Background: Left atrial thrombus (LAT) often complicates with atrial fibrillation (AF). The evidence whether fibrin D-dimer levels could be used as a predictive biomarker for LAT is contradictory. This study firstly investigated the relationship between ‘normal range’ D-dimer and prevalent LAT. Second, we explored factors contributing to normal D-dimer levels in the presence of LAT. Methods: We studied 244 AF patients with LAT (mean age: 59.9 years, SD:11.7; 53.3% female): of these, 103 (42.2%) had normal D-dimer, 25 (10.2%) had atrial thrombus exclusion score (ATE score) of 0 19 (16.7%) males had CHA₂DS₂-VASc score of 0, 21(16.2%) females had CHA₂DS₂-VASc score of 1 and 16 had overlapped ATE score of 0 and CHA₂DS₂-VASc score of 0 (N = 8 if male) or CHA₂DS₂-VASc score of 1(N = 8 if female). Using multivariate binary analysis, larger left atrial diameter (LAD; adjusted OR: 1.06, 1.03−1.10, p = 0.001) were associated with increased D-dimer. Patients with high body mass index (BMI), hypertension history and previous anticoagulation were more likely to show normal range D-dimer levels in the presence of LAT. Conclusions: A high prevalence (42.2%) of ‘normal range’ D-dimer levels was found in AF patients with LAT, especially in those with hypertension, high BMI and prior anticoagulation. D-dimer levels of those patients with larger LAD were more likely to be increased.

Introduction Atrial fibrillation (AF) is the prevalent cardiac arrhythmia and can significantly impair the quality of life (QoL). Although catheter ablation (CA) is an established treatment for AF,post-procedural complications or perceived inadequate control of AF may diminish the QoL for some patients, potentially even to levels lower than pre-procedure. Preliminary findings from our previous pilot trial indicate that acupuncture may positively influence QoL in AF patients post-CA. This study aims to increase the sample size to evaluate the efficacy of acupuncture as an adjunctive treatment to conventional medical therapy in improving QoL of patients with AF after CA. Methods and design This multicentre randomised clinical trial will be conducted in China. A total of 146 eligible patients will be randomly assigned in a 1:1 ratio to either the acupuncture group or the sham acupuncture group. All patients will receive standard postablation care and undergo 18 sessions of acupuncture/sham acupuncture within 12 weeks following CA, followed by a 9-month follow-up period. The primary outcome is the change in the Atrial Fibrillation Effect on Quality-of-Life (AFEQT) summary score from baseline to months 6 after CA. Secondary outcomes include the changes in the AFEQT subscale scores at months 6, the AFEQT summary and subscale score at months 3 and 12, AF burden, AF recurrence, heart rate variability, number of cardioversions, repeat CA procedures, European Heart Rhythm Association score, number of arrhythmia-related hospitalisations, average heart rate, use of Six-Dimensional Health State Short Form to assess health status, costs incurred by disease treatment, Credibility/Expectancy Questionnaire and blinded assessments. Adverse events will also be meticulously recorded throughout the trial. Ethics and dissemination Ethics approval has been granted by the Ethics Committee of Beijing University of Traditional Chinese Medicine (approval no: 2020BZYLL0802) and seven other subcentres. The findings of the study results will be disseminated through presentations at scientific conferences or publications in peer-reviewed journals. Trial registration number ChiCTR2100049323.