate of ischemic stroke was 0.19 （95%CI：0.18-0.20） per 100 patient-years.In the multivariable analysis,only the CHA 2 DS 2-VASc score of 0 was significantly related to the absence of stroke （OR 5.1,95%CI：1.5-16.8,P=0.008）.Only the CHA 2 DS 2-VASc score had a significant prediction ability （c-statistic 0.72 [0.61-0.84],P=0.031）.Conclusions The CHA 2 DS 2-VASc score reliably identified the ＇lone＇ AF patients who were at ＇truly low risk＇ for thromboembolism,and was the only tested risk stratification scheme with a significant predictive ability for thromboembolism amongst lone AF patients.展开更多
The four years of my undergraduate study in China flew by,and it increased my appreciation of China’s innovation,particularly its infrastructure.My education also allowed me to see China first hand as a foreign stude...The four years of my undergraduate study in China flew by,and it increased my appreciation of China’s innovation,particularly its infrastructure.My education also allowed me to see China first hand as a foreign student I’ve been given the opportunity to explore a different world than the one I grew up in Ghana.展开更多
Single-walled carbon nanotubes（SWNTs）are regarded as one of the most promising candidates as building blocks in the next generation electronics.The most advanced opportunities demand the ability to form perfectly al...Single-walled carbon nanotubes（SWNTs）are regarded as one of the most promising candidates as building blocks in the next generation electronics.The most advanced opportunities demand the ability to form perfectly aligned,horizontal arrays of SWNTs with a uniform structure.However,synthesizing them by conventional chemical vapor deposition（CVD）methods would result in poorly-aligned nanotubes with a variety of chiral species,展开更多
文摘Background The CHA 2 DS 2-VASc schema has recently been introduced to complement the CHADS2 score and improve the identification of atrial fibrillation （AF） patients at ＇truly low risk＇ for thromboembolism.We tested the predictive ability of the CHA 2 DS 2-VASc,CHADS2 and van Walraven risk stratification schemes in a cohort of ＇lone＇ AF patients with a 12-year follow-up.Methods and Results We conducted a registry-based,observational cohort study of 345 patients initially diagnosed with ＇lone＇ AF between 1992 and 2007.At baseline,all patients had the CHADS2 and van Walraven scores of 0,and 262 （75.9%） had a CHA 2 DS 2VASc score=0.During follow-up （or within a year prior to stroke）,228 （66.1%）,234 （67.8%） and 150 patients （43.5%） retained the CHADS2,van Walraven and CHA 2 DS 2VASc scores of 0,respectively.The overall rate of ischemic stroke was 0.19 （95%CI：0.18-0.20） per 100 patient-years.In the multivariable analysis,only the CHA 2 DS 2-VASc score of 0 was significantly related to the absence of stroke （OR 5.1,95%CI：1.5-16.8,P=0.008）.Only the CHA 2 DS 2-VASc score had a significant prediction ability （c-statistic 0.72 [0.61-0.84],P=0.031）.Conclusions The CHA 2 DS 2-VASc score reliably identified the ＇lone＇ AF patients who were at ＇truly low risk＇ for thromboembolism,and was the only tested risk stratification scheme with a significant predictive ability for thromboembolism amongst lone AF patients.
文摘The four years of my undergraduate study in China flew by,and it increased my appreciation of China’s innovation,particularly its infrastructure.My education also allowed me to see China first hand as a foreign student I’ve been given the opportunity to explore a different world than the one I grew up in Ghana.
文摘Single-walled carbon nanotubes（SWNTs）are regarded as one of the most promising candidates as building blocks in the next generation electronics.The most advanced opportunities demand the ability to form perfectly aligned,horizontal arrays of SWNTs with a uniform structure.However,synthesizing them by conventional chemical vapor deposition（CVD）methods would result in poorly-aligned nanotubes with a variety of chiral species,
